Sex-dependent association of serum vitamin D with muscle strength in older adults: NHANES 2001-2002.

BACKGROUND: Although several studies have suggested a potential positive association between serum vitamin D levels and muscle strength in older adults, it remains unclear whether this relationship is sex-dependent. AIM: To evaluate the association between serum 25 hydroxyvitamin D [25(OH)D] levels and muscle strength in older adults and to assess whether this association is dependent on sex. METHODS: This cross-sectional study utilized data from the National Health and Nutrition Examination Survey (NHANES) conducted between 2001 and 2002. A total of 1173 individuals aged 50-85 years (630 men and 543 women) were included in the analysis. The peak isokinetic force of the knee extensor was assessed using a kinetic communicator isokinetic dynamometer. Serum 25(OH)D levels were measured using the standardized liquid chromatography-tandem mass spectrometry method. Linear regression analyses were conducted to estimate coefficients and 95% confidence intervals for muscle strength across tertiles of serum vitamin D levels, adjusting for potential confounders. RESULTS: Tertiles of serum vitamin D were positively associated with muscle strength in older men (p-trend = 0.007), whereas no association was observed in older women (p-trend = 0.140) or in the total sample (men and women together; p-trend = 0.139). CONCLUSION: Serum vitamin D levels were positively associated with muscle strength specifically in older men, whereas no association was observed in older women. These results suggest that the relationship between vitamin D and strength may be sex-dependent.

Association between caffeine metabolites in urine and muscle strength in young and older adults: A cross-sectional study from NHANES 2011-2012.

BACKGROUND: Elevated levels of reactive oxygen species may contribute to the gradual decline in muscle strength over time. Although caffeine and its metabolites have antioxidant properties that can mitigate oxidative stress, the association of caffeine and its metabolites with muscle strength remains unknown. AIM: To investigate whether caffeine metabolites in urine are associated with muscle strength in young and older adults. METHODS: A cross-sectional study was conducted with 1145 individuals aged over 20 years (n = 801 < 60 years and n = 344 ≥ 60 years) from the National Health and Nutrition Examination Survey (NHANES) 2011-2012. Muscle strength was assessed using a handgrip dynamometer, and combined grip strength was determined by summing the highest value from each hand. Caffeine and its metabolites in urine were quantified using ultra-high-performance liquid chromatography-electrospray ionization-tandem mass spectrometry (1-methyluric acid, 3-methyluric acid, 7-methyluric acid, 1,3-dimethyluric acid, 1,7-dimethyluric acid, 3,7-dimethyluric acid, 1,3,7-trimethyluric acid, 1-methylxanthine, 3-methylxanthine, 7-methylxanthine, 1,3-dimethylxanthine, 1,7-dimethylxanthine, 3,7-dimethylxanthine, 1,3,7-trimethylxanthine, 5-acetylamino-6-amino-3-methyluracil). Linear regression analyses were performed to determine the association of caffeine and its metabolites with muscle strength in young and older adults, adjusting for confounders. RESULTS: Positive associations between muscle strength and levels of 7-methyluric acid (ß = 0.029; p = 0.021), 1,3-dimethyluric acid (ß = 0.008; p = 0.004), 3,7-dimethyluric acid (ß = 0.645; p = 0.012), 3-methylxanthine (ß = 0.020; p = 0.002), 7-methylxanthine (ß = 0.020; p = 0.006), 1,3-dimethylxanthine (theophylline) (ß = 0.030; p = 0.004) and 3,7-dimethylxanthine (theobromine) (ß = 0.035; p = 0.029) were observed in older adults. In contrast, no such associations were noted in young adults. CONCLUSION: Our study indicates a positive association between certain caffeine metabolites in urine and muscle strength in older adults, but not in younger individuals. These findings indicate that specific caffeine metabolites may contribute to an antioxidant role especially in older adults.

Neutrophil-lymphocyte Ratio and C-Reactive Protein Levels are not Associated with Strength, Muscle Mass, and Functional Capacity in Kidney Transplant Patients.

