Batsis JA et al. (2008) Effect of bariatric surgery on the metabolic syndrome: a population-based, long-term controlled study. Mayo Clin Proc 83: 897–907

A healthy diet and exercise can improve the components of the metabolic syndrome in patients with insulin resistance, but the effect of weight loss alone was unknown. Now, researchers at the Mayo Clinic have found that weight loss by bariatric surgery considerably reduces the prevalence of the metabolic syndrome in a community-based cohort of obese individuals.

Batsis et al. retrospectively examined the outcomes for patients with a BMI ≥35 kg/m2 who were evaluated for bariatric surgery between January 1990 and December 2003. Of the 337 patients, 180 underwent bariatric surgery (Roux-en-Y gastric bypass) and 157 did not; all patients received medical and dietetic care and advice about the importance of physical activity. Mean duration of follow-up was 3.5 years. Although metabolic syndrome prevalence decreased significantly in the nonsurgical group (from 85% to 75%), a much more marked decrease occurred in the surgical group (from 87% to 29%). Levels of obesity, hypertension, serum triglycerides and fasting glucose all fell significantly in the surgical group, but not in the nonsurgical group. Patients whose metabolic syndrome did not respond to surgery tended to lose less weight than responders, to be older, to have higher BMI, triglyceride and fasting glucose levels, and were more likely to have diabetes mellitus. Regression analysis suggested that % excess weight loss was a major predictor of metabolic syndrome resolution.

The authors conclude that bariatric surgery is an effective means of treating the metabolic syndrome in eligible patients.