Search Results (113)

Physical activity, particularly when practiced in natural settings, has well-established benefits for overall health, sleep, and body composition. These effects are especially important for postmenopausal women, although research specifically targeting this population remains limited. The study evaluated a 16-week multicomponent outdoor exercise program (cardiorespiratory, strength, balance, coordination, and flexibility training) in postmenopausal women, consisting of three 60 min sessions per week. Participants were non-randomly assigned to an experimental group (EG, n = 55) and a control group (CG, n = 20). Measurements were taken at baseline and after 16 weeks, including body composition, sleep (duration and quality), and connection with nature. No significant differences were observed between groups at baseline. After the intervention, the EG and CG presented significant differences (p ≤ 0.01) in the rates of change in body mass, fat mass (FM; −9.26% and −1.21%, respectively), and visceral fat level (VFL; −13.46 points and −3.80 points). These differences were also observed for the sleep fragmentation index (p ≤ 0.01), but not for connection with nature. A significant interaction effect (p < 0.01) of time × group was observed for %FM, VFL, and appendicular skeletal muscle mass. Exercise duration had an effect (p = 0.043) on participants’ personal and affective identification with nature, and the time × group × medication interaction significantly influenced sleep efficiency (p = 0.034). The exercise program proved effective in reducing total and central adiposity levels; however, it did not lead to improvements in sleep duration, sleep quality, or connection with nature. Full article

Introduction: Sarcopenia is a systemic condition linked to increased morbidity and mortality in older adults. Point-of-Care Ultrasound (POCUS) offers a rapid, bedside method to assess muscle mass. This study evaluates the diagnostic accuracy of POCUS compared to Dual-energy X-ray Absorptiometry (DXA), the gold standard method, and explores its prognostic value in old patients undergoing surgery for hip fractures. Patients and Methods: In this prospective, single-center study, 126 patients aged ≥ 70 years and hospitalized with hip fractures were included. Sarcopenia was defined according to the revised 2018 EWGSOP2 criteria. Muscle mass was assessed by the Appendicular Skeletal Muscle Mass Index (ASMI) using DXA and by the thickness of the rectus femoris (RF) muscle using POCUS. Results: Of the 126 included patients, 52 had both DXA and POCUS assessments, and 43% of them met the diagnostic criteria for sarcopenia or severe sarcopenia. RF muscle thickness measured by POCUS was significantly associated with ASMI (R² = 0.30; p < 0.001). POCUS showed a fair diagnostic accuracy in women (AUC 0.652) and an excellent accuracy in men (AUC 0.905). Optimal diagnostic thresholds according to Youden’s index were 5.7 mm for women and 9.3 mm for men. Neither RF thickness, ASMI, nor sarcopenia status predicted mortality or major postoperative complications. Conclusions: POCUS is a promising, accessible tool for diagnosing sarcopenia in old adults with hip fractures. Nonetheless, its prognostic utility remains uncertain and should be further evaluated in long-term studies. Full article

Background: The waist–calf circumference ratio (WCR) is an index that combines waist and calf circumference measurements, offering a potentially effective method for evaluating the imbalance between abdominal fat and leg muscle mass in older adults. Objective: To assess the association between WCR and indicators of body composition, muscle strength, and physical performance in community-dwelling older women. Methods: This was a cross-sectional study involving 133 older women (≥65 years) from an urban-marginal community in Guayaquil, Ecuador. The WCR was categorized into quartiles (Q1: 2.07–2.57; Q2: 2.58–2.75; Q3: 2.76–3.05; Q4: 3.06–4.76). Body indicators included fat-free mass (FFM), skeletal muscle mass (SMM), appendicular muscle mass (ASM), appendicular muscle mass index (ASMI), visceral fat (VF), fat mass (FM), and fat mass index (FMI). Handgrip strength (HGS) and the Short Physical Performance Battery test (SPPB) score were used to assess muscle strength and function, respectively. Results: The median age of the participants was 75 [IQR: 65–82] years. The mean WCR was 2.92 ± 0.93. Statistically significant associations were found between WCR and VF (p < 0.001), WCR and SMM (p = 0.039), and WCR and ASM (p = 0.016). Regarding muscle function, WCR was associated with HGS (p = 0.025) and SPPB score (p = 0.029). Conclusions: A significant association was observed between WCR and body composition, and muscle strength and function in older women. Full article

