Objectives: To compare obese with normal and overweight type 2 diabetic patients regarding body mass index (BMI) and cardiovascular risk factors, and to analyse changes in weight versus risk factors.
Design and setting: A cross-sectional study of 44 042 type 2 patients, and a 6-year prospective study of 4468 type 2 patients.
Results: Obese patients (BMI > or = 30 kg m(-2)), 37% of all patients, had high frequencies of hypertension (88%), hyperlipidaemia (81%) and microalbuminuria (29%). Only 11% had blood pressure <130/80 mmHg. Their ratio of triglycerides to HDL cholesterol was considerably elevated, whilst the mean total and LDL cholesterol were similar as in normal weight subjects. Obese patients had elevated odds ratios for hypertension, hyperlipidaemia and microalbuminuria: 2.1, 1.8 and 1.4 in the cross-sectional study, similarly confirmed in the prospective 6-year study. BMI was an independent predictor of these risk factors (P < 0.001), although only slightly associated with HbA1c and not with total or LDL cholesterol. A change in BMI during the prospective study was related to a change in HbA1c in patients treated with diet and oral hypoglycaemic agents (OHAs) but not with insulin. In all patients, an increase in BMI was related to the development of hypertension, and a change in BMI to change in blood pressure, also mostly confirmed when treated with diet, OHAs or insulin.
Conclusions: The high frequencies of risk factors in obese type 2 patients implies an increased risk of cardiovascular disease and the need for therapeutic measures. The paradox that hypoglycaemic treatment accompanied by weight gain may increase cardiovascular risk factors seems to be verified here concerning hypertension but not concerning microalbuminuria.