[Association of lifestyle and cardiometabolic risk factors with epigenetic age acceleration in adults in China].

Objective: To explore the association of lifestyle and cardiometabolic risk factors with five epigenetic age acceleration (AA) indices. Methods: This study included 980 participants of China Kadoorie Biobank, for whom genome-wide DNA methylation of peripheral blood cells had been detected in baseline survey. Five indices of DNA methylation age (DNAm age) were calculated, i.e. Horvath clock, Hannum clock, DNAm PhenoAge, GrimAge and Li clock. Epigenetic AA was defined as the residual of regressing DNAm age on chronological age. Lifestyle factors studied included smoking status, alcohol consumption, eating habits, physical activity level and body shape defined by a combination of BMI and waist circumference. Cardiometabolic risk factors included blood pressure, blood glucose level and total cholesterol level. Linear regression model was used to analyze the association of lifestyle and cardiometabolic risk factors with AA (ß). Results: GrimAge_AA was associated with smoking status, alcohol consumption, physical activity level and BMI. Compared with non-smokers, non-drinkers, or participants with BMI of 18.5- 23.9 kg/m2, the smokers who smoked 1-14 cigarettes/day (ß=0.71, 95%CI: 0.57-0.86), 15-24 cigarettes/day (ß=0.88, 95%CI: 0.73-1.03), and ≥25 cigarettes/day (ß=0.99, 95%CI: 0.81-1.18), respectively, heavy drinkers with daily pure alcohol consumption ≥60 g (ß=0.33, 95%CI: 0.11-0.55) and participants with BMI<18.5 kg/m2 (ß=0.23, 95%CI: 0.03-0.43) showed accelerated aging. Compared with those in the lowest quintile of physical activity level, participants in the top three quintile of physical activity level showed decelerated aging (ß=-0.13, 95%CI: -0.26-0.01, ß=-0.12, 95%CI: -0.26-0.02, and ß=-0.14, 95%CI: -0.27- -0.00, respectively). GrimAge_AA decreased with the increase of the number of healthy lifestyle factors (P<0.001). Compared with the participants with 0 to 1 healthy lifestyle factor, the ß of those with 2, 3, or 4 to 5 healthy lifestyle factors were -0.30 (95%CI: -0.47- -0.12), -0.47 (95%CI: -0.65- -0.30) and -0.72 (95%CI: -0.90- -0.53), respectively. The other four indices were not statistically significantly associated with most lifestyle factors. None of the five indices of AA was associated with blood pressure, blood glucose level or total cholesterol level. Conclusion: People with unhealthy lifestyle showed accelerated epigenetic aging, that is, the predicted DNAm age is older than their own chronological age.

[Family history and risk of coronary heart disease].

Objective: To evaluate the association of family history with risk of major coronary events (MCE) and ischemic heart disease (IHD). Methods: After excluding participants with heart disease, stroke or cancer at baseline survey, a total of 485 784 participants from the China Kadoorie Biobank, who had no missing data on critical variables, were included in the analysis. Cox regression analysis was used to estimate the hazard ratios (HR) and 95% CI. Subgroup analyses were performed according to the baseline characteristics. Results: During a median of 7.2 years of follow-up, we documented 3 934 incident cases of MCE and 24 537 cases of IHD. In multivariable-adjusted models, family history was significantly associated with risk of MCE and IHD. The adjusted HRs (95%CI) were 1.41 (1.19-1.65) and 1.25 (1.18-1.33), respectively. History of disease among siblings was more strongly associated with early-onset MCE than parental history (HR=2.97, 95%CI: 1.80-4.88). Moreover, the association of family history with MCE and IHD was stronger in persons who were overweight or obesive, and the association between family history and MEC was stronger in smokers. Conclusion: This large-scale, prospective study indicated that family history was an independent risk factor for MCE and IHD in China. The intervention targeting major known lifestyle risk factors and the management of chronic diseases should be strengthened for Chinese population, especially for the individuals with family history were at high risk.

[Associations between season of birth and age both at menarche and at menopause].

Objective: To examine the associations between season of birth and factors as age at menarche, age at menopause and reproductive span. Methods: A total of 285 186 female from the China Kadoorie Biobank, with complete data on critical variables and had menarche at 9-18 years old, were included. A total of 132 373 female with natural menopause were included for the analysis on age at menopause and reproductive span. Multiple linear regression models were used to assess the associations of birth season and the age at menarche, menopause, and reproductive span. Subgroup analyses were performed on birth cohorts and urban/rural residence. Results: Compared with the Spring-born (March, April, and May), participants who were born in Summer (June, July, and August), Autumn (September, October, and November), and Winter (December, January, and February) appeared late on both age at menarche and menopause. Multivariable-adjusted coefficients (95% CI) appeared as 0.14 (95% CI: 0.13-0.16), 0.26(95% CI: 0.24-0.27), 0.10 (95% CI: 0.08-0.12) for age at menarche respectively and 0.14 (95%CI: 0.08-0.20), 0.18 (95%CI: 0.12-0.24), 0.09 (95%CI: 0.03-0.16) for age at menopause respectively. No statistically significant association was found between the season of birth and reproductive span. The association was consistent between urban and rural residents and across the birth cohorts. Conclusions: female born in spring showed both earlier age on both menarche and menopause, compared to the ones born in other seasons. Our findings suggested that exposures in early life with some degree of seasonal variation might influence the development of female reproductive system.

[A review of pension status quo in China and domestic and overseas pension models].

With the aging of population and progressive decline of traditional pension model, the problems in the aged supporting have caused serious social concern in China. Since 1980' s, different opinions about pension models have been suggested in many research papers. This paper summarizes the characteristics of different pension model used in both China and abroad in terms of the financial sources of the aged supporting, life style and the combination with medical service, suggesting to establish a pension model with Chinese characteristics to provide multiple and personalized services on the basis of China' s national situation and successful experiences of other countries.

[Association between famine exposure during early life and BMI in adulthood].

Objective: To examine the influence of famine exposure during early life on BMI in adulthood. Methods: A total of 94 052 participants recruited in the baseline survey of China Kadoorie Biobank were included in this study. The participants who were born between October 1956 and September 1958, between October 1959 and September 1961 and between October 1962 and September 1964 were classified as group born before famine, group born during famine and group born after famine (control group). The regression coefficients and 95% confidence intervals (CIs) for BMI of famine exposure groups were estimated by linear regression model. And P values for interaction between famine and smoking, alcohol use, physical activity were estimated by likelihood ratio tests. Results: Compared with the group born after famine, in females, the group born during famine had higher BMI (coefficient: 0.12, 95% CI: 0.03-0.22) after adjusting other impact factors. Except physical activity (interaction: P<0.077), both smoking and alcohol use had modification effects on the associations between famine exposure and BMI (interaction: all P<0.001). Conclusion: Famine exposure during early life, especially during fetal period, might increase risks of overweight and obesity in females. Therefore, it is important to ensure the adequacy of nutrition during early life to prevent overweight or obesity in adulthood.