Protein Intake Recommendation for Korean Older Adults to Prevent Sarcopenia: Expert Consensus by the Korean Geriatric Society and the Korean Nutrition Society

Gene-Lifestyle Interactions in Renal Dysfunction: Polygenic Risk Modulation via Plant-Based Diets, Coffee Intake, and Bioactive Compound Interactions

Background: This study aimed to investigate genetic variants associated with the estimated glomerular filtration rate (eGFR) and their interactions with lifestyle factors and bioactive compounds in large hospital-based cohorts, assessing their impact on renal dysfunction risk. Methods: Participants were categorized into two groups based on eGFR: High-GFR (control; n = 51,084) and Low-GFR (renal dysfunction; n = 7617), using an eGFR threshold of 60 mL/min/1.73 m2. Genetic variants were identified through a genome-wide association analysis, and their interactions with lifestyle factors were assessed a using generalized multifactor dimensionality reduction (GMDR) analysis. Additionally, interactions between polygenic risk scores (PRS) and nutrient intake were examined. Results: Low eGFR was associated with higher urinary protein levels (4.67-fold) and correlated with a Western-style diet and with saturated fat, arginine, and isoleucine intakes but not sodium intake. The genetic model for low eGFR included variants linked to energy production and amino acid metabolism, such as rs1047891_CPS1, rs3770636_LRP2, rs5020545_SHROOM3, rs3812036_SLC34A1, and rs4715517_HCRTR2. A high PRS was associated with a 1.78-fold increased risk of low eGFR after adjusting for sociodemographic and lifestyle factors. The PRS from the 6-SNP model interacted with plant-based diets (PBDs) and coffee intake, where individuals with higher PBD and coffee consumption had a lower risk of renal dysfunction. Additionally, CPS1 rs1047891 interacted with vitamin D intake (p = 0.0436), where the risk allele was linked to lower eGFR with low vitamin D intake but not with high intake. Molecular docking showed that vitamin D3 had a lower binding energy to the CPS1 mutant type (-9.9 kcal/mol) than the wild type (-7.5 kcal/mol), supporting a potential gene-nutrient interaction influencing renal function. Conclusions: Middle-aged and elderly individuals with a high genetic risk for renal dysfunction may benefit from a plant-based diet, moderate coffee consumption, and sufficient vitamin D intake.

Association of Protein Intake with Sarcopenia and Related Indicators Among Korean Older Adults: A Systematic Review and Meta-Analysis

OBJECTIVES

Due to variations in the standards for optimal protein intake and conflicting results across studies for Korean older adults, this study aimed to quantitatively integrate existing research on the association of protein intake with sarcopenia and related indicators in Koreans aged 65 and older through meta-analysis.

METHODS

A total of 23 studies were selected according to the study selection criteria (PICOS). Sixteen cross-sectional studies, 5 randomized controlled trials (RCTs), and 2 non-RCTs were included in the review, with 9 out of 23 studies included in the meta-analysis. We used fixed-effects models and performed subgroup and sensitivity analyses.

RESULTS

A meta-analysis found that the risk of sarcopenia was significantly higher in the <0.8 g/kg/day protein intake group compared to the 0.8-1.2 g/kg/day and ≥1.2 g/kg/day groups, with odds ratios (ORs) of 1.25 (95% confidence interval (CI), 1.10 to 1.42; I2 = 55%) and 1.79 (95% CI, 1.53 to 2.10; I2 = 71%), respectively. For low hand grip strength (HGS), the risk was higher in the <0.8 g/kg/day group compared to the 0.8-1.2 g/kg/day or ≥1.2 g/kg/day groups (OR 1.31; 95% CI, 1.03 to 1.65; I2 = 28%). No significant associations were found with other sarcopenia indicators, such as skeletal muscle mass, short physical performance battery score, balance test, gait speed, and timed up-and-go test.

CONCLUSIONS

Lower protein intake is associated with a higher risk of sarcopenia and low HGS in Korean older adults. To establish protein intake recommendations for the prevention and management of sarcopenia in this population, further well-designed RCTs incorporating both protein supplementation and resistance training are necessary.

