Fewer than six and more than 10 hours of sleep per day are associated with metabolic syndrome (MetS) and its individual components, according to a new study published in the open access journal, BMC Public Health.
The study, which is the largest of its kind, included 133,608 Korean men and women aged 40-69 years from the Health Examinees (HEXA) study on the association between sleep duration and MetS. Participants' sleep duration was categorised into four categories (less than six hours; six hours to less than eight hours; eight hours to less than 10 hours; and 10 hours or more).
The authors found that compared with individuals sleeping between six and eight hours per day, fewer than six hours of sleep was associated with MetS and elevated waist circumference among men and elevated waist circumference among women. More than 10 hours sleep was associated with MetS and elevated triglycerides among men. Among women, it was linked with MetS, elevated waist circumference, elevated triglycerides, reduced high-density lipoprotein (HDL) cholesterol, and elevated fasting glucose.
The authors said further research is warranted to assess the casual relationship between sleep duration and MetS.