ACUTE EFFECT OF LOW-CALORIE AND LOW-CARBOHYDRATE DIET ON SERUM TRIIODOTHYRONINE-RESPONSE TO GLUCOSE-INGESTION AND ITS RELATION TO GLUCOSE-TOLERANCE

This study was conducted to elucidate the mechanism of glucose intoler ance due to carbohydrate restriction. 15 non-diabetic patients, aged 5 1+/-3 yr, were placed under dietary condition-I (2,012 kcal/day; carbo hydrate 299 g) for more than 3 days after admission and then condition -I was substituted by condition-II (1,156 kcal/day; carbohydrate 139 g ) for 2 weeks. At the end of condition-I and -II, 75 g OGTT was perfor med. After the comparison between condition-I and -II, patients were s ubdivided into two groups, namely, glucose tolerance-improved (n = 8) and -impaired (n = 7) groups. In the former, Sigma glucose (mg/dl) dur ing OGTT decreased from 898.1+/-28.0 to 738.5+/-36.0 (p<0.05) and Sigm a IRI (mu U/ml) decreased from 418.8+/-60.1 to 300.7+/-33.5 (p<0.05) b ut Sigma dT(3) (ng/dl) increased from 11.3+/-14.7 to 70.3+/-15.1 (p<0. 05). In the latter, Sigma glucose (mg/dl) increased from 774.6+/-46.6 to 867.1+/-50.1 (p<0.05) and Sigma IRI (mu U/ml) increased from 323.4/-47.8 to 400.8+/-47.8 (p<0.05) but Sigma dT(3) (ng/dl) decreased from 45.3+/-7.1 to 20.0+/-14.7 although it did not reach a level of statis tical significance. These results suggest that blunted serum T-3-respo nse to glucose ingestion is linked to the mechanism of glucose intoler ance due to carbohydrate restriction.