Background and Objectives: Research on the impact of leucine on older sarcopenic patients is scarce, and investigations on this subject have led to contradictory findings in the literature. Our goal was to compile data from the available studies in the literature to explore the effect of leucine supplementation on parameters associated with sarcopenia in elderly individuals. Methods: The meta-analysis included older persons over 65 years of age who were recruited on the basis of the European Working Group on Sarcopenia in Older People sarcopenia criteria. Studies that were included were those in which at least one sarcopenia criterion was measured, including grip strength, appendicular skeletal muscle mass/height², gait speed, and the short physical performance battery index. Results: The meta-analysis included ten randomized controlled trials and one prospective study. The leucine group included 566 participants, whereas the placebo group included 567 patients. Patients receiving leucine and patients receiving a placebo had significantly different handgrip (p = 0.03), appendicular skeletal muscle mass/height² (p = 0.0.2), and gait speed (p = 0.008). Patients received a high dosage of leucine, and there was a significant difference in the appendicular skeletal muscle mass/height² (p = 0.02) and gait speed (p = 0.01) between the high dosage of the leucine group and the control group. When vitamin D was combined with leucine, the appendicular skeletal muscle mass/height² (p = 0.03) significantly differed between the leucine group receiving vitamin D and the control group. Conclusions: Low-quality evidence was found that older sarcopenic patients receiving leucine may show trends toward improved skeletal muscle strength, skeletal muscle quality, and physical performance. The capacity of leucine supplementation to have a beneficial therapeutic impact in older sarcopenic individuals is restricted when it is used alone without concurrent additional therapy. Full article

Background/Objectives: The comparative efficacy and optimal combination strategies of exercise intervention, nutritional supplementation, and their integration for older women with sarcopenia remain inadequately supported by high-quality evidence. Methods: We systematically searched PubMed, Embase, Web of Science, and the Cochrane Central Register of Controlled Trials (CENTRAL) until February 2025. A frequentist random-effects network meta-analysis was conducted to compare the relative effects of different interventions. The quality of evidence was assessed using the GRADE framework, and interventions were ranked based on relative efficacy and evidence certainty. Results: A total of 21 randomized controlled trials involving 1215 participants were included. The network meta-analysis showed that combined exercise and nutritional interventions were the most effective in improving handgrip strength (MD = 1.95, 95% CI: 0.1 to 3.18; SUCRA = 74%), usual gait speed (MD = 0.11, 95% CI: 0.04 to 0.17; SUCRA = 94.49%), maximum gait speed (MD = 0.22, 95% CI: 0.06 to 0.38; SUCRA = 82.17%), and appendicular skeletal muscle mass (MD = 0.21, 95% CI: 0.05 to 0.38; SUCRA = 92.83%). Exercise alone significantly improved knee extension strength (SMD = 0.75, 95% CI: 0.41 to 1.08; SUCRA = 84.58%). However, nutritional supplementation alone did not significantly improve any outcome. No intervention demonstrated a significant effect on skeletal muscle mass index. Conclusion: Exercise interventions effectively enhance muscle mass, strength, and physical function in older women with sarcopenia. Combined exercise and nutritional supplementation may offer superior benefits compared with exercise alone. Full article

