Showing papers in "American Journal of Epidemiology in 2004"
TL;DR: Results from a limited simulation study indicate that this approach is very reliable even with total sample sizes as small as 100, and the method is illustrated with two data sets.
Abstract: Relative risk is usually the parameter of interest in epidemiologic and medical studies. In this paper, the author proposes a modified Poisson regression approach (i.e., Poisson regression with a robust error variance) to estimate this effect measure directly. A simple 2-by-2 table is used to justify the validity of this approach. Results from a limited simulation study indicate that this approach is very reliable even with total sample sizes as small as 100. The method is illustrated with two data sets.
7,045 citations
TL;DR: An illustration of the relation between odds ratios and receiver operating characteristic curves shows, for example, that a marker with an odds ratio of as high as 3 is in fact a very poor classification tool.
Abstract: A marker strongly associated with outcome (or disease) is often assumed to be effective for classifying persons according to their current or future outcome. However, for this assumption to be true, the associated odds ratio must be of a magnitude rarely seen in epidemiologic studies. In this paper, an illustration of the relation between odds ratios and receiver operating characteristic curves shows, for example, that a marker with an odds ratio of as high as 3 is in fact a very poor classification tool. If a marker identifies 10% of controls as positive (false positives) and has an odds ratio of 3, then it will correctly identify only 25% of cases as positive (true positives). The authors illustrate that a single measure of association such as an odds ratio does not meaningfully describe a marker's ability to classify subjects. Appropriate statistical methods for assessing and reporting the classification power of a marker are described. In addition, the serious pitfalls of using more traditional methods based on parameters in logistic regression models are illustrated.
1,294 citations
TL;DR: A likelihood-based estimation procedure that infers the temporal pattern of effective reproduction numbers from an observed epidemic curve for SARS revealed that epidemics in the various affected regions were characterized by markedly similar disease transmission potentials and similar levels of effectiveness of control measures.
Abstract: Severe acute respiratory syndrome (SARS) has been the first severe contagious disease to emerge in the 21st century. The available epidemic curves for SARS show marked differences between the affected regions with respect to the total number of cases and epidemic duration, even for those regions in which outbreaks started almost simultaneously and similar control measures were implemented at the same time. The authors developed a likelihood-based estimation procedure that infers the temporal pattern of effective reproduction numbers from an observed epidemic curve. Precise estimates for the effective reproduction numbers were obtained by applying this estimation procedure to available data for SARS outbreaks that occurred in Hong Kong, Vietnam, Singapore, and Canada in 2003. The effective reproduction numbers revealed that epidemics in the various affected regions were characterized by markedly similar disease transmission potentials and similar levels of effectiveness of control measures. In controlling SARS outbreaks, timely alerts have been essential: Delaying the institution of control measures by 1 week would have nearly tripled the epidemic size and would have increased the expected epidemic duration by 4 weeks.
1,151 citations
TL;DR: Future applications of these cutpoints include the comparison of morbidity risk in older persons with normal muscle mass and those with sarcopenia, the determination and comparison of sarc Openia prevalences, and the estimation of health-care costs attributable to sarcopenian disease.
Abstract: The purpose of this study was to determine skeletal muscle cutpoints for identifying elevated physical disability risk in older adults. Subjects included 4,449 older (> or = 60 years) participants from the Third National Health and Nutrition Examination Survey during 1988-1994. Physical disability was assessed by questionnaire, and bioimpedance was used to estimate skeletal muscle, which was normalized for height. Receiver operating characteristics were used to develop the skeletal muscle cutpoints associated with a high likelihood of physical disability. Odds for physical disability were compared in subjects whose measures fell above and below these cutpoints. Skeletal muscle cutpoints of 5.76-6.75 and < or =5.75 kg/m2 were selected to denote moderate and high physical disability risk in women. The corresponding values in men were 8.51-10.75 and < or =8.50 kg/m2. Compared with women with low-risk skeletal muscle values, women with moderate- and high-risk skeletal muscle values had odds for physical disability of 1.41 (95% confidence interval (CI): 0.97, 2.04) and 3.31 (95% CI: 1.91, 5.73), respectively. The corresponding odds in men were 3.65 (95% CI: 1.92, 6.94) and 4.71 (95% CI: 2.28, 9.74). This study presents skeletal muscle cutpoints for physical disability risk in older adults. Future applications of these cutpoints include the comparison of morbidity risk in older persons with normal muscle mass and those with sarcopenia, the determination and comparison of sarcopenia prevalences, and the estimation of health-care costs attributable to sarcopenia.
1,053 citations
TL;DR: The results of this study suggest that sleep-disordered breathing is independently associated with glucose intolerance and insulin resistance and may lead to type 2 diabetes mellitus.
