Recent Update on the Prevalence of Sarcopenia in Koreans: Findings from the Korea National Health and Nutrition Examination Survey

Article information

J Bone Metab. 2024;31(2):150-161

Publication date (electronic) : 2024 May 31

doi : https://doi.org/10.11005/jbm.2024.31.2.150

Shinjune Kim ¹

, Yong-Chan Ha ²

, Deog-Yoon Kim ³

, Jun-Il Yoo ⁴

¹Department of Biomedical Research Institute, Inha University Hospital, Incheon, Korea

²Department of Orthopaedic Surgery, Seoul Bumin Hospital, Seoul, Korea

³Department of Nuclear Medicine, Kyung Hee University Hospital, Kyung Hee University School of Medicine, Seoul, Korea

⁴Department of Orthopaedic Surgery, Inha University Hospital, Inha University School of Medicine, Incheon, Korea

Corresponding author: Jun-Il Yoo, Department of Orthopedic Surgery, Inha University Hospital, Inha University School of Medicine, 27 Inhang-ro, Jung-gu, Incheon 22332, Korea, Tel: +82-55-750-8688, Fax: +82-55-754-0477, E-mail: furim@hanmail.net

Received 2024 February 22; Revised 2024 April 24; Accepted 2024 April 26.

Abstract

Background

As recognized by the World Health Organization in 2016 with its inclusion in the International Classification of Diseases, Tenth Revision as M62.84, and by South Korea in 2021 as M62.5, the diagnostic guidelines for sarcopenia vary globally. Despite its prevalence in older populations, data on sarcopenia in Koreans aged 60 and above is scarce, highlighting the need for research on its prevalence in this demographic.

Methods

Utilizing the 2022 Korea National Health and Nutrition Examination Survey dataset, sarcopenia was assessed among 1,946 individuals aged 60 or older according to the Asian Working Group for Sarcopenia 2019 criteria, incorporating grip strength and bioelectrical impedance analysis measurements. Statistical analyses were performed to differentiate categorical and continuous variables using logistic regression and Student’s t-tests, respectively.

Results

The prevalence of sarcopenia was found to increase with age, with the highest prevalence observed in the oldest age group (80 years and older). The overall prevalence of sarcopenia in our study population was 6.8%. Among men, the prevalence of sarcopenia was 5.5% in the 60 or older age group, 9.6% in the 70 or older age group, and 21.5% in the 80 or older age group. Among women, the prevalence of sarcopenia was 7.9%, 10.5%, and 25.9%, respectively.

Conclusions

This study highlights the significant burden of sarcopenia in elderly Koreans, particularly among the oldest individuals. These findings call for targeted interventions to manage and prevent sarcopenia, along with further research on its risk factors, consequences, and effective mitigation strategies.

Keywords: Aging; Korea National Health and Nutrition Examination Survey; Muscle mass; Prevalence; Sarcopenia

Graphical Abstract

INTRODUCTION

Sarcopenia is a progressive age-related condition characterized by the loss of muscle mass and function.[1–4] It is associated with an increased risk of falls, disability, reduced quality of life, and higher mortality rates in older adults.[1–3] The guideline for sarcopenia diagnosis varies across different global institutions, including the European Working Group on Sarcopenia in Older People (EWGSOP), International Working Group on Sarcopenia, and Asian Working Group for Sarcopenia (AWGS).[3,5,6] Sarcopenia is also recognized as a disease, and in 2016, it was officially included in the World Health Organization’s International Classification of Diseases, Tenth Revision with the disease code (M62.84), and South Korea also included it in the diagnosis code (M62.5) in 2021.[7,8]

As the aging population becomes a global health concern, understanding the prevalence of sarcopenia in older adults is crucial for identifying the burden that this condition poses on individuals and healthcare systems. By estimating the prevalence of sarcopenia and identifying its associated risk factors and consequences, policymakers and healthcare professionals can develop targeted interventions to effectively prevent and manage sarcopenia, enhancing the overall health and well-being of older adults.[9]