Background: Sarcopenia (loss of muscle mass) and dynapenia (loss of strength) are prevalent in older adults aged 70 years and over. Both have an impact on their functional ability and quality of life, with type II muscle fibres being particularly affected. Although traditional resistance training (TRT) is effective, it presents technical difficulties and an increased risk of injury among this vulnerable population. Isometric strength training (IST) is a potentially safer, more accessible and more effective alternative. Objective: To describe the protocol of a single-arm, pre-post intervention trial designed to evaluate the efficacy and applicability of a 16-week IST programme on muscle strength, skeletal muscle mass, quality of life and applicability (safety, acceptability, perceived difficulty) in 18 older adults aged 70 years and above with a diagnosis of sarcopenia and dynapenia. The influence of genetic and environmental factors on the variability of response to IST will also be explored. Methodology: The participants, who have all been diagnosed with sarcopenia according to EWGSOP2 (European Working Group on Sarcopenia in Older People 2) criteria, will perform two IST sessions per week for 16 weeks. Each 30-min session will consist of one progressive set (total duration 45 s to 90 s) for each of the eight major muscle groups. This series will include phases at 20% and 40% of individual Maximal Voluntary Isometric Contraction (MVIC), culminating in 100% Maximal Effort (ME), using the CIEX SYSTEM machine with visual feedback. The primary outcome variables will be: change in knee extensor MVIC and change in Appendicular Skeletal Muscle Mass Index (ASMMI). Secondary variables will be measured (other components of sarcopenia, quality of life by EQ-5D-5L, use of Likert scales, posture and physiological variables), and saliva samples will be collected for exploratory genetic analyses. The main statistical analyses will be performed with t-tests for related samples or their non-parametric analogues. Discussion: This protocol details a specific IST intervention and a comprehensive evaluation plan. The results are expected to provide evidence on the feasibility and effects of IST among older adults with sarcopenia and dynapenia. Understanding individual variability in response, including genetic influence, could inform the design of more personalised and effective exercise strategies for this population in the future. Full article

Background and Objectives: Sodium-glucose cotransporter 2 (SGLT2) inhibitors are increasingly used in type 2 diabetes (T2D) due to their cardiorenal benefits and weight-lowering effects. However, concerns have emerged regarding their potential adverse impact on lean mass and muscle strength particularly in patients at risk for sarcopenia. This study aimed to evaluate the effects of empagliflozin on skeletal muscle mass. Secondary objectives were to assess changes in glycemic control, body weight, fat mass and handgrip strength. Materials and Methods: In this 24-week real-world observational study, 31 adult patients with T2D were assigned to either empagliflozin or non-SGLT2i treatment groups. Patients did not receive a high-protein diet, a resistance exercise program or any other weight-reducing medications such as glucagon-like peptide-1 (GLP-1)-based therapies. Anthropometric measurements, body composition via bioelectrical impedance analysis (BIA), and handgrip strength testing were performed at baseline and after 6 months. Sarcopenia was defined according to EWGSOP2 criteria. Results: The empagliflozin group showed significant improvements in HbA1c, fasting plasma glucose, body weight, waist circumference, and fat mass (p < 0.05 for all). No significant changes were observed in the empagliflozin group after 6 months in appendicular skeletal muscle mass index (from 7.81 ± 1.33 kg/m² to 7.84 ± 1.38 kg/m², p = 0.154). No statistically significant changes were observed in handgrip strength in either group. Conclusions: Empagliflozin treatment over six months led to favorable changes in metabolic parameters and fat mass without detrimental effects on skeletal muscle mass or muscle strength. In clinical practice, the selection of antidiabetic therapies should consider individual glycemic targets, cardiovascular and renal risks, weight management, comorbidities and sarcopenia risk. Resistance exercises and adequate dietary protein intake should be recommended to preserve muscle mass in at-risk patients. Larger randomized trials are needed to confirm the long-term effects of SGLT2 inhibitors on body composition particularly in older adults. Full article