Abstract: Clinic-based studies suggest that sleep-disordered breathing (SDB) is associated with glucose intolerance and insulin resistance. However, in the available studies, researchers have not rigorously controlled for confounding variables to assess the independent relation between SDB and impaired glucose metabolism. The objective of this study was to determine whether SDB was associated with glucose intolerance and insulin resistance among community-dwelling subjects (n=2,656) participating in the Sleep Heart Health Study (1994-1999). SDB was characterized with the respiratory disturbance index and measurements of oxygen saturation during sleep. Fasting and 2-hour glucose levels measured during an oral glucose tolerance test were used to assess glycemic status. Relative to subjects with a respiratory disturbance index of less than 5.0 events/hour (the reference category), subjects with mild SDB (5.0-14.9 events/hour) and moderate to severe SDB (> or =15 events/hour) had adjusted odds ratios of 1.27 (95% confidence interval: 0.98, 1.64) and 1.46 (95% confidence interval: 1.09, 1.97), respectively, for fasting glucose intolerance (p for trend < 0.01). Sleep-related hypoxemia was also associated with glucose intolerance independently of age, gender, body mass index, and waist circumference. The results of this study suggest that SDB is independently associated with glucose intolerance and insulin resistance and may lead to type 2 diabetes mellitus.
1,027 citations
TL;DR: It is suggested that, to minimize possible spurious associations, epidemiologic studies of diet, demography, or lifestyle and health take dietary supplement use into account because of supplements' large contribution to nutrient intake and differential use of supplements by demographic and lifestyle characteristics.
Abstract: Data from the 1999–2000 National Health and Nutrition Examination Survey, a nationally representative, crosssectional survey of US health and nutrition, were analyzed to assess prevalence of dietary supplement use overall and in relation to lifestyle and demographic characteristics. Fifty-two percent of adults reported taking a dietary supplement in the past month; 35% took a multivitamin/multimineral. Vitamin C, vitamin E, B-complex vitamins, calcium, and calcium-containing antacids were taken by more than 5% of adults. In bivariate analyses, female gender, older age, more education, non-Hispanic White race/ethnicity, any physical activity, normal/ underweight, more frequent wine or distilled spirit consumption, former smoking, and excellent/very good selfreported health were associated with greater use of any supplement and of multivitamin/multiminerals; in multivariable comparisons, the latter three characteristics were not associated with supplement use. Most supplements were taken daily and for at least 2 years. Forty-seven percent of adult supplement users took just one supplement; 55% of women and 63% of adults aged ≥60 years took more than one. These findings suggest that, to minimize possible spurious associations, epidemiologic studies of diet, demography, or lifestyle and health take dietary supplement use into account because of 1) supplements’ large contribution to nutrient intake and 2) differential use of supplements by demographic and lifestyle characteristics. adult; antacids; dietary supplements; health surveys; minerals; nutrition surveys; vitamins
807 citations
TL;DR: The findings suggest that diabetes is an independent predictor of mortality from cancer of the colon, pancreas, female breast, and, in men, of the liver and bladder.
Abstract: Several studies have suggested that diabetes mellitus may alter the risk of developing a variety of cancers, and the associations are biologically plausible. To learn more about the relation between diabetes and cancer mortality, the authors examined associations with selected cancers in a large, prospective US cohort of 467,922 men and 588,321 women who had no reported history of cancer at enrollment in 1982. After 16 years of mortality follow-up, diabetes was significantly associated with fatal colon cancer in men (multivariate relative risk (RR) = 1.20, 95% confidence interval (CI): 1.06, 1.37) and women (RR = 1.24, 95% CI: 1.07, 1.43) and with pancreatic cancer in men (RR = 1.48, 95% CI: 1.27, 1.73) and women (RR = 1.44, 95% CI: 1.21, 1.72). For men, diabetes was significantly associated with liver cancer (RR = 2.19, 95% CI: 1.76, 2.72) and bladder cancer (RR = 1.43, 95% CI: 1.14, 1.80). In addition, diabetes was significantly associated with breast cancer in women (RR = 1.27, 95% CI: 1.11, 1.45). These associations were not explained by high body mass. Our findings suggest that diabetes is an independent predictor of mortality from cancer of the colon, pancreas, female breast, and, in men, of the liver and bladder.
754 citations
TL;DR: Targeted antiviral prophylaxis has potential as an effective measure for containing influenza until adequate quantities of vaccine are available and is nearly as effective as vaccinating 80% of the population.
Abstract: For the first wave of pandemic influenza or a bioterrorist influenza attack, antiviral agents would be one of the few options to contain the epidemic in the United States until adequate supplies of vaccine were available. The authors use stochastic epidemic simulations to investigate the effectiveness of targeted antiviral prophylaxis to contain influenza. In this strategy, close contacts of suspected index influenza cases take antiviral agents prophylactically. The authors compare targeted antiviral prophylaxis with vaccination strategies. They model an influenza pandemic or bioterrorist attack for an agent similar to influenza A virus (H2N2) that caused the Asian influenza pandemic of 1957-1958. In the absence of intervention, the model predicts an influenza illness attack rate of 33% of the population (95% confidence interval (CI): 30, 37) and an influenza death rate of 0.58 deaths/1,000 persons (95% Cl: 0.4, 0.8). With the use of targeted antiviral prophylaxis, if 80% of the exposed persons maintained prophylaxis for up to 8 weeks, the epidemic would be contained, and the model predicts a reduction to an illness attack rate of 2% (95% Cl: 0.2, 16) and a death rate of 0.04 deaths/1,000 persons (95% CI: 0.0003, 0.25). Such antiviral prophylaxis is nearly as effective as vaccinating 80% of the population. Vaccinating 80% of the children aged less than 19 years is almost as effective as vaccinating 80% of the population. Targeted antiviral prophylaxis has potential as an effective measure for containing influenza until adequate quantities of vaccine are available.
