Spinal volumetric trabecular bone mass in acromegalic patients: a longitudinal study

Area of Science:

• Endocrinology
• Bone Metabolism
• Acromegaly Research

Background:

• Trabecular bone mass in acromegaly is debated, with prior studies using dual X-ray absorptiometry (DXA) yielding controversial results.
• DXA measurements are influenced by bone size, potentially confounding results in conditions with bone enlargement like acromegaly.

Purpose of the Study:

• To assess the longitudinal effects of growth hormone (GH) excess on trabecular bone mass in acromegaly.
• To utilize single-energy quantitative computed tomography (QCT) for bone measurements, which is independent of bone size.

Main Methods:

• A longitudinal retrospective study involving 46 acromegaly patients followed for a median of 48 months.
• Patients were categorized into four groups based on gonadal status (eugonadal/hypogonadal) and disease activity (active/controlled).
• Spinal trabecular bone mineral density (BMD) was measured using QCT, with changes reported as annual variations in Z-values (Delta Z-QCT).

Main Results:

• Delta Z-QCT was significantly higher in eugonadal patients with active disease compared to hypogonadal patients with active or controlled disease.
• Eugonadal patients with controlled disease showed a greater Delta Z-QCT than hypogonadal patients with controlled disease.
• Multivariate analysis indicated that hypogonadal status and the duration of hypogonadism were significantly associated with Delta Z-QCT, independent of disease activity or follow-up duration.

Conclusions:

• Chronic GH excess demonstrates an anabolic effect on spinal trabecular bone mass in eugonadal acromegaly patients with active disease.
• This anabolic effect is diminished or absent in hypogonadal patients, regardless of disease activity.
• The findings highlight the crucial role of gonadal status in modulating the skeletal response to GH excess in acromegaly.