Chronic inflammation has been associated with components of sarcopenia; however, these associations are unknown in kidney transplant patients (KTPs). The aim of this study was to associate neutrophil-lymphocyte ratio (NLR) and C-reactive protein (CRP) with strength, muscle mass, and functional capacity in KTPs. A cross-sectional study evaluating 108 KTPs was performed. Strength was evaluated by handgrip strength and five-times-sit-to-stand test (5STS), and appendicular skeletal muscle mass (ASM) was estimated by bioelectrical impedance analysis. The ASM index (ASMI) was calculated using the ASM (kg)/height (m2). Functional capacity was assessed by the 4-m gait speed test and short physical performance battery (SPPB). The electrochemiluminescence method was used for analyzing CRP levels, and the cytometric method XN-3000 Sysmex was used for obtaining leukogram values to calculate the NLR. Linear regression analysis was used to assess the association between systemic inflammation and sarcopenia components, adjusting for confounders. NLR and CRP levels were not associated with handgrip strength (ß = - 0.231, p = 0.389; ß = - 0.291, p = 0.577), 5STS (ß = - 0.114, p = 0.288; ß = - 0.202, p = 0.334), ASM (ß = - 0.027, p = 0.813; ß = 0.062, p = 0.788), ASMI (ß = - 0.036, p = 0.242; ß = 0.040, p = 0.505), 4-m gait speed (ß = 0.013, p = 0.082; ß = 0.004, p = 0.769), and SPPB (ß = 0.076, p = 0.170; ß = 0.152, p = 0.157), respectively. In conclusion, NLR and CRP levels were not associated with muscle mass, strength, and functional capacity in KTPs.

Association Between Dietary Intake and Serum Uric Acid Levels in Kidney Transplant Patients.

OBJECTIVES: The aim of this study was to evaluate the association between dietary intake and uric acid (UA) levels in kidney transplant patients (KTPs). METHODS: A cross-sectional study was performed with 113 KTPs. Dietary intake assessment was carried out thorough two 24-hour dietary recalls using the 5-step multiple pass method. We evaluated the intake of energy, carbohydrate, total protein, animal protein, vegetable protein, total fat, saturated fat, trans fat, monounsaturated fat, polyunsaturated fat, omega-3 and omega-6 fatty acids, cholesterol, total sugar, added sugars, total fiber, insoluble fiber, soluble fiber, alcohol, caffeine, fructose, glucose, lactose, sucrose, vitamin A, vitamin C, vitamin E, and calcium. The intake of several food groups (portions) was also evaluated. Hyperuricemia was classified as >7.0 and >6 mg/dL for men and women, respectively. RESULTS: In odds ratio analyses, the individuals who ingested more vegetable protein (g/kg) and caffeine (mg) presented lower chance to have hyperuricemia. In linear regression, animal protein (g) intake was positively associated (ß = 0.011, P = .048), while vegetable protein (g/kg) intake was inversely associated (ß = -2.45, P = .047) with serum UA. However, after a multiple linear regression including vegetable and animal protein intakes together, only vegetable protein intake remained associated with UA. The intake of other nutrients and portions of food groups was not associated with UA. All the analyses were adjusted for sex, age, hypertension, body mass index, glomerular filtration rate, use of medicines, and caloric intake misreporting. CONCLUSIONS: Vegetable protein and caffeine intakes were inversely associated with UA in KTPs.

Intake of polyunsaturated fatty acids and ω-3 are protective factors for sarcopenia in kidney transplant patients.

OBJECTIVES: The aim of this study was to associate dietary intake with sarcopenia and its components in kidney transplant patients (KTPs). METHODS: A cross-sectional study was performed with 125 KTPs. Strength was evaluated by handgrip strength (HGS) and appendicular muscle mass was estimated by bioelectrical impedance. Functional capacity was assessed by 4-m walking test. Sarcopenia was diagnosed by revised European Consensus on Definition and Diagnosis (2019). Dietary assessment was carried out through two 24-h dietary recalls. It evaluated the consumption of energy (kcal), carbohydrates, protein (total and from animal and vegetable food sources), total fat, saturated fatty acids, monounsaturated fatty acids (MUFAs), polyunsaturated fatty acids (PUFAs), and ω-3 (g) and ω-6 (g). RESULTS: Intake of ω-3 was positively associated with appendicular skeletal muscle mass index (ASMI; kg/m2). The greater intake of PUFA (g and %) and ω-3 (g) was associated with lower chance to present low ASMI and sarcopenia. None of the other dietary components evaluated in the present study were associated with ASMI and sarcopenia. Walking speed and HGS were not associated with dietary variables. CONCLUSIONS: Intake of ω-3 and PUFAs are protective factors for sarcopenia and low muscle mass, but not for strength and functional capacity, in KTPs.