723 citations
TL;DR: The present article describes how most of these methods for estimating risk ratios from adjusted odds ratios when the outcome is common can be subsumed under a general formulation that also encompasses traditional standardization methods and methods for projecting the impact of partially successful interventions.
Abstract: Some recent articles have discussed biased methods for estimating risk ratios from adjusted odds ratios when the outcome is common, and the problem of setting confidence limits for risk ratios. These articles have overlooked the extensive literature on valid estimation of risks, risk ratios, and risk differences from logistic and other models, including methods that remain valid when the outcome is common, and methods for risk and rate estimation from case-control studies. The present article describes how most of these methods can be subsumed under a general formulation that also encompasses traditional standardization methods and methods for projecting the impact of partially successful interventions. Approximate variance formulas for the resulting estimates allow interval estimation; these intervals can be closely approximated by rapid simulation procedures that require only standard software functions.
671 citations
TL;DR: A new statistical method, reduced rank regression (RRR), is applied to extract dietary patterns from 49 food groups, specifying four diabetes-related nutrients and nutrient ratios as responses that extracted a significant risk factor for diabetes.
Abstract: Because foods are consumed in combination, it is difficult in observational studies to separate the effects of single foods on the development of diseases. A possible way to examine the combined effect of food intakes is to derive dietary patterns by using appropriate statistical methods. The objective of this study was to apply a new statistical method, reduced rank regression (RRR), that is more flexible and powerful than the classic principal component analysis. RRR can be used efficiently in nutritional epidemiology by choosing disease-specific response variables and determining combinations of food intake that explain as much response variation as possible. The authors applied RRR to extract dietary patterns from 49 food groups, specifying four diabetes-related nutrients and nutrient ratios as responses. Data were derived from a nested German case-control study within the European Prospective Investigation into Cancer and Nutrition-Potsdam study consisting of 193 cases with incident type 2 diabetes identified until 2001 and 385 controls. The four factors extracted by RRR explained 93.1% of response variation, whereas the first four factors obtained by principal component analysis accounted for only 41.9%. In contrast to principal component analysis and other methods, the new RRR method extracted a significant risk factor for diabetes.
621 citations
TL;DR: The clinical phenotype of heterozygous familial hypercholesterolemia (FH) is characterized by increased plasma levels of total cholesterol and low density lipoprotein cholesterol, tendinous xanthomata, and premature symptoms of coronary heart disease.
Abstract: The clinical phenotype of heterozygous familial hypercholesterolemia (FH) is characterized by increased plasma levels of total cholesterol and low density lipoprotein cholesterol, tendinous xanthomata, and premature symptoms of coronary heart disease. It is inherited as an autosomal dominant disorder with homozygotes having a more severe phenotype than do heterozygotes. FH can result from mutations in the low density lipoprotein receptor gene (LDLR), the apolipoprotein B-100 gene (APOB), and the recently identified proprotein convertase subtilisin/kexin type 9 gene (PCSK9). To date, over 700 variants have been identified in the LDLR gene. With the exception of a small number of founder populations where one or two mutations predominate, most geographically based surveys of FH subjects show a large number of mutations segregating in a given population. Studies of the prevalence of FH would be improved by the use of a consistent and uniformly applied clinical definition. Because FH responds well to drug treatment, early diagnosis to reduce atherosclerosis risk is beneficial. Cascade testing of FH family members is cost effective and merits further research. For screening to be successful, public health and general practitioners need to be aware of the signs and diagnosis of FH and the benefits of early treatment.
TL;DR: It is concluded that age, race, body mass index, alcohol use, and cigarette smoking are associated with the incidence of endometriosis and that some of these relations may differ by infertility status at the time of laparoscopic diagnosis.
Abstract: The authors investigated the relations of demographic, anthropometric, and lifestyle factors with endometriosis in the Nurses' Health Study II prospective cohort. During 10 years of follow-up (1989-1999), 1,721 cases of laparoscopically confirmed endometriosis were reported among women with no past infertility. The incidence rate was greatest among women aged 25-29 years and lowest among women over 44 years (p(trend) 30 vs. 19-20.4 kg/m(2): rate ratio = 0.8, 95% confidence interval: 0.6, 1.1; p(trend) = 0.004) and with current alcohol intake (for >10 vs. 0 g/day: rate ratio = 0.7, 95% confidence interval: 0.6, 0.8; p(trend) < 0.0001) but no association with height, waist/hip ratio, or caffeine intake. An inverse relation with current body mass index and current cigarette smoking was observed only when cases were concurrently infertile. The authors conclude that age, race, body mass index, alcohol use, and cigarette smoking are associated with the incidence of endometriosis and that some of these relations may differ by infertility status at the time of laparoscopic diagnosis.
