U.S. Cholesterol Profiles Improve While Obesity Persists
A ten- year analysis from the Framingham Heart Study shows that while Americans continue to become more obese, cholesterol profiles significantly show improvement. Specifically, good (HDL) levels have increased, and triglyceride levels are lower, despite obesity in America.
The news that cholesterol profiles are improving in our population - in the continued presence of overall increases in body mass index (BMI) - comes as a surprise
Study investigator Dr Sander Robins (Boston University) says, "If you ask any cardiologist what is the likelihood that a patient with increasing body weight would also have their triglycerides go down and their HDL-cholesterol levels go up, I would bet that almost 100% of them would tell you it's very unlikely this would happen. Maybe you'd find one exercise nut or something like that. The findings are counterintuitive, or counterscience, at least in terms of the science we think we know."
The analysis looked at cholesterol profiles of 1666 men and women participating in the Framingham Offspring Study, in three separate studies. Testing took place between 1991 and 2001. All of the individuals were free of heart disease and on no cholesterol lowering medicine or hormone therapy.
In all three studies, the researchers reported increased BMI in both the men and women. The study showed that total cholesterol levels remained unchanged, but triglyceride levels dropped and good cholesterol (HDL) levels increased significantly.
The Framingham study concluded: "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 [total triglycerides] despite an overall increase in BMI."
The study authors say the beneficial improvements in cholesterol levels among Americans are difficult to explain, especially given the persistence of obesity.
Dr. Robins has a theory about why HDL levels are on the rise and triglyceride levels are dropping, while obesity persists among Americans.
It may be the type of foods consumed leading to improved cholesterol profiles. Americans may be eating less saturated fat and more carbohydrates, though the researchers say there is no way to prove that from information contained in the Framingham Heart Study.
Ingelsson E, Massaro JM, Sutherland P, et al. Contemporary trends in dyslipidemia in the Framingham Heart Study. Arch Intern Med 2009; 169:279-286.