Association of HDL-C and apolipoprotein A-I with the risk of type 2 diabetes in subjects with impaired fasting glucose

Objectives: HDLs have many diverse functions. The goal of this study was to determine the association of HDL cholesterol (HDL-C) and apolipoprotein A-I (apoA-I) with the development of type 2 diabetes (T2D). In particular, this study determined the association between the ratio of HDL-C to apoA-I (HA) and incident T2D. Design and methods: A total of 27 988 subjects with impaired fasting glucose (IFG) (18 266 men and 9722 women) aged 21-91 years (mean age 40.7 years) were followed for a mean duration of 2.81 years. Results: Study subjects were divided into quartiles according to the baseline HA ratio. Age, male sex, current smoking, BMI, waist circumference, and high-sensitivity C-reactive protein decreased across the quartiles, and all metabolic profiles, including blood pressure, fasting glucose, insulin resistance as determined by homeostasis model assessment of insulin resistance, and lipid measurements such as total cholesterol, LDL cholesterol, non-HDL-C, and apoB, improved as the HA ratio increased. In addition, incident cases of T2D decreased as the HA ratio increased, independent of age, sex, BMI, current smoking, systolic blood pressure, HbA1c, fasting serum insulin, family history of diabetes, and serum triglyceride concentrations (HR (95% CI) of fourth quartile vs first quartile; 0.76 (0.67-0.86), P<0.0001). Conclusions: A higher HA ratio was associated with favorable metabolic profiles and a lower risk of T2D development in subjects with IFG.