CHANGES IN GLUCOSE-TOLERANCE AMONG ELDERLY FINNISH MEN DURING A 5-YEAR FOLLOW-UP - THE FINNISH COHORTS OF THE 7 COUNTRIES STUDY

It was the purpose of this study to report the natural history of gluc ose tolerance during a five-year follow-up among elderly Finnish men, and to evaluate the role of age and body-mass index in explaining the variation in glucose tolerance both cross-sectionally and longitudinal ly. In the survivors of the Finnish cohorts of the Seven-Countries Stu dy, aged 65 to 84 years at baseline, a two-hour oral glucose-tolerance test was performed according to current WHO criteria. Subjects with f asting blood glucose > 10 mmol/l were directly classified as having di abetes at baseline. - Findings: At baseline, of the 637 men 216 had no rmal and 234 had impaired glucose tolerance, 187 were diabetic. At fol low-up, 172 men had died; 38 (18 %) of the subjects with normal glucos e tolerance at baseline had either impaired glucose tolerance or diabe tes ; 17 (7 %) of the men with initially impaired glucose tolerance ha d developed diabetes, and 79 (34 %) were normalized. 25 (13 %) and 22 (12 %) of the initially diabetic subjects had reverted to impaired or normal glucose tolerance, respectively. The age was able to explain 1- 2 % of variation in blood glucose level in cross-sectional but not in longitudinal comparison. Body-mass index was an important predictor of abnormal glucose tolerance in previously normally responding men. By contrast, obesity did not contribute to the development of diabetes am ong men with impaired glucose tolerance. - Principal conclusions: The incidence of impaired glucose tolerance was high in these elderly Finn ish men as compared with studies in middle-aged Caucasoid subjects. Bu t the incidence of diabetes among people with impaired glucose toleran ce was within the range observed in other studies. Obesity was a signi ficant risk factor in worsening glucose tolerance in euglycaemic perso ns but not in persons with previously impaired glucose tolerance. Duri ng the follow-up obesity could, however, explain only a small portion of deterioration of glucose tolerance, suggesting that other factors t han age and obesity are required to explain the development of glucose intolerance in the elderly.