TL;DR: Significant racial/ethnic differences were found for the prevalence of most toe deformities and flat feet, as well as for corns and calluses, fungal signs, edema, ankle joint pain, tenderness to palpation, and sensory loss in older adults.
Abstract: The prevalence of foot and ankle disorders was determined in a community-based, multiethnic (non-Hispanic White, African American, and Puerto Rican) random sample of 784 community-dwelling adults aged 65 or more years in 2001-2002 in Springfield, Massachusetts. Overall, the five most common conditions were toenail disorders (74.9%), lesser toe deformities (60.0%), corns and calluses (58.2%), bunions (37.1%), and signs of fungal infection, cracks/fissures, or maceration between toes (36.3%); 30.9% had some tenderness to palpation of the foot or ankle, and 14.9% had ankle joint pain on most days in the past 4 weeks. Toenail conditions, fungal symptoms, and ulcers or lacerations were more common in men, while bunions and corns and calluses were more common in women (p < 0.001). Significant racial/ethnic differences, independent of education or gender, were found for the prevalence of most toe deformities and flat feet, as well as for corns and calluses, fungal signs, edema, ankle joint pain, tenderness to palpation, and sensory loss. Foot and ankle disorders are common in these older adults. Examination of their prevalence in different segments of the community may inform future studies to determine etiology and means of prevention.
TL;DR: The findings suggest that the cause of the winter increase in US mortality is singular and probably influenza, and the primary determinant appears to be the influenza virus.
Abstract: In economically developed countries, mortality increases distinctly during winter. Many causes have been suggested, including light-dark cycles, temperature/weather, and infectious agents. The authors analyzed monthly mortality in the United States during the period 1959-1999 for four major disease classes. The authors isolated the seasonal component of mortality by removing trends and standardizing the time series. They evaluated four properties: coincidence in mortality peaks, autocorrelation structure and autoregressive integrated moving average (ARIMA) models, magnitude, and age distribution. Peak months of mortality for ischemic heart disease, cerebrovascular disease, and diabetes mellitus coincided appropriately with peaks in pneumonia and influenza, and coefficients of autocorrelation and ARIMA models were essentially indistinguishable. The magnitude of the seasonal component was highly correlated with traditional measures of excess mortality and was significantly larger in seasons dominated by influenza A(H2N2) and A(H3N2) viruses than in seasons dominated by A(H1N1) or B viruses. There was an age shift in mortality during and after the 1968/69 pandemic in each disease class, with features specific to influenza A(H3N2). These findings suggest that the cause of the winter increase in US mortality is singular and probably influenza. Weather and other factors may determine the timing and modulate the magnitude of the winter-season increase in mortality, but the primary determinant appears to be the influenza virus.
TL;DR: The roles of folate-pathway genes, folate, and related dietary factors in colorectal neoplasia are complex and research priorities are suggested.
Abstract: Epidemiologic and mechanistic evidence suggests that folate is involved in colorectal neoplasia. Some polymorphic genes involved in folate metabolism--methylenetetrahydrofolate reductase (MTHFR C677T and A1298C), methionine synthase (MTR A2756G), methionine synthase reductase (MTRR A66G), cystathionine beta-synthase (CBS exon 8, 68-base-pair insertion), and thymidylate synthase (TS enhancer region and 3' untranslated region)--have been investigated in colorectal neoplasia. For MTHFR C677T and A1298C, the variant allele is associated with reduced enzyme activity in vitro. For the other polymorphisms, functional data are limited and/or inconsistent. Genotype frequencies for all of the polymorphisms show marked ethnic and geographic variation. In most studies, MTHFR 677TT (10 studies, >4,000 cases) and 1298CC (four studies, >1,500 cases) are associated with moderately reduced colorectal cancer risk. In four of five genotype-diet interaction studies, 677TT subjects who had higher folate levels (or a "high-methyl diet") had the lowest cancer risk. In two studies, 677TT homozygote subjects with the highest alcohol intake had the highest cancer risk. Findings from six studies of MTHFR C677T and adenomatous polyps are inconsistent. There have been only one or two studies of the other polymorphisms; replication is needed. Overall, the roles of folate-pathway genes, folate, and related dietary factors in colorectal neoplasia are complex. Research priorities are suggested.
TL;DR: The association between low education and increased AD risk was not mediated by adult SES or socioeconomic mobility, which suggests that early life factors may be relevant.
