Sarcopenia and homocysteine: is there a possible association in the elderly? A narrative review

Associations of micronutrient dietary patterns with sarcopenia among US adults: a population-based study

Background

Current epidemiological evidence points to an association between micronutrient (MN) intake and sarcopenia, but studies have focused on single MN, and no combined effects on MNs have been reported. The aim of this study was to investigate the relationship between different MN intake patterns and sarcopenia and skeletal muscle mass.

Methods

We performed a population-based cross-sectional study, with a total of 5,256 U.S. adults aged 20-59 years, and we collected total daily MN intake and appendicular skeletal muscle mass measured by Dual-Energy X-ray Absorptiometry (DXA). Principal component analysis (PCA) was used to obtain nutrient patterns and principal component scores based on the intake of 14 MNs, and logistic regression analysis was used to assess the effects of single MN and MN intake patterns on sarcopenia and muscle mass.

Results

We defined three MN intake patterns by PCA: (1) adherence to VitB-mineral, high intake of vitamin B and minerals; (2) adherence to VitAD-Ca-VB12, high intake of vitamin A, vitamin D, calcium and vitamin B12; and (3) adherence to Antioxidant Vit, high intake of antioxidant vitamins A, C, E, and K. These three nutrient patterns explained 73.26% of the variance of the population. A negative association was observed between most single MN intakes and sarcopenia, and after adjusting for confounders, adherence to the highest tertile of the three nutrient patterns was associated with a lower risk of sarcopenia and relatively higher skeletal muscle mass compared to the lowest adherence. In subgroup analysis, MN intake patterns were significantly correlated with sarcopenia in middle-aged females.

Conclusion

Nutritional patterns based on MN intake were significantly related to sarcopenia, indicating that MNs interact with each other while exerting their individual functions, and that MN dietary patterns may provide promising strategies for preventing the loss of muscle mass, with further prospective studies warranted in the future.

The association of lipid metabolism and sarcopenia among older patients: a cross-sectional study

Sarcopenia has become a heavy disease burden among the elderly. Lipid metabolism was reported to be involved in many degenerative diseases. This study aims to investigate the association between dysregulated lipid metabolism and sarcopenia in geriatric inpatients. This cross-sectional study included 303 patients aged ≥ 60, of which 151 were diagnosed with sarcopenia. The level of total cholesterol (TC), triglyceride (TG), high-density lipoprotein (HDL), low-density lipoprotein (LDL), homocysteine (HCY), BMI, and fat percentage, were compared between sarcopenia and non-sarcopenia patients. The Spearman correlation coefficient was used to estimate the association between sarcopenia and the level of lipid metabolism. To determine risk factors related to sarcopenia, a multivariate logistic regression analysis was carried out. Risk prediction models were constructed based on all possible data through principal component analysis (PCA), Logistic Regression (LR), Support Vector Machine (SVM), k-Nearest Neighbor (KNN), and eXtreme Gradient Boosting (XGboost). We observed rising prevalence of sarcopenia with increasing age, decreasing BMI, and fat percentage (p < 0.001, Cochran Armitage test). Multivariate logistic regression analysis revealed sarcopenia's risk factors, including older age, male sex, lower levels of BMI, TC, and TG, and higher levels of LDL and HCY (p < 0.05). The sarcopenia risk prediction model showed the risk prediction value of sarcopenia, with the highest area under the receiver operating curve (AUC) of 0.775. Our study provided thorough insight into the risk factors associated with sarcopenia. It demonstrated that an increase in lipid metabolism-related parameters (BMI, TG, TC), within normal reference ranges, may be protective against sarcopenia. The present study can illuminate the direction and significance of lipid metabolism-related factors in preventing sarcopenia.

