Bariatric surgery improves CV risk factors, but too many patients stop their cardiac medications

June 26, 2011

Bariatric surgery improves cardiovascular (CV) risk factors, with glycemia responding the most dramatically following surgery, said Sayeed Ikramuddin, MD. Over the long term, systolic blood pressure (SBP) and low-density lipoprotein (LDL) cholesterol respond less favorably, which may be partially explained by inappropriate cessation of medicines, he said.

Bariatric surgery improves cardiovascular (CV) risk factors, with glycemia responding the most dramatically following surgery, said Sayeed Ikramuddin, MD. Over the long term, systolic blood pressure (SBP) and low-density lipoprotein (LDL) cholesterol respond less favorably, which may be partially explained by inappropriate cessation of medicines, he said.
      The safety and efficacy of bariatric surgery must be further elucidated as a push is made to expand candidates to include those with a body mass index (BMI) as low as 30 kg/m2. Currently, the National Institutes of Health considers persons with a BMI > 40 kg/m2, or those with a BMI > 35 kg/m2 with severe medical disease of obesity, as candidates.
      The 4 types of procedures currently in use are the laparoscopic adjustable gastric band (the safest and easiest to perform with the best data behind it, according to Ikramuddin); the Roux-en-Y gastric bypass (the “gold standard,” he said); the laparoscopic duodenal switch (“the new kid on the block,” which avoids postgastric-bypass hypoglycemia); and the laparoscopic sleeve gastrectomy (“a rather significant player in terms of weight loss,” usually reserved for the morbidly obese).
      The malabsorptive procedures (ie, duodenal switch) have the largest effect on glycemia, superior to the gastric banding procedures, said Ikramuddin, Director of the Division of Gastrointestinal Surgery at the University of Minnesota, Minneapolis. Overall, complete resolution of diabetes occurs in about three-fourths of patients undergoing bariatric procedures.
      In one study of adjustable gastric banding (Dixon et al, JAMA 2008;299:316-323), the proportion of patients qualifying for a diagnosis of metabolic syndrome dropped from 97% to 28% at 2 years.
      In a study of Roux-en-Y vs. routine medical management in patients with baseline BMI >40 kg/m2, the proportion of patients who achieved their goals in hemoglobin A1c, SBP, and LDL cholesterol improved from 10.2% at baseline to 38.2% at 2-year follow-up in the surgery group, but only from 13.9% to 17.4% in group assigned to routine medical management (Obesity Surgery, in review). Dramatic reductions in the use of antihypertensive medication and the use of medications for hyperlipidemia occurred in the group undergoing surgery, but 2 years following the Roux-en-Y procedure, 34.9% and 23.2% of patients did not meet their goals for SBP and LDL cholesterol, respectively. Of the patients who did not meet their goals, 21.6% and 47.0% had their medications for hypertension and hyperlipidemia, respectively, inappropriately discontinued, said Ikramuddin.