Low circulating estradiol and adrenal androgens concentrations in men on glucocorticoids: a potential contributory factor in steroid-induced osteoporosis

Abstract

Reductions in circulating estradiol concentrations could be implicated in the pathogenesis of steroid-induced osteoporosis (SIOP) in men. We assessed serum estradiol and adrenal androgens (dehydroepiandrosterone sulfate [DHEAS] and androstenedione) in 77 men (group A: idiopathic osteoporosis [IOP], n = 38, aged [mean +/- SD] 57.7 +/- 12.1 years; group B: SIOP, n = 39, aged 55.3 +/- 13.1 years). We also studied the relationship between bone mineral density (BMD) and serum estradiol in the group of men with SIOP. In group B, we observed a higher prevalence of low serum testosterone concentrations (<9.0 nmol/L) (P =.0052), which was significantly correlated with steroid dosage (r = -0.42, P =.0089) and estradiol concentrations (r = 0.42, P =.012). There was a significant positive association between BMD at the lumbar spine and serum estradiol (P =.004) in the men with SIOP (group B). A high proportion of subjects had low serum estradiol concentrations (<48 pmol/L) in both groups (group A: 44.7 %, group B: 36 %). Serum adrenal androgens concentrations were also significantly suppressed in group B (serum androstenedione-group A: 4.99 +/- 1.8; Group B: 2.1 +/- 1.6 nmol/L; P =.0001). Serum DHEAS was undetectable in 59% of patients in group B versus 6% in group A (P =.001). Reductions in androstenedione also correlated with steroid dosage (r = -0.35, P =.01). In conclusion, the data show that adrenal androgens synthesis is markedly suppressed in men with SIOP. The clinical relevance of this finding remains to be determined. This study also shows a positive association between serum estradiol and BMD and a high prevalence of low serum estradiol in men with SIOP. Low serum estradiol may contribute to bone loss in men with SIOP.