GONADAL STATUS IS AN IMPORTANT DETERMINANT OF BONE-DENSITY IN ACROMEGALY

OBJECTIVE To measure bone mineral density (BMD) in patients with acrom egaly and to look for clinical features which may explain previously r eported discrepant results. DESIGN Prospective case controlled observa tional study. PATIENTS 18 patients with acromegaly (seven women, 11 me n; mean age 53.2 +/- 3.5 years). Eight patients had active disease and 10 had controlled acromegaly. Growth hormone and insulin-like growth factor-1 (IGF-1) concentrations were measured to assess disease activi ty. MEASUREMENTS BMD was measured at four sites on the lumbar spine, t hree at the femoral neck and at Ward's triangle using a Hologic dexa s canner. Results were compared to a locally determined control populati on (n = 1800). In eight patients with active acromegaly, urinary free pyridinoline and deoxypyridinoline, and serum osteocalcin, propeptide of type 1 procollagen, vitamin D, 1000 h parathyroid hormone, bone spe cific alkaline phosphatase, calcium and phosphate concentrations were measured before and after 6 months treatment with octreotide. RESULTS The mean BMD for all acromegalic patients was not significantly differ ent from the control population except at the femoral neck where it wa s increased (P = 0.05), At all sites, the BMD of patients who had been hypogonadal (n = 12/18) was significantly lower (P < 0.05-0.01) than that of patients who had been eugonadal (n = 6/18). BMD for hypogonada l patients was lower than the control population at Ward's triangle (P = 0.03). Eugonadal acromegalic patients had BMD greater than non-acro megalic controls at all sites. Patients with controlled acromegaly had a higher BMD than non-acromegalic controls, but there were no differe nces in BMD between patients with active and controlled acromegaly. Se rum IGF-1 concentrations decreased from 64.5 +/- 5.1 nmol/l to 37.5 +/ - 6.9 nmol/l (P = 0.02) after 6 months treatment with octreotide, but there was no change in any of the biochemical markers of bone turnover . CONCLUSIONS Eugonadal acromegalic patients have increased lumbar spi ne and femoral neck BMD compared to hypogonodal acromegalic patients a nd the general population, but it is reduced if patients have been hyp ogonadal.