Clinical endocrinology
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Clinical endocrinology · Oct 1991
Levels of GH binding activity, IGFBP-1, insulin, blood glucose and cortisol in intensive care patients.
To investigate levels of serum GH binding activity, insulin-like growth factor binding protein-1 (IGFBP-1), blood glucose, serum insulin, and cortisol in patients on the Intensive Therapy Unit. ⋯ We have previously reported that critically ill patients have low levels of IGF-I with augmented basal levels of GH. The present results demonstrate that these changes in the GH-IGF-I axis are associated with insulin resistance with respect to blood glucose and high levels of IGFBP-1 when patients are fasted. However, when fed, the inverse relationship of IGFBP-1 to insulin is preserved. Patients have low levels of GH binding activity and increased mean cortisol levels. Interventional studies in this patient group with GH and IGF-I must take account of these changes in binding protein and cortisol levels.
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Clinical endocrinology · Sep 1991
Correlation of plasma insulin and insulin-like growth factor-I with indices of androgen transport and metabolism in women with polycystic ovary syndrome.
Polycystic ovary syndrome (PCOS) is said to be associated with hyperinsulinaemia. Insulin stimulates androgen production by ovarian tissue in vitro and previous studies have identified a positive correlation of insulin with androstenedione. The aim of the present study was to discover whether insulin levels correlate with clinical presentation and with markers of androgen transport and metabolism in women with PCOS. ⋯ These data suggest that, in vivo, the major effect of insulin on androgen secretion is mediated by changes in SHBG rather than by direct stimulation of ovarian androgen production. Higher insulin concentrations in anovulatory compared with ovulatory women with hyperandrogenaemia may indicate that insulin resistance in the ovary contributes to the mechanism of anovulation in PCOS.
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Clinical endocrinology · Jul 1991
Critically ill patients have high basal growth hormone levels with attenuated oscillatory activity associated with low levels of insulin-like growth factor-I.
The aim was to study the relationship between growth hormone (GH) and insulin-like growth factor-I (IGF-I) in critically ill patients. ⋯ We have demonstrated that critically ill patients have low IGF-I levels associated with augmented baseline GH levels which show reduced oscillatory activity. The results would be compatible with the hypothesis that there is an adaptive change in critically ill patients away from the indirect effects of GH (stimulation of IGF-I production and anabolism) and toward the direct effects (lipolysis and insulin antagonism) which increase the availability of energy substrates. The pattern of GH levels seen in our patients may be important in this adaptation.
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Clinical endocrinology · Dec 1989
Elevated serum intact parathyroid hormone levels in elderly patients with hip fracture.
It has been postulated that secondary hyperparathyroidism contributes to bone loss and the high incidence of hip fractures in the elderly population, but there are no data on serum intact parathyroid hormone concentrations in these patients. In this study, serum intact parathyroid hormone (PTH) levels have been measured in 39 elderly patients with hip fracture; in addition, serum 25-hydroxyvitamin D3 and 1,25-dihydroxyvitamin D3 concentrations have been measured. ⋯ These results provide the first direct evidence for secondary hyperparathyroidism in elderly patients with hip fracture. Vitamin D deficiency is unlikely to be the sole cause of secondary hyperparathyroidism in these subjects and calcium deficiency by itself may also contribute.