We all know that weight loss and exercise are essential for a better health. A healthy life style reduces cardiovascular risk, obesity, and Type 2 Diabetes. In a previous post, I briefly touched upon the idea that weight loss and exercise make HDL, or our “good cholesterol,” better at reducing cholesterol circulating the bloodstream. In the latest issue of the ATVB journal, in the translational section, a new study from Baker Heart and Diabetes Institute in Melbourne, Australia looked at this specific idea. They asked how does weight loss and exercise affect HDL in patients. So I thought it would be interesting to share the results from this study.
The study examined 95 patients with metabolic syndrome and compared them to healthy individuals. Metabolic syndrome patients have characteristics that include obesity, high blood glucose levels, hypertension and/or dyslipidemia. These patients tend to have dysfunctional HDL, and its level fail to predict the possibility of future cardiovascular events. In the study, patients were divided into 3 groups. The first group had to reduce their caloric intake by 600 calories a day. The second group also reduced their caloric intake by 600 calories and, in addition, had to exercise for 3-4 sessions of about 30 minutes each. The third group kept their usual dietary and exercise patterns. The patients were monitored for 12 weeks and tested at the beginning and at the end of the study. Both groups resulted in similar weight loss. However, the researchers found evidence that the group of patients that followed both healthier diets and an exercise regimen had the most change in HDL capacity to excrete cholesterol.
Upon looking at the details of the study, the researchers first observed that metabolic syndrome patients had smaller HDL particles with different composition, and lesser ability to get rid of cholesterol easily. With diet and exercise, the size of HDL particles in those patients got bigger and their ability to function in cholesterol efflux assay improved making these particles overall better in excreting blood cholesterol.
Despite the small sample size of the study, these results are promising in providing a better understanding of how life style changes can impact HDL function and overall reduce risk for CVD and Type 2 Diabetes. For me personally, this study make me wonder if exercise alone would effect HDL function, since it has become apparent that while exercise is important, exercise alone without appropriate dietary changes are not sufficient to lead to weight loss. Can exercise alone improve HDL composition and function? While this study does not provide an answer to my question, I am sure more studies will come out to address this question specifically. So until we know more, keep those healthy salads and spinning classes coming.
Dalia Gaddis is a postdoctoral fellow at the La Jolla Institute for Allergy and Immunology. She has a Ph.D. in microbiology and immunology. She is currently working on understanding the interactions between the immune system and atherosclerosis development.