Rh. Rao, INSULIN-RESISTANCE DURING EUGLYCEMIC CLAMP STUDIES IN CHRONICALLY UNDERNOURISHED RATS WITH MILD STREPTOZOCIN DIABETES, Metabolism, clinical and experimental, 44(11), 1995, pp. 1422-1427
Malnutrition has been shown to impair insulin sensitivity, but it is n
ot known whether this effect has any impact on coexisting diabetes. In
sulin sensitivity was therefore studied using the glucose clamp techni
que in rats with chronic nutritional deprivation superimposed on mild
streptozocin (STZ) diabetes mellitus. In pair-feeding experiments, 4 w
eek-old littermate rats were either allowed ad libitum access to food
or restricted to 50% of ad libitum intake for 8 weeks, and were inject
ed with STZ 40 mg/kg intraperitoneally halfway through the experiment.
Fasting plasma glucose (FPG) was similar in both groups of rats, but
fasting plasma insulin (FPI) was lower in the undernourished group (P
=.016). Undernourished rats were significantly more insulin resistant
during euglycemic hyperinsulinemia of the same degree, with glucose di
sposal rate being impaired by 50% as compared with that in ad libitum-
fed diabetic littermates (24.4 +/- 2.8 v 51.5 +/- 4.4 mu mol/kg/min, P
=.0008). The insulin sensitivity index was significantly lower in the
undernourished group (3.03 +/- 0.32 v 5.67 +/- 0.6, P =.0057). The re
sults show that chronic undernutrition markedly reduces insulin sensit
ivity in rats with mild STZ diabetes. This is further evidence that ch
ronic undernutrition is a deleterious modifying influence on coexistin
g diabetes mellitus. It suggests that the insulin resistance of malnut
rition-related diabetes mellitus (MRDM) could potentially he an acquir
ed defect mediated by the coexistent undernutrition, rather than a ''d
istinctive'' feature that is intrinsically unique to this diabetic syn
drome. Copyright (C) 1995 by W.B. Saunders Company