Background/Objectives: Exercise is a key nonpharmacological strategy for the management of sarcopenic obesity (SO), characterized by low muscle mass and excess fat. However, long-term interventions and specific modalities, such as power training (PT), remain unexplored in this population. Methods: In this 32-week randomized controlled trial, 40 community-dwelling women (mean age: 77.0 ± 6.8 years) with sarcopenic obesity (per the EWGSOP2 and ESPEN criteria) were assigned to power training (PT), multicomponent training (MT), or a non-exercise control group (CG). Body composition, strength, and function were assessed pre- and post-intervention using within- and between-group analyses with effect size estimation. Nutritional intake was evaluated at baseline. Results: Significant pre–post intervention between-group differences were observed in appendicular skeletal muscle mass index (ASMI; p = 0.039), body fat percentage (BF%; p = 0.002), visceral fat (VF; p = 0.044), appendicular muscle mass (ASM; p = 0.021), gait speed (GS; p = 0.018), timed up and go test (TUG; p = 0.005), five-times sit-to-stand test (5STS; p < 0.001), and Short Physical Performance Battery (SPPB; p = 0.002). Large effect sizes (Cohen’s d > 0.8) were found in the PT group for all these variables. Post hoc analyses indicated that PT was significantly superior to MT in improving 5STS (p = 0.005) and TUG (p = 0.025). Notably, 35.7% of the PT participants no longer met diagnostic criteria for SO after the intervention. Conclusions: PT was more effective than MT and the CG in improving muscle mass, reducing fat, and enhancing functional performance in older women with SO. These findings support PT as a feasible and promising intervention. Full article

Background: The prevalence of malnutrition is high in post-intensive care unit (ICU) coronavirus disease 2019 (COVID-19) patients during hospitalization and after hospital discharge. This paper presents prospective results from the NutriEcoMuscle study, a multicenter observational study. The study aimed to evaluate changes in nutritional and functional status in post-ICU COVID-19 patients following nutritional and physical rehabilitation interventions. Secondary aims included assessing adherence to and tolerance of the oral nutritional supplement (ONS) used in the nutritional intervention. Methods: The study enrolled adults who had been admitted to the ICU due to severe COVID-19. At hospital discharge, the patients underwent a nutritional intervention based on oral nutritional supplements (ONSs) with 100% serum lactoprotein enriched with leucine and vitamin D and a physical rehabilitation program. They were followed up during three months. Performed assessments included Subjective Global Assessment (SGA), Global Leadership Initiative on Malnutrition (GLIM) criteria, Barthel index (BI), handgrip strength and Timed Up and Go test, bioelectrical impedance analysis (BIA), nutritional ultrasound (US), and tolerance and adherence to ONS. Sample size was calculated based on handgrip strength, and parametric and non-parametric tests were used to assess differences between the baseline and three-month outcomes. Results: The study included 96 patients (71.9% male, mean age 58.8 years, mean body mass index (BMI) of 28.8 kg/m², 36.5% obese). A total of 85 patients (62 men and 23 women) completed the 90-day follow-up. The mean weight gain after the intervention was 6.8 (SD 5.2) kg (similar in men and women; p = 0.263). The proportion of patients with malnutrition according to the SGA or GLIM criteria decreased from 100% to 11.8% and 36.4%, respectively (p < 0.00001 in both cases). The proportion of patients with functional limitations by BI decreased from 66.7% to 27.0% (p < 0.0001). Handgrip strength increased more than 40% in both men and women (p < 0.00001). The time to perform the Timed Up and Go (TUG) test decreased more than 40% in both men and women (p < 0.00001). According to BIA, the mean fat mass did not increase significantly in either men or women. The mean fat-free mass index (FFMI) increased significantly in both men and women. There were also significant increases in body cell mass, skeletal muscle mass index, and appendicular skeletal muscle mass index. The phase angle (PhA) increased significantly in both men (26.5%) and women (17.4%). In a multivariate analysis, age and baseline PhA were related to the PhA increase (adjusted R² = 0.5573). The US study showed a significant increase in the mean measurements of muscle area, muscle circumference, X-axis, and Y-axis in the rectus femoris. Regarding abdominal fat, there were no significant increases in total, superficial, or preperitoneal adipose tissue by US. Participants engaged in a median interquartile range (IQR) of 70 (0–120) min/week of strength exercise and 60 (0–120) min/week of moderate physical exercise. The supplement was well tolerated, and poor adherence (less than 50%) was low (4% of the participants). Conclusions: A three-month intervention, including ONS and physical rehabilitation, is associated with a significant improvement in nutritional and functional status. Patients gained weight primarily by increasing their muscle mass. There was no significant increase in fat mass, as measured by BIA or US. The intervention was well tolerated and had good adherence. Full article