Relationship Between Plasma Homocysteine and Bone Density, Lean Mass, Muscle Strength and Physical Function in 1480 Middle-Aged and Older Adults: Data from NHANES

Hyperhomocysteinemia induces oxidative stress and chronic inflammation (both of which are catabolic to bone and muscle); thus, we examined the association between homocysteine and body composition and physical function in middle-aged and older adults. Data from the National Health and Nutrition Examination Survey was used to build regression models. Plasma homocysteine (fluorescence immunoassay) was used as the exposure and bone mineral density (BMD; dual-energy X-ray absorptiometry; DXA), lean mass (DXA), knee extensor strength (isokinetic dynamometer; newtons) and gait speed (m/s) were used as outcomes. Regression models were adjusted for confounders (age, sex, race/Hispanic origin, height, fat mass %, physical activity, smoking status, alcohol intakes, cardiovascular disease, diabetes, cancer and vitamin B12). All models accounted for complex survey design by using sampling weights provided by NHANES. 1480 adults (median age: 64 years [IQR: 56, 73]; 50.3% men) were included. In multivariable models, homocysteine was inversely associated with knee extensor strength (β = 0.98, 95% CI 0.96, 0.99, p = 0.012) and gait speed (β = 0.85, 95% CI 0.78, 0.94, p = 0.003) and borderline inversely associated with femur BMD (β = 0.84, 95% CI 0.69, 1.03, p = 0.086). In the sub-group analysis of older adults (≥ 65 years), homocysteine was inversely associated with gait speed and femur BMD (p < 0.05) and the slope for knee extensor strength and whole-body BMD were in the same direction. No significant associations were observed between homocysteine and total or appendicular lean mass in the full or sub-group analysis. We found inverse associations between plasma homocysteine and muscle strength/physical function, and borderline significant inverse associations for femur BMD.

Association between serum homocysteine and sarcopenia among hospitalized older Chinese adults: a cross-sectional study

OBJECTIVE

Hyperhomocysteinemia (HHcy) is considered to increase the risk of sarcopenia (S) and remains controversial. In this study, we aimed to investigate the prevalence of S among older Chinese adults and explore whether homocysteine (Hcy) was independently associated with S.

METHODS

This cross-sectional study was performed among older adults hospitalized in the Geriatric Hospital of Nanjing Medical University between June 2017 and December 2021. We measured all participants' serum Hcy levels, hand grip strength, gait speed and appendicular skeletal muscle index(ASMI) using bioelectrical impedance analysis (BIA). S was defined based on the criteria of the Asian Working Group for Sarcopenia 2 (AWGS2), which included muscle mass (ASMI< 7.0 kg/m² for men and ASMI< 5.7 kg/m² for women by BIA) and low muscle strength (handgrip strength < 28 kg for men and < 18 kg for women), and/or gait speed < 1.0 m/s. HHcy defined as Hcy ≥10 μmol/L. The strength of the association between Hcy and the risk of S was analyzed by multivariate logistic regression using three models that adjusted for possible confounding variables to calculate the odds ratios (ORs) and 95% confidence intervals (CIs).

RESULTS

Among the 441 subjects, 161 (36.5%) were diagnosed with S, and 343 (77.8%) were diagnosed with HHcy. A significant association was detected between S and serum Hcy per 1-μmol/L increase after adjustment for age, gender, education, smoking, body mass index (BMI), Mini Nutritional Assessment Short Form (MNA-SF), alanine aminotransferase (ALT), C-reactive protein (CRP), hemoglobin (Hb), albumin (ALB), diabetes, kidney disease, and statin use (OR = 1.07, 95% CI = 1.03-1.12, P = 0.002). The OR for S in the HHcy group (≥10 μmol/L) was nearly 5-fold that in the normal Hcy group (OR 4.96, 95% CI 2.67-9.24, P < 0.001). In a gender-based subgroup analysis that adjusted for age, education, smoking, BMI, MNA-SF, ALT, CRP, Hb, and ALB, female subjects with HHcy had an increased risk of S (OR 10.35, 95% CI 2.84-37.68, P < 0.001).

CONCLUSIONS

Our results demonstrated that elevated Hcy levels have an independent association with S in older adults. This suggests that the downward adjustment of HHcy (cutoff value < 10 μmol/l) might decrease the risk of S.