Abstract: In this study, the authors evaluated whether the association between low educational level and increased risk of Alzheimer's disease (AD) and dementia may be explained by occupation-based socioeconomic status (SES). A cohort of 931 nondemented subjects aged > or = 75 years from the Kungsholmen Project, Stockholm, Sweden, was followed for 3 years between 1987 and 1993. A total of 101 incident cases of dementia, 76 involving AD, were detected. Less-educated subjects had an adjusted relative risk of developing AD of 3.4 (95% confidence interval: 2.0, 6.0), and subjects with lower SES had an adjusted relative risk of 1.6 (95% confidence interval: 1.0, 2.5). When both education and SES were introduced into the same model, only education remained significantly associated with AD. Combinations of low education with low or high SES were associated with similar increased risks of AD, but well-educated subjects with low SES were not at high risk. Low SES at 20 years of age, even when SES was high at age 40 or 60 years, was associated with increased risk; however, this increase disappeared when education was entered into the model. In conclusion, the association between low education and increased AD risk was not mediated by adult SES or socioeconomic mobility. This suggests that early life factors may be relevant.
TL;DR: Overall, greater intake of fruits and vegetables was associated with lower risk of all-cause, cancer, and cardiovascular disease death, and this findings support the general health recommendation to consume multiple servings ofruits and vegetables (5-9/day).
Abstract: Higher intake of fruits, vegetables, and antioxidants may help protect against oxidative damage, thus lowering cancer and cardiovascular disease risk. This Washington County, Maryland, prospective study examined the association of fruit, vegetable, and antioxidant intake with all-cause, cancer, and cardiovascular disease death. CLUE participants who donated a blood sample in 1974 and 1989 and completed a food frequency questionnaire in 1989 (N = 6,151) were included in the analysis. Participants were followed to date of death or January 1, 2002. Compared with those in the bottom fifth, participants in the highest fifth of fruit and vegetable intake had a lower risk of all-cause (cases = 910; hazard ratio (HR) = 0.63, 95% confidence interval (CI): 0.51, 0.78; p-trend = 0.0004), cancer (cases = 307; HR = 0.65, 95% CI: 0.45, 0.93; p-trend = 0.08), and cardiovascular disease (cases = 225; HR = 0.76, 95% CI: 0.54, 1.06; p-trend = 0.15) mortality. Higher intake of cruciferous vegetables was associated with lower risk of all-cause mortality (HR = 0.74, 95% CI: 0.60, 0.91; p-trend = 0.04). No statistically significant associations were observed between dietary vitamin C, vitamin E, and beta-carotene intake and mortality. Overall, greater intake of fruits and vegetables was associated with lower risk of all-cause, cancer, and cardiovascular disease death. These findings support the general health recommendation to consume multiple servings of fruits and vegetables (5-9/day).
TL;DR: Preliminary research indicates that the FH phenotype is influenced by other genetic and environmental factors; however, it is not clear if these are synergistic interactions or simply additive effects.
Abstract: Familial hypercholesterolemia (FH) is an autosomal disorder characterized by increased levels of total cholesterol and low density lipoprotein cholesterol. The FH clinical phenotype has been shown to be associated with increased coronary heart disease and premature death. Mutations in the low density lipoprotein receptor gene (LDLR) can result in the FH phenotype, and there is evidence that receptor-negative mutations result in a more severe phenotype than do receptor-defective mutations. Mutations in the apolipoprotein B-100 gene (APOB) can result in a phenotype that is clinically indistinguishable from familial hypercholesterolemia, and mutations in this gene have also been shown to be associated with coronary heart disease. Preliminary research indicates that the FH phenotype is influenced by other genetic and environmental factors; however, it is not clear if these are synergistic interactions or simply additive effects.
TL;DR: Among SARS patients, males may be more severely affected by the disease than females are, and this finding could be related to a nonuniform case definition of SARS disease, a different treatment regimen, a past smoking history, work-environment factors, or gender-specific immune-defense factors, for instance.
Abstract: Severe acute respiratory syndrome (SARS) has been reported in 30 countries and regions, with a cumulative total of 8,099 probable cases and 774 deaths as of July 31, 2003, according to the World Health Organization. In Hong Kong, People's Republic of China, 1,755 SARS cases and 299 deaths had occurred as of September 22, 2003. The authors analyzed data from the Department of Health, Hong Kong SAR. The data series includes details regarding sex, age, and chronic disease history. Using data from early March to September 22, 2003, the authors found that males had a significantly (p < 0.0001) higher case fatality rate than females did, 21.9% versus 13.2%; the relative risk was 1.66 (95% confidence interval (CI): 1.35, 2.05), and it was 1.62 (95% CI: 1.21, 2.16) after adjustment for age. Subgroup analysis was conducted by excluding health care workers (n = 386) from the analysis. The overall crude relative risk of mortality was 1.41 (95% CI: 1.15, 1.74), and the adjusted relative risk was 1.48 (95% CI: 1.10, 2.00). Thus, among SARS patients, males may be more severely affected by the disease than females are. This finding could be related to a nonuniform case definition of SARS disease, a different treatment regimen, a past smoking history, work-environment factors, or gender-specific immune-defense factors, for instance.
TL;DR: The authors concluded that programs aimed at preventing human immunodeficiency virus transmission should emphasize the influence of substance use during sex on increased risk behavior.
