Chengyi Han

Dose–Response Association Between Physical Activity and Incident HypertensionNovelty and Significance: A Systematic Review and Meta-Analysis of Cohort Studies

Despite the inverse association between physical activity (PA) and incident hypertension, a comprehensive assessment of the quantitative dose–response association between PA and hypertension has not been reported. We performed a meta-analysis, including dose–response analysis, to quantitatively evaluate this association. We searched PubMed and Embase databases for articles published up to November 1, 2016. Random effects generalized least squares regression models were used to assess the quantitative association between PA and hypertension risk across studies. Restricted cubic splines were used to model the dose–response association. We identified 22 articles (29 studies) investigating the risk of hypertension with leisure-time PA or total PA, including 330 222 individuals and 67 698 incident cases of hypertension. The risk of hypertension was reduced by 6% (relative risk, 0.94; 95% confidence interval, 0.92–0.96) with each 10 metabolic equivalent of task h/wk increment of leisure-time PA. We found no evidence of a nonlinear dose–response association of PA and hypertension (Pnonlinearity=0.094 for leisure-time PA and 0.771 for total PA). With the linear cubic spline model, when compared with inactive individuals, for those who met the guidelines recommended minimum level of moderate PA (10 metabolic equivalent of task h/wk), the risk of hypertension was reduced by 6% (relative risk, 0.94; 95% confidence interval, 0.92–0.97). This meta-analysis suggests that additional benefits for hypertension prevention occur as the amount of PA increases.

Association of obesity categories and high blood pressure in a rural adult Chinese population.

Limited information is available on the prevalence of obesity and high blood pressure (HBP) in rural China. We conducted a cross-sectional survey in a rural adult Chinese population during July to August of 2007 and 2008. The relationship between various obesity categories and HBP was analysed by gender for 20 194 participants. Obesity categories were classified as general and central obesity in terms of body mass index (BMI) and waist circumference (WC), respectively; cross-classification of BMI and WC created another four groups: both BMI and WC normal (BNWN), BMI obesity and WC normal (BOWN), BMI normal and WC obesity (BNWO), and both BMI and WC obesity (BOWO). The rates of HBP for BNWN, BOWN, BNWO and BOWO groups were 20.8, 63.3, 39.8 and 48.7%, respectively, for men and 20.1, 28.0, 34.7 and 54.2%, respectively, for women. As compared with BNWN group, the adjusted odds ratio (OR) and 95% confidence interval (CI) of BOWN and BOWO for having HBP in men were 6.227 (2.712–14.300) and 4.842 (4.036–5.808), respectively. As compared with BNWN women, BNWO and BOWO women showed increased risk of HBP (adjusted OR=1.342, 95%CI=1.139–1.581 and adjusted OR=4.530, 95%CI=4.004–5.124, respectively). The prevalence of general and central obesity was strongly related to HBP. Men with obese BMI but normal WC may be at increased risk of HBP. Women should pay more attention to changes in visceral adipose distribution and keep both BMI and WC values within normal ranges to reduce obesity-related health problems.

Development and Validation of a Risk-Score Model for Type 2 Diabetes: A Cohort Study of a Rural Adult Chinese Population

Some global models to predict the risk of diabetes may not be applicable to local populations. We aimed to develop and validate a score to predict type 2 diabetes mellitus (T2DM) in a rural adult Chinese population. Data for a cohort of 12,849 participants were randomly divided into derivation (n = 11,564) and validation (n = 1285) datasets. A questionnaire interview and physical and blood biochemical examinations were performed at baseline (July to August 2007 and July to August 2008) and follow-up (July to August 2013 and July to October 2014). A Cox regression model was used to weigh each variable in the derivation dataset. For each significant variable, a score was calculated by multiplying β by 100 and rounding to the nearest integer. Age, body mass index, triglycerides and fasting plasma glucose (scores 3, 12, 24 and 76, respectively) were predictors of incident T2DM. The model accuracy was assessed by the area under the receiver operating characteristic curve (AUC), with optimal cut-off value 936. With the derivation dataset, sensitivity, specificity and AUC of the model were 66.7%, 74.0% and 0.768 (95% CI 0.760–0.776), respectively. With the validation dataset, the performance of the model was superior to the Chinese (simple), FINDRISC, Oman and IDRS models of T2DM risk but equivalent to the Framingham model, which is widely applicable in a variety of populations. Our model for predicting 6-year risk of T2DM could be used in a rural adult Chinese population.

