Clinical endocrinology
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Clinical endocrinology · May 1994
Comparative StudyRelations of endogenous anabolic hormones and physical activity to bone mineral density and lean body mass in elderly men.
It has been proposed that declining activities of the somatotrophic or gonadotrophic axes, or sedentary life style, are partial causes for geriatric losses of bone mineral density (BMD) and of lean body mass (LBM). The present study tested these hypotheses by determining, in both free-living and institutionalized elderly men, the correlations of bone mineral density (BMD), total body bone mineral content (TBBMC) and lean body mass (LBM) with the following predictor variables: age, body mass index, body weight, serum insulin-like growth factor I (IGF-I), serum testosterone, habitual physical activity and mobility. ⋯ In aging independent men, low levels of testosterone are associated with demineralization of the skeleton. Immobility and under-weight are associated with the osteopenia of old men residing in nursing homes. In this cross-sectional study of elderly men, there was no evidence of a relation of the somatotrophic axis to bone status or LBM, or of the gonadotrophic axis to LBM.
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Clinical endocrinology · May 1994
Comparative StudyEffect of atrial natriuretic factor infusion on basal and CRH-stimulated ACTH, cortisol and aldosterone levels in patients with Cushing's or Addison's disease.
While it has been shown that atrial natriuretic factor (ANF) is able to inhibit CRH-stimulated ACTH secretion in vitro, in normal men conflicting results on its effect on ACTH/cortisol responses to insulin and CRH have been reported. Since no data are available concerning the possible influence of ANF on the hypothalamic-pituitary-adrenal axis in states of ACTH hypersecretion, the effect of ANF on pituitary-adrenal function in basal conditions and after CRH stimulation has been investigated in patients with Cushing's (n = 4) and Addison's disease (n = 4). ⋯ (1) In patients with corticotrophin hypersecretion ANF does not influence basal and CRH-stimulated ACTH secretion; (2) in Cushing's disease ANF inhibits cortisol and aldosterone basal secretion; this effect is not mediated by ACTH and is over-ridden by CRH stimulation.
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Clinical endocrinology · May 1994
Comparative StudyThe effect of pharmacological dosages of glucocorticoids on free living total energy expenditure in man.
Weight gain had previously been thought to be due to increased calorie intake alone though no information on its effect on total energy expenditure is available in humans. We therefore assessed whether weight gain associated with glucocorticoids is due to a reduction in energy expenditure. ⋯ Body weight increased on betamethasone entirely due to an increase in fat mass. This occurred despite a rise in total energy expenditure which involved specifically that component accounted for by physical activity plus thermogenesis. The most likely explanation is that betamethasone increased dietary energy intake significantly in excess of expenditure. We estimate that an average extra energy intake of 2.8 MJ/day would have had to be consumed for this rise in fat mass to occur even before taking into account the energy intake cost of the rise in expenditure.
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Clinical endocrinology · Mar 1994
Case ReportsMetastatic thyroid cancer presenting as thyrotoxicosis: report of three cases.
Three patients with metastatic thyroid follicular carcinoma developed thyrotoxicosis. Two had mild T3 toxicosis without detectable TSH binding inhibitor immunoglobulins (TBII) or thyroid stimulating antibodies (TSAb). ⋯ The third patient developed thyrotoxicosis several months after treatment with 131I had commenced and this was associated with concurrent increase in both TBII (90%; normal, less than 11%) and TSAb (2100%). We conclude that thyrotoxicosis in patients with metastatic thyroid carcinoma may result from a large bulk of tumour functioning either autonomously or after stimulation by TSH receptor antibodies.