Association of low plasma selenium concentrations with poor muscle strength in older community-dwelling adults: the InCHIANTI Study

Association between the composite dietary antioxidant index and sarcopenia among United States adults: A cross-sectional study

BACKGROUND

Diets high in antioxidants are associated with decreased prevalence of sarcopenia. This study aimed to investigate whether the composite dietary antioxidant index (CDAI) and sarcopenia have an underlying relationship.

METHODS

We used the data from the National Health and Nutrition Examination Survey 2011-2018. According to dietary antioxidant intake, the CDAI was calculated for each individual. Appendicular skeletal muscle mass index was employed to determine sarcopenia. Multivariate weighted logistic models and restricted cubic spline regression analysis was undertaken to determine the association between CDAI and sarcopenia.

RESULTS

A total of 7012 participants were enrolled in this study, including 473 with sarcopenia (weighted percentage, 5.6%). Compared with the lowest tertile, those in the highest tertile of the CDAI exhibited a greater likelihood of being male, with lower body mass index, higher education level and economic standard, and more chance of being single or separated. In multivariate weighted logistic models, model 3 revealed a noteworthy inverse association between the CDAI and sarcopenia (odds ratio = 0.94; 95% CI, 0.91-0.98; P = 0.003). Compared with the lowest tertile, the highest tertile of CDAI was associated with a 0.57-fold risk of sarcopenia (95% CI, 0.42-0.77; P < 0.001). The inverse association between CDAI and sarcopenia strengthened in the participants with elevated education levels (P for interaction = 0.003).

CONCLUSION

The CDAI was inversely correlated with the prevalence of sarcopenia. As a comprehensive measurement representing antioxidant status, the CDAI may help manage and prevent sarcopenia.

Dietary selenium intake and sarcopenia in American adults

Background

The relationship between dietary selenium intake and sarcopenia remains poorly understood. Therefore, this study investigates the associations between dietary selenium intake and sarcopenia among American adults.

Methods

This cross-sectional study analyzed data from 19,696 participants in the National Health and Nutrition Examination Survey (NHANES) for the periods 1999-2006 and 2011-2018. Appendicular muscle mass, assessed using dual-energy x-ray absorptiometry and adjusted for body mass index, was used as a marker for sarcopenia. Dietary selenium intake was evaluated using the 24-h dietary recall system, and the study accounted for the complex sampling methodology and incorporated dietary sample weights in the analysis.

Results

Among the 19,696 participants, the prevalence of sarcopenia was found to be 8.46%. When compared to the lowest quintile of dietary selenium intake (Q1, < 80.10 μg/day), the odds ratios for sarcopenia in the second quintile (Q2, 80.10-124.61 μg/day) and the third quintile (Q3, >124.61 μg/day) were 0.80 [95% confidence interval (CI): 0.70-0.92, p = 0.002] and 0.61 (95% CI: 0.51-0.73, p < 0.001), respectively. A negative relationship was observed between dietary selenium intake and sarcopenia (non-linear: p = 0.285). Furthermore, sensitivity analyses revealed a robust association between selenium intake and the prevalence of sarcopenia after further adjusting for blood selenium levels.

Conclusion

The results suggest an inverse association between dietary selenium intake and the prevalence of sarcopenia among American adults.

Associations between dietary total antioxidant capacity and sarcopenia: a cross-sectional study

BACKGROUND

No study has investigated the relationship between dietary total antioxidant capacity and sarcopenia so far.

OBJECTIVE

This study aimed to investigate the association between dietary Total Antioxidant Capacity (d-TAC) and sarcopenia in elderly adults.

METHODS

In this cross-sectional study we enrolled 300 elderly people (150 men and 150 women) aged ≥ 55 years using cluster random sampling method. Sarcopenia was defined based on European Working Group on Sarcopenia (EWGSOP) definition. A DXA scanner, a squeeze bulb dynamometer and a 4-Meter walk gait speed test was used to measure Appendicular Skeletal Muscle (ASM), muscle strength and muscle performance respectively. We also used a Block-format 117-item food frequency questionnaire (FFQ) to assess dietary intakes of participants. Multivariable logistic regression models were applied to examine the association between d-TAC and sarcopenia.

RESULTS

Mean ± SD age of study participants and their BMI was 66.8 ± 7.72 year and 27.3 ± 4.2 kg/m2, respectively. People in the highest tertile of d-TAC had the greatest hand grip strength (11.9 ± 3.63 vs. 10.4 ± 3.55 psi, p = 0.009) and had lower odds of sarcopenia compared with those in the lowest tertile, either before (OR = 0.39; 95% CI: 0.17, 0.88) or after adjustment for potential confounders (OR = 0.33; 95% CI: 0.11, 0.95). No other significant association was seen between d-TAC and components of sarcopenia.

CONCLUSION

We found an inverse association between dietary total antioxidant capacity and odds of sarcopenia. No significant association was seen between d-TAC and individual components of sarcopenia. Further studies are needed to confirm our findings.

Selenium Status of Southern Africa

Selenium is an essential trace element that exists in inorganic forms (selenite and selenates) and organic forms (selenoamino acids, seleno peptides, and selenoproteins). Selenium is known to aid in the function of the immune system for populations where human immunodeficiency virus (HIV) is endemic, as studies suggest that a lack of selenium is associated with a higher risk of mortality among those with HIV. In a recent study conducted in Zambia, adults had a median plasma selenium concentration of 0.27 μmol/L (IQR 0.14-0.43). Concentrations consistent with deficiency (<0.63 μmol/L) were found in 83% of adults. With these results, it can be clearly seen that selenium levels in Southern Africa should be investigated to ensure the good health of both livestock and humans. The recommended selenium dietary requirement of most domesticated livestock is 0.3 mg Se/kg, and in humans above 19 years, anRDA (recommended daily allowance) of 55 mcg Se/per dayisis recommended, but most of the research findings of Southern African countries have recorded low levels. With research findings showing alarming low levels of selenium in soils, humans, and raw feed materials in Southern Africa, further research will be vital in answering questions on how best to improve the selenium status of Southern African soils and plants for livestock and humans to attain sufficient quantities.