Secular trends in the prevalence of type 2 diabetes in adults in China from 1995 to 2014: A meta‐analysis

The aim of the present study was to estimate trends in the prevalence of type 2 diabetes mellitus (T2DM) in adults in China.

Effect of dynamic change in body mass index on the risk of hypertension: Results from the Rural Chinese Cohort Study

OBJECTIVES To examine the effect of change in body mass index (BMI) on incident hypertension by gender and age groups. METHODS A total of 10,145 non-hypertensive participants 18-75years old from rural areas in the middle of China were selected for this cohort study. Questionnaire interview and anthropometric and laboratory measurements were performed at baseline (during July to August 2007 and July to August 2008) and follow-up (during July to August 2013 and July to October 2014). Multiple logistic regression analysis was used to examine the relationship between change in BMI and incident hypertension. RESULTS During a mean follow-up of 6.03±0.69years, hypertension developed in 794 of 3986 men and 1184 of 6159 women. Both genders who were obese (BMI ≥28kg/m2 for Chinese people) at follow-up, regardless of their obesity status at baseline, showed greater risk of hypertension than those who were non-obese (BMI <28kg/m2) at both baseline and follow-up. We found a dose-response relationship between change in BMI and incident hypertension. Risk of hypertension was markedly greater with a BMI gain of the highest quartile or more as compared with a BMI reduction of the lowest quartile or more, except for women 60-75years old. CONCLUSIONS Risk of hypertension was high for non-hypertensive people in rural China with stable obesity. BMI dynamic gain may be related to incident hypertension for men of all ages and young and middle-aged women.

High pulse pressure is related to risk of type 2 diabetes mellitus in Chinese middle-aged females

BACKGROUND To examine the association of risk of incident type 2 diabetes mellitus (T2DM) with high pulse pressure (PP) by sex. METHODS We performed a prospective cohort study of 12,272 eligible participants (4664 males and 7608 females) without diabetes at baseline. Participants were classified as having normal PP (20-60mmHg) and high PP (>60mmHg) at baseline. The analysis was further stratified by sex, quartiles of age and high PP categories. RESULTS During 6years of follow-up, T2DM developed in 775 participants and the incidence was 10.57/1000person-years. With PP 70 to 76mmHg, the multivariable adjusted hazard ratio (HR) (95% confidence interval) for incident T2DM in females was 1.722 (1.093-2.714) after adjustment for baseline age, smoking, alcohol intake, physical activity level and family history of T2DM, and 1.634 (1.037-2.575) after adjustment for the above factors and body mass index, waist circumference, blood lipid levels and fasting plasma glucose (FPG) category. After stratification by quartiles of age, for females aged 52 to 59, the multivariable adjusted HRs (95% CI) for high PP as compared to normal PP were 2.263 (1.517-3.377) and 2.140 (1.426-3.210) in different models. During follow-up, levels of FPG, fasting plasma insulin and homeostatic model assessment of insulin resistance index (HOMA-IR) were higher in females with higher than normal PP group, but β-cell function was impaired in the high PP group (P<0.05). CONCLUSION High PP may be related to incident T2DM among female in China, especially women 52 to 59years old.

Risk of type 2 diabetes mellitus associated with plasma lipid levels: The rural Chinese cohort study

AIM To investigate the association of type 2 diabetes mellitus (T2DM) risk and plasma lipid levels in rural Chinese. METHODS Each lipid variable was divided into quartiles and dichotomized by clinical cutoff points. Cox proportional-hazards model was used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) for the association of T2DM risk and plasma lipid levels and explore the interaction between plasma lipid levels and other risk factors. RESULTS 11,929 participants were included in the analysis. We documented 720 incident cases of T2DM over 70,720.84 person-years of follow-up, for an incidence of 10.18/1,000 person-years. In the multivariable-adjusted model, risk of T2DM was increased with the highest versus lowest quartiles of total cholesterol (TC) and triglycerides (TG) levels and TC/high-density lipoprotein-cholesterol (HDL-C) and TG/HDL-C ratios. The HRs (95% CIs) for the fourth quartiles, for example, were 1.34 (1.03-1.74), 2.32 (1.73-3.13), 1.66 (1.23-2.25), and 1.84 (1.38-2.45), respectively. In addition, risk of T2DM was increased with high TG level and TC/HDL-C and TG/HDL-C ratios by clinical cutoffs. The HRs (95% CIs) were 1.50 (1.25-1.80), 1.24 (1.03-1.48), and 1.44 (1.18-1.75), respectively. Risk of T2DM was associated with interactions between all lipid variables and age and BMI. TG level and TG/HDL-C ratio additionally interacted with gender (all Pinteraction < 0.0001). CONCLUSIONS Risk of T2DM was increased with elevated serum levels of TC and TG and TC/HDL-C and TG/HDL-C ratios and also with interactions between high TC and TG levels and TC/HDL-C and TG/HDL-C ratios and age and BMI in a rural Chinese population.

