Factors associated with low and elevated plasma high density lipoprotein cholesterol and apolipoprotein A-I levels in the Framingham Offspring Study.

A decreased high density lipoprotein (HDL) cholesterol level (< 35 mg/dl) has been shown to be a significant independent risk factor for coronary heart disease (CHD). Moreover, increased HDL cholesterol levels (> or = 60 mg/dl) are associated with a decreased CHD risk. Levels of HDL cholesterol and apoA-I, the major protein constituent of HDL, were measured in plasma from fasting participants in the Framingham Offspring Study (1,584 men and 1,639 women, mean age 49 +/- 10 years). In this population, an HDL cholesterol value < 35 mg/dl was observed in 18.2% of men and 3.8% of women, and these subjects had mean apoA-I levels of 104 and 106 mg/dl, respectively, and triglyceride levels of 234 and 261 mg/dl, respectively. CHD was observed in 14.2% of men and 14.5% of women in this category. An HDL cholesterol level > or = 60 mg/dl was observed in 11.7% of men and 39.3% of women, and these subjects had mean apoA-I levels of 182 and 185 mg/dl, respectively, and mean triglyceride levels of 81 and 75 mg/dl, respectively. CHD was noted in 2.7% of men and 1.9% of women in this category. HDL cholesterol levels were much more strongly related to triglycerides (r = -0.54 in men and -0.47 in women) than was apoA-I (r = -0.26 in men and -0.13 in women). The relationship between plasma HDL cholesterol and triglyceride levels was not linear. In both men and women, triglycerides, body mass index (BMI), and alcohol intake contributed significantly to HDL cholesterol and apoA-I variability.