Weight-loss surgery reduces CV risk factors, CHD risk
MedWire News: Weight loss after bariatric surgery can lead to major reductions in cardiovascular (CV) risk factors, as well as a decrease in predicted coronary heart disease (CHD) risk, show findings from a systematic review.
"The data show marked rates of remission or improvement for hypertension, diabetes, and dyslipidemia," say the researchers. "These resolutions were verified by mean decreases in systolic and diastolic blood pressure to within normal ranges, as well as positive alterations in lipid parameters," they add.
Helen Heneghan and colleagues, from the Cleveland Clinic in Ohio, USA, performed a systematic review of all studies published in English from January 1950 through July 2010 that contained data on CV outcomes, risk factors, and risk reduction in obese patients following any form of bariatric surgery. In total, 52 studies, involving 16,867 patients with a mean follow-up period of 34 months, met criteria for inclusion in the final analysis.
At baseline, the prevalence of hypertension, diabetes, and dyslipidemia were 49%, 28%, and 46%, respectively.
Mean weight loss after bariatric surgery was 52%, and most studies reported significant postoperative decreases in the prevalence of hypertension, diabetes, and dyslipidemia, which were resolved in 68%, 75%, and 71% of patients, respectively.
When the researchers examined the effects of weight-loss surgery on objective measures of cardiac function, disease, or disease risk, they observed significant postoperative improvements.
Specifically, mean levels of total cholesterol, low-density lipoprotein cholesterol, and triglycerides decreased by 36, 24, and 66 mg/dl (0.93, 0.62, and 0.75 mmol/l), respectively, while high-density lipoprotein cholesterol increased by 3 mg/dl (0.08 mmol/l).
Mean systolic blood pressure reduced from 139 to 124 mmHg and mean diastolic blood pressure reduced from 87 to 77 mmHg, report Heneghan and co-authors. In addition, mean C-reactive protein levels decreased by 61.6% (from 4.5 to 1.7 mg/dl) and mean flow-mediated dilation of the brachial artery, a measure of endothelial function, increased from 6% at baseline to 16% postoperatively (normal range 10-15%).
Finally, the team reports that the mean Framingham risk score decreased significantly after surgery, from 6.3% preoperatively to 3.8% postoperatively, representing a 40.0% relative risk reduction for 10-year CHD risk.
Commenting on their findings in the American Journal of Cardiology, the researchers say that these data suggest that bariatric surgery "compares favorably" to current primary and secondary prevention strategies, such as antihypertensive agents or lipid-lowering drugs.
It also provides "further evidence to support surgical treatment of obesity to achieve CV disease risk reduction," they conclude.
MedWire (www.medwire-news.md) is an independent clinical news service provided by Springer Healthcare Limited. © Springer Healthcare Ltd; 2011
By Nikki Withers