Dietary Intake, Menopausal Symptoms, and Body Composition Associated with Possible Sarcopenia Among Vietnamese Middle-Aged Women: A Cross-Sectional Study

Background: This study aims to investigate the prevalence of possible sarcopenia and its associated factors among middle-aged Vietnamese women. Methods: A cross-sectional study was conducted on 205 women aged 40-55 years who were admitted to the Can Tho Obstetrics and Gynecology Hospital between February and December 2023. The presence of possible sarcopenia was determined according to the AWGS 2019 criteria. Associated factors were dietary intake (total energy, protein, lipid, and carbohydrate intake), the severity of menopausal symptoms by using the Kupperman index, and body composition by using the bioelectrical impedance analysis device, Inbody S10. Logistic regressions were built to analyze the association between possible sarcopenia and its associated factors. Results: The prevalence of possible sarcopenia was 29.8%, with a mean age of 47.2. Possible sarcopenia was detected in 23% of the participants based on the criterion of low handgrip strength, whereas 83.6% of the participants when considered low performance in the chair stand test. Adjusted logistic regression analysis showed that living in a rural area (adjusted odds ratio [AOR]: 2.16, 95% confidence interval [95% CI]: 1.22-4.72), energy intake <25 kcal/body weight, (AOR: 1.94, 95% CI: 1.75-5.06), protein intake <0.91 g/body weight (AOR: 2.42, 95% CI: 1.51-5.76), skipping breakfast (AOR: 2.03, 95% CI: 0.91-4.54), mild menopausal symptoms (AOR: 2.68, 95% CI: 1.61-5.36), and obesity (AOR: 1.59, 95% CI: 1.29-3.67) were significantly associated with higher risk of possible sarcopenia. Conversely, higher muscle mass and higher upper limb mass were associated with a decreased risk of possible sarcopenia (total muscle mass AOR: 0.20, 95% CI: 0.07-0.59). Conclusions: These findings would provide a basis for enhancing management and prevention strategies to reduce the risk of sarcopenia in Vietnam. In particular, attention to nutrient intake and the management of menopausal symptoms may reduce the risk of sarcopenia.

Usefulness of the mini nutritional assessment short-form for evaluating nutritional status in patients with nontuberculous mycobacterial pulmonary disease: a prospective cross-sectional study

BACKGROUND

Although the Mini Nutritional Assessment (MNA) is recognized as a useful tool for evaluating nutritional status in patients with various diseases, its applicability in patients with nontuberculous mycobacterial pulmonary disease (NTM-PD) remains undetermined.

METHODS

We designed a prospective cross-sectional study to investigate whether the MNA Short-Form (MNA-SF) score can serve as a screening tool to assess the nutritional status of patients with NTM-PD. The MNA-SF was conducted upon patient enrollment, and correlation analyses were performed to compare MNA-SF scores with other nutritional measurements and disease severity. Multivariable logistic regression analyses were conducted to evaluate the association between MNA-SF scores and NTM-PD severity.

RESULTS

The 194 patients with NTM-PD included in the analysis had a median age of 65.0 (59.0-69.0) years; 59.3% (n = 115) had low MNA-SF scores (< 12). The low MNA-SF group exhibited a lower body mass index (19.7 vs. 22.4 kg/m2, p < 0.001) and fat-free mass index (14.7 vs. 15.6 kg/m2, p < 0.001) than the normal MNA-SF group, as well as higher incidences of sarcopenia (20.0% vs. 6.3%, p = 0.008) and adipopenia (35.7% vs. 5.1%, p < 0.001). However, no significant differences in calorie and protein intakes were observed between the two groups. Low MNA-SF scores were associated with radiographic severity (adjusted odds ratio 2.72, 95% confidence interval 1.38-5.36) but not with forced vital capacity.

CONCLUSIONS

The MNA-SF can effectively assess the nutritional status of patients with NTM-PD and can serve as an important clinical indicator in NTM-PD where treatment timing is determined by clinical judgment.

Start with muscle mass or muscle strength in diagnosis and management of sarcopenia? A systematic review of guidance documents

BACKGROUND AND OBJECTIVES

Sarcopenia has garnered extensive attention in clinical practice since its high prevalence and significant impact on clinical outcomes. Multiple organizations have published guidance documents on sarcopenia, offering evidence-based recommendations for clinical practice and/or research. We aimed to appraise the methodological quality of the included documents and synthesize available recommendations for the screening, diagnosis, and intervention of sarcopenia.

METHODS AND STUDY DESIGN

We conducted a search on PubMed, Embase, Scopus, Cochrane Library, China National Knowledge Infrastructure, guideline database, and guideline organizations and professional societies websites for clinical practices, consensus statements and position papers in terms of sarcopenia, muscle atrophy or muscle loss published before April 17, 2023. The AGREE II instrument was used by three independent reviewers to assess the methodological quality of these documents.

RESULTS

Thirty-six guidance documents published between 2010 and 2023 were included. Seven documents fulfilled ≥ 50% of all the AGREE II domains. Seven underwent a Delphi process and six graded the strength of the recommendations. The process of screening (n=21), early diagnosis of sarcopenia (n=12), diagnosis of sarcopenia and severe sarcopenia (n=10), and management (n=21) were increasingly recommended. SARC-F (n=14) was the most recommended screening tool, and the assessment of muscle function was considered the first step in diagnosing sarcopenia. The management strategy for both age-related and disease-related sarcopenia mainly focused on exercise and nutrition intervention.

