1.Relative Grip Strength as a Predictor of Nonalcoholic Fatty Liver Disease Incidence: A Longitudinal Study by Metabolic Syndrome Status and Risk Factors Aged 51 to 88 Years
DooYong PARK ; Buseok KIM ; On LEE ; Yeon Soo KIM
The Korean Journal of Sports Medicine 2025;43(4):238-246
Purpose:
Previous studies have struggled to confirm independent associations between grip strength and nonalcoholic fatty liver disease (NAFLD) when considering individual metabolic syndrome (MetS) risk factors. The primary aim of this study was to elucidate the association between relative grip strength (RGS) and the incidence of NAFLD, with a focus on MetS, using longitudinal data.
Methods:
The study included 1,702 general adult participants aged 51 to 88 years who completed surveys during the 2013−2020 periods. NAFLD was assessed using the hepatic steatosis index, while RGS was measured with the JAMA 5030J1 (Saehan) device. A Cox proportional hazards regression model was employed to evaluate the relationship between RGS, MetS risk factors, and the risk of developing NAFLD. Hazard ratio (HR) and 95% confidence interval (CI) were calculated for NAFLD incidence.
Results:
After adjusting for various confounding variables, a 76% reduction in the HR for NAFLD incidence was observed in both the non-MetS and MetS groups among individuals with high RGS levels compared to those with low RGS levels (HR, 0.24; 95% CI, 0.15−0.38). High RGS levels were significantly associated with a reduced HR for NAFLD incidence across all MetS risk factors compared to low RGS levels. Notably, a significant association between moderate RGS and reduced NAFLD incidence risk was found only in the high triglyceride and low high-density lipoprotein-cholesterol group.
Conclusion
This study demonstrates that high levels of RGS are independently associated with a reduced risk of developing NAFLD, particularly in relation to MetS status.
2.Relationship between Change in Sitting Time and Risk of Cancer Incidence:A Prospective Cohort Study
DooYong PARK ; Buseok KIM ; Yeon Soo KIM
The Korean Journal of Sports Medicine 2025;43(4):218-227
Purpose:
Cancer remains a leading global cause of morbidity and mortality; few studies have explored the impact of long-term changes in sitting time (ST) or its associations with cancer incidence risk across levels of insulin resistance. The aim of this study is to examine the association between daily ST, changes in ST over 2 years, and cancer risk.
Methods:
We analyzed data from 2,474 older adults participating in a Korean community-based cohort study. Daily ST and 2-year changes in ST were assessed using validated self-report questionnaires. Daily ST was categorized as <5 hours, ≥5 and <10 hours, and ≥10 hours per day. Two-year changes in ST were classified into four groups:consistently low (consistently inactive), decreased (formerly active), increased (newly active), and consistently high (consistently active). Cancer was classified according to the survey question. Multivariable extended Cox regression models were used to estimate hazard ratios (HR) and 95% confidence intervals (CI) for cancer incidence.
Results:
Daily ST of ≥ 10 hours was associated with an 85% increased risk of cancer, even after adjusting for other confounding variables (HR, 1.84; 95% CI, 1.18−2.85). Also, after adjusting for confounding variables, the consistently ST group showed a 55% higher cancer risk (HR, 1.55; 95% CI, 1.02−2.36). These findings underscore the independent and interactive contributions of daily ST, changes in ST, and insulin resistance to cancer risk.
Conclusion
This study demonstrates that daily ST of 10 hours or more or sustained high levels of ST over 2 years are associated with an elevated risk of cancer
3.Joint Association of Relative Grip Strength and Regular Exercise Participation with Nonalcoholic Fatty Liver Disease: A Prospective Cohort Study
The Korean Journal of Sports Medicine 2024;42(4):262-269
Purpose:
Our primary aim was to elucidate the joint association between relative grip strength (RGS) and regular exercise participation with non-alcoholic fatty liver disease (NAFLD) incidence, utilizing longitudinal data.
Methods:
A total of 1,702 participants in this study comprised general adults aged 51 to 88 years, who had engaged in the survey both in 2013 to 2018 and during the subsequent follow-up in 2019 to 2020. NAFLD were determined by using the hepatic steatosis index. RGS was determined using the JAMA-5030J1 equipment (SAEHAN). To validate the relationship between the interaction of RGS and regular exercise participation and its impact on risk of developing NAFLD, a proportional hazards Cox regression model was used. Subsequently, we computed the hazard ratio (HR) and 95% confidence interval (95% CI) for NAFLD.
