Moderate to vigorous physical activity is associated with improving insulin resistance in overweight and obese adults. However, effect of light physical activity on insulin resistance remains to be fully elucidated. The purpose of this study was to investigate the effect of light physical activity on insulin resistance in overweight and obese men. Thirty-seven overweight and obese middle-aged men (28.9 ± 1.8 kg/m², 51.0 ± 8.8 years) participated in this study. They took part in the lifestyle intervention (calorie restricted diet and exercise) for 12 weeks. Anthropometric parameters, fasting glucose, HbA1c, fasting insulin, and HOMA-IR were assessed at baseline and post intervention. Physical activity was objectively measured using a triaxial accelerometer at baseline and during intervention. Light physical activity (+17.7 min/day) and moderate-vigorous physical activity (+33.2 min/day) increased significantly, while body weight (-12.4 kg), fasting glucose (-9.5 mg/ml), fasting insulin (-4.2 μU/ml), and HOMA-IR (-1.1) decreased significantly. The change in light physical activity from baseline to during intervention were inversely related to change in fasting insulin (r = 0.18, P = 0.02) and change in HOMA-IR (r = -0.16, P = 0.03), after adjustment for several confounders. These results suggest that an increase of light physical activity improves insulin resistance in overweight and obese men.

Background: Muscle–liver crosstalk plays an important role in the development and progression of non-alcoholic fatty liver disease (NAFLD). The measurement of muscle echo-intensity during ultrasonography is a realtime, non-invasive method of assessing muscle quality. In this retrospective study, we investigated the significance of poor muscle quality (namely, a greater mass of non-contractile tissue, including intramuscular fat) as a risk factor for advanced liver fibrosis and considered whether it may represent a useful tool for the diagnosis of advanced liver fibrosis. Methods: We analyzed data from 307 patients with NAFLD (143 men and 164 women) who visited the University of Tsukuba Hospital between 2017 and 2022. The patients were stratified into the following tertiles of muscle quality according to their muscle echo-intensity on ultrasonography: modest (84.1 arbitrary units [A.U.]), intermediate (97.4 A.U.), and poor (113.6 A.U.). We then investigated the relationships between muscle quality and risk factors for advanced liver fibrosis and calculated appropriate cutoff values. Results: Patients with poor muscle quality showed a significant, 7.6-fold greater risk of liver fibrosis compared to those with modest muscle quality. Receiver operating characteristic curve analysis showed that muscle quality assessment was as accurate as the fibrosis-4 index and NAFLD fibrosis score in screening for liver fibrosis and superior to the assessment of muscle quantity and strength, respectively. Importantly, a muscle echo-intensity of ≥92.4 A.U. may represent a useful marker of advanced liver fibrosis. Conclusion Muscle quality may represent a useful means of identifying advanced liver fibrosis, and its assessment may become a useful screening tool in daily practice.

Background: Muscle–liver crosstalk plays an important role in the development and progression of non-alcoholic fatty liver disease (NAFLD). The measurement of muscle echo-intensity during ultrasonography is a realtime, non-invasive method of assessing muscle quality. In this retrospective study, we investigated the significance of poor muscle quality (namely, a greater mass of non-contractile tissue, including intramuscular fat) as a risk factor for advanced liver fibrosis and considered whether it may represent a useful tool for the diagnosis of advanced liver fibrosis. Methods: We analyzed data from 307 patients with NAFLD (143 men and 164 women) who visited the University of Tsukuba Hospital between 2017 and 2022. The patients were stratified into the following tertiles of muscle quality according to their muscle echo-intensity on ultrasonography: modest (84.1 arbitrary units [A.U.]), intermediate (97.4 A.U.), and poor (113.6 A.U.). We then investigated the relationships between muscle quality and risk factors for advanced liver fibrosis and calculated appropriate cutoff values. Results: Patients with poor muscle quality showed a significant, 7.6-fold greater risk of liver fibrosis compared to those with modest muscle quality. Receiver operating characteristic curve analysis showed that muscle quality assessment was as accurate as the fibrosis-4 index and NAFLD fibrosis score in screening for liver fibrosis and superior to the assessment of muscle quantity and strength, respectively. Importantly, a muscle echo-intensity of ≥92.4 A.U. may represent a useful marker of advanced liver fibrosis. Conclusion Muscle quality may represent a useful means of identifying advanced liver fibrosis, and its assessment may become a useful screening tool in daily practice.

Background: Muscle–liver crosstalk plays an important role in the development and progression of non-alcoholic fatty liver disease (NAFLD). The measurement of muscle echo-intensity during ultrasonography is a realtime, non-invasive method of assessing muscle quality. In this retrospective study, we investigated the significance of poor muscle quality (namely, a greater mass of non-contractile tissue, including intramuscular fat) as a risk factor for advanced liver fibrosis and considered whether it may represent a useful tool for the diagnosis of advanced liver fibrosis. Methods: We analyzed data from 307 patients with NAFLD (143 men and 164 women) who visited the University of Tsukuba Hospital between 2017 and 2022. The patients were stratified into the following tertiles of muscle quality according to their muscle echo-intensity on ultrasonography: modest (84.1 arbitrary units [A.U.]), intermediate (97.4 A.U.), and poor (113.6 A.U.). We then investigated the relationships between muscle quality and risk factors for advanced liver fibrosis and calculated appropriate cutoff values. Results: Patients with poor muscle quality showed a significant, 7.6-fold greater risk of liver fibrosis compared to those with modest muscle quality. Receiver operating characteristic curve analysis showed that muscle quality assessment was as accurate as the fibrosis-4 index and NAFLD fibrosis score in screening for liver fibrosis and superior to the assessment of muscle quantity and strength, respectively. Importantly, a muscle echo-intensity of ≥92.4 A.U. may represent a useful marker of advanced liver fibrosis. Conclusion Muscle quality may represent a useful means of identifying advanced liver fibrosis, and its assessment may become a useful screening tool in daily practice.