Serum Uric Acid Is Positively Associated with Muscle Mass and Strength, but Not with Functional Capacity, in Kidney Transplant Patients.

BACKGROUND: Our aim was to associate serum uric acid (UA) with muscle mass, strength and functional capacity in kidney transplant patients (KTPs). METHODS: A cross-sectional study was performed on 113 KTPs. The fat-free mass and total and appendicular muscle mass were estimated by performing a bioelectrical impedance analysis. The strength was evaluated using the handgrip strength test (HGS) and the five times sit to stand test (5STS). The functional capacity was evaluated using the 4 m walk test and the short physical performance battery (SPPB). RESULTS: Linear regression showed that the UA levels were positively associated with the muscle mass, fat-free mass, appendicular muscle mass, muscle mass index and appendicular muscle mass index. The 5STS results (seconds) were inversely associated with the UA levels, showing that individuals with higher UA were more likely to have more strength. However, UA was not associated with the HGS, 4 m walk test and SPPB results. CONCLUSION: UA levels were positively associated with muscle mass and strength, but not with functional capacity, in KTPs.

Body Mass Index, waist circumference or sagittal abdominal diameter: Which parameter is better correlated with body fat changes in postmenopausal women after combined training protocol?

OBJECTIVE: We aimed to verify whether exercise-induced changes in body mass index (BMI), waist circumference (WC) and sagittal abdominal diameter (SAD) are correlated with changes in body fat (BF) in postmenopausal women. METHODS: Seventeen postmenopausal women performed combined training three times a week, for 12 weeks. Correlations of delta (Δ) BMI, Δ WC, and Δ SAD with Δ total BF, Δ android and Δ gynoid fats were performed. RESULTS: Weight, BMI and android fat decreased over time. A tendency of reductions in gynoid fat was found (p = 0.070). Delta BMI was positively correlated with Δ total BF (r = 0.56; p < 0.05), Δ android fat (r = 0.64; p < 0.05), and Δ gynoid fat (r = 0.72; p < 0.05). The Δ WC was only correlated with Δ gynoid fat (r = 0.55; p < 0.05). The Δ SAD was not correlated with all the Δ body fat parameters evaluated. CONCLUSION: We conclude that changes in BMI were better associated with body fat changes induced by combined training when compared to WC and SAD in postmenopausal women. The patients were part of a 12-week training study (ClinicalTrials.gov Identifier: NCT03200639).

Association of phase angle with sarcopenia and its components in physically active older women.

OBJECTIVE: The aim of the present study was to associate phase angle (PhA) with sarcopenia and its components in physically active older women. METHODS: A cross-sectional study was performed with 94 physically active older women. PhA and muscle mass were assessed by bioelectrical impedance. Muscle strength was measured by handgrip strength (HGS) and functional capacity was evaluated by 4-meter walk test. Sarcopenia was diagnosed according to the European Consensus on Definition and Diagnosis of Sarcopenia (2010). Participants were evaluated according to the PhA tercile. The individuals were divided into two groups: 1st vs. 2nd and 3rd terciles. The individuals in the first tercile were considered having low PhA (< 5.7º). RESULTS: Low PhA was not associated with sarcopenia (OR = 1.50 (0.520-4.319)), low muscle mass index (OR = 1.50 (0.520-4.319)), low HGS (OR = 3.15 (0.954-10.401)) and low walk speed (OR = 1.46 (0.384-5.534)). In addition, PhA had a weak correlation with walk speed (r = 0.24, p = 0.023) and walk speed was able to predict the PhA variations by 3.9%. CONCLUSION: PhA was not associated with sarcopenia and its components in physically active older women. Although PhA was correlated with walk speed, the biological meaning of this association is questionable, since the power of the prediction was low.

(Dis) Agreement between the first and the recent European consensus on definition and diagnosis for sarcopenia in kidney transplant patients.