Results:
In the non-regular exercise group, middle RGS and high RGS reduced the HR for NAFLD by 29% (HR,0.71; 95% CI, 0.51–0.99) and 78% (HR, 0.22; 95% CI, 0.13–0.35), respectively, compared to low RGS. Significantassociations were observed only between high RGS and HR for NAFLD in the regular exercise group (HR, 0.40;95% CI, 0.22–0.72). Furthermore, in all subjects, both the high RGSon-regular exercise and high RGS/regular exercise groups showed a respective 60% (HR, 0.40; 95% CI, 0.29–0.56) and 54% (HR, 0.44; 95% CI, 0.31–0.63)lower HR for NAFLD compared to the low RGSon-regular exercise group.
Conclusion
This study investigates that high level of RGS were independently associated with reducing risk of developing NAFLD. RGS is an important factor that can predict the risk of developing NAFLD, and regular exercise participation is essential for increasing RGS.
4.Joint Association of Relative Grip Strength and Regular Exercise Participation with Nonalcoholic Fatty Liver Disease: A Prospective Cohort Study
The Korean Journal of Sports Medicine 2024;42(4):262-269
Purpose:
Our primary aim was to elucidate the joint association between relative grip strength (RGS) and regular exercise participation with non-alcoholic fatty liver disease (NAFLD) incidence, utilizing longitudinal data.
Methods:
A total of 1,702 participants in this study comprised general adults aged 51 to 88 years, who had engaged in the survey both in 2013 to 2018 and during the subsequent follow-up in 2019 to 2020. NAFLD were determined by using the hepatic steatosis index. RGS was determined using the JAMA-5030J1 equipment (SAEHAN). To validate the relationship between the interaction of RGS and regular exercise participation and its impact on risk of developing NAFLD, a proportional hazards Cox regression model was used. Subsequently, we computed the hazard ratio (HR) and 95% confidence interval (95% CI) for NAFLD.
Results:
In the non-regular exercise group, middle RGS and high RGS reduced the HR for NAFLD by 29% (HR,0.71; 95% CI, 0.51–0.99) and 78% (HR, 0.22; 95% CI, 0.13–0.35), respectively, compared to low RGS. Significantassociations were observed only between high RGS and HR for NAFLD in the regular exercise group (HR, 0.40;95% CI, 0.22–0.72). Furthermore, in all subjects, both the high RGSon-regular exercise and high RGS/regular exercise groups showed a respective 60% (HR, 0.40; 95% CI, 0.29–0.56) and 54% (HR, 0.44; 95% CI, 0.31–0.63)lower HR for NAFLD compared to the low RGSon-regular exercise group.
Conclusion
This study investigates that high level of RGS were independently associated with reducing risk of developing NAFLD. RGS is an important factor that can predict the risk of developing NAFLD, and regular exercise participation is essential for increasing RGS.
5.Joint Association of Relative Grip Strength and Regular Exercise Participation with Nonalcoholic Fatty Liver Disease: A Prospective Cohort Study
The Korean Journal of Sports Medicine 2024;42(4):262-269
Purpose:
Our primary aim was to elucidate the joint association between relative grip strength (RGS) and regular exercise participation with non-alcoholic fatty liver disease (NAFLD) incidence, utilizing longitudinal data.
Methods:
A total of 1,702 participants in this study comprised general adults aged 51 to 88 years, who had engaged in the survey both in 2013 to 2018 and during the subsequent follow-up in 2019 to 2020. NAFLD were determined by using the hepatic steatosis index. RGS was determined using the JAMA-5030J1 equipment (SAEHAN). To validate the relationship between the interaction of RGS and regular exercise participation and its impact on risk of developing NAFLD, a proportional hazards Cox regression model was used. Subsequently, we computed the hazard ratio (HR) and 95% confidence interval (95% CI) for NAFLD.
Results:
In the non-regular exercise group, middle RGS and high RGS reduced the HR for NAFLD by 29% (HR,0.71; 95% CI, 0.51–0.99) and 78% (HR, 0.22; 95% CI, 0.13–0.35), respectively, compared to low RGS. Significantassociations were observed only between high RGS and HR for NAFLD in the regular exercise group (HR, 0.40;95% CI, 0.22–0.72). Furthermore, in all subjects, both the high RGSon-regular exercise and high RGS/regular exercise groups showed a respective 60% (HR, 0.40; 95% CI, 0.29–0.56) and 54% (HR, 0.44; 95% CI, 0.31–0.63)lower HR for NAFLD compared to the low RGSon-regular exercise group.
