In China, ages at menarche and menopause are not associated with diabetes. Later menarche and menopause are associated with decreasing CVD risk and earlier menopause with higher osteoporosis risk. Menarche and menopause history may help identify women with increased risk of developing CVD and osteoporosis.

ObjectiveTo assess associations between napping and night-time sleep duration with impaired glucose regulation, insulin resistance (IR) and glycated haemoglobin (HbA1c).DesignCross-sectional study.SettingFujian Province, China, from June 2011 to January 2012.ParticipantsThis study enrolled 9028 participants aged 40–65 years. Data of 7568 participants with no diabetes were included for analysis. Type 2 diabetes was defined applying WHO criteria.Outcome measuresParticipants’ daytime napping and night-time sleep duration data were collected using a standardised self-reported Chinese-language questionnaire about sleep frequency and quality. Anthropometric and laboratory parameters were also measured. IR was defined as a HOMA-IR index value >2.50. ORs and 95% CIs were derived from multivariate logistic regression models.ResultsParticipants (mean age 51.1±7.0 years) included 3060 males and 4508 females with average night-time sleep of 7.9 h. A higher proportion of males napped than females. After adjustment for potential confounders, ORs for HbA1c >6.0% were 1.28 and 1.26 for those napping ≤1 h and >1 h (p=0.002 and p=0.018), respectively. Statistically significant differences in IR between nappers and non-nappers were only marginal clinically. Odds for HbA1c >6.0% were significantly lower in participants with longer night-time sleep durations than in the reference group (>8 h vs 6–8 h). Odds for IR were significantly lower in participants whose night-time sleep hours deviated from the reference group (<6 h, >8 h vs 6–8 h)ConclusionsChinese middle-aged adults with no diabetes who napped had higher HbA1c and IR; those with shorter night-time sleep durations had increased HbA1c. Night-time sleep hours that are either <6 or >8 tend to be associated with lower odds for IR. Further studies are necessary to determine the underlying clinical significance and mechanisms behind these associations.

Purpose:To explore the association between bone mineral density (BMD) and β-cell function.Methods:A cross-sectional study was performed in Fujian, China, from 2011 to 2012. The study included 572 elderly men older than age 60 years and 1558 postmenopausal women aged 45 to 86 years, excluding those with diabetes and insulin resistance. Fasting glucose and insulin concentrations were measured. Pancreatic β-cell function was estimated by using the homeostasis model assessment (HOMA-β). Calcaneus BMD was measured by using quantitative ultrasonography. Multiple regression analyses were applied to explore the association.Results:Participants with decreased BMD had lower fasting glucose (P < 0.001 in postmenopausal women; P = 0.007 in elderly men) and greater HOMA-β (P = 0.001 in postmenopausal women; P = 0.008 in elderly men) than those with normal BMD, whereas no statistical differences in insulin were seen among categories of BMD. After adjustment for all confounders, HOMA-β was still significantly negatively related to BMD in both groups (all P < 0.001), and remarkable positive relationships were found between BMD and fasting glucose. Furthermore, binary logistic regression presented fully adjusted odds ratios for diabetes in those with osteoporosis vs those with normal BMD: 0.60 [95% confidence interval (CI), 0.38 to 0.94] and 0.66 (95% CI, 0.49 to 0.91) in the original selected population of elderly men (n = 1070) and postmenopausal women (n = 2825), respectively.Conclusions:BMD was independently inversely associated with HOMA-β and positively associated with fasting glucose in both elderly men and postmenopausal women, suggesting that bone mass may be a predictor of glucose metabolism. Further research is needed to verify the associations and determine the exact mechanism underlying them.