Abstract
The aim of this study was to identify problems encountered in using the diagnostic criteria based on oral glucose tolerance test (OGTT) levels recommended by the Japan Diabetic Society (JDS-recommended levels) in evaluating OGTT data for elderly patients of diabetes mellitus. We analysed a total of 451 cases (144 male and 307 female), all inmates of the Yokufukai Home for the Aged who had underwent a 50-gram OGTT while alive. All of them were subjected to autopsy upon decease, with respect to vital prognosis and autoptic findings. They were divided into the following four groups by category of glucose tolerance: normal, borderline, diabetic (DM1 and DM2). Of those patients aged less than 75 and not less than 60 at the time of the OGTT, the diabetic group with fasting plasma glucose levels in excess of 140mg/dl (DM2 group) is found to be the poorest in vital prognosis, giving the highest incidence of myocardial infarction, advanced cerebral atherosclerosis and cerebral infarction occuring individually or in combination. While the diabetic group with fasting plasma glucose levels below 140mg/dl (DM1 group) is similar to the borderline group in prognosis and in incidence of any of the three types of atherosclerotic lesions, falling in between the normal group and the DM2 group. Of those patients aged not less than 75 at the time of the OGTT, the four glucose tolerance groups show no significant differences between them in vital prognosis and in incidence of any of the three types of atheroscleotic lesions. These results indicate that, considerling the effect of glucose intolerance on the vital prognosis and cardiovascular lesions, it is clinically practical to set the diagnostic criteria for diabetes by specifying a minimum fasting plasma glucose level of 140mg/dl for aged patients. While the diabetic groups below the 140mg/dl level should be treated simillarly to the borderline group. Our results also suggest that glucose intolerance in patients in their mid seventies and above does not significantly affect their vital prognosis or the development of their atherosclerotic lesions.