Conclusion
This study investigates that high level of RGS were independently associated with reducing risk of developing NAFLD. RGS is an important factor that can predict the risk of developing NAFLD, and regular exercise participation is essential for increasing RGS.
6.Joint Association of Relative Grip Strength and Regular Exercise Participation with Nonalcoholic Fatty Liver Disease: A Prospective Cohort Study
The Korean Journal of Sports Medicine 2024;42(4):262-269
Purpose:
Our primary aim was to elucidate the joint association between relative grip strength (RGS) and regular exercise participation with non-alcoholic fatty liver disease (NAFLD) incidence, utilizing longitudinal data.
Methods:
A total of 1,702 participants in this study comprised general adults aged 51 to 88 years, who had engaged in the survey both in 2013 to 2018 and during the subsequent follow-up in 2019 to 2020. NAFLD were determined by using the hepatic steatosis index. RGS was determined using the JAMA-5030J1 equipment (SAEHAN). To validate the relationship between the interaction of RGS and regular exercise participation and its impact on risk of developing NAFLD, a proportional hazards Cox regression model was used. Subsequently, we computed the hazard ratio (HR) and 95% confidence interval (95% CI) for NAFLD.
Results:
In the non-regular exercise group, middle RGS and high RGS reduced the HR for NAFLD by 29% (HR,0.71; 95% CI, 0.51–0.99) and 78% (HR, 0.22; 95% CI, 0.13–0.35), respectively, compared to low RGS. Significantassociations were observed only between high RGS and HR for NAFLD in the regular exercise group (HR, 0.40;95% CI, 0.22–0.72). Furthermore, in all subjects, both the high RGSon-regular exercise and high RGS/regular exercise groups showed a respective 60% (HR, 0.40; 95% CI, 0.29–0.56) and 54% (HR, 0.44; 95% CI, 0.31–0.63)lower HR for NAFLD compared to the low RGSon-regular exercise group.
Conclusion
This study investigates that high level of RGS were independently associated with reducing risk of developing NAFLD. RGS is an important factor that can predict the risk of developing NAFLD, and regular exercise participation is essential for increasing RGS.
7.Joint Association of Relative Grip Strength and Regular Exercise Participation with Nonalcoholic Fatty Liver Disease: A Prospective Cohort Study
The Korean Journal of Sports Medicine 2024;42(4):262-269
Purpose:
Our primary aim was to elucidate the joint association between relative grip strength (RGS) and regular exercise participation with non-alcoholic fatty liver disease (NAFLD) incidence, utilizing longitudinal data.
Methods:
A total of 1,702 participants in this study comprised general adults aged 51 to 88 years, who had engaged in the survey both in 2013 to 2018 and during the subsequent follow-up in 2019 to 2020. NAFLD were determined by using the hepatic steatosis index. RGS was determined using the JAMA-5030J1 equipment (SAEHAN). To validate the relationship between the interaction of RGS and regular exercise participation and its impact on risk of developing NAFLD, a proportional hazards Cox regression model was used. Subsequently, we computed the hazard ratio (HR) and 95% confidence interval (95% CI) for NAFLD.
Results:
In the non-regular exercise group, middle RGS and high RGS reduced the HR for NAFLD by 29% (HR,0.71; 95% CI, 0.51–0.99) and 78% (HR, 0.22; 95% CI, 0.13–0.35), respectively, compared to low RGS. Significantassociations were observed only between high RGS and HR for NAFLD in the regular exercise group (HR, 0.40;95% CI, 0.22–0.72). Furthermore, in all subjects, both the high RGSon-regular exercise and high RGS/regular exercise groups showed a respective 60% (HR, 0.40; 95% CI, 0.29–0.56) and 54% (HR, 0.44; 95% CI, 0.31–0.63)lower HR for NAFLD compared to the low RGSon-regular exercise group.
Conclusion
This study investigates that high level of RGS were independently associated with reducing risk of developing NAFLD. RGS is an important factor that can predict the risk of developing NAFLD, and regular exercise participation is essential for increasing RGS.
8.Association of Changes in Sitting Time with the Risk of Developing Diabetes:A Community-Based Cohort Study
DooYong PARK ; Yeon Soo KIM ; EunKyung KIM
The Korean Journal of Sports Medicine 2024;42(1):46-54
Purpose:
The purpose of the present study was to investigate the relationship between changes in sitting time (ST) with the risk of developing metabolic syndrome.