CONCLUSIONS

The guidance documents have provided referential recommendations that have great guiding significance. But the inconsistency in recommendations and variation in methodological rigour suggests that high-quality evidence is lacking yet.

Potential nutritional strategies to prevent and reverse sarcopenia in aging process: Role of fish oil-derived ω-3 polyunsaturated fatty acids, wheat oligopeptide and their combined intervention

INTRODUCTION

Nutritional support is potentially considered an essential step to prevent muscle loss and enhance physical function in older adults.

OBJECTIVES

This study aimed to assess the role of potential nutritional strategies, i.e., fish oil-derived ω-3 polyunsaturated fatty acids (PUFAs), wheat oligopeptide and their combined intervention, in preventing and reversing sarcopenia in aging process.

METHODS

One hundred 25-month-old Sprague-Dawley rats were randomly divided into 10 groups, and 10 newly purchased 6-month-old rats were included in young control group (n = 10). Fish oil (200, 400 or 800 mg/kg body weight), wheat oligopeptide (100, 200 or 400 mg/kg body weight), fish oil + wheat oligopeptide (800 + 100, 400 + 200 or 200 + 400 mg/kg body weight) or the equal volume of solvent were administered daily by gavage for 10 weeks. The effects of these interventions on natural aging rats were evaluated.

RESULTS

All intervention groups had a significant increase in muscle mass and grip strength and reduction in perirenal fat weight when compared to the aged control group (P < 0.05). The results of biochemical parameters, magnetic resonance imaging, proteomics and western blot suggested that the combination of wheat oligopeptide and fish oil-derived ω-3 PUFA, especially group WFM 2 (400 + 200 mg/kg body weight fish oil + wheat oligopeptide), was found to be more effective against aging-associated muscle loss than single intervention. Additionally, the interventions ameliorated fatty infiltration, muscle atrophy, and congestion in the intercellular matrix, and inflammatory cell infiltration in muscle tissue. The interventions also improved oxidative stress, anabolism, hormone levels, and inflammatory levels of skeletal muscle.

CONCLUSIONS

The combination of fish oil-derived ω-3 PUFA and wheat oligopeptide was found to be a promising nutritional support to prevent and reverse sarcopenia. The potential mechanism involved the promotion of protein synthesis and muscle regeneration, as well as the enhancement of muscle strength.

Sarcopenia as the Mobility Phenotype of Aging: Clinical Implications

Sarcopenia, which is characterized by an age-related decline in muscle mass and function, poses significant challenges to geriatric care. Its definition has evolved from muscle-specific criteria to include muscle mass, muscle function, and physical performance, recognizing sarcopenia as a physical frailty. Sarcopenia is associated with adverse outcomes, including mortality, falls, fractures, cognitive decline, and admission to long-term care facilities. Neuromechanical factors, protein-energy balance, and muscle protein synthesis-breakdown mechanisms contribute to its pathophysiology. The identification of sarcopenia involves screening tests and a comprehensive assessment of muscle mass, strength, and physical function. Clinical approaches aligned with the principles of comprehensive geriatric assessment prioritize patient-centered care. This assessment aids in identifying issues related to activities of daily living, cognition, mood, nutrition, and social support, alongside other aspects. The general approach to factors underlying muscle loss and functional decline in patients with sarcopenia includes managing chronic diseases and evaluating administered medications, with interventions including exercise and nutrition, as well as evolving pharmacological options. Ongoing research targeting pathways, such as myostatin-activin and exercise mimetics, holds promise for pharmacological interventions. In summary, sarcopenia requires a multifaceted approach, acknowledging its complex etiology and tailoring interventions to individual patient needs.

The role of nutraceuticals in heart failure muscle wasting as a result of inflammatory activity. The International Lipid Expert Panel (ILEP) Position Paper

Muscle wasting is one of the main causes for exercise intolerance and ventilatory inefficiency in patients with heart failure and a strong predictor of frailty and reduced survival. The prevalence of sarcopenia is at least 20% in patients with heart failure. Patients with heart failure often have subclinical systemic inflammation, which may exert sustained effects on skeletal muscle. Besides exercise, nutrition should also be carefully evaluated as an appropriate diet with selected nutraceuticals may be able to stimulate muscle anabolism and inhibit muscle catabolism. This review summarizes the epidemiological and clinical trial evidence supporting the recommendations for the use of nutraceuticals with anti-inflammatory properties in heart failure and provides an overview of the state of the evidence for nutraceutical supplementation to prevent and/or mitigate heart failure muscle wasting.

