Association Between Sleep and the Metabolic Syndrome Differs Depending on Age

Abstract

Objectives: Sleep quality and duration are significantly associated with metabolic syndrome (MetS), especially among individuals in the middle-aged and elderly age groups; however, it is inconsistent among the age groups in previous studies. This study investigated the effect of age on the association between sleep and MetS in a large sample size.Methods: Health-related data on MetS in males and females (n=22,995; age: 23–79 years) were collected from annual health examinations, including the Pittsburgh Sleep Quality Index (PSQI). MetS was diagnosed based on the 2009 Joint Interim Statement.Results: In total, 4,660 (20.3%) participants were diagnosed with MetS. The data showed a significant association between poor sleep quality (PSQI >5), shorter sleep durations (<6 hours), and MetS in the older group (≥40 years) after adjusting for age, smoking status, alcohol consumption, sex, and exercise. However, this association was not observed in the younger group (<40 years). Regardless of age, global PSQI scores and sleep durations were significantly related to abdominal obesity (male ≥90 cm, female ≥85 cm in waist circumference) and general obesity (body mass index ≥30 kg/m<sup>2</sup>).Conclusions: This study demonstrates that sleep quality and duration are related to obesity across all age groups and that sleep quality and duration are only related to MetS in older individuals. These findings suggest that satisfactory sleep in adults aged ≥40 years may play a crucial role in preventing MetS.