Insulin sensitivity was increased in untreated patients with aldosterone producing adenoma. Enhanced insulin receptor binding may contribute to this increased insulin sensitivity.
Abstract. Troglitazone (T) and d-chiroinositol (DCI) have been reported to improve insulin resistance associated with obesity and NIDDM. We tested whether these compounds counteract the insulin antagonistic effects of recombinant human GH. Male Wistar rats were allocated to 4 different treatment groups, rhGH (n=8), rhGH+T (n=7), rhGH+DCI (n=8) and control (saline, n=8). rhGH (2 IU/100 g/day) was injected sc twice daily for 2 days. T and DCI were given (20 mg/day) po for 5 days preceding and 2 days along with rhGH. Euglycemic hyperinsulinemic clamp studies were done to assess the hepatic glucose output (HGO) and glucose disappearance rate (GDR). Fasting plasma glucose, insulin, serum FFA and basal HGO were similar in all 4 treatment groups. During the hyperinsulinemic clamp which raised plasma insulin levels to 7.2 ± 0.4 ng/ml, HGO was suppressed in the control and rhGH+T treated rats but not in the rats treated with rhGH and rhGH+DCI. GDR decreased in the rats which received rhGH (18.1 ± 5.8 vs 30.3 ± 5.2 mg/kg/min) compared to the control rats. The rats given either T (24.7 ± 2.7) or DCI (31.4 ± 2.7) along with rhGH showed comparable GDR to the control rats. These results indicated that rhGH induced hepatic and peripheral insulin resistance. Troglitazone counteracted the insulin-antagonistic action of rhGH both in the liver and the peripheral tissues. DCI was effective in offsetting peripheral insulin resistance but without any effect on hepatic insulin resistance associated with rhGH treatment.
SummaryWe report a case of a 15-year-old girl with a midline neck mass that was first noted 2 or 3 years previously. She had been treated with levothyroxine (L-T4) for congenital hypothyroidism until 11 years of age. Ultrasonography revealed an atrophic right thyroid (1.0 × 1.6 × 2.6 cm in size) and a mass (2.3 × 1.0 × 3.5 cm in size) in the upper part of the neck. No left lobe of the thyroid was detected. On further evaluation, Tc-99m pertechnetate thyroid scintigraphy and CT showed ectopic thyroid tissue in the lingual region and infrahyoid region. Thus, she was diagnosed as having dual ectopic thyroid and thyroid hemiagenesis. The atrophic right thyroid was thought be non-functional. Treatment with L-T4 was started to reduce the size of the dual ectopic thyroid tissue. This may be the first reported case of dual ectopic thyroid associated with hemiagenesis detected only by ultrasonography.Learning points:Ultrasonography can confirm the presence or absence of orthotopic thyroid tissue in patients with ectopic thyroid.The cause of congenital hypothyroidism should be examined.Clinical manifestation of ectopic thyroid may appear when the treatment with L-T4 is discontinued.Annual follow-up is needed in all children when their thyroid hormone replacement is stopped.
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