Decreased physical fitness in borderline glucose tolerance men

To investigate the primary changes in glucose intolerance, physical characteristics and daily-life activity (pattern) were compared in the normal glucose tolerance (NGT, n=7) and the borderline glucose tolerance (BGT, n=9) subjects based on the criteria adopted by the Committee on the Diagnosis of Diabetes mellitus of Japan Diabetes Society. The basal glucose and insulin concentrations in the BGT group (90.7±4.1mg/dl, 9.2±1.1 μU/ml) were slightly higher than that in the NGT group (82.0±3.2mg/dl, 6.7±1.0μU/ml), while the glucose response following an oral glucose load in the BGT group was quite different from that of the NGT group. The area under the curve (AUC) of plasma glucose level following an oral glucose load was significantly higher in the BGT group than that in the NGT group (p<0.05), while the AUC of plasma insulin level in the BGT group did not significantly differ from that in the NGT group (p>0.05). The maximal oxygen uptake was significantly lower in the BGT group than that in the NGT group (32.4±2.8 vs. 42.5±2.6ml/kg/min, p<0.05). Systolic blood pressure was significantly higher in the BGT group (134±3mmHg) than that in the NGT group (122±4mmHg, p<0.05). However, body mass index, the percentage of body fat, and waist-to-hip ratio in the BGT group did not differ from those in the NGT group. These results thus suggested that decreased physical fitness may be the primary change which induces glucose intolerance.