Xizhuo Sun

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.

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.

Comparison of body mass index, waist circumference, conicity index, and waist-to-height ratio for predicting incidence of hypertension: the rural Chinese cohort study

This study compared the ability of body mass index (BMI), waist circumference (WC), conicity index, and waist-to-height ratio (WHtR) to predict incident hypertension and to identify the cutoffs of obesity indices for predicting hypertension in rural Chinese adults. This prospective cohort study recruited 9905 participants aged 18–70 years during a median follow-up of 6 years in rural China. Logistic regression and receiver operating characteristic (ROC) curve analyses were used to assess the association, predictive ability, and optimal cutoffs (in terms of hypertension risk factors) of the four obesity indices: BMI, WC, conicity index, and WHtR. The 6-year cumulative incidence of hypertension was 19.89% for men and 18.68% for women, with a significant upward trend of increased incident hypertension with increasing BMI, WC, conicity index, and WHtR (P for trend < 0.001) for both men and women. BMI and WHtR had the largest area under the ROC curve for identifying hypertension for both genders. The optimal cutoff values for BMI, WC, conicity index, and WHtR for predicting hypertension were 22.65 kg/m2, 82.70 cm, 1.20, and 0.49, respectively, for men, and 23.80 kg/m2, 82.17 cm, 1.20, and 0.52, respectively, for women. BMI, WC, conicity index, and WHtR cutoffs may offer a simple and effective way to screen hypertension in rural Chinese adults. BMI and WHtR were superior to WC and conicity index for predicting incident hypertension for both genders.

Association of long-term dynamic change in body weight and incident hypertension: The Rural Chinese Cohort Study

OBJECTIVES The association of long-term dynamic change in body weight and incident hypertension among general Chinese adults is still unknown. The aim of this study was to evaluate the hypertension risk in a large prospective study of rural Chinese adult using relative weight gain or loss. METHODS A total of 10 149 nonhypertensive Chinese adults 18 to 75 y of age completed a questionnaire interview and anthropometric and laboratory measurements at both baseline (2007-2008) and follow-up (2013-2014). Participants were divided into five categories based on relative weight change. Logistic regression analysis was used to estimate odds ratios (ORs) and 95% confidence intervals (CIs) for hypertension risk by categories of weight change. RESULTS During 6 y of follow-up, about one-third of the participants retained a stable weight (33.3%) or gained >6% (32.7%). Only 7.9% lost >6% weight. For every 1% increase in relative body weight, systolic and diastolic blood pressures increased 0.27 and 0.22 mm Hg, respectively. Risk for hypertension was reduced and increased with weight loss >6% (OR, 0.78; 95% CI, 0.61-0.99) and gain >6% (OR, 2.08; 95% CI, 1.79-2.42), respectively, compared with weight loss or gain ≤3%. With baseline prehypertension, compared with maintaining a stable weight, weight loss >6% reduced the risk for hypertension (OR, 0.71; 95% CI, 0.54-0.95). With baseline overweight, compared with maintaining the overweight status during follow-up, changing to normal weight reduced the risk for hypertension (OR, 0.67; 95% CI, 0.49-0.92), but changing to general obesity increased the risk (OR, 1.73; 95% CI, 1.35-2.22). CONCLUSIONS Long-term excessive weight gain is positively associated with increased risk for incident hypertension. Losing weight by lifestyle modification could be helpful for the primary prevention of hypertension in the general rural Chinese population.

