Fracture risk and bone health in adrenal adenomas with mild autonomous cortisol secretion/subclinical hypercortisolism: a systematic review, meta-analysis and meta-regression

Adrenal adenomas/incidentalomas with mild autonomous cortisol secretion (MACS)/subclinical hypercortisolism (SH) are often associated with metabolic syndrome, glucocorticoid-induced osteoporosis, and fractures. In this background, the present systematic review and meta-analysis aimed to collate the available evidence and provide a summary of the effect of MACS/SH on bone health in terms of fractures, osteoporosis/osteopenia, microarchitecture, and bone turnover. PubMed/MEDLINE, Embase, and Web of Science databases were systematically searched for observational studies reporting prevalence of fractures, osteoporosis/osteopenia or data on bone microarchitecture/bone turnover markers (BTMs). Following literature search, 16 observational studies were included. Pooled prevalence of any fractures (vertebral and non-vertebral), vertebral fractures, and osteoporosis/osteopenia in MACS/SH were 43% [95% confidence intervals (CI): 23%, 62%], 45% (95% CI: 22%, 68%) and 50% (95% CI: 33%, 66%), respectively. On meta-regression, age, sex, 24-hour urinary free cortisol, and dehydroepiandrosterone-sulfate did not predict fracture risk. The likelihood of any fractures [odds ratio (OR) 1.61; 95% CI: 1.18, 2.20; P = 0.0026], vertebral fractures (OR 2.10; 95% CI: 1.28, 3.45; P = 0.0035), and osteoporosis/osteopenia (OR 1.46; 95% CI: 1.15, 1.85; P = 0.0018) was significantly higher in adrenal adenomas and MACS/SH than non-functional adrenal adenomas. Subjects with MACS/SH had significantly lower bone mineral density (BMD) at lumbar spine [mean difference (MD) -0.07 g/cm2; 95% CI: -0.11, -0.03; P = 0.0004) and femoral neck (MD -0.05 g/cm2; 95% CI: -0.08, -0.02; P = 0.0045) than their non-functional counterparts. Limited data showed no significant difference in BTMs. Publication bias was observed in the pooled prevalence of any fractures, vertebral fractures and pooled MD of femoral neck BMD. To conclude, people with adrenal adenomas/incidentalomas and MACS/SH are at a 1.5- to 2-fold higher likelihood of fractures and osteoporosis/osteopenia compared to non-functional adrenal adenomas and should routinely be screened for bone disease. Nevertheless, considering the modest sample size of studies and evidence of publication bias, larger and high-quality studies are required (CRD42023471045). Mild autonomous cortisol secretion (MACS), often also referred to as subclinical hypercortisolism (SH), is usually associated with an underlying adrenal incidentaloma (AI), an adrenal mass incidentally found during abdomen imaging. Although signs of overt cortisol excess are lacking, subjects with MACS/SH often have features of metabolic syndrome, osteoporosis and fractures. The present systematic review and meta-analysis showed that the pooled prevalence of any fractures (vertebral and non-vertebral), vertebral fractures, and osteoporosis/osteopenia in MACS/SH were 43%, 45%, and 50%, respectively. People with adrenal adenomas/incidentalomas and MACS/SH are at a 1.5- to 2-fold higher likelihood of fractures and osteoporosis/osteopenia compared to non-functional adrenal adenomas. Besides, subjects with MACS/SH had significantly lower bone mineral density at lumbar spine and femoral neck than their non-functional counterparts. It is thus imperative to assess bone health in all subjects with MACS/SH.