Association of Serum Concentrations of Copper, Selenium, and Zinc with Grip Strength Based on NHANES 2013-2014

Increasing evidence has found metals to be strongly associated with muscle strength, but the correlations between serum copper (Cu), selenium (Se), and zinc (Zn) with grip strength in adult populations have not yet been established. We examined the linear and non-linear associations between these three metals and grip strength via multiple linear regression and restricted cubic spline (RCS) regression using data from the National Health and Nutrition Examination Survey (NHANES) 2013-2014. A higher concentration of serum Cu was monotonically linked with lower grip strength [β = - 0.004 m2 (95% CI: - 0.005, - 0.002)], and serum Zn was positively associated with grip strength [β = 0.004 m2 (95% CI: 0.002, 0.006)]. We observed a positive association between serum Se and grip strength in the unadjusted model but not in covariate-adjusted models. Interestingly, the results of RCS regression showed that serum Cu had an L-shaped non-linear association with grip strength in all participants and subgroups. We further found a linear-increased trend between serum Zn and the grip strength in all participants. There were also non-linear associations that varied across different subgroups. Taken together, serum Cu and Zn were significantly associated with grip strength, while Se was not. This study offers new evidence to help formulate a reference concentration range for serum Cu and Zn.

Blood Selenium Concentrations Are Inversely Associated with the Risk of Undernutrition in Older Adults

BACKGROUND

Selenium is an essential trace element with an antioxidant and anti-inflammatory capacity that has been associated in experimental studies with beneficial effects on appetite control, the regulation of the gut microbiota, and control of the anabolic-catabolic balance. The main aim of the present study was to evaluate the association between circulating selenium concentrations and the risk of developing undernutrition in older adults.

METHODS

This was a cohort study with 1398 well-nourished community-dwelling individuals aged ≥ 65 years residing in Spain in 2017, who were followed for a mean of 2.3 years. Whole blood selenium was measured at baseline using inductively coupled plasma-mass spectrometry. Undernutrition was assessed at baseline and at follow-up, and defined as having at least one of the three GLIM phenotypic criteria (involuntary weight loss, a low body mass index, and a reduced muscle mass) and at least one of the two etiologic criteria (reduced food consumption or nutrient assimilation and inflammation/disease burden).

RESULTS

During the follow-up, 142 participants (11%) developed moderate undernutrition and 113 (8.8%) severe undernutrition. The standardized relative risks of moderate and severe undernutrition at the 75th percentile of Se levels versus the 25th were 0.90 and 0.70, respectively. In dose-response analyses, the risk of severe undernutrition decreased linearly with increasing selenium concentrations. This association was independent of protein intake or diet quality and was stronger among participants with a diagnosis of a musculoskeletal disorder.

CONCLUSIONS

The results suggest that an adequate dietary selenium status is needed to prevent undernutrition in older adults. Also, this may open the door for clinical trials with selenium supplementation, at doses considered as safe, to prevent undernutrition.

The Crucial Role of Diet Therapy and Selenium on the Evolution of Clinical and Paraclinical Parameters in Patients with Metabolic Syndrome

Oxidative stress (OS) is associated with metabolic syndrome (MS) and represents a complex disease association that has become a major challenge in the field of public health. The aim of this study was to investigate the effectiveness of introducing selenium in the management of OS, while considering a balanced diet based on a healthy lifestyle and dietary therapy. A total of 206 individuals participated voluntarily in the study, divided into three groups: the control group with 35 individuals (17.0%) designated as control lot (LC), the group undergoing diet therapy with 119 individuals (57.8%) designated as diet therapy lot (LD), and the group undergoing diet therapy supplemented with selenium consisting of 52 individuals (25.2%) designated as diet therapy with selenium lot (LD + Se). The study assessed various clinical parameters (such as body mass index (BMI), body weight status, fat mass, visceral fat, and sarcopenic index), paraclinical parameters (including HOMA index, cholesterol, triglycerides, C-reactive protein, and glycosylated haemoglobin (HGS)), as well as OS parameters (measured using the FORD test, FORT test, and MIXED test). The LD + Se group demonstrated the most favourable results in terms of BMI reduction, decreased fat and visceral mass, reduced levels of C-reactive protein, and improved glycosylated haemoglobin levels. By implementing a balanced diet therapy and supplementing the diet with selenium, it was possible to achieve a reduction in adipose tissue and glycosylated haemoglobin levels, ultimately contributing to the reduction of OS in the body.

Minerals and Sarcopenia in Older Adults: An Updated Systematic Review

OBJECTIVE

This systematic review aims to reevaluate the role of minerals on muscle mass, muscle strength, physical performance, and the prevalence of sarcopenia in community-dwelling and institutionalized older adults.

DESIGN

Systematic review.

SETTING AND PARTICIPANTS

In March 2022, a systematic search was performed in PubMed, Scopus, and Web of Sciences using predefined search terms. Original studies on dietary mineral intake or mineral serum blood concentrations on muscle mass, muscle strength, and physical performance or the prevalence of sarcopenia in older adults (average age ≥65 years) were included.

METHODS

Eligibility screening and data extraction was performed by 2 independent reviewers. Quality assessment was performed with the Effective Public Health Practice Project (EPHPP) Quality Assessment Tool for Quantitative Studies. Risk of bias was evaluated using the Risk Of Bias In Non-randomized Studies-of Exposure (ROBINS-E) tool.

RESULTS

From the 15,622 identified articles, a total of 45 studies were included in the review, mainly being cross-sectional and observational studies. Moderate quality of evidence showed that selenium (n = 8) and magnesium (n = 7) were significantly associated with muscle mass, strength, and physical performance as well as the prevalence of sarcopenia. For calcium and zinc, no association could be found. For potassium, iron, sodium, and phosphorus, the association with sarcopenic outcomes remains unclear as not enough studies could be included or were nonconclusive (low quality of evidence).

CONCLUSIONS AND IMPLICATIONS

This systematic review shows a potential role for selenium and magnesium on the prevention and treatment of sarcopenia in older adults. More randomized controlled trials are warranted to determine the impact of minerals on sarcopenia in older adults.