Body mass index and risk of all-cause mortality with normoglycemia, impaired fasting glucose and prevalent diabetes: results from the Rural Chinese Cohort Study

Background Previous evidence of an association between body mass index (BMI) and mortality in patients with diabetes was inconsistent. The BMI–mortality association with normal fasting glucose (NFG), impaired fasting glucose (IFG) and prevalent diabetes is still unclear in the Chinese population. Methods We analysed data for 17 252 adults from the Rural Chinese Cohort Study during 2007–2008 and followed for mortality during 2013–2014. Participants were classified with NFG, IFG and diabetes according to baseline measurement values of fasting glucose and self-reported diabetes. Multivariable Cox proportional hazard models were used to calculate HRs and 95% CIs across BMI categories by glycemic status. Results During the 6-year follow-up, 1109 participants died (563/10 181 with NFG, 349/5572 with IFG and 197/1499 with diabetes). The BMI–mortality association was curvilinear, with low BMI (even in normal range) associated with increased mortality regardless of glycemic status. In adjusted Cox models, risk of mortality showed a decreasing trend with BMI≤18 kg/m2, 18<BMI≤20 kg/m2 and 20<BMI≤22 kg/m2 vs 22<BMI≤24 kg/m2: HR 2.83 (95% CI 1.78 to 4.51), 2.05 (1.46 to 2.87) and 1.45 (1.10 to 1.90), respectively, for NFG; 2.53 (1.25 to 5.14), 1.36 (0.86 to 2.14) and 1.09 (0.76 to 1.57), respectively, for IFG; and 4.03 (1.42 to 11.50), 2.00 (1.05 to 3.80) and 1.52 (0.88 to 2.60), respectively, for diabetes. The risk of mortality was lower for patients with diabetes who were overweight or obese versus normal weight. Conclusions Low BMI was associated with increased mortality regardless of glycemic status. Future studies are needed to explain the ‘obesity paradox’ in patients with diabetes.

Utility of three novel insulin resistance-related lipid indices for predicting type 2 diabetes mellitus among people with normal fasting glucose in rural China: 在空腹血糖正常的中国农村人群中使用3种新的胰岛素抵抗相关血脂指标来预测2型糖尿病

Inexpensive and easily measured indices are needed for the early prediction of type 2 diabetes mellitus (T2DM) in rural areas of China. The aim of this study was to compare triglyceride glucose (TyG), visceral adiposity (VAI), and lipid accumulation product (LAP) with traditional individual measures and their ratios for predicting T2DM.

Dose-response association between the triglycerides: High-density lipoprotein cholesterol ratio and type 2 diabetes mellitus risk: The rural Chinese cohort study and meta-analysis: TG/HDL-C ratio and T2DM

High triglyceride (TG) and low high‐density lipoprotein cholesterol (HDL‐C) levels are traditional risk factors for type 2 diabetes mellitus (T2DM). This study evaluated the dose–response relationship between the TG/HDL‐C ratio and T2DM risk.

Sleep Duration Interacts With Lifestyle Risk Factors and Health Status to Alter Risk of All-Cause Mortality: The Rural Chinese Cohort Study

STUDY OBJECTIVES Many studies suggest an association of both short and long sleep duration with all-cause mortality, but the effect of co-occurrence of sleep duration and other lifestyle risk factors or health status remains unclear. METHODS A total of 17,184 participants aged 18 years or older from rural areas of China were examined at baseline from 2007 to 2008 and followed up from 2013 to 2014. Cox proportional hazard models were used to estimate the hazard ratio (HR) and 95% confidence interval (CI). RESULTS During 6-year follow-up, we identified 1,101 deaths. The multivariable-adjusted mortality risk was significantly higher with short-duration sleepers (< 6.5 hours) (HR = 1.37, 95% CI 1.01-1.86) and long-duration sleepers (≥ 9.5 hours) (HR = 1.35, 95% CI 1.05-1.74) versus 6.5-7.5 hours. The multiplicative interaction of long sleep duration with some lifestyle risk factors and health statuses increased the mortality risk in men (low level of physical activity: HR = 1.03, 95% CI 1.02-1.04; hypertension: HR = 1.06, 95% CI 1.04-1.09; type 2 diabetes mellitus [T2DM]: HR = 1.07, 95% CI 1.04-1.11). Similar results were found in women (low level of physical activity: HR = 1.03, 95% CI 1.02-1.05; T2DM: HR = 1.07, 95% CI 1.05-1.10). CONCLUSIONS Sleep duration could be a predictor of all-cause mortality and its interaction with physical activity, hypertension, and T2DM may increase the risk of mortality.