South Korea is experiencing significant demographic changes, primarily due to declining birth rates and increasing life expectancy.[10,11] The proportion of elderly individuals participating in economic activities has risen from 30.9% in 2017 to 36.9% in 2020, along with an increase in the number of older adults living alone or with their spouse.[12] Consequently, the country is faced with an aging population, necessitating a focus on understanding the health needs of older adults.[10] Among the various health conditions, sarcopenia stands out as a prevalent issue that poses a particular challenge to the health and well-being of Korean older adults. Despite its significance, there is a scarcity of data on the prevalence of sarcopenia, especially among Koreans aged 60 and above.

The prevalence of sarcopenia varies among different populations and changes over time, influenced by diagnostic criteria, the equipment used, and the specific population groups under study.[3,13,14] For example, a 2016 study involving 302 participants with an average age of 75.0 years reported a sarcopenia prevalence of 8.9%, whereas a 2019 study with 521 participants averaging 71.6 years found a prevalence rate of 9.8%.[15,16] Both studies used the EWGSOP definition of sarcopenia but varied in their methods of body composition and muscle function assessment. Additionally, the prevalence of sarcopenia is typically reported to be in the range of 10% to 20% in South Korea.[17–19] This underscores the need to utilize the most recent data to investigate the prevalence of sarcopenia in Koreans. This study aimed to determine the prevalence of sarcopenia in Koreans.

METHODS

1. Study design

This study utilized cross-sectional data from the Korea National Health and Nutrition Examination Survey (KNHANES), a comprehensive and nationally representative survey conducted in Korea, to collect and analyze the health and nutritional status data of the Korean population.[20,21] For this study, we focused on individuals aged 60 years and older who participated in KNHANES in the 2022 survey period. From the KNHANES dataset, 6,265 participants were initially identified (Fig. 1). After excluding 4,023 individuals under the age of 60, the remaining population comprised 2,242 participants aged 60 years or older, consisting of 982 men and 1,260 women. During the data refinement phase, 300 individuals were initially excluded because of the absence of grip strength data, followed by another 460 individuals due to missing bioelectrical impedance analysis (BIA) data. Ultimately, additional 568 participants were excluded because they lacked grip strength or BIA measurements. After applying these exclusion criteria, the final sample size for the study was 1,674 participants who met the inclusion criteria.

Fig. 1

Selection process of study subjects from Korea National Health and Nutrition Examination Survey 2022. HGS, handgrip strength; BIA, bioelectrical impedance analysis.

The variables extracted for analysis included age, sex, body composition, grip strength, and health conditions such as hypertension, dyslipidemia, and diabetes. These factors were selected for their relevance to the research objectives and were carefully considered for further examination.

2. Measurement of sarcopenia

Sarcopenia was diagnosed based on the AWGS’s 2019 criteria. [5] Specifically, the determination of sarcopenia in this study was based on muscle mass and grip strength. Muscle mass was quantified using BIA, which is different from the dual energy X-ray absorptiometry (DXA) method, and is still recognized for its practicality in large population studies. For the purposes of this study, the operational thresholds for low muscle mass were set at a BIA-measured muscle mass divided by height squared (kg/m²) of less than 7.0 for men and 5.7 for women.[5] Grip strength thresholds were defined as less than 28 kg for men and 18 kg for women.[5] As part of our supplementary investigation, we investigated the prevalence rates of sarcopenia when diagnosed using only grip strength or BIA separately.

3. Data analysis

Data acquired from the KNHANES were analyzed using R-Studio statistical software. The methodological approach for group comparisons was tailored according to the type of variables involved. Categorical variables were evaluated by logistic regression analysis, whereas continuous variables were assessed using Student’s t-test to determine any significant differences between the groups. Our primary objective was to elucidate the relationships between the groups. The dataset was visualized using the ggplot2 package, which provided insightful graphical representations of the trends and patterns within our data.[22]

Descriptive statistics were used to identify the demographic and clinical characteristics of the study population. Cases with missing data were excluded from the statistical computation to ensure the integrity of the results. Significance levels were established at P-values of 0.05, 0.01, and 0.001, denoted by ^a), ^b), and ^c), respectively.