Selenium Deficiency Leads to Reduced Skeletal Muscle Cell Differentiation by Oxidative Stress in Mice

Selenium (Se) is one of the essential trace elements in animal organisms with good antioxidant and immune-enhancing abilities. In this study, we investigated the effect and mechanism of Se deficiency on skeletal muscle cell differentiation. A selenium-deficient skeletal muscle model was established. The skeletal muscle tissue and blood Se content were significantly reduced in the Se deficiency group. HE staining showed that the skeletal muscle tissue had a reduced myofiber area and nuclei and an increased myofascicular membrane with Se deficiency. The TUNEL test showed massive apoptosis of skeletal muscle cells in Se deficiency. With Se deficiency, reactive oxygen species (ROS) and malondialdehyde (MDA) increased, and the activities of glutathione peroxidase (GSH-Px), total antioxidant capacity (T-AOC), superoxide dismutase (SOD), and catalase (CAT) were inhibited. In in vitro experiments, microscopic observations showed that the low-Se group had reduced C2C12 cell fusion and a reduced number of differentiated myotubes. In addition, qPCR results showed that differentiation genes (Myog, Myod, Myh2, Myh3, and Myf5) were significantly reduced in the low Se group. Meanwhile, Western blot analysis showed that the levels of differentiation proteins (Myog, Myod, and Myhc) were significantly reduced in the low-Se group. This finding indicates that Se deficiency reduces the expression of skeletal muscle cell differentiation factors. All the above data suggest that Se deficiency can lead to oxidative stress in skeletal muscle, resulting in a reduction in the differentiation capacity of muscle cells.

Association between composite dietary antioxidant index and handgrip strength in American adults: Data from National Health and Nutrition Examination Survey (NHANES, 2011-2014)

Background

The Composite Dietary Antioxidant Index (CDAI), a composite score of multiple dietary antioxidants (including vitamin A, C, and E, selenium, zinc, and carotenoids), represents an individual's comprehensive dietary antioxidant intake profile. CDAI was developed based on its combined effect on pro-inflammatory markers Tumor Necrosis Factor-α (TNF-α) and anti-inflammatory effects of Interleukin-1β (IL-1β), which are associated with many health outcomes, including depression, all-cause mortality, colorectal cancer, etc. Handgrip strength is used as a simple measure of muscle strength, not only is it highly correlated with overall muscle strength, but also serves as a diagnostic tool for many adverse health outcomes, including sarcopenia and frailty syndromes.

Purpose

The association between CDAI and Handgrip strength (HGS) is currently unclear. This study investigated the association between CDAI (including its components) and HGS in 6,019 American adults.

Method

The research data were selected from the 2011-2014 National Health and Nutrition Survey (NHANES), and a total of 6,019 American adults were screened and included. A weighted generalized linear regression model was used to evaluate CDAI (including its components) and HGS.

Results

(1) CDAI was significantly positively correlated with HGS (β = 0.009, 0.005∼0.013, P < 0.001), and the trend test showed that compared with the lowest quartile of CDAI, the highest quartile of CDAI was positively correlated with HGS (β = 0.084, 0.042∼0.126, P = 0.002) and significant in trend test (P for trend < 0.0100). Gender subgroup analysis showed that male CDAI was significantly positively correlated with HGS (β = 0.015, 0.007∼0.023, P = 0.002), and the trend test showed that compared with the lowest quartile of CDAI, the highest quartile of CDAI was positively correlated with HGS (β = 0.131, 0.049∼0.213, P = 0.006) and the trend test was significant (P for trend < 0.0100). There was no correlation between female CDAI and HGS, and the trend test was not statistically significant (P > 0.05). (2) The intake of dietary vitamin E, Zinc and Selenium showed a significant positive correlation with HGS (β = 0.004, 0.002∼0.007, P = 0.006; β = 0.007, 0.004∼0.009, P < 0.001; β = 0.001, 0.001∼0.001, P < 0.001), vitamin A, vitamin C and carotenoid were significantly associated with HGS in the Crude Model, but this significant association disappeared in the complete model with the increase of control variables. Gender subgroup analysis showed that in model 3, male dietary intake levels of vitamin E, Zinc, and Selenium were significantly positively correlated with HGS (β = 0.005, 0.002∼0.009, P = 0.011; β = 0.007, 0.004∼0.011, P = 0.001; β = 0.001, 0.001∼0.001, P = 0.004), the rest of the indicators had no significant correlation with HGS. Among the female subjects, dietary zinc intake was significantly positively correlated with HGS (β = 0.005, 0.001∼0.008, P = 0.008), and there was no significant correlation between other indicators and HGS (P > 0.05).

Conclusion

There was an association between the CDAI and HGS, but there was a gender difference, and there was an association between the CDAI and HGS in male, but the association was not significant in female. Intake of the dietary antioxidants vitamin E, selenium, and zinc was associated with HGS in male, but only zinc was associated with HGS among dietary antioxidants in female.

Nutrition in the prevention and management of sarcopenia - A special focus on Asian Indians

Sarcopenia, characterized by loss of muscle mass and strength, is common in advanced old age but can be accelerated by chronic disease, malnutrition and physical inactivity. Early initiation of intervention to achieve and maintain a higher peak muscle mass and strength may allow for prevention or delay of sarcopenia and facilitate independent living even in old age. In this context, malnutrition, a significant contributor to sarcopenia, is often overlooked among the Indian population. Maintenance of an optimal energy and protein balance with adequate physical activity level is essential to preserve physical function in the aging population. However, research on the role of micronutrients in muscle maintenance, is still in its infancy. This narrative review, therefore, aims to explore the current status of International and Indian research on the role of nutrition in sarcopenia mitigation and the way forward.

Long-Term Selenium-Yeast Supplementation Does Not Affect Bone Turnover Markers: A Randomized Placebo-Controlled Trial

