Analysis of the optimal psoas muscle mass index cut‐off values, as measured by computed tomography, for the diagnosis of loss of skeletal muscle mass in Japanese people

Abstract

Aim This study aimed to determine the optimal psoas muscle mass index (PMI) cut‐off values for diagnosis of skeletal muscle mass loss. Methods We evaluated PMI in two groups of normal controls: a medical check‐up group and a liver donation candidate group. We analyzed two novel PMI cut‐off values, one based on the mean – two standard deviations (2SD) and one based on the lower 5%. Skeletal muscle mass index (SMI) evaluations using computed tomography (sliceOmatic; TomoVision) and bioelectrical impedance analysis and PMI evaluation were undertaken simultaneously. We analyzed the correlation between our PMI cut‐off values and the Japan Society of Hepatology‐defined SMI cut‐off values. The prevalence of skeletal muscle mass loss in patients with liver disease was assessed using the novel PMI cut‐off values. Results In 504 normal controls aged ≤50 years, the PMI cut‐off values based on mean –2SD and the lower 5% were set at 3.30 cm2/m2 for men and 1.69 cm2/m2 for women and 3.74 cm2/m2 for men and 2.29 cm2/m2 for women, respectively. The PMI cut‐off values based on the lower 5% alone showed that skeletal muscle mass loss increased with age. Furthermore, they correlated well with Japan Society of Hepatology‐defined SMI (sliceOmatic) cut‐off values and showed a significantly higher prevalence of skeletal muscle mass loss in patients with liver cirrhosis than those without liver cirrhosis. Conclusions We propose the following PMI cut‐off values: 3.74 cm2/m2 for male individuals and 2.29 cm2/m2 for female individuals. These cut‐off values can facilitate accurate diagnosis and management of sarcopenia in patients with chronic liver disease.

Changes in the estimated renal function after hepatitis C virus eradication with direct‐acting antiviral agents: Impact of changes in skeletal muscle mass

“…We have previously reported that patients with advanced liver fibrosis or elderly patients had lower skeletal muscle mass. 16 A recent study revealed that in HCVinfected patients with low skeletal muscle mass, skeletal muscle mass significantly increased after successful HCV eradication by DAAs. 18 Therefore, we speculated that changes in serum creatinine levels are affected by changes in skeletal muscle mass after successful HCV eradication by DAAs.…”

“…The psoas muscle mass index (PMI) of the patients was calculated using paired computed tomography (CT), as previously reported. 16 The sum of the L3 level cross-sectional areas of the right and left psoas muscle masses was measured using manual tracing. The calculated value was divided by height squared 16,17 in patients who underwent paired CT examination within 6 months of treatment initiation and at 12 or more than SVR48.…”

“…16 The sum of the L3 level cross-sectional areas of the right and left psoas muscle masses was measured using manual tracing. The calculated value was divided by height squared 16,17 in patients who underwent paired CT examination within 6 months of treatment initiation and at 12 or more than SVR48. To evaluate the monthly change in PMI, the Δ PMI/month was calculated as follows: Δ PMI/ month = [(the psoas muscle area on CT scan at ≥12 months after DAA treatment completion-the psoas muscle area on the baseline CT scan)/the psoas muscle area on the baseline CT scan]/the interval between CT scans (month).…”

“…To evaluate the monthly change in PMI, the Δ PMI/month was calculated as follows: Δ PMI/ month = [(the psoas muscle area on CT scan at ≥12 months after DAA treatment completion-the psoas muscle area on the baseline CT scan)/the psoas muscle area on the baseline CT scan]/the interval between CT scans (month). 16,19…”

“…The cause of this discrepancy between patients with LC and others, patients with low albumin and others, or patients >70 years and others has not been clarified. However, both patients with LC and the elderly have been reported to lose skeletal muscle rapidly 16,17. Thus, the increase in skeletal muscle mass due to successful HCV eradication by DAAs might be lost and needs to be studied further.The accurate assessment of renal function is critical for prioritization for liver transplantation 24.…”