Hypertriglyceridemia-waist and risk of developing type 2 diabetes: The Rural Chinese Cohort Study

Limited information is available on the effect of hypertriglyceridemia–waist (HTGW) combination and its dynamic status on the risk of type 2 diabetes mellitus (T2DM) in rural China. A cohort of 12,086 participants 18 to 92 years old was retained in this study. Kaplan-Meier analysis yielded the cumulative incidence of T2DM for each phenotype group (based on TG level and waist circumference [WC] at baseline). Cox regression yielded hazard ratios relating HTGW (based on TG level and WC at baseline and follow-up) to risk of developing T2DM. After a median follow-up of 6.0 years (71,432 person-years of follow-up), T2DM developed in 621 participants. For HTGW participants, the incidence of T2DM was 26.4/1000, 20.6/1000, and 21.9/1000 person-years for males, females, and overall, respectively. The adjusted HR for HTGW associated with T2DM was 7.63 (95% CI 4.32–13.49) for males and 7.75 (4.71–12.78) for females. Compared with consistent HTGW, with transformation from baseline HTGW to normal WC and normal triglycerides level at follow-up, the risk of developing T2DM was reduced by 75% and 78% for males and females. HTGW is a major risk factor for T2DM, but the risk could be reduced by improved triglycerides level and WC.

Leisure-time physical activity and incident metabolic syndrome: a systematic review and dose-response meta-analysis of cohort studies.

BACKGROUND Leisure-time physical activity (LTPA) has been suggested to reduce risk of metabolic syndrome (MetS). However, a quantitative comprehensive assessment of the dose-response association between LTPA and incident MetS has not been reported. We performed a meta-analysis of studies assessing the risk of MetS with LTPA. METHOD MEDLINE via PubMed and EMBase databases were searched for relevant articles published up to March 13, 2017. Random-effects models were used to estimate the summary relative risk (RR) of MetS with LTPA. Restricted cubic splines were used to model the dose-response association. RESULTS We identified 16 articles (18 studies including 76,699 participants and 13,871 cases of MetS). We found a negative linear association between LTPA and incident MetS, with a reduction of 8% in MetS risk per 10 metabolic equivalent of task (MET) h/week increment. According to the restricted cubic splines model, risk of MetS was reduced 10% with LTPA performed according to the basic guideline-recommended level of 150min of moderate PA (MPA) per week (10METh/week) versus inactivity (RR=0.90, 95% CI 0.86-0.94). It was reduced 20% and 53% with LTPA at twice (20METh/week) and seven times (70METh/week) the basic recommended level (RR=0.80, 95% CI 0.74-0.88 and 0.47, 95% CI 0.34-0.64, respectively). CONCLUSION Our findings provide quantitative data suggesting that any amount of LTPA is better than none and that LTPA substantially exceeding the current LTPA guidelines is associated with an additional reduction in MetS risk.

Body mass index and waist circumference combined predicts obesity-related hypertension better than either alone in a rural Chinese population

Limited information is available on the association of obesity defined by both body mass index (BMI) and waist circumference (WC) with incident hypertension in rural China. A total of 9,174 participants ≥18 years old from rural areas in middle of China, free of hypertension, diabetes, myocardial infarction and stroke, were selected in this cohort study. Questionnaire interview and anthropometric and laboratory measurements were performed at baseline (2007–2008) and follow-up (2013–2014). During the 6 years of follow-up, hypertension developed in 733/3,620 men and 1,051/5,554 women. After controlling for age, education level, smoking, drinking, physical activity, and family history of hypertension, the relative risk of hypertension was lower for participants with high BMI but normal WC than those with both BMI and WC obesity for men 18–39 and 40–59 years old. Women 18–39 years old with normal BMI but high WC showed a 1.96-fold risk of hypertension, and being female with age 40–59 years and high BMI but normal WC was independently associated with hypertension incidence as compared with both normal BMI and WC. BMI is more associated with hypertension as compared with WC in both genders. High WC tends to add additional risk of hypertension in young women.