Higher selenium status has been associated with lower bone turnover markers (BTM) in epidemiological studies. However, the long-term impact of selenium supplementation on BTMs has not been studied. We investigated the effects of selenium supplementation on BTMs including osteocalcin (OC), procollagen type I N-terminal propeptide (PINP), collagen type I cross-linked C-telopeptide (CTX), and bone alkaline phosphatase (BALP) in the short (6 months) and long term (5 years). A total of 481 Danish men and women (60-74 years) were randomized to receive placebo-yeast versus 100, 200, or 300 μg selenium as selenium-enriched yeast daily for 5 years. Plasma selenium concentration was measured using inductively coupled plasma mass spectrometry, and BTMs were measured in nonfasted samples at baseline, 6 months, and 5 years. Data were analyzed by ANCOVA to investigate the shape of the dose-response relationships. Covariates included age, body mass index, baseline selenium status, baseline BTM, smoking, alcohol, supplement use, and medication. Plasma selenium concentration (mean 86.5 μg/d at baseline) increased significantly with increasing selenium supplementation to 152.6, 209.1, and 253.7 μg/L after 6 months and remained elevated at 5 years (158.4, 222.4, and 275.9 μg/L for 100, 200, and 300 μg supplemental selenium/d, respectively (p < 0.001)). There was no change in plasma selenium concentration in the placebo-treated group. There was no significant effect of selenium supplementation on OC (6 months p = 0.37; 5 years p = 0.63), PINP (6 months p = 0.37; 5 years p = 0.79), CTX (6 months p = 0.91; 5 years p = 0.58) or BALP (6 months p = 0.17; 5 years p = 0.53). The relatively replete baseline selenium status in the study participants may explain this lack of effect. Testing in more deficient populations may provide further insights into the impact of selenium supplementation on bone health. © 2022 The Authors. Journal of Bone and Mineral Research published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research (ASBMR).

High Adherence to the Mediterranean Diet is Associated with Higher Physical Fitness in Adults: a Systematic Review and Meta-Analysis

Although prior research has synthesized the relationships between the Mediterranean diet (MD) and components of physical fitness (PF) in adults, they are limited and inconclusive. This study aimed to synthesize the associations between high (compared with low) MD adherence and PF levels with each of its components (cardiorespiratory, motor, and musculoskeletal) in adulthood. We conducted a systematic search in 5 databases from inception to January 2022. Observational studies and randomized controlled trials were included. Pooled odds ratios (ORs) and effect sizes (Cohen d index) with their 95% CIs were calculated via a random effects model. A total of 30 studies were included (19 cross-sectional in young, middle-aged, and older adults; 10 prospective cohort in older adults; and 1 randomized controlled trial in young adults) involving 36,807 individuals (mean age range: 20.9-86.3 y). Pooled effect sizes showed a significant cross-sectional association between higher MD adherence scores (as a continuous variable) and overall PF (d = 0.45; 95% CI: 0.14, 0.75; I2 = 91.0%, n = 6). The pooled ORs from cross-sectional data showed that high adherence to MD was associated with higher cardiorespiratory fitness (OR: 2.26; 95% CI: 2.06, 2.47; I2 = 0%, n = 4), musculoskeletal fitness (OR: 1.26; 95% CI: 1.05, 1.47; I2 = 61.4%, n = 13), and overall PF (OR: 1.44; 95% CI: 1.20, 1.68; I2 = 83.2%, n = 17) than low adherence to MD (reference category: 1). Pooled ORs from prospective cohort studies (3- to 12-y follow-up) showed that high adherence to MD was associated with higher musculoskeletal fitness (OR: 1.20; 95% CI: 1.01, 1.38; I2 = 0%, n = 4) and overall PF (OR: 1.14; 95% CI: 1.02, 1.26; I2 = 9.7%, n = 7) than low adherence to MD (reference category: 1). Conversely, no significant association was observed between MD and motor fitness. High adherence to MD was associated with higher PF levels, a crucial marker of health status throughout adulthood. This trial was registered at PROSPERO as CRD42022308259.

Association of Frailty Status and Dietary Patterns in a Nationally Representative Sample of United States Adults with Olfactory Dysfunction

Background: Olfactory dysfunction (OD) is a strong, independent predictor of frailty and mortality risk. This study evaluated the association of dietary patterns and frailty status in older adults with OD. Methods: This cross-sectional study utilized the 2013–2014 National Health and Nutrition Examination Survey. Dietary patterns (DPs) characteristic of OD were derived using exploratory factor analysis (EFA). Multiple logistic regressions adjusted for demographics and frailty risk factors assessed the association of DPs with two frailty metrics: the frailty index (FI) and physical frailty (PF). Results: EFA yielded six distinct DPs in persons with OD. The protein/selenium (OR 0.82 [95% CI 0.74–0.92], p = 0.041) and β-carotene/vitamin A DPs (OR 0.76 [95% CI 0.66–0.88], p = 0.028) were independently associated with frailty by FI. Only the protein/selenium DP (OR 0.82 [95% CI 0.74–0.92], p = 0.036) was associated with frailty by PF. No DPs were associated with either frailty measure in normosmic persons. Conclusions: Dietary patterns high in protein/selenium and β-carotene/vitamin A are associated with lower frailty prevalence in adults with OD. While the relationship between OD and frailty is likely multifaceted, these findings suggest that dietary patterns are uniquely associated with frailty in older adults with OD.

From the Bench to the Bedside: Branched Amino Acid and Micronutrient Strategies to Improve Mitochondrial Dysfunction Leading to Sarcopenia

With extended life expectancy, the older population is constantly increasing, and consequently, so too is the prevalence of age-related disorders. Sarcopenia, the pathological age-related loss of muscle mass and function; and malnutrition, the imbalance in nutrient intake and resultant energy production, are both commonly occurring conditions in old adults. Altered nutrition plays a crucial role in the onset of sarcopenia, and both these disorders are associated with detrimental consequences for patients (e.g., frailty, morbidity, and mortality) and society (e.g., healthcare costs). Importantly, sarcopenia and malnutrition also share critical molecular alterations, such as mitochondrial dysfunction, increased oxidative stress, and a chronic state of low grade and sterile inflammation, defined as inflammageing. Given the connection between malnutrition and sarcopenia, nutritional interventions capable of affecting mitochondrial health and correcting inflammageing are emerging as possible strategies to target sarcopenia. Here, we discuss mitochondrial dysfunction, oxidative stress, and inflammageing as key features leading to sarcopenia. Moreover, we examine the effects of some branched amino acids, omega-3 PUFA, and selected micronutrients on these pathways, and their potential role in modulating sarcopenia, warranting further clinical investigation.

Prevalence and correlates of low plasma selenium concentrations in peritoneal dialysis patients

OBJECTIVE

Selenium is a key component in multiple enzyme systems, and dialysis patients with lower levels have been reported to have increased mortality. Low selenium levels were commonly reported in historic hemodialysis patients, but not in recent studies. There have been very few studies in peritoneal dialysis (PD) patients, and with the increasing age and frailty of our PD population we wished to review factors associated with lower selenium in PD patients.

