Association between circadian preference and blood lipid levels using a 1:1:1 propensity score matching analysis.

Background: Previous studies indicate that circadian preference is associated with various energy metabolism and metabolic disorders. However, little is known about the associations between a circadian rhythm and blood lipid levels, especially in humans.

Objective: The aim of the study was to investigate whether the circadian rhythm affects serum lipid levels in Korean adults.

Methods: We designed a cross-sectional study to evaluate the associations between circadian preference and blood lipid levels in Korean adults. A total of 1984 participants (range of age 19-81 years) were included in this study. Propensity scores were calculated using logistic regression with age, sex, and body mass index. A total of 435 subjects were evaluated by propensity score matching analysis, equally distributed into morningness, intermediate, and eveningness groups, each with 145 subjects. Circadian preference was evaluated by the Morningness-Eveningness Questionnaire.

Results: Participants with the evening preference had significantly higher levels of total cholesterol, triglyceride, low-density lipoprotein cholesterol, and non-high-density lipoprotein cholesterol (non-HDL-C) when compared with those with morning or intermediate preference, after adjusting for confounding variables. Regarding other lipid parameters, both total cholesterol/HDL-C and low-density lipoprotein cholesterol/HDL-C in the evening preference are significantly higher than those of other circadian preferences. Evening preference was also significantly associated with a higher atherogenic index of plasma.

Conclusion: Our study demonstrates that there is a significant association between circadian preference and blood lipid levels. Our findings suggest that individuals with evening preference could have a greater risk of atherosclerotic cardiovascular diseases.