Abstract: Prior reports associating substance use with sexual risk behavior have generally used summary measures and have not adjusted for participants' background levels of substance use. In this 1999-2001 US study (the EXPLORE study), the authors determined whether substance use during sex was independently associated with sexual risk during recent sexual episodes, as reported by 4,295 human immunodeficiency virus-negative men who have sex with men. The main outcome measure was serodiscordant unprotected anal sex (SDUA). The influence of participant-level characteristics was examined by using repeated-measures logistic models. In assessing the influence of episode-level predictors on SDUA, the influence of participant-level characteristics, including 6-month substance use, was removed by using conditional logistic regression, in effect making each participant his own control. The authors also adjusted for partner characteristics. Eleven percent of participants reported heavy alcohol use, 37% used poppers, 19% sniffed cocaine, and 13% used amphetamines. In the participant-level analysis, use of poppers, amphetamines, and sniffed cocaine as well as heavy alcohol use in the prior 6 months were independently associated with SDUA. In the conditional analysis, consumption of > or = 6 alcoholic drinks or use of poppers, amphetamines, or sniffed cocaine just before or during sex was independently associated with SDUA. The authors concluded that programs aimed at preventing human immunodeficiency virus transmission should emphasize the influence of substance use during sex on increased risk behavior.
TL;DR: Dietary intakes of choline were associated with reduced NTD risks and study findings for dietary components other than folic acid offer additional clues about the complex etiologies of NTDs.
Abstract: Periconceptional intake of folic acid prevents some neural tube defects (NTDs). Other nutrients may also contribute to NTD etiologies; a likely candidate is choline. Similar to folic acid, choline is involved in one-carbon metabolism for methylation of homocysteine to methionine. The authors investigated whether maternal periconceptional dietary intakes of choline and its metabolite betaine influence NTD risk. Data were derived from a case-control study of fetuses and infants with NTDs among 1989-1991 California births. In-person interviews were conducted with mothers of 424 NTD cases and with mothers of 440 nonmalformed controls. A standard 100-item food frequency questionnaire was used to assess nutrient intake. Dietary intakes of choline were associated with reduced NTD risks. Controlling for intake of supplemental folic acid, dietary folate, dietary methionine, and other covariates did not substantially influence risk estimates for choline. NTD risk estimates were lowest for women whose diets were rich in choline, betaine, and methionine. That is, for women whose intake was above the 75th percentile compared with below the 25th percentile for all three nutrients, the odds ratio was 0.17 (95% confidence interval: 0.04, 0.76). Study findings for dietary components other than folic acid offer additional clues about the complex etiologies of NTDs.
TL;DR: This study provides further evidence that obesity increases the risk of overall cancer, non-Hodgkin's lymphoma, leukemia, multiple myeloma, and cancers of the kidney, colon, rectum, breast (in postmenopausal women), pancreas, ovary, and prostate.
Abstract: The authors conducted a population-based, case-control study of 21,022 incident cases of 19 types of cancer and 5,039 controls aged 20-76 years during 1994-1997 to examine the association between obesity and the risks of various cancers. Compared with people with a body mass index of less than 25 kg/m(2), obese (body mass index of > or = 30 kg/m(2)) men and women had an increased risk of overall cancer (multivariable adjusted odds ratio = 1.34, 95% confidence interval (CI): 1.22, 1.48), non-Hodgkin's lymphoma (odds ratio = 1.46, 95% CI: 1.24, 1.72), leukemia (odds ratio = 1.61, 95% CI: 1.32, 1.96), multiple myeloma (odds ratio = 2.06, 95% CI: 1.46, 2.89), and cancers of the kidney (odds ratio = 2.74, 95% CI: 2.30, 3.25), colon (odds ratio = 1.93, 95% CI: 1.61, 2.31), rectum (odds ratio = 1.65, 95% CI: 1.36, 2.00), pancreas (odds ratio = 1.51, 95% CI: 1.19, 1.92), breast (in postmenopausal women) (odds ratio = 1.66, 95% CI: 1.33, 2.06), ovary (odds ratio = 1.95, 95% CI: 1.44, 2.64), and prostate (odds ratio = 1.27, 95% CI: 1.09, 1.47). Overall, excess body mass accounted for 7.7% of all cancers in Canada-9.7% in men and 5.9% in women. This study provides further evidence that obesity increases the risk of overall cancer, non-Hodgkin's lymphoma, leukemia, multiple myeloma, and cancers of the kidney, colon, rectum, breast (in postmenopausal women), pancreas, ovary, and prostate.
TL;DR: It is suggested that, although midlife women tend to experience increases in weight and waist circumference over time, maintaining or increasing participation in regular physical activity contributes to prevention or attenuation of those gains.
