Paravertebral Muscles as Indexes of Sarcopenia and Sarcopenic Obesity: Comparison With Imaging and Muscle Function Indexes and Impact on Cardiovascular and Metabolic Disorders

OBJECTIVE. The objectives of this study were to propose the use of the cross-sectional area of paravertebral muscle (PMA) and the ratio of the PMA to the cross-sectional area of visceral fat (PVR) as new indexes of sarcopenia or sarcopenic obesity through comparison with existing indexes and to show the clinical associations of PMA and PVR with hypertension and diabetes. SUBJECTS AND METHODS. A total of 1270 participants (608 men and 662 women; mean [+/- SD] age, 63.57 +/- 6.94 years) were recruited from a community-based population of elderly individuals. PMA and PVR were measured on single-slice abdominal CT images. Pearson correlation was used to evaluate the correlation of PMA and PVR with widely used imaging and muscle function indexes of sarcopenia and sarcopenic obesity. Tertile categories of PMA and PVR were evaluated to investigate associations with risks for hypertension and diabetes in men and women, by use of separate multivariable logistic regression models. RESULTS. PMA was correlated with the cross-sectional area of thigh muscle on CT, appendicular skeletal muscle mass (ASM) on dual-energy x-ray absorptiometry, height-adjusted ASM (calculated as ASM divided by the height in meters squared), and body mass index (BMI)-adjusted ASM (calculated as ASM divided by BMI) (p <.01). PMA was also correlated with hand grip strength and gait speeds ( p <.01). PVR was correlated with height-adjusted ASM and BMI-adjusted ASM (p <.01). A high PVR significantly decreased the odds ratios for hypertension and diabetes in the unadjusted model and the model adjusted for age, smoking, and drinking status. The ratio of the cross-sectional area of thigh muscle to the cross-sectional area of visceral fat and the BMI-adjusted ASM produced results similar to those of PVR in terms of the odds ratios for hypertension and diabetes. CONCLUSION. Single-slice abdominal CT can supply PMA and visceral fat information together. PMA and PVR were found to be reliable indexes of sarcopenia and sarcopenic obesity. A high PVR was associated with low risks for hypertension and diabetes.