BIA muscle mass assessment was comprehensive and included measurements of the lean mass of both arms and legs. Specifically, we measured the lean masses of the right arm, left arm, right leg, and left leg.

RESULTS

Based on the data presented in Figure 2, the prevalence of sarcopenia among different age and sex groups was analyzed using grip strength and BIA measurements. In the male population, the prevalence of sarcopenia increases with age. Among men aged 60 to 64 years, sarcopenia was observed in only 1.1% of the population. However, this percentage rose steadily in older age groups, with 2.3% in the 65 to 69 age group, 5.1% in the 70 to 74 age group, 7.9% in the 75 to 79 age group, and reaching 21.5% in men aged 80 years and above. Similarly, in the female population, a trend of increasing sarcopenia with age was observed. The prevalence was 1.8% in the 60 to 64 age group and increased to 3.8% in the 65 to 69 age group, 9.2% in the 70 to 74 age group, and 14.2% in the 75 to 79 age group, peaking at 25.9% in women aged 80 years and above. The prevalence of sarcopenia in the elderly Korean population was analyzed using the following diagnostic criteria: grip strength and BIA (Fig. 2), grip strength alone (Fig. 3), and BIA alone (Fig. 4).

Fig. 2

Prevalence of sarcopenia using grip strength and bioelectrical impedance analysis. (A) Detailed age groups. (B) Consolidated age categories.

Fig. 3

Prevalence of sarcopenia using grip strength. (A) Detailed age groups. (B) Consolidated age categories.

Fig. 4

Prevalence of sarcopenia using bioelectrical impedance analysis. (A) Detailed age groups. (B) Consolidated age categories.

Figure 5 and 6, which use both grip strength and BIA, show a gradual increase in the prevalence of sarcopenia with age in both men and women. For example, the prevalence of sarcopenia in males aged 60 and older was 5.5%, rising to 21.5% in those older than 80. Similarly, in females aged 60 years and older, it was 7.9%, which increased to 25.9% in those aged >80 years.

Fig. 5

Comparison of sarcopenia prevalence in male using three criteria: bioelectrical impedance analysis (BIA), grip strength (GS), and both GS and BIA. (A) Detailed age groups. (B) Consolidated age categories.

Fig. 6

Comparison of sarcopenia prevalence in female using three criteria: bioelectrical impedance analysis (BIA), grip strength (GS), and both GS and BIA. (A) Detailed age groups. (B) Consolidated age categories.

By contrast, when grip strength was used as the sole diagnostic criterion, the prevalence of sarcopenia increased significantly across all age groups. Males 60 years and older had a prevalence of 10.9%, which increased dramatically to 34.2% among those 80 and older. A similar pattern was observed in females, where prevalence increased from 12.9% in those 60 and over to 37.6% in those 80 and older. The prevalence of sarcopenia was notably higher when BIA was used as the only diagnostic measure. For males 60 years and older, the prevalence reached 25.1%, and for those over 80, it soared to 60.8%. In females, the prevalence was 26.2% in the 60+ age group and increased to 57.6% in those aged 80 years and older.

Table 1 shows that when comparing the characteristics of patients diagnosed with sarcopenia using grip strength and BIA, significant associations were evident with certain health conditions, such as hypertension, dyslipidemia, obesity, and diabetes. There was no significant relationship between sarcopenia and hypertension (P=0.089). However, dyslipidemia was significantly associated with sarcopenia (P=0.018*). The relationship between obesity and sarcopenia, as indicated in Table 1, revealed a significant correlation (P<0.000***) with varying sarcopenia prevalence across different body mass index (BMI) categories. A higher prevalence of sarcopenia was observed in the underweight group (<18.5 kg/m²), and a higher prevalence of sarcopenia was noted. This group, representing 1.8% of the study population, accounted for 10.5% of all sarcopenia cases. For the normal weight category (18.5 kg/m² to <25.0 kg/m²), which comprised the majority of the study population (61.9%), there was a higher occurrence of sarcopenia, accounting for 79.8% of the cases. In the overweight/obese category (≥25.0 kg/m²), which made up 38.0% of the study participants, sarcopenia cases were only 9.6%. Additionally, the analysis indicated no significant relationship between the presence of sarcopenia and diabetes (P=0.854) among groups.

