Does gastric restriction surgery reduce the risks of metabolic diseases?

Certain risk factors for arteriosclerosis are associated with obesity, e.g. hypertension, insulin resistance, the high triglyceride - low HDL pattern. One aim in treating morbid obesity is to reduce these risk factors. This study was designed to follow metabolic risk factors after weight loss in 165 morbidly obese patients who underwent a gastric restriction operation.

Lipid and hormone levels were analyzed before surgery and after 25, 50, 75 and 100% loss of excess weight. Mean cholesterol and triglyceride levels were normal or slightly elevated. HDL cholesterol was also normal (41 mg/dl). Thirty eight percent of the patients had elevated cholesterol and triglyceride levels. Insulin levels were measured as an indicator of potential insulin resistance, and with a mean of 21 microU/ml it was at the upper normal level.

After reaching 75% reduction of overweight in a mean time of 10 months, serum cholesterol levels were unchanged. Serum triglycerides, however, decreased by 35% (P<0.0001) and HDL cholesterol increased by 24% (P<0.0001). Insulin levels decreased to 8 microU/ml (P<0.0001).

We found an amelioration in the metabolic parameters in 75% of the patients. Nevertheless morbidly obese patients were found to have fewer abnormalities in lipid and glucose metabolism than expected from data of overweight patients with metabolic syndrome. Further long-term studies with careful evaluation of the metabolic parameters as risk factors in patients with morbid obesity need to be performed.