Effect of BMI, insulin dose and number of injections on glycaemic control in insulin-using diabetic patients

Abstract

Background: Strict glucose control is essential to the prevention of diabetic complications. The level of glycaemic control in insulin-treated patients with diabetes mellitus (DM) in a routine clinical setting is not known.Methods: In a cross-sectional survey comprising 8 hospitals in the Rijnmond area, The Netherlands, age, body mass index (BMI), insulin dose, number of injections, and HbA1c were scored in 712 patients with insulin-dependent DM (IDDM) and 462 patients with non-insulin-dependent DM (NIDDM).Results: In IDDM and NIDDM patients, respectively, age (mean ± SD) was 40 ± 17 and 65 ± 12 years, BMI was 24.1 ± 3.5 and 27.3 ± 4.1 kg/m2, daily insulin dose was 49 ± 18 and 44 ± 18 U (P < 0.001). Intensive therapy (≥ 4 injections or continuous subcutaneous insulin infusion) was used in 59% of IDDM and 13% of NIDDM patients. HbA1c below the upper normal limit was achieved in 11% of the patients, and within 20% above the upper normal limit in 37%. Obesity was positively associated with HbA1c in NIDDM patients (P < 0.01). A higher insulin dose was associated with higher HbA1c in both IDDM and NIDDM patients (P < 0.01).Conclusions: Good glycaemic control was established in 37% of our patients. Intensive insulin treatment and higher insulin dose did not improve glucose regulation. Obesity is a risk factor for poor glycaemic control.