DESIGN & METHODS

We retrospectively reviewed plasma selenium, normal laboratory >0.8 umol/L, measurements from a cohort of PD patients, attending for routine peritoneal membrane assessments, along with measurement of dialysis adequacy (Kt/Vurea), and normalized nitrogen appearance rate (nPNA) and bioimpedance measured extracellular water (ECW)/total body water (TBW), and skeletal muscle mass indexed for height (SMMI).

RESULTS

The median plasma selenium was 0.84 (IQR-0.72-1.01) umol/L in 406 PD patients, 61.1 % male, mean age 59.0 ± 15.5 years, 44.9 % diabetic with 15.8 % designated as clinically frail (CFS). 41.4 % had selenium deficiency (<0.8 umol/L), and was more common with increasing CFS (χ2-6.8, p < 0.009), comorbidity grade(χ2-26.74, p < 0.001).Plasma selenium correlated with serum total protein (TP) (r = 0.352), albumin (r = 0.358), nPNA (r = 0.263), and negatively with ECW/TBW (r= -0.321) all p < 0.001, and positively with SMMI (rho = 0.109, p = 0.03). On multivariable analysis selenium was independently associated with TP (β 0.799 ± 0.15,95 % confidence limits (95CL) (0.505-1.093), p=<0.001), and negatively with C reactive protein (CRP) (β -0.02 ± 0.01, (95CL -0.047 to -0.005) p = 0.01), and ECW/TBW (β -1.499 ± 0.42 (95CL -2.33 to -0.666) p=<0.001).

CONCLUSIONS

Compared to recent studies in hemodialysis patients, we report a 41 % prevalence for low selenium levels. Plasma selenium was positively associated with total serum protein, and negatively with CRP and ECW/TBW. Thus, lower selenium concentrations were linked to reduced dietary protein intake, and increasing frailty, inflammation and ECW/TBW ratios.

Adherence to the Mediterranean diet assessed by a novel dietary biomarker score and mortality in older adults: the InCHIANTI cohort study

BACKGROUND

Dietary biomarkers may complement dietary intake assessment made by dietary questionnaires. We developed an a-posteriori dietary biomarkers score based on Mediterranean diet food groups and evaluated its association with mortality.

METHODS

642 participants (56% female), aged ≥65 years, with complete data on dietary biomarkers were followed during 20 years in the InCHIANTI cohort study (Tuscany, Italy). The main outcomes were all-cause, cardiovascular, and cancer mortality. Dietary biomarkers were selected from literature and from correlation analyses with dietary intakes of Mediterranean diet food groups in the study. The baseline levels of the following dietary biomarkers were chosen: urinary total polyphenols and resveratrol metabolites, and plasma carotenoids, selenium, vitamin B12, linolenic, eicosapentaenoic and docosahexaenoic acids, and the mono-unsaturated/saturated fatty acid ratio. Associations of the Mediterranean diet score using dietary biomarkers and a validated food frequency questionnaire (FFQ) (as tertiles) with mortality were assessed through Cox regression.

RESULTS

During the 20-year follow-up [median (Q1-Q3), 14 (8-18) years], and 435 deaths occurred (139 from cardiovascular diseases and 89 from cancer-related causes). In the fully adjusted models, the dietary biomarker-Mediterranean diet score was inversely associated with all-cause (HR_T3vs.T1 0.72; 95%CI 0.56-0.91) and cardiovascular (HR_T3vs.T1 0.60; 95%CI 0.38-0.93), but not with cancer mortality. Associations between the FFQ-Mediterranean diet score and mortality were not statistically significant.

CONCLUSIONS

A greater adherence at baseline to a Mediterranean diet assessed by a dietary biomarker score was associated with a lower risk of mortality in older adults during a 20-year follow-up. The measurement of dietary biomarkers may contribute to guide individualized dietary counseling to older people.

TRIAL REGISTRATION

NCT01331512.

Development of a diagnostic model focusing on nutritional indicators for frailty classification in people with chronic heart failure

AIMS

Frailty has a great impact on the quality of life of patients with chronic heart failure (CHF), which needs to be judged in time. To develop a diagnostic model based on nutritional indicators to judge the frailty status of patients with chronic heart failure (Frailty-CHF).

METHODS AND RESULTS

In the data collection part of this study, questionnaire method and biomedical measurement method were adopted. The trace elements in serum samples were detected by high performance liquid chromatography, chemiluminescence, and inductively coupled plasma mass spectrometry. We used Excel for data consolidation, and then imported the data into R software for modelling. Lasso method was used for variable screening, and Logistics regression fitting model was used after variables were determined. The internal validation of the model was completed by Bootstrap re-sampling. A total of 123 patients were included in this study. After variables' screening, age, nutritional status-heart failure, New York Heart Association Functional Class (NYHA), micronutrients B12, Ca, folic acid, and Se were included in the model, the c statistic and Brier score of the original model were 0.9697 and 0.0685, respectively. After Bootstrap re-sampling adjustment, the c statistic and Brier score were 0.8503 and 0.1690.

CONCLUSION

In this study, a diagnostic model of age, nutritional status-heart failure, NYHA, the micronutrients B12, Ca, folic acid, and Se was established. It could help healthcare professionals better identify the frailty status in patients with CHF.

Concentrations of Lead, Mercury, Selenium, and Manganese in Blood and Hand Grip Strength among Adults Living in the United States (NHANES 2011-2014)

Exposure to lead and mercury can cause deficits in neuromotor function. Selenium and manganese are essential elements, hence both deficiency and excess could result in decreased neuromotor function. We aimed to examine hand grip strength, a marker of neuromotor function, and blood concentrations of lead, mercury, selenium, and manganese in the general U.S. population. We used data from the National Health and Nutrition Examination Survey (NHANES, 2011–2014) on 6199 participants ages 20–79 years. We assessed associations of blood concentration for these elements and grip strength with generalized regression models, and cubic splines to detect possible nonlinear relations, adjusting for confounders. The results showed that mercury and manganese were not associated with grip strength. Lead was associated with weaker grip strength in women (for 10-fold increase in lead, −2.4 kg; 95% CI: −4.2, −0.5), but not in men. Higher selenium was associated with stronger grip strength in women (8.5 kg; 95% CI: 1.9, 15.1) and men (4.6; 95% CI: −11.9, 21.0), although the association was not significant in the latter. In conclusion, lead exposure was associated with weaker grip strength in women, even at the low exposure levels in the population. Furthermore, low blood selenium level was associated with weaker grip strength, suggesting that some individuals might have selenium deficiency manifesting with poorer neuromotor function.

