[Changes on patterns of sleep duration: findings from China Health and Nutrition Survey in population in 9 provinces]

Association between non-alcoholic fatty liver disease and metabolically healthy deterioration across different body shape phenotypes at baseline and change patterns

Non-alcoholic fatty liver disease (NAFLD) is a hepatic manifestation of metabolic syndrome (MetS), and the relationship between NAFLD and metabolic deterioration remains unclear. This study aimed to investigate dynamic changes in metabolically healthy phenotypes and to assess the impact of non-alcoholic fatty liver disease (NAFLD) on the conversion from metabolically healthy (MH) to metabolically unhealthy (MU) phenotypes across body shape phenotypes and phenotypic change patterns. We defined body shape phenotypes using both the body mass index (BMI) and waist circumference (WC) and defined metabolic health as individuals scoring ≤ 1 on the NCEP-ATP III criteria, excluding WC. A total of 12,910 Chinese participants who were MH at baseline were enrolled in 2013 and followed-up in 2019 or 2020. During a median follow-up of 6.9 years, 27.0% (n = 3,486) of the MH individuals developed an MU phenotype. According to the multivariate Cox analyses, NAFLD was a significant predictor of conversion from the MH to MU phenotype, independent of potential confounders (HR: 1.12; 95% confidence interval: 1.02–1.22). For the MH-normal weight group, the relative risk of NAFLD in phenotypic conversion was 1.21 (95% CI 1.03–1.41, P = 0.017), which was relatively higher than that of MH-overweight/obesity group (HR: 1.14, 95% CI 1.02–1.26, P = 0.013). Interestingly, the effect of NAFLD at baseline on MH deterioration was stronger in the “lean” phenotype group than in the “non-lean” phenotype group at baseline and in the “fluctuating non-lean” phenotype change pattern group than in the “stable non-lean” phenotype change pattern group during follow-up. In conclusion, lean NAFLD is not as benign as currently considered and requires more attention during metabolic status screening.

Proportion of kindergarten children meeting the WHO guidelines on physical activity, sedentary behaviour and sleep and associations with adiposity in urban Beijing

Background

World Health Organisation (WHO) Guidelines on Physical Activity, Sedentary Behaviour and Sleep for Children under 5 Years of Age were released in 2019. The aim of this study was to examine the proportion of Chinese kindergarten children who met each individual guideline and each combination of the guidelines and the associations with adiposity.

Methods

Participants were 254 kindergarten children aged 4.1–6.3 years recruited from three kindergartens in urban area of Beijing. Physical activity, sedentary behaviour and sleep duration were assessed using 24-h accelerometry over three consecutive days. Screen time was reported by parents. Weight and height were measured; and children were categorised into normal weight and overweight/obese groups according to the WHO age- and sex- specific criteria. Frequency analyses were performed to examine the proportion of children meeting individual and combination of these guidelines. Logistics regression analyses were conducted to examine the associations between guideline compliance and adiposity.

Results

The proportion of children who met the physical activity (≥ 3 h daily physical activity, including ≥1 h daily moderate- to vigorous-intensity physical activity (MVPA)), sedentary screen time (< 1 h/day), and sleep guidelines (10-13 h/day) were 65.4, 88.2 and 29.5%, respectively; only 15.0% met all three guidelines and 2.7% did not meet any of the guidelines. Not meeting the physical activity guideline, sleep guideline, or combination of any two guidelines, or all three guidelines was not associated with overweight or obesity; however, children who did not meet the sedentary screen time guidelines were at higher risk for overweight and obesity (odds ratio = 3.76, 95% CI: 1.50–9.45).

Conclusions

In our study, only a small proportion of children met all three guidelines. Most Chinese kindergarten children met physical activity guidelines or screen time guidelines, whereas fewer children met sleep guideline. Not meeting sedentary screen time guidelines was associated with adiposity, which warrant further interventions for limiting screen time in young children.

Long Sleep Duration is Associated with Increased High-Sensitivity C-Reactive Protein: A Nationwide Study on Chinese Population

PURPOSE

High-sensitivity C-reactive protein (hs-CRP) has been shown as an important predictor of cardiovascular risk, and sleep duration is an important factor influencing health outcomes. However, the association between hs-CRP and sleep duration among Chinese adults remained unknown and controversial. We aimed to explore the associations between sleep duration and hs-CRP levels among Chinese adults, and the differences in sex and geographical regions.

METHODS

This cross-sectional study was based on nationally representative Chinese samples from the 2009 China Health and Nutrition Survey, which employed multistage, random cluster designs. Habitual sleep duration was self-reported with short and long sleep duration defined as ≤6h and ≥9h per day, respectively. Participants were divided into 4 groups based on the categories of self-reported sleep duration (≤6h, 7h, 8h, ≥9h per day), excluding hs-CRP levels ≥10 mg/L. Subset samples were stratified by sex and geographical regions.

RESULTS

A total of 8170 Chinese adults with a mean age of 50.0±14.9 years and 4369 (53.5%) men were included. Participants sleeping eight hours had the lowest hs-CRP levels. Long sleep duration (≥9h) was significantly associated with elevated hs-CRP levels after adjusting for multiple covariates in full samples (β=0.0356; 95% CI: 0.0050-0.0663; P=0.0228), but the associations of short sleep duration (≤ 6h) were limited to the unadjusted model. Long sleep duration was associated with elevated hs-CRP levels in women (β= 0.0512; 95% CI: 0.0097-0.0927; P=0.0155) and in the northern region of China (β=0.0699; 95% CI: 0.0210-0.1187; P=0.0051), but not in men or the southern region.

CONCLUSION

Long but not short sleep duration was positively associated with elevated hs-CRP levels, independent from traditional risk factors among Chinese adults, and sex and geographical differences were observed. Our findings imply that modifications of long sleep duration might be added to behavioral therapy to reduce cardiovascular risk in Chinese adults.