Evaluation of high-density lipoprotein cholesterol levels in Japanese women.

Objective: The aim of the present study was to clarify the significance of high levels of high-density lipoprotein cholesterol (HDL-C) in Japanese women receiving an annual health check-up.

Methods: A total of 1879 women who were not taking medication for hypertension, diabetes or dyslipidemia, with no prior history of ischemic heart disease, cerebrovascular disease or chronic renal failure were analyzed. First, the association between HDL-C and homeostasis model assessment of insulin resistance (HOMA-IR) was studied. Next, the association between HDL-C and the number of metabolic syndrome (MetS) risk factors, including HOMA-IR, was determined. In addition, clinical parameters including HOMA-IR, number of MetS risk factors, smoking, exercise, and alcohol consumption habits were compared according to HDL-C level.

Results: HOMA-IR was lower in subjects with elevated HDL-C. Additionally, a lower body mass index (BMI), waist circumference (WC), fasting plasma glucose (FPG), and triglycerides (TG) were observed in subjects with higher HDL-C. Moreover, the proportion of subjects who were obese, or those who had high FPG, high TG, and a high number of MetS risk factors was lower in subjects with higher HDL-C. Both obesity and smoking were associated with reduced HDL-C levels. Increasing levels of alcohol consumption, from < 25 g/day, to 25 -< 50 g/day, to 50 -< 75 g/day, were associated with a progressive increase in HDL-C level, but a progressive reduction in HOMA-IR. However, this apparent benefit of alcohol intake on HDL-C and HOMA-IR disappeared in subjects who drank ≥ 75 g/day.

Conclusions: Female subjects who were not obese, did not smoke, and drank < 75 g alcohol/day had elevated HDL-C levels, which were associated with improved insulin sensitivity. Drinking alcohol in excess of 75 g/day appeared to provide no advantages in terms of HDL-C or HOMA-IR levels. Thus, it might be important for females to keep their alcohol intake below 75 g/day.