The lack of association between dietary antioxidant quality score with handgrip strength and handgrip endurance amongst Tehranian adults: A cross-sectional study from a Middle East country

OBJECTIVE

The association between dietary antioxidant quality score (DAQS) and handgrip strength (HS) and handgrip endurance (HE) is still unclear. We aimed to investigate whether adherence to dietary antioxidant quality score (DAQS) is associated with handgrip strength (HS) and handgrip endurance (HE) amongst adults in Tehran.

METHODS

This cross-sectional study was conducted on 270 (43.7% males, mean age 37 years and 56.3% females, mean age 35 years) apparently healthy adult subjects (53.2% were married) selected from different parts of Tehran, Iran. Dietary intake was assessed using a 168-item validated food frequency questionnaire. DAQS was calculated using antioxidant-nutrient intake. Body composition was measured using a body composition analyser. Handgrip strength and endurance were measured by a digital handgrip dynamometer. Relative muscle strength was expressed as the ratio of handgrip strength by body mass index (BMI).

RESULTS

The results showed that DAQs had no significant association with HS (P = .67, adjusted R²  = .60) and HE (P = .19, adjusted R²  = .08) after adjusting for potential confounders. However, a significant positive association was found between selenium intake and HE even after adjusting for potential confounders (P = .01, adjusted R²  = .10). After controlling for potential confounders no differences in the mean of HS (P = .29) and also HE (P = .61) amongst tertiles of DAQS was found. Positive linear association was found between vitamin C (P = .02, adjusted R²  = .53) and vitamin E (P = .03, adjusted R²  = .55) intake with relative muscle strength.

CONCLUSION

Our results revealed that no significant association between DAQS and HE and HS. It was found that more intake of selenium was positively linked to HE. Dietary intake of vitamin C and vitamin E are associated with higher relative muscle strength. It is evident that more prospective studies are needed to confirm the veracity of our results.

Effect of selenium supplementation on musculoskeletal health in older women: a randomised, double-blind, placebo-controlled trial

BACKGROUND

Observational and preclinical studies show associations between selenium status, bone health, and physical function. Most adults in Europe have serum selenium below the optimum range. We hypothesised that selenium supplementation could reduce pro-resorptive actions of reactive oxygen species on osteoclasts and improve physical function.

METHODS

We completed a 6-month randomised, double-blind, placebo-controlled trial. We recruited postmenopausal women older than 55 years with osteopenia or osteoporosis at the Northern General Hospital, Sheffield, UK. Participants were randomly assigned 1:1:1 to receive selenite 200 μg, 50 μg, or placebo orally once per day. Medication was supplied to the site blinded and numbered by a block randomisation sequence with a block size of 18, and participants were allocated medication in numerical order. All participants and study team were masked to treatment allocation. The primary endpoint was urine N-terminal cross-linking telopeptide of type I collagen (NTx, expressed as ratio to creatinine) at 26 weeks. Analysis included all randomly assigned participants who completed follow-up. Groups were compared with analysis of covariance with Hochberg testing. Secondary endpoints were other biochemical markers of bone turnover, bone mineral density, short physical performance battery, and grip strength. Mechanistic endpoints were glutathione peroxidase, highly sensitive C-reactive protein, and interleukin-6. This trial is registered with EU clinical trials, EudraCT 2016-002964-15, and ClinicalTrials.gov, NCT02832648, and is complete.

FINDINGS

120 participants were recruited between Jan 23, 2017, and April 11, 2018, and randomly assigned to selenite 200 μg, 50 μg, or placebo (n=40 per group). 115 (96%) of 120 participants completed follow-up and were included in the primary analysis (200 μg [n=39], 50 μg [n=39], placebo [n=37]). Median follow-up was 25·0 weeks (IQR 24·7-26·0). In the 200 μg group, mean serum selenium increased from 78·8 (95% CI 73·5-84·2) to 105·7 μg/L (99·5-111·9). Urine NTx to creatinine ratio (nmol bone collagen equivalent:mmol creatinine) did not differ significantly between treatment groups at 26 weeks: 40·5 (95% CI 34·9-47·0) for placebo, 43·4 (37·4-50·5) for 50 μg, and 42·2 (37·5-47·6) for 200 μg. None of the secondary or mechanistic endpoint measurements differed between treatment groups at 26 weeks. Seven (6%) of 120 participants were withdrawn from treatment at week 13 due to abnormal thyroid-stimulating hormone concentrations (one in the 200 μg group, three in the 50 μg group, and three in the placebo group) and abnormal blood glucose (one in the 50 μg group). There were three serious adverse events: a non-ST elevation myocardial infarction at week 18 (in the 50 μg group), a diagnosis of bowel cancer after routine population screening at week 2 (in the placebo group), and a pulmonary embolus due to metastatic bowel cancer at week 4 (in the 200 μg group). All severe adverse events were judged by the principal investigator as unrelated to trial medication.

INTERPRETATION

Selenium supplementation at these doses does not affect musculoskeletal health in postmenopausal women.

FUNDING

UK National Institute for Health Research Efficacy and Mechanism Evaluation programme.

A Short-Term Resistance Training Circuit Improved Antioxidants in Sedentary Adults with Down Syndrome

Previous studies have found aerobic training improved oxidative damage in people with Down syndrome (DS). However, there is a lack of information regarding the influence of resistance training on redox imbalance in this population. Accordingly, this study was conducted to determine the effect of resistance training (RT) on antioxidant defence system in sedentary adults with DS. Thirty-six male adults with DS were recruited through different community support groups. Eighteen were randomly assigned to perform a circuit RT program with 6 stations, 3 days/week for 12 weeks. Plasma total antioxidant status (TAS), reduced glutathione (GHS), ascorbate, serum α-tocopherol, and erythrocyte glutathione reductase activity were assessed. Plasma malondialdehyde (MDA) and carbonyl groups (CG) were assessed as markers of oxidative damage. Muscle strength was also measured. Dynamic torque of knee extensors and flexors as well as maximal handgrip strength was significantly improved after the completion of the training program. Plasma levels of TAS and erythrocyte glutathione reductase (GR) activity were significantly increased. Conversely, MDA and CG levels were significantly reduced. It was concluded RT improved antioxidant defence system and reduced oxidative damage in adults with DS. Further, long-term studies are required to determine whether the increased antioxidant system may improve clinical outcomes of adults with DS.

