Background: Recent cross-sectional population studies in the United States have shown an increase in obesity, a decrease in cholesterol values, but no changes in levels of high-density lipoprotein cholesterol (HDL-C) or triglycerides (TG).
Methods: Plasma total cholesterol, HDL-C, and TG levels, measured by the same methods at the 3 most recently completed examinations of Framingham Offspring Study participants (1991-2001), were compared in 1666 participants without prevalent cardiovascular disease, lipid therapy, or hormone replacement therapy (56% were men; mean ages of participants at the first and last examinations, 53 and 60 years, respectively). Changes in age- and multivariate-adjusted mean lipid levels were related to changes in body mass index (BMI).
Results: Over the 3 examinations, comparing the findings of the earliest examination with those of the most recent examination, the mean HDL-C level was significantly increased (multivariate-adjusted means, 44.4 and 46.6 mg/dL in men; 56.9 and 60.1 mg/dL in women; P value for trend, P <.001 in both sexes), whereas levels of TG were decreased (144.5 and 134.1 mg/dL in men; 122.3 and 112.3 mg/dL in women; P value for trend, P = .004 in men and <.001 in women). Over the same time interval, BMI (calculated as weight in kilograms divided by height in meters squared) increased (27.8 and 28.5 in men; 27.0 and 27.6 in women; P value for trend, P < .001 in men and P = .001 in women). There was an inverse relationship between changes in BMI and magnitude of dyslipidemia (ie, individuals with the least increase in BMI had the most favorable changes in levels of HDL-C and TG).
Conclusion: During a 10-year period of recent examinations in the Framingham Heart Study there was a decrease in dyslipidemia with an increase in HDL-C levels and a decrease in levels of TG despite an overall increase in BMI.