Decreased serum creatinine to cystatin C ratio is associated with low tongue pressure

Tongue strength plays an important role in the process of food intake, and low tongue pressure has been associated with aspiration pneumonia, cognitive decline, and mortality. However, special equipment for tongue pressure measurement is uncommon in general practice. Recently, the serum creatinine-to-cystatin C (Cr/CysC) ratio has been validated as a marker of muscle volume mass. Thus, we aimed to investigate the association of the serum Cr/CysC ratio with tongue pressure in a cross-sectional study.

This single-center, cross-sectional study enrolled 73 participants (mean age, 71.7 years; men, 49.3%) who regularly attended the hospital for treatment of chronic disease. A tongue pressure of <30 kPa was defined as low tongue pressure. We evaluated the relationships between the serum Cr/CysC ratio and tongue pressure using multiple regression analysis.

The serum Cr/CysC ratio was correlated with tongue pressure (R²  = 0.25, P < 0.0001). In multiple regression analyses adjusted for confounders including age, sex, body mass index, and serum albumin, the association remained significant (P = 0.0001). In logistic analyses, the multivariable-adjusted odds ratios of the Cr/CysC ratio for tertiles 1 and 2 compared with tertile 3 for low tongue pressure were 7.81 (95% confidence interval, 1.45-51.73) and 2.71 (95% confidence interval, 0.60-13.19), respectively.

We demonstrated that a decreased serum Cr/CysC ratio was associated with a higher risk of low tongue pressure. Our findings suggest that this simple serum surrogate marker may be a first step toward an intervention for oral function by general practitioners. Geriatr Gerontol Int 2024; 24: 102-108.