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.

Recent Trends in Sedentary Behaviors among Chinese Children According to Demographic and Social Characteristics.

OBJECTIVE: This study aims to explore trends in sedentary behavior among Chinese children aged 6-17 years per demographic and social characteristics. METHODS: A total of 4,341 children aged 6-17 years who participated in the China Health and Nutrition Survey from 2004 to 2015 were included. Repeated measures from mixed-effects models were applied to test trends in sedentary behaviors, which were further analyzed after applying stratification according to gender, age, urbanization level, residential area, and region. Random-effects ordinal regression models were used to examine the trends at sedentary levels. RESULTS: From 2004 to 2015, sedentary time among children aged 6-17 years increased from 23.9 ± 0.6 h/week to 25.7 ± 0.6 h/week ( P < 0.001). Increases of 3.1 h/week ( P < 0.001), 2.3 h/week ( P = 0.012), and 1.3 h/week ( P = 0.042) were found among the low-, medium-, and high-urbanization groups respectively and increased by 2.0 h/week ( P < 0.001) and 1.3 h/week ( P = 0.002) among rural and urban children, respectively. The proportion of Chinese children with average daily screen time below 2 hours declined by 10.2% ( OR = 0.51, 95% CI: 0.42-0.63, P < 0.001); a decreasing trend was observed in both boys and girls. CONCLUSIONS: Sedentary time among Chinese children aged 6-17 years showed an upward trend from 2004 to 2015, especially among children residing in rural areas and regions with low urbanization levels.

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.

Sociodemographic Factors Associated with Dietary Intake of Thiamine, Riboflavin, and Niacin among Chinese Adults in 2015.

OBJECTIVE: To estimate the association between three B-vitamin intakes and sociodemographic factors among adults in China. METHODS: We derived our data from the China Health and Nutrition Survey (CHNS) among 12,241 individuals aged 18-64 years. Log binomial regression was used to estimate adjusted prevalence ratios for factors associated with the inadequate intake of B-vitamins. RESULTS: Females with low incomes and living in the north had a higher prevalence of inadequate riboflavin intake than those with high incomes and living in the south. Both males and females living in a village had a higher prevalence of inadequate riboflavin intake than adults living in a city. Adults with low income, low education, and living in the north or in a village had a higher prevalence of inadequate niacin intake than adults with a high income, high education, and living in the south or in a city. CONCLUSION: We found that income, region, and area of residence were associated with riboflavin intake. Education, income, region, and area of residence were associated with niacin intake. Well-tailored strategies and policies are needed to improve nutritional status in China.

Secular trends in sedentary behaviors and associations with weight indicators among Chinese reproductive-age women from 2004 to 2015: findings from the China Health and Nutrition Survey.

BACKGROUND: Overweight and obesity are rising among Chinese reproductive-age women, while some studies have focused on the relationship between sedentary behavior and obesity in certain populations, none has focused on Chinese reproductive-age women specifically. This study examined secular trends in leisure time sedentary behaviors (watching television time, computer time and reading time, and the total sedentary time) among Chinese reproductive-age women and the association of those behaviors with five weight indicators-body mass index (BMI), waist circumference (WC) and overweight, obesity, and abdominal obesity status. METHODS: A prospective cohort study was conducted with Chinese reproductive-age women aged 15-49 who had participated in two or more rounds of the China Health and Nutrition Survey (CHNS), and completed the questionnaire and anthropometric measurements. The exposure variables were the average weekly time spent on three leisure time sedentary behaviors (watching television, using computer, and reading) and the total sedentary time (the sum of the above three sedentary time and video game time). Mixed-effect linear models were produced to explore the secular trends of the mean hours of these sedentary behaviors and the total sedentary time after adjusting covariates. Models were also produced to study the effects of these types of sedentary behavior levels on BMI and WC. Mixed-effect logistic regression models were produced to study the effects of the sedentary behavior levels on overweight, obesity, and abdominal obesity status. RESULTS: The total sedentary time among the reproductive-age women increased over time across most of age, region, educational levels, and income groups from 2004 to 2015. Television hours fluctuated, it increased and then declined over time across most of age, region, and income groups. Computer hours continually increased over time across all age, region, educational level, and income groups. Reading hours gradually decreased over time across most of age, region, educational level, and income groups. Those with a moderate level of television time (14 to <35 h/week) had 1.08 cm larger WCs and were 1.31 times more likely to have abdominal obesity than those with a low level of television time (<14 h/week). Those with a high level of television time (≥35 h/week) had 1.74 cm larger WCs, 0.66 kg/m2 larger BMIs, were 1.50 times more likely to be overweight and were 1.47 times more likely to have abdominal obesity than those with a low level of television time (<14 h/week). Greater computer, reading time, and total sedentary time were not associated with WC, BMI, overweight, obesity, or abdominal obesity. CONCLUSIONS: These findings showed that among Chinese reproductive-age women ages 15-49, secular trends of computer time increased rapidly, reading time decreased gradually and television time fluctuated but showed not much difference from 2004 to 2015. The sharp increase in computer time far outweighed the decline in reading time. As a result, the overall sedentary behavior time of Chinese reproductive-age women gradually increased. These findings provided strong evidence that greater television time was significantly associated with higher BMI, WC, and higher risks of overweight, abdominal obesity among Chinese reproductive-age women. Computer, reading, and the total sedentary time were not associated with those weight indicators.

Dietary Zinc Intake and Its Association with Metabolic Syndrome Indicators among Chinese Adults: An Analysis of the China Nutritional Transition Cohort Survey 2015.

The dietary zinc consumed in Chinese households has decreased over the past decade. However, the national dietary zinc intake in the last five years has seldom been investigated. Using data from 12,028 participants 18 to 64 years old (52.9% male) in the China Nutritional Transition Cohort Survey (CNTCS) 2015, we describe the intake of dietary zinc and the contributions of major foods and we examine the relationship between the level of dietary zinc intake and metabolic syndrome indicators, including blood pressure, fasting glucose, and triglycerides (TG), in Chinese adults. We assessed dietary zinc intake using 24 h recalls on three consecutive days. The mean daily dietary zinc intake for all participants was 10.2 milligrams per day (males 11.2 mg/day, females 9.4 mg/day, p < 0.001). The mean daily dietary zinc density for all participants was 5.2 mg/day per 1000 kilocalories. Among all participants, 31.0% were at risk of zinc deficiency, with dietary zinc intakes of less than the Estimated Average Requirement (EAR) (males 49.2%, females 14.8%, p < 0.050), and 49.9% had adequate dietary zinc intakes, equal to or greater than the recommended nutrient intake (RNI) (males 30.7%, females 67.0%, p < 0.050). We found substantial gender differences in dietary zinc intake and zinc deficiency, with nearly half of the men at risk of zinc deficiency. Males of younger age, with higher education and incomes, and who consumed higher levels of meat, had higher zinc intakes, higher zinc intake densities, and higher rates of meeting the EAR. Among all participants, grains, livestock meat, fresh vegetables, legumes, and seafood were the top five food sources of zinc, and their contributions to total dietary zinc intake were 39.5%, 17.3%, 8.9%, 6.4%, and 4.8%, respectively. The groups with relatively better dietary zinc intakes consumed lower proportions of grains and higher proportions of livestock meat. For males with adequate dietary zinc intake (≥RNI), TG levels increased by 0.219 millimoles per liter (mmol/L) compared with males with deficient dietary zinc intake (