Selenium and impaired physical function in US and Spanish older adults

Background

Selenium (Se) is a trace element with a narrow safety margin.

Objectives

To evaluate the cross-sectional and longitudinal dose-response association between Se exposure and measures of impaired physical function and disability in older adults.

Design

NHANES 2011–2014 cross-sectional (US, n = 1733, age ≥60 years) and Seniors-ENRICA-2 2017–2019 cross-sectional and longitudinal (Spain, n = 2548 and 1741, respectively, age ≥65 years) data were analyzed. Whole blood and serum Se levels were measured using inductively coupled plasma-mass spectrometry. Lower-extremity performance was assessed with the Short Physical Performance Battery, and muscle weakness with a dynamometer. Incident mobility and agility limitations, and disability in instrumental activities of daily living (IADL) were ascertained with standardized questionnaires. Analyses were adjusted for relevant confounders, including physical activity. Results across studies were pooled using random-effects meta-analysis.

Results

Meta-analyzed odds ratios (95% confidence interval) per log2 increase in whole blood Se were 0.54 (0.32; 0.76) for weakness, 0.59 (0.34; 0.83) for impaired lower-extremity performance, 0.48 (0.31; 0.68) for mobility limitations, 0.71 (0.45; 0.97) for agility limitations, and 0.34 (0.12; 0.56) for disability in at least one IADL. Analyses for serum Se in NHANES showed similar results. Findings suggest the inverse association with grip strength is progressive below 140 μg/L (p-value for non-linear trend in the Seniors-ENRICA-2 study = 0.13), and above 140 μg/L (p-value for non-linear trend in NHANES = 0.11). In the Seniors-ENRICA-2 cohort, with a 2.2 year follow-up period, a doubling in baseline Se levels were associated with a lower incidence of weakness [odds ratio (95% confidence interval): 0.45 (0.22; 0.91)], impaired lower-extremity performance [0.63 (0.32; 1.23)], mobility [0.43 (0.21; 0.91)] and agility [0.38 (0.18; 0.78)] limitations.

Discussion

In US and Spanish older adults, Se concentrations were inversely associated with physical function limitations. Further studies are needed to elucidate underlying mechanisms.

Dietary Selenium Intakes and Musculoskeletal Function in Very Old Adults: Analysis of the Newcastle 85+ Study

Background: Selenium is a trace element essential for health. Severe selenium deficiencies are associated with poor musculoskeletal (MSK) function. However, the effects of moderate deficiency on MSK function, especially in older adults, is unclear. Objectives: To determine the associations between selenium intake and MSK function in very old adults. Methods: Selenium intake at baseline and, hand-grip strength (HGS) and timed-up-and-go (TUG) at four phases over 5 years, were available in 791 participants in the Newcastle 85+ Study, a community-based, longitudinal cohort of ≥85 year old individuals. We investigated relationships between selenium intake and HGS and TUG in cross-sectional analyses at baseline using multivariate analyses and, prospectively using linear mixed models to explore HGS and TUG changes over 5 years in association with baseline selenium intake. Results: At baseline, 53% of participants had selenium intakes that were classified as low. These individuals had 2.80 kg lower HGS and were 2.30 s slower performing the TUG, cross-sectionally. In multivariate, baseline analyses, selenium intake had no significant impact on HGS or TUG. Selenium intake had no significant effect on MSK function, prospectively. Conclusion: Low selenium intake is common among very old adults and, in cross-sectional analyses, is associated with poorer MSK function.

Nutrition and Sarcopenia-What Do We Know?

Muscle health is important for the functionality and independence of older adults, and certain nutrients as well as dietary patterns have been shown to offer protective effects against declines in strength and function associated with aging. In this paper, micronutrients, macronutrients, and food groups have been reviewed, along with their studied effects on the prevalence and incidence of sarcopenia, as well as their ability to preserve muscle mass and optimize physical performance. Randomized controlled trials appear to suggest a critical role for dietary intake of protein in preventing sarcopenia and muscle loss, although the optimal dose and type of protein is unknown. There are some promising data regarding the role of vitamin D and sarcopenia, but it is unclear whether the dose, frequency of dose, or length of treatment impacts the efficacy of vitamin D on improving muscle mass or function. Selenium, magnesium, and omega 3 fatty acids have been studied as supplements in clinical trials and in the diet, and they appear to demonstrate a potential association with physical activity and muscle performance in older individuals. Following the Mediterranean diet and higher consumption of fruits and vegetables have been associated with improved physical performance and protection against muscle wasting, sarcopenia, and frailty.

Selenium Status in Elderly People: Longevity and Age-Related Diseases

BACKGROUND

Selenium (Se) is a trace element active in selenoproteins, which can regulate oxidative stress. It is generally perceived as an import factor for maintaining health in the elderly.

METHODS

The goal of this review is to discuss selenium concentration in biological samples, primarily serum or plasma, as a function of age and its relation with longevity. The elemental level in various age-related diseases is reviewed.

CONCLUSION

Highest selenium values were observed in healthy adults, while in an elderly population significantly lower concentrations were reported. Variables responsible for contradictory findings are mentioned. Risk and benefits of Se-supplementation still remain under debate.

The Biological Foundations of Sarcopenia: Established and Promising Markers

Sarcopenia, the progressive loss of muscle mass and strength, is one of the major health issues in older adults, given its high prevalence accompanied by huge clinical and socioeconomic implications. Age-related changes in skeletal muscle can be attributed to mechanisms both directly and indirectly related to muscle homeostasis. Indeed, a wide spectrum of age-related modifications in the organism was shown to play a key role in the pathogenesis of sarcopenia. Not surprisingly, sarcopenia has sometimes been indicated as a syndrome stemming from the aging process, and not as univocal standalone disease. Due to the multidimensionality of sarcopenia, a single biomarker approach is not enough to explain the biology of this condition. The aim of this review is to suggest innovative and promising sarcopenia markers investigating the link between skeletal muscle and brain. Indeed, as a neurological origin of sarcopenia has been hypothesized, a new perspective on sarcopenia biomarkers may focus on the dysfunction of the neuromuscular junctions (NMJs). The core SNARE synaptosomal-associated protein of 25 kDa (SNAP25) accumulates in the plasma membrane of nerve terminals at NMJs and regulates exocytosis at peripheral and central synapses. Interestingly, mice studies have shown that SNAP25 affects the neuromuscular function. SNARE complex and, in particular, SNAP25 may represent a promising pathway to explore the molecular and cellular mechanisms regulating muscular homeostasis and concur at profiling the sarcopenia biological background.