Table 1

Characteristics comparison of sarcopenia based on grip strength and BIA measurements

Furthermore, after conducting propensity score matching for the sarcopenia group focusing solely on sex and age adjustments, the comparison between 228 non-sarcopenic and 114 sarcopenic individuals yielded results similar to those observed prior to the application of propensity score matching (Table2).

Table 2

Characteristics comparison of sarcopenia based on grip strength and BIA measurements through propensity score matching

DISCUSSION

Using data from the KNHANES, this study sheds light on the prevalence and characteristics of sarcopenia among Koreans aged 60 years or older. Using grip strength and BIA as the diagnostic criteria, this study identified key trends and their associations with age, sex, obesity, dyslipidemia, and other health conditions. The key finding of this study was that the prevalence of sarcopenia increases with age in both male and female populations. This progression is consistent with the existing research, which emphasizes sarcopenia as an age-related condition.[2,3,5,23] Notably, individuals aged 80 and above exhibited a significant increase in prevalence, underscoring the necessity for age-specific interventions.

The study also highlighted sex differences in the impact of sarcopenia, with women exhibiting a higher prevalence, especially in the older age groups. Furthermore, when sarcopenia was classified using grip strength and BIA criteria, the prevalence in men and women in their 60s ranged from 1.1% to 3.8%; however, in women in their 70s, the prevalence ranged from 9.2% to 14.2%, compared to men at 5.1% to 7.9%, indicating a slightly higher prevalence in women. In the 80s age group, women showed a higher prevalence than men (4.4%). This disparity might be due to differences in muscle mass and strength decline, hormonal changes, and lifestyle factors between men and women, emphasizing the need for sex-specific approaches to manage and prevent sarcopenia.[24–26] In addition, there was a significant association between sarcopenia and dyslipidemia, suggesting a higher propensity for dyslipidemia among individuals with sarcopenia.[27] This adds to the body of evidence connecting sarcopenia with metabolic disorders and emphasizes the importance of lipid profile monitoring in older adults with sarcopenia.

Contrary to the traditional belief that a higher BMI protects against muscle loss, our findings demonstrate that sarcopenia is prevalent across various weight categories, including overweight and obese individuals. This indicates a complex interaction between muscle mass, fat mass, and overall body composition, challenging the conventional understanding of the impact of obesity on muscle health.

Interestingly, no significant relationship was found between sarcopenia and hypertension or diabetes, emphasizing the multifactorial nature of sarcopenia and the intricate interactions between various factors affecting muscle health.

In addition, it’s worth noting that the prevalence of sarcopenia among Koreans aged 60 and older in this study is consistent with global trends. Studies from various countries have highlighted the differing prevalence rates when examining the global incidence of sarcopenia. Research by Liu and colleagues [28] on over 4,500 elderly individuals aged above 60 years in China revealed a sarcopenia prevalence of 19.3%. Similarly, Du et al. [29] conducted a study on 2,458 seniors aged 65 and older in the United States, finding a prevalence rate of 15.51%. Reports indicate that sarcopenia affects 5% to 13% of people between the ages of 60 and 70, with a notable increase of 11% to 50% among those over the age of 80. Compared with these findings, the occurrence of sarcopenia in Korea appears to be relatively low. This variance could be attributed to several factors, including dietary habits, environmental influences, cultural differences, and genetic characteristics specific to each race.[30,31] These statistics suggest that trends in sarcopenia among Koreans are not significantly different from those in other countries.[32,33]

Several critical constraints were encountered in this study. First, the study relied on data derived from a cross-sectional survey, indicating the need for longitudinal research to comprehensively understand how sarcopenia correlates with grip strength and BIA. Additionally, making direct comparisons with findings from other studies is challenging because of variations in measurement techniques, instruments used, and demographic factors such as ethnicity, age, sex, and BMI. The adoption of uniform protocols to measure global grip strength is essential to address these discrepancies.

