Association between plasma mid-regional pro-adrenomedullin levels and muscle properties.

AIM: Adrenomedullin exerts a vasodilative effect and is thought to be associated with skeletal muscle properties by regulating microcirculation. This cross-sectional study aimed to clarify the possible association in older adults aged ≥65 years.

METHODS

The study population included 978 community residents (mean age 71.5 years) who participated in the medical checkup. Mid-thigh skeletal muscle mass and fat infiltration into the muscle was assessed using computed tomography images. Plasma levels of mid-regional pro-adrenomedullin, a stable fragment derived from pro-adrenomedullin in a 1:1 ratio with adrenomedullin, were measured using blood drawn at the medical checkup, and quartiles were calculated for analysis.

RESULTS

Mid-regional pro-adrenomedullin did not show significant association with the mid-thigh skeletal muscle cross-sectional area, an index of muscle mass (Q1: 217 ± 50, Q2: 218 ± 48, Q3: 215 ± 48, Q4: 212 ± 45 cm2, P = 0.544). Muscle subtype analysis showed that mid-regional pro-adrenomedullin was inversely associated with fewer fat (high intensity) muscle areas and positively associated with fat-rich (low intensity) muscle areas, resulting in an inverse association with mean muscle intensity, an index of muscle quality (Q1: 50.3 ± 4.2, Q2: 49.6 ± 4.5, Q3: 49.1 ± 4.3, Q4: 47.1 ± 4.6 HU, P < 0.001). This association remained significant after adjustment of possible covariates, including anthropometric factors and glycemic factors (Q1: reference, Q2: β = -0.078, P = 0.018, Q3: β = -0.099, P = 0.004, Q4: β = -0.180, P < 0.001).

CONCLUSION

Adrenomedullin is associated with muscle quality, but not with muscle mass. Geriatr Gerontol Int 2025; 25: 1418-1424.