Relationship between protein intake and grip strength in qualitative and quantitative aspects among the elderly in Korea: results from the Korea National Health and Nutrition Examination Survey

BACKGROUND

This study investigated the association between quantitative and qualitative protein intake and grip strength (GS) in the South Korean population to explore nutritional management for the prevention of sarcopenia.

METHODS

This cross-sectional study was based on data from a nationally representative sample of the South Korean elderly population, consisting of 1,531 men and 1,983 women aged 65 years and older who participated in the Korean National Health and Nutrition Examination Survey from 2016 to 2019. Low GS was defined as GS < 28 kg in men and GS < 18 kg in women. Protein intake was assessed using 1-day 24-h recall, and we analyzed absolute protein intake, protein intake by food source, and protein intake compared to dietary reference intake with per body weight or absolute daily recommended value.

RESULTS

The total and animal protein intake and protein intake from legumes, fish and shellfish were significantly lower in women with a low GS than in those with a normal GS. After adjusting for confounding factors, women who consumed more protein than the estimated average requirement (EAR, 40 g/day for women) were 0.528 times less likely to have low GS than women consuming less protein than the EAR (95% CI: 0.373-0.749), and consuming any amount of protein from legumes were 0.656 times less likely (95% CI: 0.500-0.860) to have low GS than women who did not consume any amount of legume protein.

CONCLUSIONS

This study provides epidemiological evidence that adequate protein intake above EAR and protein intake from legumes should be guided for preventing low GS, especially in elderly women.

Management of Sarcopenia in Primary Care Settings

With aging, loss of skeletal muscle mass and muscle function increases, resulting in an increased risk of falls, fractures, long-term institutional care, cardiovascular and metabolic diseases, and even death. Sarcopenia, which is derived from the Greek words "sarx" or flesh+"penia" or loss, is defined as a condition characterized by low muscle mass and low muscle strength and performance. In 2019, the Asian Working Group for Sarcopenia (AWGS) published a consensus paper on the diagnosis and treatment of sarcopenia. The AWGS 2019 guideline, specifically, presented strategies for case-finding and assessment to help diagnose "possible sarcopenia" in primary care settings. For case finding, the AWGS 2019 guideline proposed an algorithm that recommends calf circumference measurement (cut-off <34 cm in men, <33 cm in women) or the SARC-F (strength, assistance with walking, rising from a chair, climbing stairs, and falls) questionnaire (cut-off ≥4). If this case finding is confirmed, handgrip strength (cutoff <28 kg in men, <18 kg in women) or the 5-time chair stand test (≥12 seconds) should be performed to diagnose "possible sarcopenia." If an individual is diagnosed as "possible sarcopenia," AWGS 2019 recommends that the individual should start lifestyle interventions and related health education for primary healthcare users. Because no medication is available to treat sarcopenia, exercise and nutrition is essential for sarcopenia management. Many guidelines, recommend physical activity, with a focus on progressive resistance (strength) training, as a first-line therapy for the management of sarcopenia. It is essential to educate older adults with sarcopenia on the need to increase protein intake. Many guidelines recommended that older people should consume at least 1.2 g of proteins/kg/d. This minimum threshold can be increased in the presence of catabolic or muscle wasting. Previous studies reported that leucine, a branched-chain amino acid, is essential for protein synthesis in muscle, and a stimulator for skeletal muscle synthesis. A guideline conditionally recommends that diet or nutritional supplements should be combined with exercise intervention for older adults with sarcopenia.

Factors Affecting the Quality of Life in Low-Income Older Adults with Sarcopenia: A Cross-Sectional Study

PURPOSE

This study aimed to identify the factors influencing quality of life (QoL) of low-income older adults (LOAs) with sarcopenia.

METHODS

A convenience sample of 125 older adults was recruited from Jeonbuk Province, South Korea. Data were collected using a self-report questionnaire that included nutritional status, the Depression Anxiety Stress Scale-21, and the World Health Organization Quality of Life Instrument-Older Adults Module. Additionally, grip strength and appendicular skeletal muscle mass, were evaluated, along with the short physical performance battery.

RESULTS

Sarcopenia and severe sarcopenia were observed in 43.2% and 56.8% of participants, respectively. Using multiple regression analysis, depression (β = -.40, p < .001), nutritional status (β = .24, p = .003), and anxiety (β = -.15, p = .042) were identified as factors affecting the QoL of the older adults in low-income groups with sarcopenia, the explanatory power of these variables was 44%.

CONCLUSION

The results of this study can be used to develop a nursing intervention program and establish policies to improve depression, anxiety, and nutritional status to enhance QoL of LOAs with sarcopenia.

