METABOLIC CONTROL AND COMPLICATIONS OVER 3 YEARS IN PATIENTS WITH INSULIN-DEPENDENT DIABETES (IDDM) - THE STOCKHOLM DIABETES INTERVENTION STUDY (SDIS)

Abstract. In a planned 5‐year study, 97 patients with insulin dependent diabetes mellitus (IDDM), non‐proliferative retinopathy and unsatisfactory blood glucose control were monitored for 3 years. The patients were randomized to an intensified conventional treatment (ICT, n=44) or a regular treatment (RT, n=53) group. HbA1c (normal range 3.9‐5.7%) was reduced from 9.5 ± 0.2 (mean value±SEM) to 7.4 ± 0.1% in the ICT group (P=0.0001), and from 9.4 ± 0.2 to 9.0 ± 0.2% in the RT group (P=0.004). Nerve conduction velocities in the sural and peroneal nerves (P=0.01‐0.0001) were impaired in the RT group, but not in the ICT group. Retinopathy increased in both groups. The condition of 22 ICT patients (50%, 95% confidence interval 34‐66%) and 37 RT patients (73%, 61‐84%) deteriorated with regard to at least one microvascular complication (retinopathy, nephropathy, neuropathy) (P=0.024). Lower HbA1c levels during the study significantly reduced the risk of deterioration (P=0.01). In total, 57% of the ICT patients had at least one episode of serious hypoglycaemia, compared with 23% in the RT group (P=0.001). The patients in the ICT group also gained weight (P=0.0001). Improved blood glucose control slowed down the progression of microangiopathy during a 3‐year period in patients with non‐proliferative retinopathy, but at the price of an increased frequency of serious hypoglycaemic episodes, and some gain in body weight. 1990 Blackwell Publishing Ltd