Management of obesity in NIDDM (non-insulin-dependent diabetes mellitus)

Obesity is common in NIDDM; in a cohort of 314 diabetics in Singapore, 44.3% are overweight. Management of obesity in diabetics differs from that in non-diabetics in that it is more urgent; weight maintenance is more difficult and hypoglycaemic medication may cause weight changes. Like in the non-diabetic, management of obesity in diabetic requires a pragmatic and realistic approach. A team approach is required: the help of the nurse educator, the dietitian, behaviour modification therapist, exercise therapist etc are required. A detailed history, careful physical examination and relevant investigations are required to assess the severity of the diabetic state and to exclude an occasional underlying cause of the obesity in the obese NIDDM. Weight loss is urgent in the obese NIDDM, especially those with android obesity. There must be a reduction in caloric intake. Weight loss leads to improvement in the glucose tolerance, insulin sensitivity, reduction in lipid levels and fall in blood pressure in the hypertensive. Exercise is of limited value except in the younger obese NIDDM. Metformin is the hypoglycaemic drug of choice as it leads to consistent weight reduction. The sulphonylureas may cause weight gain. Insulin should be avoided where possible as it causes further weight gain. Other hypoglycaemic agents include Glucobay (alpha-glucosidase inhibitor) and Troglitazone (insulin sensitizer) which do not alter the weight. Orlistat (lipase inhibitor) is promising as it causes reduction of weight, blood-glucose and lipid levels. Anti-obesity drugs (noradrenergic and serotonergic agents) have modest effects on weight reduction in the obese NIDDM; a widely use preparation, Dexfenfluramine (Adifax) has been withdrawn because of side effects. Surgery such as gastric plication is the last resort in treating the morbidly obese NIDDM. The discovery of leptin in 1994 has led to intense research into energy homeostasis in obesity; hopefully this will lead to better treatment of obesity in diabetics and non-diabetics.