Association of High-Density Lipoprotein Subclasses Levels with Sleep Duration and Other Lifestyles in Middle-Aged and Elderly Women: Cross-Sectional Study

Objective: We aimed at investigating the association of high-density lipoprotein subclasses (HDL2-C and HDL3-C) levels with sleep duration, in comparison to other lifestyles in middle-aged and elderly women.Materials and Methods: A total of 69 women aged older than 40 who underwent "Anti-aging Health Checkups" were enrolled in the study. The analyses were conducted for all the subjects using personal data regarding clinical characteristics and lifestyle. Sleep duration was categorized into two groups of less than or more than 6 hrs. First, an analysis was performed to assess the correlation of two major HDL subclasses with various factors. Next, a multiple regression analysis was conducted to identify the association for each HDL2-C and HDL3-C with lifestyles such as sleep duration, daily breakfast, dinner time, habitual exercise, and drinking. Moreover, we examined the associations between HDL2-C and sleep duration combined with other lifestyle factors such as dinner time, daily breakfast, habitual exercise, and drinking.Results: In comparison to lifestyles, sleep duration had a strong association with only HDL2-C after adjustment for confounders. The "less 6 hrs sleep" group in combination with the "no exercise habit" or the "routine drinking habit" significantly decreased HDL2-C levels more than the assumed reference group. Regarding breakfast, there is a significant association between the "less than 6 hrs sleep with no daily breakfast" and the "more than 6 hrs sleep with daily breakfast."Conclusion: The results of this study may suggest that sufficient sleep might be significant for maintaining appropriate HDL2-C levels in middle-aged and elderly women under the condition that lifestyle might change during the ongoing COVID-19 pandemic.