Relationship between hyperhomocysteinemia and coexisting obesity with low skeletal muscle mass in asymptomatic adult population

The relationship between hyperhomocysteinemia (HHcy) and obesity with low skeletal muscle mass (LMM) has not been established. We aim to assess the association between HHcy and the coexistence of obesity and LMM in asymptomatic adult population. We conducted a population-based cross-sectional study among asymptomatic individuals who underwent measurements of plasma homocysteine and body composition analysis. HHcy was defined as > 15 umol/L, obesity as body mass index ≥ 25 (kg/m²), and LMM as skeletal muscle index less than 2 SD below the sex-specific mean of young adults. The participants were classified into ‘control’, ‘obesity alone’, ‘LMM alone’, and ‘obesity with LMM’. Among 113,805 participants, the prevalence of HHcy was 8.3% in control, 8.7% in obesity alone, 10.0% in LMM alone, and 13.0% in obesity with LMM (p for trend < 0.001). In a multivariable logistic regression analysis, the associations showed a positive trend for HHcy along the groups from obesity alone, to LMM alone, and to obesity with LMM. HHcy was independently associated with the presence of LMM alone (adjusted odds ratio 1.186 [95% confidence interval 1.117–1.259]) and obesity with LMM (1.424 [1.134–1.788]), respectively. This study demonstrated that HHcys was more strongly associated with coexistence of obesity and LMM than either condition alone in the adult population.

The Association of Circulating Amino Acids and Dietary Inflammatory Potential with Muscle Health in Chinese Community-Dwelling Older People

Amino acids (AAs) and dietary inflammatory potential play essential roles in muscle health. We examined the associations of dietary inflammatory index (DII) of habitual diet with serum AA profile, and ascertained if the associations between DII and muscle outcomes were mediated by serum AAs, in 2994 older Chinese community-dwelling men and women (mean age 72 years) in Hong Kong. Higher serum branched chain AAs (BCAAs), aromatic AAs and total glutathione (tGSH) were generally associated with better muscle status at baseline. A more pro-inflammatory diet, correlating with higher serum total homocysteine and cystathionine, was directly (90.2%) and indirectly (9.8%) through lower tGSH associated with 4-year decline in hand grip strength in men. Higher tGSH was associated with favorable 4-year changes in hand grip strength, gait speed and time needed for 5-time chair stands in men and 4-year change in muscle mass in women. Higher leucine and isoleucine were associated with decreased risk of sarcopenia in men; the associations were abolished after adjustment for BMI. In older men, perturbations in serum sulfur AAs metabolism may be biomarkers of DII related adverse muscle status, while the lower risk of sarcopenia with higher BCAAs may partly be due to preserved BMI.

Plasma homocysteine levels and handgrip strength in postmenopausal women

OBJECTIVE

This study evaluated handgrip strength (HGS), circulating homocysteine levels and related factors in postmenopausal women.

METHODS

This study is a sub-analysis of a prospective cohort of 303 postmenopausal women aged 62.7 ± 6.9 years who had HGS measures with a digital dynamometer as the primary outcome, and plasma homocysteine and creatinine levels and glomerular filtration rate (GFR) measures as the secondary outcomes.

RESULTS

The average HGS was 22.5 ± 4.0 kg, 29.4% of women had dynapenia (HGS < 20 kg), adiposity was 40.3 ± 5.4% and 9.57% of women had hyperhomocysteinemia (homocysteine >15 μmol/l). There were no differences between tertiles of homocysteine and HGS (p = 0.641). Plasma homocysteine levels were unrelated to HGS (r = -0.06) and correlated with age (r = 0.17), GFR (r = -0.28) and creatinine (r = 0.23). Hyperhomocysteinemia was not associated with HGS (odds ratio [OR] = 0.98 [95% confidence interval (CI): 0.89; 1.08]) or dynapenia (OR = 1.10 [95% CI: 0.45; 2.47]). The risk of presenting low HGS were not significantly associated with homocysteine (OR = -0.08 [95% CI: -0.21; 0.06]) and were associated with age (OR = -0.23 [95% CI: -0.29; -0.17]), adiposity (OR = -6.52 [95% CI: -9.53; -3.50]) and creatinine (OR = 6.22 [95% CI: 2.48; 9.97]).

CONCLUSIONS

HGS and dynapenia were unrelated to hyperhomocysteinemia. Age, GFR and creatinine were significantly associated with plasma homocysteine levels.