We previously detected that ~50% of kidney transplant patients (KTPs) present sarcopenia using the first European Working Group on Sarcopenia in Older People (EWGSOP1) consensus. Our aim was to evaluate the agreement between the sarcopenia diagnosis using EWGSOP1 and the new consensus (EWGSOP2) in KTPs. A cross-sectional study was performed evaluating 127 KTPs. Total and appendicular muscle mass were estimated by bioelectrical impedance. Strength was evaluated by handgrip strength (HGS) and five times sit to stand (5STS). Functional capacity was evaluated by 4-m walk test and short physical performance battery. Sarcopenia was diagnosed by EWGSOP1 and EWGSOP2. The agreement between EWGSOP1 and EWGSOP2 (using HGS criteria for muscle strength) was fair (k = 0.341-0.402). Slight agreement was observed between EWGSOP1 and EWGSOP2 using 5STS criteria for muscle strength (k = 0.031-0.046). We conclude that EWGSOP2 definitions have a low agreement with EWGSOP1 in KTPs.

Phase Angle Is Associated With Handgrip Strength but Not With Sarcopenia in Kidney Transplantation Patients.

OBJECTIVES: Phase angle (PhA) is a cell health marker and has been associated with muscle mass and strength in non-kidney disease individuals. However, it is unknown whether PhA is a predictor of sarcopenia and its components in kidney transplantation patients. The aim of the present study was to associate PhA with sarcopenia and its components in kidney transplantation patients. DESIGN AND METHODS: One hundred and twenty-nine kidney transplantation individuals were evaluated in a cross-sectional study. PhA and muscle mass were evaluated using bioelectrical impedance. Handgrip strength (HGS) was performed with a hand dynamometer and functional capacity with 4-m walk test. Sarcopenia was diagnosed according to the European Consensus Diagnostic Criteria for Sarcopenia. Participants were divided according to the PhA tercile, and 2 groups were evaluated: first versus second and third terciles, according to sex. The individuals in the first tercile had PhA values <5.8° and <6.2° for women and men, respectively. RESULTS: Individuals in the lower tercile of PhA showed lower odds of having higher values of HGS (kg; odds ratio [OR] = 0.89; 95% confidence interval [CI]: 0.82-0.97) and higher odds to have low HGS (OR = 5.97; 95% CI: 1.05-33.98). However, PhA was not associated with sarcopenia (OR = 1.95; 95% CI: 0.71-5.39), low muscle mass index (OR = 1.17; 95% CI: 0.41-3.36), and low functional capacity (OR = 2.47; 95% CI: 0.45-13.48). CONCLUSION: PhA was associated with HGS but not with sarcopenia and its other components. These results suggest that PhA can be used as a possible predictor of muscle strength in kidney transplantation patients.

Adductor pollicis muscle thickness has a low association with muscle mass and lean mass in kidney transplantation patients.

BACKGROUND AND AIMS: The use of adductor pollicis muscle thickness (APMT) as a predictor of muscle and lean mass is not fully understood and little is known whether the APMT evaluation presents advantages when compared to simpler anthropometric measurements, such as body weight. We aimed to associate APMT, alone and plus body weight, with muscle mass and lean mass in kidney transplantation patients. METHODS: A cross-sectional study was carried out with 129 kidney transplantation patients of both sexes that presented a high time of kidney transplant (95.6 ± 78.3 months). Body weight and height were performed and APMT was measured using a caliper. Lean mass and muscle mass were estimated by bioelectrical impedance. RESULTS: After linear regression analysis, APMT explained the variances of muscle mass and lean mass by 20% (R2 = 0.208; ß = 0.456; p < 0.001) and by 26% (R2 = 0.264; ß = 0.514; p < 0.001), respectively. Body weight predicted muscle mass by 21% (R2 = 0.216; ß = 0.465; p < 0.001) and lean mass by 68% (R2 = 0.684; ß = 0.828; p < 0.001). Analyzing weight plus APMT, the prediction of muscle mass and lean mass increased by 8% (R2 = 0.29; ß = 0.325; p < 0.001) and by 3% (R2 = 0.71; ß = 0.749; p < 0.001), respectively; when compared to weight alone. CONCLUSION: Compared with body weight, APMT presented a similar association with muscle mass, but showed a lower prediction of lean mass. In this way, the evaluation of body weight, instead of APMT, seems to have a better cost-benefit to predict both muscle mass and lean mass in kidney transplantation patients.