Abstract: Controversy exists regarding the extent to which age, menopausal status, and/or lifestyle behaviors account for the increased weight, fat mass, and central adiposity experienced by midlife women. To address this question, the authors longitudinally examined the relations of aging, menopausal status, and physical activity to weight and waist circumference in 3,064 racially/ethnically diverse women aged 42-52 years at baseline who were participating in the Study of Women's Health Across the Nation (SWAN), an observational study of the menopausal transition. Over 3 years of follow-up (1996-1997 to 1999-2000), mean weight increased by 2.1 kg (standard deviation (SD), 4.8) or 3.0% (SD, 6.5) and mean waist circumference increased by 2.2 cm (SD, 5.4) or 2.8% (SD, 6.3). Change in menopausal status was not associated with weight gain or significantly associated with increases in waist circumference. A one-unit increase in reported level of sports/exercise (on a scale of 1-5) was longitudinally related to decreases of 0.32 kg in weight (p < 0.0001) and 0.10 cm in waist circumference (not significant). Similar inverse relations were observed for daily routine physical activity (biking and walking for transportation and less television viewing). These findings suggest that, although midlife women tend to experience increases in weight and waist circumference over time, maintaining or increasing participation in regular physical activity contributes to prevention or attenuation of those gains.
TL;DR: The need for increased attention by the public health community to primary and secondary prevention of gender-based violence, with a specific need to reduce risk among South African adolescents, is confirmed.
Abstract: Gender-based violence is a key health risk for women globally and in South Africa. The authors analyzed data from 1,395 interviews with women attending antenatal clinics in Soweto, South Africa, between November 2001 and April 2002 to estimate the prevalence of physical/sexual partner violence (55.5%), adult sexual assault by nonpartners (7.9%), child sexual assault (8.0%), and forced first intercourse (7.3%). Age at first experience of each type of violence was modeled by the Kaplan-Meier method, and Cox hazard models with time-varying covariates were used to explore whether child sexual assault and forced first intercourse were associated with risk of violent revictimization in adulthood. Child sexual assault was associated with increased risk of physical and/or sexual partner violence (risk ratio = 2.43, 95% confidence interval: 1.93, 3.06) and with adult sexual assault by a nonpartner (risk ratio = 2.33, 95% confidence interval: 1.40, 3.89). Forced first intercourse was associated with increased risk of physical and/or sexual partner violence (risk ratio = 2.64, 95% confidence interval: 2.07, 3.38) and nonsignificantly with adult sexual assault by a nonpartner (risk ratio = 2.14, 95% confidence interval: 0.92, 4.98). This study confirms the need for increased attention by the public health community to primary and secondary prevention of gender-based violence, with a specific need to reduce risk among South African adolescents.
TL;DR: Mexican Americans experience a substantially greater ischemic stroke and intracerebral hemorrhage incidence compared with non-Hispanic Whites, and measures to target this population for stroke prevention are critical.
Abstract: Mexican Americans are the largest subgroup of Hispanics, the largest minority population in the United States. Stroke is the leading cause of disability and third leading cause of death. The authors compared stroke incidence among Mexican Americans and non-Hispanic Whites in a population-based study. Stroke cases were ascertained in Nueces County, Texas, utilizing concomitant active and passive surveillance. Cases were validated on the basis of source documentation by board-certified neurologists masked to subjects' ethnicity. From January 2000 to December 2002, 2,350 cerebrovascular events occurred. Of the completed strokes, 53% were in Mexican Americans. The crude cumulative incidence was 168/10,000 in Mexican Americans and 136/10,000 in non-Hispanic Whites. Mexican Americans had a higher cumulative incidence for ischemic stroke (ages 45-59 years: risk ratio = 2.04, 95% confidence interval: 1.55, 2.69; ages 60-74 years: risk ratio = 1.58, 95% confidence interval: 1.31, 1.91; ages >or=75 years: risk ratio = 1.12, 95% confidence interval: 0.94, 1.32). Intracerebral hemorrhage was more common in Mexican Americans (age-adjusted risk ratio = 1.63, 95% confidence interval: 1.24, 2.16). The subarachnoid hemorrhage age-adjusted risk ratio was 1.57 (95% confidence interval: 0.86, 2.89). Mexican Americans experience a substantially greater ischemic stroke and intracerebral hemorrhage incidence compared with non-Hispanic Whites. As the Mexican-American population grows and ages, measures to target this population for stroke prevention are critical.
TL;DR: This paper examined the relation between changes in body weight and body fat distribution (1986-1996) and subsequent risk of diabetes (1996-2000) among 22,171 men in the Health Professionals Follow-up Study.
Abstract: Although previous studies have linked obesity to diabetes, the risks associated with weight gain or changes in body fat distribution have not been fully elucidated The authors therefore prospectively examined the relations between changes in body weight and body fat distribution (1986-1996) and the subsequent risk of diabetes (1996-2000) among 22,171 men in the Health Professionals Follow-up Study Weight gain was monotonically related to risk, and for every kilogram of weight gained, risk increased by 73% A gain in abdominal fat was positively associated with risk, independent of the risk associated with weight change Compared with men who had a stable waist, men who increased waist circumference by 146 cm or more had 17 (95% confidence interval: 10, 28) times the risk of diabetes after controlling for weight gain In contrast, men who lost more than 41 cm in hip girth had 15 (95% confidence interval: 10, 23) times the risk of diabetes compared with men with stable hip circumference Fifty-six percent of the cases of diabetes in this cohort could be attributed to weight gain greater than 7 kg, and 20 percent of the cases could be attributed to a waist gain exceeding 25 cm Our findings underscore the critical importance of maintaining weight and waist to reduce the risk of diabetes
TL;DR: In this cohort of formaldehyde-industry workers, some evidence was found of an exposure-response relation with mortality from nasopharyngeal cancer (based on small numbers) but not for cancers of the pancreas, brain, lung, or prostate.
