Background/Objective: In order to address the current knowledge gap with regard to serum calcium-to-magnesium ratio (Ca/Mg) in patients with adrenal incidentalomas, we aimed to analyze Ca/Mg in menopausal women diagnosed with these tumors versus (tumor-free) controls across DXA categories. Methods. This is a retrospective, real-world, cross-sectional study in 474 menopausal women admitted at a single tertiary center of endocrinology. Results. Tumor group (N=111) had osteoporosis/osteopenia/normal DXA prevalence: 17.1%, 36.9% and 46%, respectively, control group: 13.8%, 45.5%, and 40.8%. Ca/Mg ratio was similar between DXA sub-groups in each group. Tumor group: Ca/Mg corelated with age (r=0.288, p=0.047), P1NP (r= -0.459, p=0.011), osteocalcin (r= -0.37, p=0.026) and CrossLaps (r= -0.446, p=0.006) in subjects with normal DXA (N=51), while in those osteoporotic (N=19), with glycated hemoglobin A1c (r=0.596, p=0.025). Control group (N=363): Ca/Mg corelated with age (N=165, r=0.178, p=0.034), fasting glycemia (r=0.253, p=0.003), glycated hemoglobin A1c (r=0.22, p=0.045), osteocalcin (r= -0.196, p=0.03), and CrossLaps (r= -0.193, p=0.034) in osteopenic subjects (N=165) and with P1NP (r= -0.249, p=0.027) in normal DXA (N=148). Conclusion. Osteopenic subjects (regardless tumor diagnosis) showed a direct age-Ca/Mg association, while the ratio was correlated with the bone turnover biomarkers distinctively across DXA sub-groups. Additionally, the ratio might reflect a more severe glucose profile.
