Bone mineral density and androgen levels in elderly males.

To clarify the relationship of sex male hormones and bone in men, we studied in 140 healthy elderly men (aged 55-90 years) the relation between serum levels of androgens and related sex hormones, bone mineral density (BMD) at different sites, and other parameters related to bone metabolism. Our results show a slight decrease of serum-free testosterone with age, with an increase of follicle stimulating hormone (FSH) and luteinizing hormone (LH) in a third of the elderly subjects studied. BMD decreased significantly with age in all regions studied, except in the lumbar spine. We found a positive correlation between body mass index (BMI) and BMD at the lumbar spine and femoral neck (P < 0.001). No relationship was found (uni- and multivariate regression analysis) between serum androgens or sex hormone-binding globulin (SHBG) and BMD. We found a positive correlation of vitamin D binding protein (DBP) and osteocalcin with lumbar spine BMD and with BMI, DBP, IGF-1, and PTH with femoral neck BMD. In conclusion, there is a slight decline in free testosterone and BMD in the healthy elderly males. However, sex male hormones are not correlated to the decrease in hip BMD. Other age-related factors must be associated with bone loss in elderly males.

[Study on the activity of acromegaly: evaluation of IGF-I]. / Estudio sobre la actividad de la acromegalia: valoración del IGF-I.

The evaluation of acromegaly only with GH levels can be difficult. We have evaluated in 32 acromegalic patients the clinical activity and baseline GH after oral glucose and THR. IGF-I was also evaluated. According GH suppression by glucose, three groups were established. A) minimum GH less than ng/ml, B) minimum GH 2-5 ng/ml and C) GH less than 2 ng/ml. IGF-1 in group A was 8.8 +/- 4.1 U/ml (mean +/- SD) and in group C IGF-I was 1.4 +/- 0.5 U/ml. Group B presented heterogeneous clinic and IGF-I levels. A 4 years clinical and hormonal follow-up could be performed in 20 patients. Those patients who were clinically inactive maintained their GH levels less than 2 ng/ml, with normal IGF-I titers throughout the follow-up period. In summary, IGF-I is very reliable in the evaluation of acromegaly activity and only requires a baseline determination being thus very useful in initial screening. It also determines with great reliability the treatment effectiveness in the evolutive study.

Correlation among plasma osteocalcin, growth hormone, and somatomedin C in acromegaly.

Plasma osteocalcin (BGP), growth hormone (GH), and somatomedin C(SmC) were measured in 12 patients with acromegaly [7 clinically active (aA), 5 cured (cA)] and 9 control subjects (C). Basal plasma values for the three parameters were higher in aA than in C and in cA. No significant difference was found between cA and C. A significant linear correlation between BGP and GH and between BGP and SmC was obtained. These results suggest an effect of GH on BGP synthesis, possibly mediated by SmC, although a direct effect of GH on bone cannot be excluded.

Hyperprolactinemia in chronic renal failure: impaired responsiveness to stimulation and suppression. Normalization after transplantation.

(PRL) secretion was investigated in 12 undialyzed patients with chronic renal failure (CRF), 30 hemodialyzed patients (HD), 19 renal transplant (RT) recipients and 17 controls. Basal PRL levels in CRF and HD patients were higher than in controls and RT subjects. Plasma PRL values were higher in CRF than in HD patients. In the HD group, plasma PRL concentrations were significantly higher in men with reduced sexual potency than in those in which it was normal. After TRH stimulation in CRF and HD the PRL response was considerably less and the time of peak delayed with respect to the controls. In RT subjects PRL did not return towards baseline after 120 min. After bromocriptine, plasma PRL suppression in CFR and HD patients ws lower than in controls and RT subjects. These findings suggest that some factor which accumulates in uremia, is only partially removed by hemodialysis, and might be responsible for the hyperprolactinemia and might also interfere with the binding of TRH and bromocriptine to their respective pituitary receptors. Although a pituitary defect seems to be prevalent, a concomitant hypothalamic disorder cannot be excluded. Hyperprolactinemia seems to play a role in the sexual disturbances showed by some HD men. Whatever the alterations responsible for the impaired PRL regulation in uremia are, they are reversed by successful renal transplant.