Despite these limitations, this study serves as a foundation for understanding the trends in sarcopenia prevalence in the elderly Korean population. This will pave the way for future research to track changes in the rate of sarcopenia among Koreans, enriching our understanding of and approach to managing this condition. Furthermore, the study’s examination of sarcopenia through various diagnostic criteria, including grip strength, smartwatches, AI cameras, and motion capture, as well as their combined use, highlights the evolving landscape of comprehensive assessments for sarcopenia diagnosis.[34–37] Variations in prevalence rates based on these criteria underscore the necessity for standardized diagnostic approaches that encompass multiple aspects of muscle health.

In conclusion, this study highlights the significant burden of sarcopenia among Koreans aged 60 or older, with a prevalence of 6.8%. The prevalence of sarcopenia increased with age, particularly in the oldest age group. These findings underscore the importance of implementing targeted interventions and strategies to prevent and manage sarcopenia among older adults. The health and quality of life of older adults in Korea can be improved by addressing and mitigating the effects of sarcopenia.

Supplementary Information

jbm-2024-31-2-150-Supplementary-Table-1.pdf

jbm-2024-31-2-150-Supplementary-Table-2.pdf

jbm-2024-31-2-150-Supplementary-Table-3.pdf

Notes

Funding

This study was supported by the National Research Foundation of Korea (NRF) grant funded by the Korean Government (MSIT) (No. 2022R1C1C1004134).

Ethics approval and consent to participate

This study was conducted in accordance with the principles of the Declaration of Helsinki, and all patients provided informed consent for the publication of the results.

Conflict of interest

No potential conflict of interest relevant to this article was reported.

References

1. Santilli V, Bernetti A, Mangone M, et al. Clinical definition of sarcopenia. Clin Cases Miner Bone Metab 2014;11:177–80.

2. Larsson L, Degens H, Li M, et al. Sarcopenia: aging-related loss of muscle mass and function. Physiol Rev 2019;99:427–511. https://doi.org/10.1152/physrev.00061.2017.

3. Cruz-Jentoft AJ, Bahat G, Bauer J, et al. Sarcopenia: revised European consensus on definition and diagnosis. Age Ageing 2019;48:601. https://doi.org/10.1093/ageing/afz046.

4. Ligibel JA, Schmitz KH, Berger NA. Sarcopenia in aging, obesity, and cancer. Transl Cancer Res 2020;9:5760–71. https://doi.org/10.21037/tcr-2019-eaoc-05.

5. Chen LK, Woo J, Assantachai P, et al. Asian working group for sarcopenia: 2019 consensus update on sarcopenia diagnosis and treatment. J Am Med Dir Assoc 2020;21:300–7.e2. https://doi.org/10.1016/j.jamda.2019.12.012.

6. Fielding RA, Vellas B, Evans WJ, et al. Sarcopenia: an undiagnosed condition in older adults. Current consensus definition: prevalence, etiology, and consequences. International working group on sarcopenia. J Am Med Dir Assoc 2011;12:249–56. https://doi.org/10.1016/j.jamda.2011.01.003.

7. Anker SD, Morley JE, von Haehling S. Welcome to the ICD-10 code for sarcopenia. J Cachexia Sarcopenia Muscle 2016;7:512–4. https://doi.org/10.1002/jcsm.12147.

8. Yoo JI, Kim JT, Park CH, et al. Diagnosis and management of sarcopenia after hip fracture surgery: current concept review. Hip Pelvis 2022;34:1–9. https://doi.org/10.5371/hp.2022.34.1.1.

9. Yuan S, Larsson SC. Epidemiology of sarcopenia: prevalence, risk factors, and consequences. Metabolism 2023;144:155533. https://doi.org/10.1016/j.metabol.2023.155533.

