Association between habitual daytime napping and metabolic syndrome: a population-based study

Abstract

Objective

Our objective was to evaluate the association between habitual daytime napping and the prevalence of metabolic syndrome.

Materials and Methods

We conducted a population-based study of 8,547 subjects aged 40years or older. Metabolic syndrome was defined according to a harmonized definition from a joint statement and the recommended thresholds for the Chinese population. Information about sleep duration was self-reported.

Results

The prevalence of metabolic syndrome in the no daytime napping group, the 0 to 1hour daytime napping group and the more than 1hour daytime napping group were 35.0%, 36.0% and 44.5% among the females (P<0.0001). Increased daytime napping hours were positively associated with parameters of metabolic syndrome in the female subjects, including waist circumference, systolic blood pressure, triglycerides and fasting plasma glucose (P<0.05 for all). Multivariate adjusted logistic regression analysis revealed that, compared to the no habitual daytime napping females, napping for more than 1hour was independently associated with an increased prevalence of metabolic syndrome (odds ratio 1.39, 95% confidence interval, 1.13–1.72). Compared to the female subjects in the no daytime napping group, those habitually napped for more than 1hour exhibited 46% and 26% increases in the prevalence of central obesity and hypertriglyceridemia (all P<0.05). No statistically significant associations were detected between daytime napping hours and metabolic syndrome among the male subjects.

Conclusion

Daytime napping is associated with an increased prevalence of metabolic syndrome in middle-aged non-obese Chinese women.