Effects of fasting blood glucose levels and blood pressure and treatment of diabetes and hypertension on the incidence of cardiovascular disease: a study of 740 patients with incident Type 2 diabetes with up to 30 years' follow-up.

AIMS:To analyse the effects of hyperglycaemia and hypertension and treatment of diabetes and hypertension on cardiovascular disease incidence in patients with Type 2 diabetes with up to 30 years of follow-up. METHODS:A total of 740 patients with incident Type 2 diabetes were registered at the Laxå Primary Health Care Centre, Sweden between 1972 and 2001. Annual data on mean fasting blood glucose, systolic, diastolic and mean arterial blood pressure, and type of diabetes and hypertension treatment were obtained from patient records, and information on cardiovascular disease, myocardial infarction and stroke events was obtained from national registers. RESULTS:During the follow-up period, cumulative cardiovascular disease incidence increased significantly with male sex (hazard ratio 1.48, 95% CI 1.21-1.82), number of previous cardiovascular disease events (hazard ratio 1.13, 95% CI 1.08-1.18), age, per year (HR 1.05, 95% CI 1.04-1.07), mean fasting blood glucose, per mmol/l (hazard ratio 1.05, 95% CI 1.00-1.10) BMI (hazard ratio 1.04, 95% CI 1.01-1.06), mean arterial blood pressure, per mmHg (hazard ratio 1.02, 95% CI 1.01-1.03), and decreased significantly with metformin treatment (hazard ratio 0.58, 95% CI 0.38-0.90) and sulfonylurea (hazard ratio 0.73, 95% CI 0.55-0.97). Cumulative myocardial infarction incidence increased significantly with male sex, number of previous myocardial infarction events, mean fasting blood glucose level, BMI, age and mean arterial blood pressure, and decreased with metformin treatment. Cumulative stroke incidence increased with number of previous stroke events, age and mean arterial blood pressure. CONCLUSIONS:The cumulative incidence of cardiovascular disease and myocardial infarction increased with number of previous events and presence of hyperglycaemia and hypertension and decreased with pharmacological treatment of diabetes. A higher number of previous stroke events increased the cumulative incidence of stroke but no protective effect of pharmacological treatment was observed.