Showing papers by "Shankuan Zhu published in 2003"

The Metabolic Syndrome: Prevalence and Associated Risk Factor Findings in the US Population From the Third National Health and Nutrition Examination Survey, 1988-1994

Abstract: Coronary heart disease (CHD) is the leading cause of death in the United States.1 Factors associated with an increased risk of developing CHD that tend to cluster in individuals include older age, high blood pressure, a low level of high-density lipoprotein (HDL) cholesterol, a high triglyceride level, a high plasma glucose concentration, and obesity.2 These associated risk factors have been called syndrome X,3 the insulin resistance syndrome,4 or the metabolic syndrome.5 The mechanisms underlying the metabolic syndrome are not fully known; however, resistance to insulin-stimulated glucose uptake seems to modify biochemical responses in a way that predisposes to metabolic risk factors.3,6,7 Insulin resistance is thought to be primarily due to obesity or an inherited genetic defect.8 As the prevalence of obesity increases in the United States, the prevalence of the metabolic syndrome may be expected to increase markedly. Estimates of the prevalence of the metabolic syndrome have varied substantially in part because of the variability of evaluated populations and of diagnostic criteria.9 The recent Third Report of the National Cholesterol Education Program Adult Treatment Panel (ATP III) included clinical diagnosis guidelines for the metabolic syndrome.10 Compared with findings from earlier studies3-5 and World Health Organization guidelines, the new ATP III defines criteria readily measured in clinical practice. These consensus-generated guidelines provide the opportunity to assess the overall prevalence of the metabolic syndrome in the US population according to an accepted standard definition. In an initial study, Ford et al11 reported un-adjusted and age-adjusted metabolic syndrome prevalences of 21.8% and 23.7%, respectively, for the US population. The objectives of this study are to examine the prevalence of the metabolic syndrome by ethnicity, age, body mass index (BMI) (calculated as weight in kilograms divided by the square of height in meters), socioeconomic status, and lifestyle factors.

The metabolic syndrome is associated with elevated circulating C-reactive protein in healthy reference range, a systemic low-grade inflammatory state

Abstract: OBJECTIVE: To elucidate the underlying mechanisms between C-reactive protein (CRP) and cardiovascular disease, we exa-mined the association of circulating CRP in healthy reference range (≤1.0 mg/dl) measured by high-sensitive CRP assay with the metabolic syndrome (MS). DESIGN: Cross-sectional study of circulating CRP in adult men. SUBJECTS: A total of 3692 Japanese men aged 34–69 y. MEASUREMENTS: Serum CRP, total cholesterol, triglycerides, LDL-cholesterol, fasting glucose, fasting insulin, uric acid, systolic blood pressure, diastolic blood pressure, and body mass index (BMI). RESULTS: There was a statistically significant positive correlation between CRP and BMI (r=0.25), total cholesterol (r=0.096), triglycerides (r=0.22), LDL-cholesterol (r=0.12), fasting glucose (r=0.088), fasting insulin (r=0.17), uric acid (r=0.13), systolic blood pressure (r=0.12), and diastolic blood pressure (r=0.11), and a significant negative correlation of CRP with HDL-cholesterol (r=0.24). After adjusting for age, smoking, and all other components of MS, obesity, hypertriglyceridemia, hyper-LDL-cholesterolemia, diabetes, hyperinsulinemia, and hyperuricemia were significantly associated with both mildly (≥0.06 mg/dl) and moderately (≥0.11 mg/dl) elevated CRP. Compared with men who had no such components of the MS, those who had one, two, three, four, and five or more components were, respectively, 1.48, 1.84, 1.92, 3.42, and 4.17 times more likely to have mildly elevated CRP levels (trend P<0.001). As for moderately elevated CRP, the same association was observed. CONCLUSIONS: These results indicate that a variety of components of the MS are associated with elevated CRP levels in a systemic low-grade inflammatory state.

Obesity and quality of life: mediating effects of pain and comorbidities.

Abstract: Objective: To estimate the association between body mass index (BMI) and health-related quality of life (HRQL) and examine whether joint pain and obesity-related comorbidities mediate the BMI-HRQL association. Research Methods and Procedures: Population-based survey data from the 1999 Behavioral Risk Factor Surveillance Survey. Adults (N = 155, 989) were classified according to BMI as underweight (<18.5 kg/m2), desirable weight (18.5 to 24.9 kg/m2), overweight (25 to 29.9 kg/m2), obese class I (30 to 34.9 kg/m2), obese class II (35 to 39.9 kg/m2), and obese class III (≥40 kg/m2). Data including general health status, unhealthy days in the past 30 caused by physical problems and mental problems, and total unhealthy days in the past 30 were collected. Results: After adjusting for age, sex, race, smoking, education, and income, we observed J-shaped associations between BMI and HRQL. Compared with desirable weight adults, underweight, overweight, and obesity classes I, II, and III adults [odds ratio (OR) = 1.57, 1.19, 1.95, 2.72, and 4.36, respectively] were significantly (p < 0.001) more likely to report fair/poor general health status. For unhealthy days caused by physical problems, the corresponding ORs were 1.51, 1.15, 1.66, 2.27, and 3.61 (p < 0.001). For unhealthy days caused by mental problems, the ORs were 1.35, 1.14 1.43, 1.57, and 2.25 (p < 0.001). For total unhealthy days, the corresponding ORs were 1.27, 1.09, 1.37, 1.73, and 2.46 (p < 0.01). Adding joint pain and obesity-related comorbidities into models attenuated BMI-HRQL associations. Discussion: Associations between BMI and HRQL indices were J-shaped. Joint pain and comorbidities may mediate BMI-HRQL associations.

