Association of sleep duration and quality with small dense low-density lipoprotein cholesterol

Although the association between sleep duration and lipid profiles and/or cardiovascular disease has been extensively studied, evidence regarding sleep quality remains limited.

This study aimed to investigate the association of sleep duration and quality with lipid parameters, including serum concentration of small dense low-density lipoprotein cholesterol (sdLDL-C) in a Japanese population.

A total of 24,984 Japanese men and women who had a medical checkup between April 2018 and March 2019 were included in this study. Data on sleep duration and sleep quality were obtained using self-reported questionnaires. Participants were classified into 3 groups based on sleep duration (<6 hours, 6-8 hours, and ≥8 hours). Sleep quality was categorized as either good or poor. Blood samples were used to measure serum lipid profiles, including sdLDL-C. Group comparison and multivariate analyses were performed to assess the association between sleep and these lipid parameters.

In the <6-hour group, poor sleepers had significantly higher serum levels of median sdLDL-C than good sleepers in both genders (34.1 vs 31.7 mg/dL in men, 26.9 vs 24.0 mg/dL in women, respectively). A similar trend was observed in the 6-8-hour group, whereas no significant difference was found in the ≥8-hour group. Multivariable log-linear regression showed that poor sleep quality was associated with higher sdLDL-C levels independent of confounders.

Poor sleep quality is associated with unfavorable lipid profiles, especially elevated sdLDL-C levels. Recognizing sleep quality as a modifiable lifestyle factor could contribute to reducing lipid abnormalities and preventing cardiovascular disease.