Effects of Whey Protein, Leucine, and Vitamin D Supplementation in Patients with Sarcopenia: A Systematic Review and Meta-Analysis

(1) Background: In this study, a meta-analysis was performed to investigate the effects of whey protein, leucine, and vitamin D in sarcopenia; (2) Methods: We searched PubMed, Cochrane Library, Embase, and Scopus databases and retrieved studies published until 5 December 2022. Randomized controlled trials were included to evaluate muscle mass, strength, and function, after using whey protein, leucine, and vitamin D supplementation in patients with sarcopenia; (3) Results: A total of three studies including 637 patients reported the effectiveness of using whey protein, leucine, and vitamin D supplementation in patients with sarcopenia. Without considering whether or not a physical exercise program was combined with nutritional supplementation, no significant differences in grip strength or short physical performance battery (SPPB) scores between the experimental and control groups were noted. However, appendicular muscle mass significantly improved in the experimental group compared to the control group. The results were analyzed according to the presence or absence of a concomitant physical exercise program. With the use of a concomitant physical exercise program, handgrip strength and SPPB scores in the experimental group significantly improved when compared to the control group. In contrast, when physical exercise was not combined, there was no significant improvement in the handgrip strength and SPPB scores of patients with sarcopenia. In addition, the appendicular muscle mass significantly increased regardless of the presence of a concomitant physical exercise program; (4) Conclusions: Whey protein, leucine, and vitamin D supplementation can increase appendicular muscle mass in patients with sarcopenia. In addition, combining a physical exercise program with whey protein, leucine, and vitamin D supplementation can improve muscle strength and function.

The Inverse Association of Sarcopenia and Protein-Source Food and Vegetable Intakes in the Korean Elderly: The Korean Frailty and Aging Cohort Study

The aging population contributes to increasing economic and social burden worldwide. Sarcopenia, an age-related degenerative disease and progressive disorder, is characterized by a reduction in skeletal muscle mass and function. This study aims to assess the association between dietary factors and sarcopenia in the Korean elderly using nationwide data. A total of 801 subjects aged 70–84 years were included in this analysis. Subjects were divided into two groups: sarcopenic and nonsarcopenic groups according to the sarcopenia criteria established by the Asian Working Group for Sarcopenia. Nutrient and food intakes were assessed using a 24-h recall method. Logistic regression analysis was used to assess the association between sarcopenia and food group and nutrient intakes. In the multivariable models, the meat/fish/egg/legume food group, vegetable group, and total food intake were inversely associated with the prevalence of sarcopenia. The high intakes of energy, carbohydrate, protein, fiber, zinc, carotene, and vitamin B₆ were associated with the lower prevalence of sarcopenia. Therefore, consuming sufficient nutrients through various protein source foods and vegetables will help prevent sarcopenia in the Korean elderly.

Comparison of intradialytic neuromuscular electrical stimulation and oral nutritional supplements in hemodialysis patients: study protocol for a multicenter, parallel-group, randomized controlled trial in Korea

Background

The prevalence of sarcopenia increases as renal function decreases, and a considerable number of hemodialysis (HD) patients have sarcopenia. Exercise and nutritional support are established interventions to prevent and treat sarcopenia. Recently, many studies evaluating intradialytic neuromuscular electrical stimulation (NMES) showed improvement of muscular strength and mass, functional capacity, and quality of life (QOL). However, there has been no research about the effect of simultaneous nutritional support and NMES in HD patients.

Methods

This is a 12-week, randomized controlled, parallel-group, multicenter trial of intradialytic NMES and protein supplementation for HD patients. Seventy-two patients receiving HD will be randomly assigned in a 1:1:1:1 ratio to control, intradialytic NMES only, protein supplementation only, and intradialytic NMES combined with protein supplementation groups. NMES will be delivered to a total of four areas of the bilateral vastus medialis and vastus lateralis using a 4-channel NMES instrument. A total of 25 g of protein supplements will be provided at the beginning of every dialysis session or after the NMES. The primary endpoint is the difference of hand grip and leg muscle strength at 12 weeks among 4 treatment groups. Secondary endpoints include muscle mass, physical performances, and questionnaires about QOL and physical activity.

Discussion

In this study, we will evaluate the differential effectiveness of nutritional support and NMES during HD on muscle strength, muscle mass, physical function, and QOL. We expect that this study can provide guidelines for a new therapeutic option for HD patients who are unable or hesitant to exercise. Furthermore, this option can offer an opportunity to improve the physical function, QOL, and prognosis of HD patients.

Trial registration

Clinical Research Information Service (CRIS), Korea, KCT0005573. Retrospectively registered on 03 November 2020

Association between dairy protein and body composition in middle-aged and older women: A community-based, 12-year, prospective cohort study

BACKGROUND & AIMS

Changes in body composition during aging include decreased muscle mass and increased fat mass. Women with low muscle mass with abdominal obesity (LMAO), in particular, could be at higher risk of morbidities and mortality than those with either sarcopenia or obesity alone. Dairy products, which contain whey protein and all essential amino acids, could have a beneficial role in preserving muscle mass and reducing obesity. We aimed to analyze the association between dairy protein and the development of LMAO in women using a large-scale, community-based prospective cohort.