Methods:
This study examined 2,814 adults aged 40 to 69 years who participated in the Korean Genome and Epidemiology Study, a community-based cohort study, for a total of 10 years. Changes in ST were assessed using the results obtained from physical activity questionnaires completed during the baseline and follow-up surveys. The diagnosis of metabolic syndrome was classified according to the criteria established by the International Diabetes Federation. We conducted survival analysis by the multivariate extended Cox regression model. The significance level for all analyses was set at p< 0.05.
Results:
We compared the newly ST group with ST less than 7 hours in the baseline and more than 7 hours in the first follow-up to the consistently non-ST group with ST less than 7 hours in both the baseline and the first follow-up. In this comparison, we found that the hazard ratio (HR) for the incidence of metabolic syndrome increasedby 33% (HR, 1.33; 95% confidence interval [CI], 1.02–1.74) for changes in total daily sedentary time and by 47% (HR, 1.47; 95% CI, 1.13–1.92) for changes in weekday sedentary time in the newly ST group.
Conclusion
Changes in ST are associated with the risk of developing metabolic syndrome. These findings can serve as fundamental data for further research on the relationship between changes in ST, and the occurrence of metabolic syndrome.
9.Association between Change in Sitting Time and Risk of Developing Hypertension:An 8-Year Longitudinal Follow-up Study with Cohort Data Analysis in Korea
The Korean Journal of Sports Medicine 2024;42(3):193-201
Purpose:
This study aims to investigate the association between changes in sitting time based on sex and levels of physical activity participation and the risk of hypertension.
Methods:
Conducted as a follow-up to the 2011–2012 baseline survey in the Korean Genome and Epidemiology Study community-based cohort study, the 4th tracking took place from 2019 to 2020 in Korea, involving adults aged 49 to 79 years. Hypertension status was determined based on systolic blood pressure ≥ 140 mm Hg, diastolic blood pressure ≥ 90 mm Hg, self-reported diagnosis, or medication usage. Change in sitting time was measured using a physical activity questionnaire. The study utilized multivariate extended Cox regression models to calculate independent risk ratios and 95% confidence intervals (CIs) for risk of developing hypertension based on change in sitting time, with a significance level set at p< 0.05.
Results:
Despite adjusting for various factors affecting sitting time and hypertension, total sitting time (hazard ratio [HR], 1.37; 95% CI, 1.05–1.78) and weekday sitting time (HR, 1.34; 95% CI, 1.03–1.76) in the newly ST group showed increased risk of developing hypertension. It was observed that increased total and weekday sitting time in males could elevate hypertension risk (total newly ST: HR, 1.52; 95% CI, 1.05–2.21; weekday newly ST: HR, 1.57; 95% CI, 1.08–2.28). Additionally, the association between changes in sitting time and risk of developing hypertension varied based on leisure-related physical activity levels.
Conclusion
The study confirms that increased sitting time raises the risk of hypertension and that reducing sitting time in physically inactive adults can lower the risk of developing hypertension.
10.Joint Association of Relative Grip Strength and Resting Heart Rate with the Risk of Developing Diabetes in Middle-Aged Adults
DooYong PARK ; YeonSoo KIM ; Eunkyung KIM
The Korean Journal of Sports Medicine 2023;41(4):216-224
Purpose:
Our primary aim was to elucidate the association between relative grip strength levels and the risk of developing diabetes, utilizing longitudinal data.
Methods:
A total of 1,935 participants in this study comprised general adults aged 51 to 81 years, who had engagedin the survey both in 2013–2014 and during the subsequent follow-up in 2019–2020. The criteria for diagnosingdiabetes included receiving a diabetes diagnosis and treatment. grip strength was converted into relative grip strength by dividing it by body mass index. To validate the relationship between the interaction of relative grip strength and resting heart rate and its impact on risk of developing diabetes, a proportional hazards Cox regression model was used.Subsequently, we computed the hazard ratio (HR) and 95% confidence interval (CI) for risk of developing diabetes.
Results:
After adjusting for various confounding variables, we observed a significant 46% reduction in the risk of developing diabetes in the high relative grip strength group compared to the low relativegrip strength group (HR,0.54; 95% CI, 0.36–0.80). However, upon additional adjustment for waist circumference, no significant findings couldbe yielded. Furthermore, we found significant differences the relationship between relative grip strength, resting heart rate, and the risk of developing diabetes among different groups.
Conclusion
This study investigates the relationship between relative grip strength and incidence of diabetes, attributed to the accumulation of body fat. Notably, both resting heart rate and relative grip strength emerge as predictive indicators for assessing the risk of diabetes development.

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