Background: Sarcopenia is characterized by a loss of muscle mass, strength, and function. At present, there are no effective methods available for prevention or treatment. Oxidative Balance Score (OBS) has been shown to be significantly correlated with a decreased risk of sarcopenia. Nevertheless, gender-specific studies still exhibit certain limitations. Methods: Individuals who completed dual-energy X-ray absorptiometry and the diet and lifestyle questionnaires from the National Health and Nutrition Examination Survey were enrolled. OBSs were calculated according to dietary or lifestyle variables and physical activity. Sarcopenia with low muscle mass (SLM) was identified based on the ratio of appendicular skeletal muscle mass to body mass index. A logistic regression analysis investigated the association between OBS and the risk of SLM in different gender groups. Kaplan–Meier survival and subgroup analyses and Cox regression analyses were used to explore the relationship between OBS and mortality in individuals with SLM in each gender subgroup. Results: The level of OBS in the SLM group was lower (20.40 vs. 17.07, p < 0.05). A multivariate logistic regression analysis showed that the OR between individual dietary nutrients and lifestyle and the risk of SLM exhibition was gender-specific. Stratified analyses revealed that total OBS, as well as diet and lifestyle OBS were negatively associated with the risk of SLM within each gender subgroup (all p < 0.05, all trends p < 0.05). Furthermore, a restriction cubic spline regression analysis showed that diet and lifestyle OBSs were negatively correlated with the risk of SLM in females (nonlinear p = 0.0469, nonlinear p = 0.0254). The KM curve showed that OBS was not significantly associated with all-cause mortality in the male and female subgroups (female, p = 0.064, male, p = 0.53). Conclusions: This study establishes a significant negative correlation between OBS and the risk of SLM, particularly among females. Consequently, adopting an antioxidant diet and lifestyle may prove to be more advantageous for females. Full article

Background/Objective: Leukocyte cell-derived chemotaxin-2 (LECT2), a hepatokine, is implicated in non-alcoholic fatty liver disease (NAFLD). Although NAFLD and sarcopenia are closely linked, the relationship between plasma LECT2 levels and sarcopenia remains unclear. Methods: We analyzed plasma LECT2 levels in 400 older adults aged 70–84 years old living in the community enrolled in the Korean Frailty and Aging Cohort Study. The appendicular skeletal muscle mass (ASM) and handgrip strength (HGS), both adjusted for the BMI, were used to evaluate the muscle mass and strength. A low muscle mass (LMM) was defined using the sex-specific lowest quintile of ASM/BMI as the cutoff value, while a low muscle strength (LMS) was determined based on the lowest quintile of the HGS/BMI. Sarcopenia was defined by the coexistence of an LMM and LMS. Results: NAFLD was identified using a fatty liver index > 30. The participants with NAFLD had significantly higher plasma LECT2 levels compared to their non-NAFLD counterparts (34.4 [29.3–41.1] vs. 29.0 [24.7–36.7] ng/mL, p < 0.001). Circulating LECT2 levels were inversely correlated with ASM/BMI (r = −0.506, p < 0.001) and HGS/BMI (r = −0.474, p < 0.001), as determined by Spearman correlation analysis. Among the study participants, 79 (19.8%) were categorized as having either an LMM or LMS, and 31 (7.8%) were identified as having sarcopenia. In multivariate logistic regression, the highest LECT2 quartile had markedly greater odds of an LMM (OR 3.31, 95% CI 1.41–7.75), LMS (OR 2.85, 95% CI 1.29–6.26), and sarcopenia (OR 5.48, 95% CI 1.57–19.05) relative to the lowest quartile. Conclusions: Our results indicate that elevated plasma LECT2, a hepatokine increased in NAFLD, contributes to an increased risk of sarcopenia in older adults. Full article

