Association between Wakeup Frequency at Night and Atherogenic Dyslipidemia: Evidence for Sex Differences

Aim: This study aimed to determine whether sleep disturbance, defined as the wakeup frequency at night, is associated with atherogenic dyslipidemia and to explore possible sex differences. Methods: A total of 1,368 adults aged 19–70 years were included in the study of lifestyles and atherogenic dyslipidemia at the National Taiwan University Hospital in the period of 2008–2012. They completed a questionnaire regarding lifestyle information and sleep quality, including sleep hour duration, use of sleeping pills, and wakeup frequency during nighttime sleep. The measured lipid profiles included total cholesterol, triglycerides, low- and high-density lipoprotein cholesterol (LDL-C and HDL-C, respectively), non-HDL-C, and small dense LDL-C (sdLDL-C). Multivariate logistic regression was performed to determine habitual interrupted sleep and the odds ratio of atherogenic dyslipidemia following adjustment for conventional risk factors and for sex-based subgroup analysis. Results: A wakeup frequency ≥ 3 times per night was independently associated with an increased risk [odds ratio (95% confidence interval)] of dyslipidemia was 1.96 (1.17–3.28), and non-HDL-C ≥ 160 mg/dL was 1.78 (1.09–2.89). A higher wakeup frequency was associated with increased atherogenic dyslipidemia in women than in men. The multivariate adjusted relative risks for non-HDL ≥ 160 mg/dL and cholesterol ≥ 200 mg/dL were 3.05 (1.27–7.34) and 4.01(1.29-12.45) for female individuals with insomnia and those with a wakeup frequency ≥ 2 times per night, respectively. Conclusion: A higher wakeup frequency was associated with atherogenic dyslipidemia in Taiwanese adults, particularly in women. This study also provided another evidence of increasing cardiovascular diseases in subjects with habitual interrupted sleep.