Axial bone mineral density in patients with acromegaly

The purpose of this study was to assess the influence of long-term elevated levels of growth hormone and insulin-like growth factor I on bone mineral density (BMD) of the spine in patients with acromegaly.

The spinal BMD in 40 patients with acromegaly was measured with quantitative computed tomography. The result was expressed as the mean of six measurements of consecutive vertebral bodies and as a z score. Twenty age- and sex-matched healthy persons also underwent spinal BMD measurement and served as controls.

In 36 of the 40 patients, the BMD z score ranged within 2 standard deviations (SDs) above or below the mean. Only two patients (one man and one woman) had enhanced BMD loss (below 2 SD). Two other female patients had BMD values of more than 2 SD above the mean. Differences between patient subgroups were not statistically significant, but a statistically significant (P < .05) positive correlation was found between basal serum concentration of growth hormone and spinal BMD for the entire patient group. No correlation between BMD and basal serum concentration of insulin-like growth factor I was found.

Hypersecretion of growth hormone in patients with acromegaly, regardless of other factors, has no evident effect on BMD of the lumbar spine.