Managing patients with type 2 diabetes and obesity.

Diabetes risk increases exponentially with increasing BMI particularly if fat accumulates centrally and/or in the skeletal muscle, liver and other organs such as the pancreas. Those with diabetes and co-existing obesity, particularly if it is severe, are also at risk of other obesity-related conditions, such as cardiovascular disease, obstructive sleep apnoea, joint pain, many cancers and depression. In people with impaired glucose tolerance, modest weight loss can reduce the development of overt diabetes by 50% or more over four years. Once diabetes has developed weight loss can also be of benefit. Supporting patients to lose weight should be considered a key goal of diabetes care for all overweight and obese patients with type 2 diabetes. Increased physical activity improves insulin sensitivity and can help weight loss maintenance. Metformin is the first-line therapy and is generally considered weight neutral. Of the oral therapies available second line, DPP-IV inhibitors are weight neutral and the newer SGLT2 inhibitors can produce 2-3 kg of weight loss on average. Insulin often causes weight gain and patients should be counselled about this. Adjunctive treatment with metformin, SGLT2 inhibitors, DPP-IV inhibitors and GLP-1 analogues can help keep insulin doses lower and limit weight gain. Currently in the UK, obesity pharmacotherapy in type 2 diabetes is limited to orlistat which has been shown to improve glucose control. NICE recommends bariatric surgery as a clinically and cost effective option for obese patients with type 2 diabetes, particularly those with severe obesity. It typically results in 20-30% of body weight loss.