10. Yun J, Kim CY, Son SH, et al. Birth rate transition in the Republic of Korea: trends and prospects. J Korean Med Sci 2022;37:e304. https://doi.org/10.3346/jkms.2022.37.e304.

11. Kim KW, Kim OS. Super aging in South Korea unstoppable but Mitigatable: a sub-national scale population projection for best policy planning. Spat Demogr 2020;8:155–73. https://doi.org/10.1007/s40980-020-00061-8.

12. Baek JY, Lee E, Jung HW, et al. Geriatrics fact sheet in Korea 2021. Ann Geriatr Med Res 2021;25:65–71. https://doi.org/10.4235/agmr.21.0063.

13. Stuck AK, Basile G, Freystaetter G, et al. Predictive validity of current sarcopenia definitions (EWGSOP2, SDOC, and AWGS2) for clinical outcomes: a scoping review. J Cachexia Sarcopenia Muscle 2023;14:71–83. https://doi.org/10.1002/jcsm.13161.

14. Wu WY, Dong JJ, Huang XC, et al. AWGS2019 vs EWGSOP2 for diagnosing sarcopenia to predict long-term prognosis in Chinese patients with gastric cancer after radical gastrectomy. World J Clin Cases 2021;9:4668–80. https://doi.org/10.12998/wjcc.v9.i18.4668.

15. Kim JH, Kim DH, Park YS. Body composition, sarcopenia, and suicidal ideation in elderly Koreans: Hallym aging study. J Korean Med Sci 2016;31:604–10. https://doi.org/10.3346/jkms.2016.31.4.604.

16. Choo YJ, Chang MC. Prevalence of sarcopenia among the elderly in Korea: a meta-analysis. J Prev Med Public Health 2021;54:96–102. https://doi.org/10.3961/jpmph.21.046.

17. Yoo JI, Choi H, Ha YC. Mean hand grip strength and cut-off value for sarcopenia in Korean adults using KNHANES VI. J Korean Med Sci 2017;32:868–72. https://doi.org/10.3346/jkms.2017.32.5.868.

18. Sun S, Lee H, Yim HW, et al. The impact of sarcopenia on health-related quality of life in elderly people: Korean National Health and Nutrition Examination Survey. Korean J Intern Med 2019;34:877–84. https://doi.org/10.3904/kjim.2017.182.

19. Kim TN, Lee EJ, Hong JW, et al. Relationship between sarcopenia and albuminuria: the 2011 Korea national health and nutrition examination survey. Medicine (Baltimore) 2016;95:e2500. https://doi.org/10.1097/md.0000000000002500.

20. Oh K, Kim Y, Kweon S, et al. Korea national health and nutrition examination survey, 20th anniversary: accomplishments and future directions. Epidemiol Health 2021;43:e2021025. https://doi.org/10.4178/epih.e2021025.

21. Ministry of Health & Welfare, Korea Centers for Disease Control & Prevention. Korea health statistics 2019–2021: Korea national health and nutrition examination survey (KNHANES V-III) Sejong, KR: Korea Centers for Disease Control and Prevention; 2022.

22. Villanueva RAM, Chen ZJ. Ggplot2: elegant graphics for data analysis, 2nd edition. Meas-Interdiscip Res 2019;17:160–7. https://doi.org/10.1080/15366367.2019.1565254.

23. Delmonico MJ, Beck DT. The current understanding of sarcopenia: emerging tools and interventional possibilities. Am J Lifestyle Med 2017;11:167–81. https://doi.org/10.1177/1559827615594343.

24. Hwang J, Park S. Gender-specific risk factors and prevalence for sarcopenia among community-dwelling young-old adults. Int J Environ Res Public Health 2022;19:7232. https://doi.org/10.3390/ijerph19127232.

25. Tay L, Ding YY, Leung BP, et al. Sex-specific differences in risk factors for sarcopenia amongst community-dwelling older adults. Age (Dordr) 2015;37:121. https://doi.org/10.1007/s11357-015-9860-3.