Background and Objectives: Sarcopenia is a notable comorbidity of rheumatoid arthritis (RA), affecting about one third of patients. However, the characteristic of muscle function and its association with RA disease remains unknown. Materials and Methods: This cross-sectional study collected clinical data from a real-world Chinese RA cohort. Sarcopenia was defined as both myopenia and low muscle function (LMF). Myopenia was defined as appendicular skeletal muscle mass index (ASMI) < 7.0 kg/m² in men and <5.7 kg/m² in women. LMF was defined as low muscle strength (LMS, hand grip < 28 kg in men and <18 kg in women) or low physical performance (LPP, 6 m gait speed < 1.0 m/s). Results: Among 1125 RA patients recruited in this study, 928 RA patients were eligible for analysis. The prevalence of sarcopenia, myopenia, LMF, LMS, and LPP in all RA patients was 36.5%, 46.1%, 69.0%, 57.8%, and 37.1%, respectively. According to their trends in age and disease activity, there were 111 (11.9%) patients in the young (age < 50 years) and remission (CDAI ≤ 2.8) subgroup, 199 (21.4%) patients in the young and active (CDAI > 2.8) subgroup, 198 (21.3%) patients in the old (age ≥ 50 years) and remission subgroup, and 420 (45.2%) patients in the old and active subgroup. Compared with the two remission subgroups, respectively, the young and active subgroup had significantly lower grip strength, higher prevalence of sarcopenia, LMF, and LMS, and worse activity function. After adjustment for potential confounders, multivariate multinominal logistic regression analysis showed that the young and active subgroup was positively associated with sarcopenia (OR = 3.193, 95%CI: 1.477–6.899), LMF (OR = 2.390, 95%CI: 1.207–4.731), and LMS (OR = 3.520, 95%CI: 1.743–7.110). Conclusions: Worse muscle strength, rather than reduced physical performance, is more common in patients with active RA at a young age. It underscores the critical need for early identification and intervention of muscle dysfunction to improve their quality of life. Full article

Objectives: Systemic sclerosis (SSc) patients exhibit a heightened vulnerability to sarcopenia, a condition characterized by the loss of muscle mass and strength. This study aims to determine the prevalence of sarcopenia in patients with SSc and to investigate the associated factors contributing to this condition. Methods: Eighty patients with SSc were included in the study, and their demographic and clinical characteristics, body composition by bioelectrical impedance analysis, SARC-F score, chair-stand test performance, and 4 m walking speed were recorded. Results: Among the 80 participants, 91.3% were female, with a median age of 56.5 years (range 45–65). The majority (70%) had limited SSc, and 71.3% reported at least one comorbidity. According to the International Physical Activity Questionnaire, only 12.5% of participants met the criteria for an active lifestyle. The SARC-F questionnaire indicated that 20% of patients were at risk for sarcopenia. The prevalence of sarcopenia among patients showed considerable variability: 5% (95% CI 0.1–9) were identified through the appendicular skeletal muscle index (ASMI), 8.8% (95% CI 2.4–15) via the fat-free mass index (FFMI), and a concerning 20% (95% CI 11–29) according to the skeletal muscle mass index (SSMI). A multivariate logistic regression analysis identified age as the only factor significantly influencing the SARC-F score, with an odds ratio of 1.081 (95% CI 1.012–1.154, p = 0.020). Additionally, the older age group demonstrated a lower level of physical activity, poorer chair-stand test outcome, and slower 4 m gait speeds (p = 0.013, p = 0.008, p = 0.001, respectively), as well as a higher reported frequency of falls (p = 0.039). Conclusions: Sarcopenia is a prevalent issue among individuals with SSc, particularly in the older population. This study did not identify a direct correlation between sarcopenia and SSc subtype, disease activity, or other clinical parameters. However, the need for an improved cut-off value for diagnosing sarcopenia in this specific cohort is evident. Full article