METHODS

Our analysis included 4251 women from the Korean Genome and Epidemiology Study. Participants were categorized into three groups by the tertile of dairy protein intake, which was assessed using a semi-quantitative 103-food item food frequency questionnaire. Appendicular skeletal muscle mass was estimated using the anthropometric equation. Low muscle mass (LM) was defined as a muscle mass of less than 15 kg in women. Abdominal obesity (AO) was defined as a weight to height ratio of 0.58 or greater. LMAO was defined as LM in combination with AO. Multiple Cox hazard regression analysis was conducted to examine associations between dairy protein intake and incident LMAO.

RESULTS

During follow-up (mean, 9.6 years), 280 women newly developed LMAO. According to Cox proportional regression models, the hazard ratios (95% confidence interval) for incident LMAO in the middle and highest tertiles were 0.89 (0.74-1.06) and 0.71 (0.59-0.86), compared with lowest tertile, after adjusting for confounding variables.

CONCLUSIONS

These findings indicate that high dairy protein intake is inversely related with LMAO development in Korean women. Dairy protein intake could be effective in preventing incident LMAO.

Steady exercise improves hand grip and leg muscle strength in hemodialysis patients

Sarcopenia due to chronic inflammation and biochemical disturbances in chronic kidney disease is severer and more prevalent in hemodialysis (HD) patients. We longitudinally evaluated the hand grip strength (HGS) and leg muscle strength (LMS) and evaluated the role of exercise in muscle strength in HD patients. We screened (January, n=127) and followed up (June, n=110 and December 2020, n=104). HGS and LMS at single center by using digital hand and leg dynamometer. HGS (24.2 kg vs. 15.5 kg) and LMS (32.8 kg vs. 22.5 kg) were better in men (P<0.001 and P<0.001, respectively). Older patients (≥60 years) showed decreased LMS than others in women (P=0.01). Patients who performed steady home- or hospital-based exercise showed marginally higher HGS (23.1 kg vs. 19.8 kg, P=0.07) and significantly higher LMS (33.7 kg vs. 25.9 kg, P=0.004). Steady exercise improved LMS throughout the study period (30.3 kg vs. 33.2 kg from Jan to Jun 2020, P=0.004; 30.3 kg vs. 34.2 kg from Jan to Dec 2020, P=0.014). Multiple linear regression analysis proved steady exercise was independently associated with better HGS and LMS. Steady exercise showed greater impact on LMS in male patients with longer HD vintage (≥44 months) and on HGS in younger male patients with shorter HD vintage (<44 months). Steady exercise was an important determinant of muscle strength in HD patients. We need to encourage patients to steadily perform regular home- or group-exercise before sarcopenia develops.

Using Dietary Macronutrient Patterns to Predict Sarcopenic Obesity in Older Adults: A Representative Korean Nationwide Population-Based Study

Older adults with sarcopenic obesity (SO) are at increased risk of adverse health outcomes. It has not been identified which pattern of macronutrient intake is appropriate in relation to SO. We aimed to compare the patterns of macronutrient intake for predicting SO in older adults. Data from a total of 3828 older adults who participated in the 2008–2011 Korea National Health and Nutrition Examination Survey were analyzed. The one-day 24 h dietary recall method was used to assess macronutrient intake. SO was defined by a combination of body mass index (BMI) ≥ 25 kg/m² and BMI adjusted-appendicular skeletal muscle mass <0.789 for men and <0.512 for women. Weighted logistic regression analysis revealed the odds ratio (95% confidence interval) for SO of total calorie intake per 100 increments and carbohydrate (CHO) intake (g/kg/day) per 1 increment to be 0.95 (0.91–0.99) and 0.83 (0.74–0.94), respectively, after adjusting for confounding variables in women. The predictive power for SO of CHO intake (g/kg/day) was higher compared with the other patterns of macronutrient intake both in men and women. In conclusion, total calorie intake and CHO intake (g/kg/day) are inversely related to SO in women. CHO intake (g/kg/day) could be the best index for determining SO.

Long-term effect of a 24-week multicomponent intervention on physical performance and frailty in community-dwelling older adults

Introduction

Multicomponent interventions improve physical function and frailty in older adults, but their long-term benefit remains uncertain.

Methods

This prospective non-randomised study was conducted in 383 older Koreans (mean age, 76.8 years; female 72.3%) who were living alone or receiving medical aid. Of these, 187 individuals chose to receive a 24-week intervention that consisted of group exercise, nutritional supplements, depression management, deprescribing and home hazard reduction. The remaining 196 individuals received usual care. We compared the short physical performance battery (SPPB) score (0–12 points), frailty phenotype scale (0–5 points) and deficit-accumulation frailty index (0–1) at baseline, 6, 18 and 30 months.

