Associations of sleep duration and prediabetes prevalence in a middle‐aged and elderly Chinese population with regard to age and hypertension: The China Health and Retirement Longitudinal Study baseline survey

BACKGROUND: The aim of the present study was to examine the age-specific associations between self-reported sleep duration and prevalent prediabetes in middle-aged and elderly Chinese with or without hypertension. METHODS: In all, 2985 Chinese adults aged ≥45 years from the China Health and Retirement Longitudinal Study (CHARLS) baseline survey were selected for analysis. Sleep duration was assessed by structured questionnaires and then categorized into three groups (≤6, 6-8, and >8 h). The prevalence of prediabetes was defined using fasting plasma glucose (100-125 mg/dL) and/or HbA1c (5.7%-6.4%) in conjunction with no previous diabetes diagnosis and no antidiabetic medication. Relationships between self-reported sleep duration and prevalent prediabetes were examined according to age (45-60 years, middle-aged; ≥60 years, elderly) and hypertension groups using Poisson regression models to estimate prevalence ratios (PRs) and 95% confidence intervals (CI). RESULTS: Compared with the reference group of 6-8 h sleep/night, short sleep (≤6 h/night) was associated with an increased risk of prediabetes in the whole sample (PR 1.09, 95% CI 1.01-1.17) after adjusting for confounders. This association was more pronounced in elderly participants without hypertension (PR 1.27, 95% CI 1.07-1.51). CONCLUSION: This study suggests that participants with a short sleep period are at a moderately increased risk of prediabetes, particularly in elderly subjects without hypertension. Aging and hypertension may be important in the relationship between short sleep and impaired glucose metabolism.