Effects of gastric banding on glucose tolerance, cardiovascular and renal function, and diabetic complications: a 13-year study of the morbidly obese.

BACKGROUND: Limited information is available on weight loss, metabolic control, cardiovascular disease and diabetic complications in morbidly obese patients undergoing gastric banding (LAGB) compared with morbidly obese patients receiving medical treatment.

OBJECTIVE: To assess the long-term effects of laparoscopic adjustable gastric banding (LAGB) on glucose tolerance, arterial hypertension, and cardiovascular disease and prevention of diabetic complications (retinopathy and renal function) in morbidly obese patients.

SETTING: University hospitals, Italy.

MATERIALS AND METHODS: In this retrospective study, 87 morbidly obese patients who underwent LAGB (20 with diabetes) and 87 morbidly obese patients who did not undergo surgery (36 with diabetes) for the treatment of obesity during the period 1995 to 2003 consented for re-examination after a mean (±standard deviation) period of 13.8±2.04 years. At baseline, all mobidly obese patients had a body mass index (BMI)≥35 kg/m(2) and were aged 18 to 65 years.

RESULTS: At follow-up, LAGB patients maintained a lower weight compared with baseline values and demonstrated significant decreases in both blood pressure and heart rate measurements compared with control patients. LAGB patients also experienced greater improvement of glucose tolerance than did control patients (28% versus 10%, respectively; P<.01) and reduction of insulin and homeostasis model assessment for insulin resistance. Fewer LAGB patients developed carotid plaques than did control patients (10% versus 26%, respectively; P<.01). Intensification of antihypertensive therapy was required in 31% of surgery versus 60% of control patients (P<.05). Among diabetic patients, improved glucose tolerance occurred in 55% of surgery patients versus 0% in the control group (P<.01). In addition, insulin treatment was necessary in 9 control patients versus 0 in the surgery group (P<.05), and carotid plaques occurred in 10% of LAGB patients versus 50% of control patients (P<.01). Creatinine levels and the estimated glomerular filtration rate improved in LAGB diabetic patients but not in control patients (P< .05).

CONCLUSION: Despite a very small weight loss over the long term (i.e., 2.2 kg/m(2)), improvement of glucose tolerance persisted for long periods after LAGB, with no unfavorable effect on kidney function and retinopathy. In contrast, no effect was observed on prevention of arterial hypertension or cardiovascular disease.