Short sleep duration is associated with increased risk of pre-hypertension and hypertension in Chinese early middle-aged females.

PURPOSE: The aim of this study is to investigate the relationship between sleep duration and hypertension in a middle-aged Chinese population. METHODS: Cross-sectional data of 20,505 individuals aged 35-64 years from Taizhou longitudinal study was used. Logistic regression models were used to calculate odds ratios (ORs) for the risk of pre-hypertension and hypertension in association with sleep duration. RESULTS: Short sleep duration was associated with high systolic and diastolic blood pressure in comparison with sleep duration of 7-8 h in females. Short sleep duration was also associated with an increased risk of hypertension in females. Age-stratified analysis showed that as compared with sleep duration of 7-8 h, sleep duration <6 h increased risk of hypertension after controlling for multiple covariates with an OR of 1.766 (1.024-2.775) in early middle-aged females of 35-44 years. More importantly, sleeping less than 6 h is associated with increased risk of pre-hypertension in females of this age category, after controlling for multiple covariates with an OR of 1.769 (1.058-2.958). CONCLUSIONS: Sleeping less than 6 h a day is associated with increased risk of pre-hypertension and hypertension in Chinese early middle-aged females. The high-risk populations require sufficient sleep, which could probably prevent the increased risk of pre-hypertension as well as hypertension.

Association of mitochondrial DNA haplogroups with exceptional longevity in a Chinese population.

BACKGROUND: Longevity is a multifactorial trait with a genetic contribution, and mitochondrial DNA (mtDNA) polymorphisms were found to be involved in the phenomenon of longevity. METHODOLOGY/PRINCIPAL FINDINGS: To explore the effects of mtDNA haplogroups on the prevalence of extreme longevity (EL), a population based case-control study was conducted in Rugao--a prefecture city in Jiangsu, China. Case subjects include 463 individuals aged > or = 95 yr (EL group). Control subjects include 926 individuals aged 60-69 years (elderly group) and 463 individuals aged 40-49 years (middle-aged group) randomly recruited from Rugao. We observed significant reduction of M9 haplogroups in longevity subjects (0.2%) when compared with both elderly subjects (2.2%) and middle-aged subjects (1.7%). Linear-by-linear association test revealed a significant decreasing trend of N9 frequency from middle-aged subjects (8.6%), elderly subjects (7.2%) and longevity subjects (4.8%) (p = 0.018). In subsequent analysis stratified by gender, linear-by-linear association test revealed a significant increasing trend of D4 frequency from middle-aged subjects (15.8%), elderly subjects (16.4%) and longevity subjects (21.7%) in females (p = 0.025). Conversely, a significant decreasing trend of B4a frequency was observed from middle-aged subjects (4.2%), elderly subjects (3.8%) and longevity subjects (1.7%) in females (p = 0.045). CONCLUSIONS: Our observations support the association of mitochondrial DNA haplogroups with exceptional longevity in a Chinese population.