Causal effects of homocysteine levels on the components of sarcopenia: A two-sample mendelian randomization study

Background: Currently, it is unclear whether there is a causal association between genetically predicted plasma homocysteine (Hcy) levels and the risk of sarcopenia. We performed a Mendelian randomization (MR) study to assess the association between circulating Hcy levels and the components [grip strength, walking pace, and appendicular lean mass (ALM)] of sarcopenia. Methods: Independent single nucleotide polymorphisms (SNPs) significantly associated with plasma Hcy levels served as instrumental variables. Summary-level data regarding the components of sarcopenia. Were obtained from the UK Biobank. Inverse variance weighted (IVW) as the primary method was used for Mendelian randomization (MR) analysis. We also use four models, weighted median, MR-Egger regression, Maximum likelihood, and Penalised weighted median, as supplementary methods to IVW. The MR-Egger intercept test, Cochran's Q test, and "leave-one-out" sensitivity analysis were performed to evaluate the horizontal pleiotropy, heterogeneities, and stability of the causal association between Hcy levels and the components of sarcopenia. Results: The IVW-MR analysis suggested significant negative associations of increased plasma Hcy levels with grip strength (right: effect = -0.036, SE = 0.032, p = 5.53E-4; left: effect = -0.045, SE = 0.010, p = 1.45E-5), walking pace (effect = -0.038, SE = 0.011, p = 3.18E-4), and ALM (effect = -0.058, 0.013, p = 1.03E-5). However, there were no significant associations of decreased plasma Hcy levels with grip strength (right: effect = 0.005, SE = 0.021, p = 0.82; left: effect = -0.006, SE = 0.014, p = 0.64), walking pace (effect = 0.01, 0.020, p = 0.61), or ALM (effect = -0.034, SE = 0.018, p = 0.06).The accuracy and robustness of these findings were confirmed by sensitivity tests. Conclusion: Increased circulating Hcy levels were associated with lower grip strength, slower walking pace, and decreased ALM.

COVID-19 Pandemic as Risk Factors for Excessive Weight Gain in Pediatrics: The Role of Changes in Nutrition Behavior. A Narrative Review

During the coronavirus disease 2019 (COVID-19) pandemic, social isolation, semi-lockdown, and "stay at home" orders were imposed upon the population in the interest of infection control. This dramatically changes the daily routine of children and adolescents, with a large impact on lifestyle and wellbeing. Children with obesity have been shown to be at a higher risk of negative lifestyle changes and weight gain during lockdown. Obesity and COVID-19 negatively affect children and adolescents' wellbeing, with adverse effects on psychophysical health, due in large part to food choices, snacking between meals, and comfort eating. Moreover, a markable decrease in physical activity levels and an increase in sedentary behavior is associated with weight gain, especially in children with excessive weight. In addition, obesity is the most common comorbidity in severe cases of COVID-19, suggesting that immune dysregulation, metabolic unbalance, inadequate nutritional status, and dysbiosis are key factors in the complex mechanistic and clinical interplay between obesity and COVID-19. This narrative review aims to describe the most up-to-date evidence on the clinical characteristics of COVID-19 in children and adolescents, focusing on the role of excessive weight and weight gain in pediatrics. The COVID-19 pandemic has taught us that nutrition education interventions, access to healthy food, as well as family nutrition counselling should be covered by pediatric services to prevent obesity, which worsens disease outcomes related to COVID-19 infection.

Perspective: Practical Approach to Preventing Subclinical B12 Deficiency in Elderly Population

Vitamin B12 (also known as cobalamin) is an essential water-soluble vitamin that plays a pivotal role for several physiologic functions during one's lifespan. Only certain microorganisms are able to synthetize B12, thus humans obtain cobalamin exclusively from their diet, specifically from animal-derived foods. Specific sub-group populations are at risk of vitamin B12 subclinical deficiency due to different factors including poor intake of animal source foods and age-dependent decrease in the capacity of intestinal B12 uptake. Consumption of animal products produces some negative health issues and negatively impacts sustainability while a plant-based diet increases the risk of B12 deficiency. Taking a cue from the aforementioned considerations, this narrative review aims to summarize facts about B12 deficiency and the burden of inadequate dietary intake in elderly population, as well as to discuss sustainable approaches to vitamin B12 deficiency in aging population.