Clinical Trial Service Unit

About: Clinical Trial Service Unit is a based out in . It is known for research contribution in the topics: Population & Stroke. The organization has 428 authors who have published 1387 publications receiving 181920 citations.

Regression dilution bias in blood total and high-density lipoprotein cholesterol and blood pressure in the Glostrup and Framingham prospective studies.

Abstract: Background In epidemiological studies, within-person variability in measured values of a risk factor may underestimate the association between prolonged or 'usual' levels of a risk factor with risk of disease - 'regression dilution'. The importance of regression dilution for high-density lipoprotein (HDL)-cholesterol and the extent to which this may differ from that for total cholesterol is not known. The aim of this study was to assess the magnitude of regression dilution bias for HDL-cholesterol, total cholesterol and blood pressure after varying intervals of follow-up in two prospective cohort studies. Methods Regression dilution ratios were estimated for each risk factor using the correlations between baseline and re-survey values in the Glostrup Population Studies and the NHLBI Framingham Heart Study after various time intervals. The regression dilution ratios in each cohort after a fixed interval between measurements were compared. Results The regression dilution ratios after 10 years were 0.51 and 0.56 for systolic blood pressure in Glostrup and Framingham, respectively; 0.52 and 0.54 for diastolic blood pressure; and 0.68 and 0.63 for total cholesterol. In both studies, the regression dilution ratios for these risk factors became more extreme with increasing intervals between measurements. The regression dilution ratio for HDL-cholesterol after 10 years in Glostrup was 0.72, which suggests that the importance of regression dilution for HDL-cholesterol was similar to that for total cholesterol. Conclusion Failure to correct for increasing regression dilution with longer follow-up may account for some of the discrepant results obtained for the importance of these risk factors in epidemiological studies at varying intervals of follow-up.

[The China Kadoorie Biobank: related methodology and baseline characteristics of the participants].

Abstract: Objective To study the separate and combined effects of environment, lifestyle, physical characteristics, blood biomarkers and genetic factors on aetiology of major chronic diseases in adult Chinese. Methods China Kadoorie Biobank （CKB） is a large blood-based prospective cohort study. The baseline survey took place in 5 urban and 5 rural areas across China during 2004-2008, with collection of data through questionnaire, physical examination and blood samples. Following the baseline survey, 5% of the randomly selected participants were surveyed in 2008, and repeated every 4-5 years. All participants would be followed for cause-specific mortality and morbidity through registries and for any hospital admission through linkages with health insurance databases. Results Overall, 512 891 adults aged 30-79 years （mean 51.5） were recruited, including 41.0% men and 55.9% from rural areas. Blood collection was successfully done in 99.98% of the participants. The prevalence of current regular smoking was 61.3% in men and 2.4% in women. The prevalence of regular alcohol consumption （i.e., weekly） was 33.4% in men and 2.1% in women. At the baseline,41.8% of men and 45.3% of women were overweight or obese （i.e., BMI≥24.0 kg/m2） and 32.2% of men and 30.2% of women were hypertensive （i.e., SBP ≥ 140 mm Hg or DBP ≥90 mm Hg）. For each of the main baseline variables, there were large variations on age, sex and areas of study. Conclusion CKB seemed to be a powerful and rich resource in studying the environmental and genetic determinants of major chronic diseases in the Chinese population. Key words: Chronic disease; Cohort study; Biobank

Gallstone Disease and the Risk of Ischemic Heart Disease

Abstract: Objective—Gallstone disease (GSD) is related to multiple cardiovascular risk factors; the present study was to prospectively examine the association between GSD and ischemic heart disease (IHD). Approach and Results—We examined the association of GSD with IHD among 199 292 men and 288 081 women aged 30−79 years in the China Kadoorie Biobank study. Participants with cancer, heart disease, and stroke at baseline were excluded. Cox proportional hazards regression model was used to estimate the association of GSD with IHD. The prevalence of self-reported GSD was 3.7% in men and 7.3% in women at baseline. During 3 431 124 person-years of follow-up between 2004 and 2013 (median, 7.2 years), we documented 10 245 incident IHD cases in men and 14 714 in women. As compared with men without GSD at baseline, the multivariate-adjusted hazard ratio for IHD was 1.11 (95% confidence interval, 1.02−1.22) for men with GSD; the respective hazard ratio was 1.27 (95% confidence interval, 1.20−1.34) in women and 1.23 (95% conf...

Soy intake and breast cancer risk: a prospective study of 300,000 Chinese women and a dose–response meta-analysis

Abstract: Epidemiological evidence on the association of soy intake with breast cancer risk is still inconsistent due to different soy intake levels across previous studies and small number of breast cancer cases. We aimed to investigate this issue by analyzing data from the China Kadoorie Biobank (CKB) study and conducting a dose–response meta-analysis to integrate existing evidence. The CKB study included over 300,000 women aged 30–79 from 10 regions across China enrolled between 2004 and 2008, and followed-up for breast cancer events until 31 December 2016. Information on soy intake was collected from baseline, two resurveys and twelve 24-h dietary recalls. We also searched for relevant prospective cohort studies to do a dose–response meta-analysis. The mean (SD) soy intake was 9.4 (5.4) mg/day soy isoflavones among CKB women. During 10 years of follow-up, 2289 women developed breast cancers. The multivariable-adjusted relative risk was 1.00 (95% confidence interval [CI] 0.81–1.22) for the fourth (19.1 mg/day) versus the first (4.5 mg/day) soy isoflavone intake quartile. Meta-analysis of prospective studies found that each 10 mg/day increment in soy isoflavone intake was associated with a 3% (95% CI 1–5%) reduced risk of breast cancer. The CKB study demonstrated that moderate soy intake was not associated with breast cancer risk among Chinese women. Higher amount of soy intake might provide reasonable benefits for the prevention of breast cancer.