INS and diabetes mellitus: After adjustment for duration of diabetes, history of diabetes complications, area of residence (centre), age, gender, educational level, alcohol consumption, smoking, blood pressure, LDL and HDL cholesterol, which all were significant and independent determinants of mortality, the hazard ratio for all-cause mortality was 3.22 [95% confidence interval: 0.87–11.9] for untreated diabetic subjects, 2.28 [0.98–5.26] for diabetics treated with metformin alone, 1.70 [0.92–3.16] for diabetics with sulfonylureas and 4.92 [1.70–14.3] for diabetic with insulin versus non-diabetic subjects.