Results

After 1:1 propensity score matching (n = 117 per group), the mean SPPB scores for the intervention and comparison groups were 7.6 versus 7.6 at baseline, 10.7 versus 7.1 at 6 months (mean difference, 3.5; 95% confidence interval [CI], 2.8–4.2), 9.1 versus 7.8 at 18 months (1.3; 95% CI, 0.6–2.0) and 8.6 versus 7.5 at 30 months (1.1; 95% CI, 0.4–1.8). The intervention group had lower frailty phenotype scale (1.1 versus 1.8; difference, −0.7; 95% CI −1.0 to −0.3) and frailty index (0.22 versus 0.27; difference, −0.04; −0.06 to −0.02) at 6 months, but similar scores at 18 and 30 months. The 30-month mean institutionalisation-free survival time was 28.5 months in the intervention group versus 23.3 months in the comparison group (difference, 5.2 months; 95% CI, 3.1–7.4).

Conclusions

The 24-week multicomponent intervention showed sustained improvement in physical function, temporary reduction in frailty and longer institutionalisation-free survival over 30 months.

Status of Constipation and Its Association with Sarcopenia in Older Adults: A Population-Based Cohort Study

(1) Background: As the clinical relevance of constipation and sarcopenia is not well studied, we aimed to investigate the association between them in older adults. (2) Methods: A cross-sectional study was conducted on 1278 community-dwelling older adults in South Korea. The Rome IV criteria were used to identify patients with clinically defined constipation, while sarcopenia was defined by the Asian Working Group for Sarcopenia consensus. The cohort was classified into three groups: no constipation, self-reported constipation only, and clinically defined constipation. (3) Results: The presence of constipation was associated with sarcopenia and slow gait speed (p < 0.001). After adjustment for possible covariates, the association with sarcopenia attenuated, while that for slow gait speed persisted. In terms of geriatric parameters, both groups with clinically defined and self-reported constipation had a higher burden of cognitive impairment, IADL disability, and lower QOL scores (p < 0.05) compared with those without constipation. (4) Conclusions: Sarcopenia and slow gait speed associated with constipation in community-dwelling older adults. Individuals with self-reported constipation symptoms alone showed comparable sarcopenic and geriatric burden to those with clinically defined constipation. Clinical suspicion for possible co-existing sarcopenia is warranted in older patients with constipation.

The Aging Study of Pyeongchang Rural Area (ASPRA): Findings and Perspectives for Human Aging, Frailty, and Disability

The Aging Study of Pyeongchang Rural Area (ASPRA) is a population-based, prospective cohort study of older adults in Pyeongchang, South Korea. Since the initial enrollment of 382 participants, the ASPRA has been maintained and has conducted comprehensive geriatric assessments annually, gradually expanding its population and coverage area. As a cohort study of aging-related conditions and their functional consequences, the ASPRA leveraged Pyeongchang's relatively low annual population movement rate and its healthcare delivery system, which was largely maintained by community health posts. Since its establishment, the ASPRA has reported numerous observational and multicomponent intervention studies on functional decline, geriatric syndrome, and frailty. Here, we discuss the findings and perspectives of ASPRA studies. We hope that the ASPRA enables the further implementation of a longitudinal study design on geriatric parameters and the development of public health strategies targeting aging-related conditions, especially in resource-limited community settings.

Hand Grip and Leg Muscle Strength in Hemodialysis Patients and Its Determinants

BACKGROUND

Chronic kidney disease is associated with chronic inflammation and progressive loss of peripheral muscle strength and the ability to exercise, and these changes are highly pronounced in patients receiving hemodialysis (HD). We evaluated hand grip strength (HGS) and leg muscle strength (LMS) in patients receiving HD and attempted to identify factors associated with muscle strength.

METHODS

We screened HGS (opposite the fistula side) and LMS (both sides) in HD patients at a single center (n = 112) by using digital hand and leg dynamometers (T.K.K. 5401 and 5710e/5715, Takei Scientific Instruments Co. Ltd., Niigata, Japan).