26. Whaikid P, Piaseu N. The prevalence and factors associated with sarcopenia in Thai older adults: a systematic review and meta-analysis. Int J Nurs Sci 2024;11:31–45. https://doi.org/10.1016/j.ijnss.2023.11.002.

27. He N, Zhang Y, Zhang L, et al. Relationship between sarcopenia and cardiovascular diseases in the elderly: an overview. Front Cardiovasc Med 2021;8:743710. https://doi.org/10.3389/fcvm.2021.743710.

28. Liu X, Hao Q, Yue J, et al. Sarcopenia, obesity and sarcopenia obesity in comparison: prevalence, metabolic profile, and key differences: results from WCHAT study. J Nutr Health Aging 2020;24:429–37. https://doi.org/10.1007/s12603-020-1332-5.

29. Du K, Goates S, Arensberg MB, et al. Prevalence of sarcopenia and sarcopenic obesity vary with race/ethnicity and advancing age. Divers Equal Health Care 2018;15:175–83.

30. Lee JE, McLerran DF, Rolland B, et al. Meat intake and cause-specific mortality: a pooled analysis of Asian prospective cohort studies. Am J Clin Nutr 2013;98:1032–41. https://doi.org/10.3945/ajcn.113.062638.

31. Guthold R, Stevens GA, Riley LM, et al. Worldwide trends in insufficient physical activity from 2001 to 2016: a pooled analysis of 358 population-based surveys with 1.9 million participants. Lancet Glob Health 2018;6:e1077–e86. https://doi.org/10.1016/s2214-109x(18)30357-7.

32. El-Sebaie M, Elwakil W. Biomarkers of sarcopenia: an unmet need. Egypt Rheumatol Rehabil 2023;50:45. https://doi.org/10.1186/s43166-023-00213-w.

33. Papadopoulou SK. Sarcopenia: A contemporary health problem among older adult populations. Nutrients 2020;12:1293. https://doi.org/10.3390/nu12051293.

34. Kim S, Park S, Lee S, et al. Assessing physical abilities of sarcopenia patients using gait analysis and smart insole for development of digital biomarker. Sci Rep 2023;13:10602. https://doi.org/10.1038/s41598-023-37794-7.

35. Kim S, Kim HS, Yoo JI. Sarcopenia classification model for musculoskeletal patients using smart insole and artificial intelligence gait analysis. J Cachexia Sarcopenia Muscle 2023;14:2793–803. https://doi.org/10.1002/jcsm.13356.

36. Lee SY, Park SJ, Gim JA, et al. Correlation between Harris hip score and gait analysis through artificial intelligence pose estimation in patients after total hip arthroplasty. Asian J Surg 2023;46:5438–43. https://doi.org/10.1016/j.asjsur.2023.05.107.

37. Cao Z, Hidalgo G, Simon T, et al. OpenPose: realtime multi-person 2D pose estimation using part affinity fields. IEEE Trans Pattern Anal Mach Intell 2021;43:172–86. https://doi.org/10.1109/tpami.2019.2929257.

Article information Continued

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Table 1

Characteristics comparison of sarcopenia based on grip strength and BIA measurements

Variables	None (N=1,560)	Sarcopenia (N=114)	P-value	Method	N
Sex			0.055	Logistic regression	1,674
Male	720 (46.2)	42 (36.8)
Female	840 (53.8)	72 (63.2)

Age (yr)	69.1±6.2	75.0±5.4	0.000^c)	Student’s t-test	1,674

Height (cm)	160.8±8.4	153.3±8.0	0.000^c)	Student’s t-test	1,674

Weight (kg)	62.8±10.1	51.3±8.0	0.000^c)	Student’s t-test	1,674

Hypertension			0.089	Logistic regression	1,673
Normal	813 (52.1)	50 (43.9)
Abnormal	746 (47.9)	64 (56.1)

Dyslipidemia			0.018^a)	Logistic regression	1,673
Normal	903 (57.9)	79 (69.3)
Abnormal	656 (42.1)	35 (30.7)

