Creatinine to Cystatin C Ratio as a Marker of Bone Property in Older Adults: The J-SHIPP Study.

OBJECTIVES

To clarify whether serum creatinine to cystatin C ratio (CCR), a marker of muscle mass and muscle function may be used as a simple marker of bone property.

DESIGN

A cross-sectional analysis.

SETTING

A general population-based observation study.

PARTICIPANTS

1,606 middle-aged to elderly (≥50 years, mean age: 66.9 ± 7.5 years old) men (n = 642) and post-menopausal women (n = 964).

MEASUREMENT

Speed of sound (SOS) at the calcaneal bone was used as a surrogate marker of bone mineral density. The cross-sectional area of the muscle at the mid-thigh was measured using computed tomography.

RESULTS

There was significant linear correlation between the quartiles of CCR and SOS (Q1: 1,495 ± 25, Q2: 1,499 ± 24, Q3: 1,507 ± 26, Q4: 1,511 ± 25 m/sec; P < 0.001) even in a sex-separated analysis. This association was independent of major covariates (Q1: β = -0.126, P < 0.001; Q2: β = -0.096, P = 0.001; Q3: β = -0.022; P = 0.412, Q4: reference) and the mid-thigh muscle mass, while creatinine alone or eGFR did not show clear association with SOS.

CONCLUSION

The CCR may be used as a simple marker of bone property independently of muscle mass in a general population with preserved renal function.