Abstract: In industrial workers, formaldehyde exposure has been associated with cancer of the nasal cavities, nasopharynx, prostate, lung, and pancreas; however, these associations are inconsistent and remain controversial. Animals exposed to formaldehyde show excesses of nasal cancer. In an extended follow-up of a large cohort of formaldehyde-exposed workers, the authors evaluated mortality from solid cancers (1,921 deaths) among 25,619 workers (865,708 person-years) employed in 10 US formaldehyde-producing or -using facilities through 1994. Exposure assessment included quantitative estimates of formaldehyde exposure. Standardized mortality ratios and relative risks were calculated. Compared with that for the US population, mortality from solid cancers was significantly lower than expected among subjects exposed and nonexposed to formaldehyde (standardized mortality ratios = 0.91 and 0.78, respectively). Relative risks for nasopharyngeal cancer (nine deaths) increased with average exposure intensity, cumulative exposure, highest peak exposure, and duration of exposure to formaldehyde (p-trend = 0.066, 0.025, <0.001, and 0.147, respectively). Formaldehyde exposure did not appear to be associated with lung (744 deaths), pancreas (93 deaths), or brain (62 deaths) cancer. Although relative risks for prostate cancer (145 deaths) were elevated for some measures of formaldehyde exposure, the trend was inconsistent. In this cohort of formaldehyde-industry workers, some evidence was found of an exposure-response relation with mortality from nasopharyngeal cancer (based on small numbers) but not for cancers of the pancreas, brain, lung, or prostate.
TL;DR: It is concluded that neonatal outcome did not deteriorate despite the women's impaired mental health during pregnancy, and no differences in Neonatal outcome between women with antenatal depressive disorders and/or anxiety disorders and healthy subjects are revealed.
Abstract: The aim of this study was to determine neonatal outcomes among women who had depressive and anxiety disorders during the second trimester of pregnancy in a population-based sample. Participants wer ...
TL;DR: In this article, the authors examined the relation of such factors to vasomotor symptoms in the multiethnic sample of 3,302 women, aged 42-52 years at baseline (1995-1997), in the Study of Women's Health Across the Nation (SWAN).
Abstract: Results of recent trials highlight the risks of hormone therapy, increasing the importance of identifying preventive lifestyle factors related to menopausal symptoms. The authors examined the relation of such factors to vasomotor symptoms in the multiethnic sample of 3,302 women, aged 42-52 years at baseline (1995-1997), in the Study of Women's Health Across the Nation (SWAN). All lifestyle factors and symptoms were self-reported. Serum hormone and gonadotropin concentrations were measured once in days 2-7 of the menstrual cycle. After adjustment for covariates using multiple logistic regression, significantly more African-American and Hispanic and fewer Chinese and Japanese than Caucasian women reported vasomotor symptoms. Fewer women with postgraduate education reported vasomotor symptoms. Passive exposure to smoke, but not active smoking, higher body mass index, premenstrual symptoms, perceived stress, and age were also significantly associated with vasomotor symptoms, although a dose-response relation with hours of smoke exposure was not observed. No dietary nutrients were significantly associated with vasomotor symptoms. These cross-sectional findings require further longitudinal exploration to identify lifestyle changes for women that may help prevent vasomotor symptoms.
TL;DR: The amount of adipose tissue stored in the intraabdominal cavity is an important, independent risk factor for MI in well-functioning, elderly women and the association with total adiposity and body fat distribution in men and women is examined.
Abstract: Assessment of body fat distribution, particularly visceral adipose tissue, may be important for accurate risk evaluation for cardiovascular disease in the elderly. This 1997-1998 US study examined the association of incident myocardial infarction (MI) with total adiposity (body mass index and fat mass) and body fat distribution (waist-to-thigh ratio, waist circumference, visceral and subcutaneous adipose tissue) in well-functioning men (n = 1,116) and women (n = 1,387) aged 70-79 years enrolled in the Health, Aging and Body Composition Study. There were 116 MI events (71 in men, 45 in women) during an average follow-up time of 4.6 (standard deviation, 0.9) years. No association was found between incident MI and the adiposity or fat distribution variables for men. For women, visceral adipose tissue was an independent predictor of MI (hazard ratio = 1.67, 95% confidence interval: 1.28, 2.17 per standard-deviation increase; p < 0.001). No association was found between body mass index or total fat mass and MI events in women. The association of visceral adipose tissue with MI in women was independent of high density lipoprotein cholesterol, interleukin-6 concentration, hypertension, and diabetes (hazard ratio = 1.79, 95% confidence interval: 1.24, 2.58 per standard-deviation increase; p < 0.01). The amount of adipose tissue stored in the intraabdominal cavity is an important, independent risk factor for MI in well-functioning, elderly women.