Volume estimates by imaging methods: model comparisons with visible woman as the reference.

Abstract: Objective: To compare the accuracy of four volume estimation models to actual tissue and organ volumes measured in the visible woman. Methods: Actual volumes were calculated from 1-mm-thick visible woman images that were segmented for five major components including subcutaneous and visceral adipose tissue across the 1730 available slices. Four available models resolved to two equations: truncated cone/truncated pyramid vs. two-column/parallel trapezium. Between-slice interval and initial slice were systematically varied when deriving component volumes using the two equations in four regions. Results: For each compartment and each between-slice interval, the means of the two-column model were always the same as the corresponding reference volumes, whereas those of the truncated cone model were smaller than the reference volumes. Similarly, the coefficient variation for the two-column model was always smaller than for the truncated cone model. Discussion: The equation based on the parallel trapezium and the two-column models is more accurate in estimating tissue volumes than the corresponding equation for truncated pyramid and truncated cone models. This finding has important implications for the volume calculations of imaging-based body compartments such as adipose tissue.

Association between weight fluctuation and fasting insulin concentration in Japanese men.

Abstract: OBJECTIVE: To investigate whether long-term weight fluctuation is associated with the fasting serum insulin concentration. DESIGN AND SUBJECTS: Weight histories of 1932 male Japanese workers aged 40–59 y were analyzed in relation to their current fasting serum insulin concentration. MEASUREMENTS:Individual weight fluctuation was calculated by root mean square error (RMSE) along the linear regression line of weight measured at five to six different ages. RESULTS: The mean RMSE and fasting insulin concentration were 1.22 kg and 4.5 μU/ml, respectively. The multivariate adjusted insulin level became higher with the increase in weight fluctuation. Subanalysis stratified by current body mass index (BMI) showed that the multivariate adjusted insulin level in individuals in the top quartile of fluctuation was 4.3 μU/ml, against 3.9 μU/ml in those in the bottom quartile (P=0.018, analysis of covariance (ANCOVA)) in the normal weight subgroup with current BMI below 25 kg/m2. In the overweight subgroup with BMI 25 kg/m2 or above, the level was 6.9 μU/ml in individuals in the top quartile and 6.2 μU/ml in those in the bottom quartile (P=0.054, ANCOVA). CONCLUSION: The results suggest that weight fluctuation increases the risk of developing hyperinsulinemia. Prospective observations together with measurement of changes in adiposity are needed for confirmation.

Long-term body weight variability is associated with elevated C-reactive protein independent of current body mass index among Japanese men.

Abstract: OBJECTIVE: To elucidate the effect of long-term weight variability on C-reactive protein (CRP) levels. DESIGN: Cross-sectional study of the circulating CRP. SUBJECTS: A total of 637 Japanese men aged 40–49 y in1997. MEASUREMENTS: Serum CRP levels, body mass index in 1997 (current BMI), the slope of weight on age (weight-slope) representing an individual's weight trend of direction and magnitude, and the root mean square error around the slope of weight on age (weight-RMSE) representing the weight fluctuation magnitude, as calculated by a simple linear regression model in which each value of the subject's five actual weights (aged 20, 25, 30 y, five years ago, and current) was a dependent variable and the subject's ages independent variables. RESULTS: After adjustment for age and confounders, including smoking and health status, the odds ratios of elevated CRP (≥0.06 mg/dl) were 1.83 (95% CI: 1.25–2.69), 2.63 (1.69–4.11), and 10.31 (2.17–48.98) for upper normal-weight (BMI: 22–<25 kg/m2), overweight (25–<30), and obese (≥30) persons, respectively, compared with lower normal-weight persons (18.5–<22). Adjusting for age, confounders, and current BMI, weight-slope was positively associated with CRP level especially among subjects with BMI≥25 kg/m2 (trend P<0.01), and weight-RMSE was positively associated with CRP level particularly among subjects with BMI <25 kg/m2 (trend P<0.05). CONCLUSION: Our results suggest a state of low-grade systemic inflammation not only in overweight and obese persons, but also in normal-weight persons with large weight fluctuation, possibly explaining in part the positive association between weight fluctuation and CVD.

U-shaped association between white blood cell count and fasting plasma glucose level.

Abstract: It is well known that hyperglycemia is associated with increased mortality from cardiovascular disease (CVD) and all-cause mortality. It has recently been reported that subjects with low fasting plasma glucose (FPG) levels also had a high risk of CVD and all-cause mortality (1). However, there is a paucity of information about the etiologic basis underlying the association between low FPG and increased CVD and all-cause mortality. Thus, in the present study, we investigated the association of FPG levels with white blood cell (WBC) counts, which indicate a state of low-grade systemic inflammation. We …