Patterns of prescription of hypoglycaemic drugs in Gran Canaria (Canary Islands, Spain) and estimation of the prevalence of diabetes mellitus

Objective: To study the patterns of hypoglycaemic treatment in our community and to estimate the prevalence of known and drug-treated diabetes mellitus. Methods: From all the diabetic patients who attended the Healthcare Centers of the National Health Service in Gran Canaria in 1999, a random sample of 2924 diabetic patients >20 years old was selected. Data on age, gender, clinical onset of diabetes, and hypoglycaemic treatment were obtained. Data on drug consumption were supplied by the National Health Service. Results: Of the DM-2 patients 4.4% (3.65-5.14) 84.2% (82.77-85.42), 9.4% (8.34-10.45) and 2.1% (1.58-2.61) received diet only, oral drugs, insulin or combination. The duration of DM-2 was associated with more oral drugs and more insulin treatment, but the duration of DM-1 was not associated with intensive insulin therapy; <50% of the type 1 patients had >= 3 daily injections. The prescriptions of biguanides were scarce; over 1/3 of them were of buformin. DM-1 and DM-2 patients were treated with similar doses of insulin, but DM-1 patients had more insulin injections (2.56 vs 2.07, P < 0.001), and more fast-acting insulins (65.2% vs 38.0%, P < 0.001). The estimated prevalences of known and drug-treated diabetes in the Gran Canaria island were 5.95% (95% Cl: 5.09-6.80%) and 5.73% (4.88-6.57%). Conclusions: Our prevalences of known and drug-treated diabetes is among the highest reported in European populations. The prescriptions of metformin and of combined therapy in DM-2, and of intensive insulin therapy in DM-1 are less frequent than expected, but nonetheless insulin therapy in DM-1 is more intensive and uses more fast-acting insulin than in DM-2.