Impact of pheochromocytoma or paraganglioma on bone metabolism: A systemic review and meta-analysis

Introduction: Preclinical and animal studies have suggested that excess catecholamines can lead to bone mineral loss. However, to date, no systematic review is available that has analyzed the impact of catecholamine excess in the context of pheochromocytoma/paraganglioma (PPGL) on bone metabolism. We conducted this meta-analysis to address this knowledge gap.

Methods: Electronic databases were searched for studies evaluating bone metabolism, including assessments of bone mineral density (BMD), quantitative computed tomography (qCT), trabecular bone score (TBS), or bone turnover markers in patients with PPGL. These markers included those of bone resorption, such as tartrate-resistant acid phosphatase 5b (TRACP-5b) and cross-linked C-telopeptide of type I collagen (CTx), as well as markers of bone formation, such as bone-specific alkaline phosphatase (BS ALP).

Results: Out of the initially screened 1614 articles, data from six studies published in four different patient cohorts with PPGL that met all criteria were analysed. Individuals with PPGL had significantly lower TBS [Mean Difference (MD) -0.04 (95% CI: -0.05–-0.03); p < 0.00001; I2 = 0%], higher serum CTx [MD 0.13 ng/ml (95% CI: 0.08–0.17); p < 0.00001; I2 = 0%], and higher BS-ALP [MD 1.47 U/L (95% CI: 0.30–2.64); p = 0.01; I2 = 1%]. TBS at 4-7 months post-surgery was significantly higher compared to baseline [MD 0.05 (95% CI: 0.02–0.07); p < 0.0001]. A decrease in CTx has been documented post-surgery.

Conclusion: Bone health deterioration is a major concern in patients with PPGL. In addition to providing a definitive cure for catecholamine excess, monitoring and treating osteoporosis is essential for individuals with secondary osteoporosis due to PPGL. Long-term studies on bone health outcomes in PPGL are warranted