Diabetes			0.854	Logistic regression	1,673
Normal	1,242 (79.7)	90 (78.9)
Abnormal	317 (20.3)	24 (21.1)

Main hand			0.268	Logistic regression	1,674
Right	1,383 (88.7)	97 (85.1)
Left	85 (5.4)	8 (7.0)
Both	92 (5.9)	9 (7.9)

1st grip strength (right)	27.1±8.2	16.9±5.0	0.000^c)	Student’s t-test	1,674

2nd grip strength (right)	28.7±8.3	17.9±5.2	0.000^c)	Student’s t-test	1,674

1st grip strength (left)	26.1±8.1	16.3±5.2	0.000^c)	Student’s t-test	1,674

2nd grip strength (left)	27.2±8.2	17.1±5.4	0.000^c)	Student’s t-test	1,674

Lean body mass	43.8±7.9	34.8±5.6	0.000^c)	Student’s t-test	1,674

Right arm muscle	2.4±0.6	1.7±0.4	0.000^c)	Student’s t-test	1,674

Left arm muscle	2.3±0.6	1.7±0.4	0.000^c)	Student’s t-test	1,674

Right leg muscle	6.6±1.4	4.9±1.1	0.000^c)	Student’s t-test	1,674

Left leg muscle	6.5±1.4	4.9±1.1	0.000^c)	Student’s t-test	1,674

Body fat mass (including head)	19.0±5.9	16.4±4.8	0.000^c)	Student’s t-test	1,674

Body fat percentage (including head)	30.2±7.2	31.7±7.1	0.032^a)	Student’s t-test	1,674

Right arm body fat mass	1.3±0.6	1.2±0.4	0.000^c)	Student’s t-test	1,674

Left arm body fat mass	1.3±0.6	1.2±0.4	0.000^c)	Student’s t-test	1,674

Torso body fat mass	9.8±3.3	8.3±2.8	0.000^c)	Student’s t-test	1,674

Right leg body fat mass	2.8±0.7	2.4±0.6	0.000^c)	Student’s t-test	1,674

Left leg body fat mass	2.7±0.7	2.4±0.6	0.000^c)	Student’s t-test	1,674

Body water	32.3±5.9	25.7±4.2	0.000^c)	Student’s t-test	1,674

Intracellular water	19.8±3.7	15.6±2.6	0.000^c)	Student’s t-test	1,674

Extracellular water	12.5±2.2	10.1±1.6	0.000^c)	Student’s t-test	1,674

Obesity (BMI)			0.000^c)	Logistic regression	1,674
<18.5 kg/m²	31 (2.0)	12 (10.5)
18.5 kg/m² ≤BMI <25.0 kg/m²	946 (60.6)	91 (79.8)
≥25.0 kg/m²	583 (37.4)	11 (9.6)

Age group			0.000^c)	Multinomial logistic regression	1,674
60–64	452 (29.0)	7 (6.1)
65–79	438 (28.1)	14 (12.3)
70–74	307 (19.7)	24 (21.1)
75–79	238 (15.3)	30 (26.3)
≥80	125 (8.0)	39 (34.2)

Grip strength			0.977	Logistic regression	1,674
Male ≥28 kg/female ≥18 kg	1,473 (94.4)	0 (0.0)
Male <28 kg/female <18 kg	87 (5.6)	114 (100.0)

BIA group			0.980	Logistic regression	1,674
0	1,244 (79.7)	0 (0.0)
1	316 (20.3)	114 (100.0)

The data is presented as mean±standard deviation or N (%).

The bioelectrical impedance analysis (BIA) group is calculated as (lean mass of right arm+lean mass of left arm+lean mass of right leg+lean mass of left leg)/(height)². If the result is less than 7 kg/m² for males or less than 5.7 kg/m² for females, the BIA group is set to 1, otherwise it's set to 0.

^a)

P<0.05,

^b)

P<0.01,

^c)

P<0.001.

BMI, body mass index.