Determinants of change in total cholesterol and HDL-C with age: the Framingham Study.

Objective: The purpose of the study was to assess the determinants of change of total cholesterol and high density lipoprotein cholesterol (HDL-C) change in an adult population.

Methods: The prospective cohort was examined at baseline and eight years later. A total of 2,222 men and 2,677 women age 20-79 years at baseline were included. Analyses were performed in 15-year age groups, and persons with cardiovascular disease or cancer during the observation period were excluded.

Results: In longitudinal analyses, body mass index (BMI) and plasma total cholesterol levels of each rose in concert among younger age groups, whereas levels declined in older individuals. Mean levels of BMI and total cholesterol peaked at a later age in women than in men. The corresponding changes in HDL-C were negative at all ages, and greater declines were seen in the elderly. A decrease in plasma total cholesterol was highly associated with greater age and a decrease in body mass index over the study interval, whereas the decline in HDL-C was proportional to change in body mass index. These changes remained significant after adjustment for baseline age and change in alcohol intake, cigarette consumption, diuretic use, and oral estrogen use.

Conclusions: The rise in plasma total cholesterol among apparently healthy young men and women and its fall in the elderly are significantly associated with similar trends for obesity. The key determinants of a decline in HDL-C are an increase in obesity and advancing age itself. A decline in total cholesterol and in HDL-C is particularly common among the elderly, and it can be expected to occur without specific dietary or pharmacologic intervention.