Natural history of diabetes presenting age 40-69 years: a prospective study of the influence of intensive dietary therapy

Two hundred and twenty-three newly-diagnosed symptomatic diabetic patients with onset age 40-69 years enrolled in a prospective study of intensive dietary management of diabetes were observed for a period of six years and the data obtained is analysed. The variables studied were weight and fasting levels of plasma glucose and insulin, and of serum total cholesterol and triglyceride. These tests were monitored throughout the study and in addition the oral glucose tolerance test was analysed at entry to the study, after six months intensive dietary management and again after 72 months. Blood pressure, electrocardiogram and the presence of posterior tibial artery pulsation were recorded at entry to the study and at 36 months and 72 months. Approximately 80 per cent of the patients were managed solely by dietary restriction for the entire six years, but 25 patients received oral hypoglycaemic drugs and 26 required insulin treatment. Weight, and fasting glucose and triglyceride values fell in the first few months of intensive dietary management. Analysis of possible risk factors in survivors and patients dead at six years showed no significant differences, apart from a higher mean age at diagnosis in those who died. During the six years of intensive dietary management the mortality from all causes in these diabetic patients was no greater than that for the general population of Northern Ireland.