Waist Circumference of the Elderly over 65 Years Old in China Increased Gradually from 1993 to 2015: A Cohort Study.

Objective: This study aimed to analyze the temporal trends and characteristics associated with waist circumference (WC) among elderly Chinese people. Methods: We used data from 3,096 adults ≥ 65 years who participated in the China Health and Nutrition Survey (CHNS), an ongoing cohort study, between 1993 and 2015. We used longitudinal quantile regression models to explore the temporal trends and characteristics associated with WC. Results: WC increased gradually among the elderly Chinese population during the survey. The WC curves shifted to the right with wider distributions and lower peaks in men and women. All WC percentile curves shifted upward with similar growth rates in the 25th, 50th, and 75th percentiles. The WC means increased from 78 cm to 86 cm during the 22 years of our study. WC significantly increased with age and body mass index and decreased with physical activity (PA). These associations were stronger in the higher percentiles than in the lower percentiles. Conclusions: WC is rising among Chinese adults ≥ 65 years. Factors affecting WC in elderly people may have different effects on different percentiles of the WC distribution, and PA was the most important protective factor in the higher percentiles of the WC distribution. Thus, different interventional strategies are needed.

Associations of Sedentary Time and Physical Activity with Metabolic Syndrome among Chinese Adults: Results from the China Health and Nutrition Survey.

OBJECTIVE: This study aimed to determine the independent and joint associations of sedentary time (ST) and physical activity (PA) with metabolic syndrome (MetS) and its components among Chinese adults. METHODS: The study analyzed data from 4,865 adults aged ≥ 18 years who participated in the 2009 and 2015 China Health and Nutrition Surveys (CHNS). Four types of leisure ST and three types of PA self-reported at baseline were collected. Multivariable logistic regressions were used to determine the independent and joint associations of ST and PA with the odds of MetS or its components. RESULTS: For independent effects, higher levels of television time and total leisure ST was associated with higher MetS risk [odds ratio ( OR) 1.3, 95% confidence interval ( CI) 1.1-1.6, P < 0.001; OR 1.4, 95% CI 1.2-1.8, P < 0.001, respectively]. The MetS risk in the computer time > 7 hours/week (h/w) group was higher than that in the < 7 h/w group in ( OR 1.5, 95% CI 1.2-1.9). Higher levels of moderate-to-vigorous-intensity physical activity (MVPA) and total PA were associated with a lower MetS risk ( OR 0.7, 95% CI 0.6-0.9, P < 0.001; OR 0.8, 95% CI 0.7-0.9, P < 0.001, respectively). For the joint effects, compared with those reporting the lowest level of total leisure ST (< 14 h/w) and the most active tertile of MVPA (≥ 61.0 MET-h/w), participants reporting the most total leisure ST (≥ 35 h/w) and the lowest level of MVPA (0 MET-h/w) had the highest odds of MetS ( OR 2.0; 95% CI 1.4-2.7). Except for people reporting ST (14-21 h/w) within the most active tertile of MVPA, the associations in all other groups were significant. With the increase of TV time and decreased MVPA, the odds of MetS almost showed a curve acceleration. CONCLUSIONS: MVPA and total PA have independent preventive effects, and sedentary behavior (mainly watching TV) has an unsafe effect on MetS and its components. Strengthening the participation of MVPA and combining the LPA to replace the TV-based ST to increase the total PA may be necessary to reduce the prevalence of MetS in Chinese adults.

[Trend of distribution of body mass index among Chinese adults in some provinces from 1989 to 2000].

OBJECTIVE: To investigate the trends of the distribution of body mass index(BMI) among Chinese adults in some provinces from 1989 to 2000. METHODS: This paper was based on data collected in the China Health and Nutrition Survey in 1989,1991,1993,1997 and 2000, and the subjects were 20- 45 years old healthy men and women. RESULTS: In the period of 1989 - 2000, the mean of BMI among Chinese adults was increasing from 1989 to 2000. The mean of BMI among male increased from 21.3kg/m(2) to 22.4kg/m(2). At the same time, the mean of BMI among female increased from 21.8 kg/m(2) to 22.5kg/m(2) . With the changing of the distribution of BMI among Chinese adults the prevalence of overweight and obesity increased from 1989 to 2000. The people who were elder than thirty years old had a faster increasing in BMI than younger age group. Moreover the people who lived in city suburb and town had a faster increasing than who lived in village. CONCLUSION: It is a big problem to control the changing of the distribution of BMI among Chinese adults.