Background: Strict glycaemic control in type 2 diabetic patients is recommended in a number of treatment protocols. However, although better glycaemic control prevents or postpones chronic diabetic complications, it remains uncertain how this affects quality of life in the short and long term.
Aim: To study the impact of insulin therapy on glycaemic control and quality of life in type 2 diabetic patients, with secondary failure on maximal oral medication.
Design of study: Two separate sets of analyses were performed: a longitudinal analysis of those patients converted to insulin therapy and a comparison of 12-week outcomes between the two randomisation groups.
Setting: Ten general practices, participating in the Nijmegen Monitoring Project.
Method: Patients, poorly controlled on maximal oral therapy, were stratified with respect to age and sex, and randomly allocated to insulin therapy in two different schedules: (a) after a 12-week period with enhanced compliance to diet and oral therapy: or (b) as soon as secondary failure was established. Patients were referred to a diabetologist to start insulin therapy and were referred back to their general practitioner (GP) as soon as glycaemic control was stable. We assessed fasting blood glucose, HbA1c functional health, and quality of life (Sickness Impact Profile, COOP/WONCA charts, Diabetes Symptom Checklist) at baseline, after the patient was referred back to the GP, and nine months later.
Results: Of the 38 included patients, three patients dropped out and seven patients were not switched over to insulin therapy. In patients starting insulin therapy, mean HbA1c and fasting blood glucose level decreased from 9.5% to 7.6%, and from 12.0 mmol to 8.4 mmol, respectively (P < 0.001). The better control was accompanied by a decrease in hyperglycaemic complaints (P = 0.01). No increase in hypoglycaemic complaints was found. There were no statistically significant changes in quality-of-life parameters. After 12 weeks, patients directly referred to insulin therapy showed a statistically significant improvement in HbA1c and fasting glucose level, in contrast to patients with enhanced compliance. Quality-of-life scores did not significantly differ statistically.
Conclusion: Insulin therapy in poorly controlled type 2 diabetic patients from general practice resulted in a significant clinical improvement of glycaemic control, accompanied by a reduction of hyperglycaemic complaints, without an increase in hypoglycaemic complaints or an adverse influence on quality of life.