RESULTS

The mean age of patients was 62.6 years, and 73.2% of the patients were male. Diabetes was the cause of kidney failure in 50% of the patients, and the median HD vintage was 34 months. A total of 77.7% of patients reported that they participated in regular home-based exercise, and 29.5% of patients regularly participated in hospital-based resistance exercise. HGS and LMS showed good correlation (r = 0.715, P < 0.001). HGS (25.1 vs. 17.0 kg) and LMS (30.1 vs. 20.4 kg) were greater in males (P < 0.001 and P < 0.001, respectively) than in females. Older patients (≥ 60 years) showed less LMS than younger patients in both males and females (P = 0.012 and P = 0.037, respectively), but HGS did not differ according to age. Patients performing regular home- or hospital-based exercise showed higher HGS than those who did not exercise (24.2 vs. 18.6 kg, P = 0.011), but LMS was not significantly different (29.3 vs. 23.6 kg, P = 0.185). Multiple linear regression analysis proved that male sex, younger age, and any type of exercise were factors associated with improved HGS and LMS. Groups of older age (≥ 60 years), male sex, and shorter duration of HD (< median) benefitted more from exercise.

CONCLUSION

Sex, age, and exercise were the most important determinants of muscle strength in HD patients. We need to encourage patients to engage in regular home or group exercise from the beginning of dialysis and introduce new feasible forms of exercise for HD patients.

Understanding Muscle Protein Dynamics: Technical Considerations for Advancing Sarcopenia Research

Sarcopenia, which is the loss of muscle mass and strength that occurs with aging, involves imbalanced muscle protein turnover (i.e., protein breakdown exceeding synthesis), which in turn exacerbates other clinical conditions such as type 2 diabetes mellitus, obesity, osteoporosis, and cancer, thereby worsening the quality of life in older adults. This imbalance is attributed in part to the resistance of aged muscle to anabolic stimuli such as dietary protein/amino acids and resistance exercise known as anabolic resistance. Despite research efforts, no practical therapeutics have been successfully discovered possibly because of a lack of understanding of the dynamic nature of muscle protein, and the use of indirect assessments of muscle mass. Herein, we briefly discuss the regulation of protein turnover in response to the abovementioned anabolic stimuli with respect to anabolic resistance and optimal protein intake, followed by methodological considerations for advancing sarcopenia research, including assessments of muscle mass and dynamics.

Different Associations of Socioeconomic Status on Protein Intake in the Korean Elderly Population: A Cross-Sectional Analysis of the Korea National Health and Nutrition Examination Survey

Socioeconomic status affects food choices. This study examined the relationships between socioeconomic status (SES) and animal and plant protein intake in the Korean elderly population whose protein intake is insufficient. We used cross-sectional data from 3512 Koreans aged 60 years or older, who had participated in the Nutrition Survey of the 2013-14 Korea National Health and Nutrition Examination Survey (KNHANES). One day 24-h recall data was used to estimate the daily total, animal, and plant protein intake. Household income and educational attainment were assessed by trained interviewers. After making adjustment, household income was positively associated with animal protein intake with a statistical significance in females (p = 0.030) and with a marginal significance in males (p = 0.069). However, plant protein intake did not show any significant association. In both sexes, educational attainment was positively associated with animal protein intake (p = 0.007 for males, p = 0.001 for females). Association of educational attainment with plant protein intake was negative in males (p = 0.037) and non-significant in females. (p = 0.945). High SES was associated with higher total protein intake and animal protein intake in the Korean elderly. Health policies and nutrition education are needed to improve protein intake of the vulnerable Korean elderly with low SES.

Protein intake per day and at each daily meal and skeletal muscle mass declines among older community dwellers in Japan

Objective:

To examine associations between protein intake per day and at different meals and skeletal muscle mass declines.

Design:

Two-year prospective cohort study among older community dwellers.

Setting:

National Institute for Longevity Sciences–Longitudinal Study of Aging (NILS-LSA) in Japan.

Participants:

Older men (n 292) and women (n 363) aged 60–87 years who participated in the baseline (2006–2008) and follow-up studies (2008–2010) of NILS-LSA and did not exhibit low skeletal muscle mass at baseline. Muscle mass was assessed using dual-energy X-ray absorptiometry at baseline and follow-up. Low muscle mass was defined as skeletal muscle mass index <7·0 kg/m2 for men and <5·4 kg/m2 for women at follow-up. Daily protein intake and protein intake at each meal were calculated from 3 d dietary records at baseline and sex-stratified tertiles were determined.

Results:

Mean (sd) protein intake at breakfast, lunch and dinner was 22·7 (7·8), 26·7 (9·3) and 37·4 (10·5) g for men and 19·3 (6·3), 23·2 (7·3) and 28·5 (7·0) g for women, respectively. After adjusting for age, baseline skeletal muscle mass and other confounders in logistic modelling, greater total protein intake was associated with lower prevalence of skeletal muscle mass decline among men at follow-up (P = 0·024). Particularly, the OR (95 % CI) for high lunchtime protein intake was low (0·11 (0·02, 0·61); P = 0·01). No significant association between total protein intake and prevalence of skeletal muscle mass decline was found among women.

Conclusions:

High total protein intake, particularly at lunchtime, is associated with retention of skeletal muscle mass in men.