Background/Objectives: Addressing the risk of malnutrition at an early stage is crucial to preventing its development, which can have a detrimental impact on physical and mental health status. This study investigates the potential role of biochemical biomarkers such as sirtuin 1 (SIRT-1), melatonin, cholecystokinin-8 (CCK-8), and total antioxidant capacity (TAC) in identifying the risk of malnutrition. Methods: This cross-sectional study assessed malnutrition risk in 153 community-dwelling older adults using the Mini Nutritional Assessment (MNA). Serum levels of SIRT-1, melatonin, and CCK-8 were analyzed with enzyme-linked immunosorbent assay (ELISA), and total antioxidant capacity (TAC) was measured using the ferric reducing ability of plasma (FRAP) method. Results: Serum levels of TAC and CCK-8 were significantly positively correlated with grip strength and visceral adipose tissue, with TAC levels also showing associations with appendicular skeletal muscle mass index (ASMI), total body water, total energy expenditure, fat-free mass index, and fat mass index (p < 0.001). CCK-8 emerged as a strong predictor of malnutrition risk (AUC = 0.58 in females, AUC = 0.64 in males), whereas SIRT-1 (AUC = 0.57 for both sexes), melatonin (AUC = 0.46 for females, AUC = 0.51 for males), and TAC (AUC = 0.42 for females, AUC = 0.54 for males) exhibited weaker predictive abilities. A multivariate model incorporating CCK-8 demonstrated excellent predictive accuracy (AUC = 0.84, 95% CI: 0.77–0.90) and indicated a potential association between elevated CCK-8 levels and a higher risk of malnutrition. Conclusions: In conclusion, this study highlights the effectiveness of a multi-parameter model incorporating CCK-8 as a reliable approach for assessing malnutrition risk in older adults, offering a comprehensive evaluation of the condition. However, further research is needed to confirm its applicability and accuracy in diverse elderly populations and clinical settings. Full article

Background/Objectives: Monoterpenes, a class of organic compounds with the molecular formula C₁₀H₁₆, have garnered significant attention for their potential medicinal benefits. Emerging evidence suggests they may positively influence skeletal muscle function. However, the impact of monoterpene exposure on muscle strength and mass in humans remains unclear. Methods: To explore this relationship, we analyzed data from 1202 adults (aged ≥ 18 years) who participated in the 2013–2014 National Health and Nutrition Examination Survey (NHANES), focusing on serum levels of three specific monoterpenes—α-pinene, β-pinene, and limonene—and their association with hand grip strength and lean muscle mass. Results: Our analysis revealed that, except for test 2 of hand 1, all grip strength measures showed a positive correlation with ln-limonene levels. The β coefficient for combined grip strength was 2.409 (S.E. = 0.891, p = 0.015). Positive associations were also found between serum limonene levels and lean muscle mass. The β coefficient for the Appendicular Skeletal Muscle Mass Index (ASMI) was 0.138 (S.E. = 0.041, p = 0.004). Furthermore, combined grip strength and ASMI significantly increased across limonene quintiles (p for trend = 0.005 and 0.006, respectively). However, none of the three monoterpene levels showed a significant association with clinically defined low muscle mass or low muscle strength. Conclusions: Our findings suggest a plausible association between exposure to limonene, hand grip strength, and lean muscle mass among adults in the United States. Further investigation is needed to fully understand the underlying mechanisms and medical significance of this association. Full article