Higher Diet Quality is Associated with Lower Odds of Low Hand Grip Strength in the Korean Elderly Population

Single nutrients or food groups have been associated with physical performance. However, little is known about the association of overall diet quality with hand grip strength (HGS), a predictive parameter in the prognosis of chronic disease morbidity and mortality, or quality of life. This study examined the association between HGS and three indices-the Korean Healthy Eating Index (KHEI), the Alternate Mediterranean Diet (aMED), and Dietary Approaches to Stop Hypertension (DASH)-using data obtained on Korean elderly persons aged ≥65 years (n = 3675) from a nationally representative database. The cross-sectional data was collected as part of the Korea National Health and Nutrition Examination Survey (KNHANES, 2014-2016). Dietary intake data from the 24-h recall method were used to calculate diet quality scores. The cutoff value for low HGS was defined as the value corresponding to the lowest 20th percentile of HGS of the study population (men, 28.6 kg; women, 16.5 kg). Higher index scores for diet quality were associated with 32%-53% lower odds of low HGS. Better overall diet quality may be associated with higher HGS in the elderly Korean population.

Association between dietary nutrient intake and sarcopenia in the SarcoPhAge study

BACKGROUND

It has been suggested that a balanced nutritional intake may be useful in preventing or even reversing sarcopenia.

AIM

To describe cross-sectional associations between dietary nutrient intake and sarcopenia.

METHODS

Subjects recruited from the SarcoPhAge study population completed a food frequency questionnaire. The micronutrient and macronutrient intake was evaluated in both sarcopenic and non-sarcopenic participants. The Nutritional Belgian Recommendations of 2016 were used, i.e., adequate intake and estimated average requirement (EAR). For micronutrients, the prevalence of insufficient intake was estimated as the proportion of subjects whose intake was below the EAR.

RESULTS

A total of 331 subjects (mean age of 74.8 ± 5.9 years, 58.9% women) had complete data and were included in this study. Among them, 51 were diagnosed with sarcopenia (15.4%). In the fully adjusted model, analyses revealed that sarcopenic subjects consumed significantly lower amounts of two macronutrients (proteins, lipids) and five micronutrients (potassium, magnesium, phosphorus, iron, and vitamin K) than non-sarcopenic subjects (all p values < 0.005). A significantly increased prevalence of insufficiency was found for sarcopenic subjects compared to non-sarcopenic subjects for potassium, magnesium, iron, calcium and vitamins E and C (all p values < 0.005). The prevalence of sarcopenic subjects who were also below the Nutritional Belgian Recommendations for protein and lipids was significantly higher than that of non-sarcopenic subjects.

DISCUSSION AND CONCLUSIONS

Sarcopenic subjects seem to consume significantly reduced amounts of many micronutrients and macronutrients compared to non-sarcopenic subjects. These results suggest that a poorly balanced diet may be associated with sarcopenia and poor musculoskeletal health, although prospective studies are needed to confirm these findings.

Mediterranean diet is associated with bone mineral density and muscle mass in postmenopausal women

PURPOSE

This study aimed to investigate the association between the Mediterranean diet (MD), body composition, and bone mineral density (BMD) in postmenopausal women.

METHODS

In this cross-sectional study, 105 apparently healthy postmenopausal women aged between 45 and 65 years were included. BMD, percentage body fat, and appendicular lean mass index (ALMI, appendicular lean mass/height squared) were assessed by dual-energy X-ray absorptiometry. Dietary intake was assessed by a validated food frequency questionnaire. Assessment of MD adherence was based on intake of cereals, vegetables, fruits, meats, dairy products, fish, red wine, and olive oil, and expressed as the Mediterranean diet score (MDS).

RESULTS

Women with higher adherence to the MD had higher ALMI (6.6 ± 0.8 kg/m² vs. 6.3 ± 0.7 kg/m²; p = 0.039) and lumbar spine BMD (1.076 ± 0.149 vs. 0.997 ± 0.143 g/cm²; p = 0.007) compared to those with lower MDS. Linear regression analysis adjusted for previous hormone therapy, previous smoking behavior, and habitual physical activity showed an independent positive contribution of MDS to lumbar spine BMD (mean difference 0.088 g/cm², 95% confidence interval 0.028-0.147; p = 0.004) and ALMI (mean difference 0.296 kg/m², 95% confidence interval 0.020-0.591; p = 0.049).

CONCLUSION

Bone mineral density at the lumbar spine and ALMI were positively associated with the MDS in a sample of postmenopausal women from a non-Mediterranean region.

Sarcopenia: assessment of disease burden and strategies to improve outcomes

Life expectancy is increasing worldwide, with a resultant increase in the elderly population. Aging is characterized by the progressive loss of skeletal muscle mass and strength - a phenomenon called sarcopenia. Sarcopenia has a complex multifactorial pathogenesis, which involves not only age-related changes in neuromuscular function, muscle protein turnover, and hormone levels and sensitivity, but also a chronic pro-inflammatory state, oxidative stress, and behavioral factors - in particular, nutritional status and degree of physical activity. According to the operational definition by the European Working Group on Sarcopenia in Older People (EWGSOP), the diagnosis of sarcopenia requires the presence of both low muscle mass and low muscle function, which can be defined by low muscle strength or low physical performance. Moreover, biomarkers of sarcopenia have been identified for its early detection and for a detailed identification of the main pathophysiological mechanisms involved in its development. Because sarcopenia is associated with important adverse health outcomes, such as frailty, hospitalization, and mortality, several therapeutic strategies have been identified that involve exercise training, nutritional supplementation, hormonal therapies, and novel strategies and are still under investigation. At the present time, only physical exercise has showed a positive effect in managing and preventing sarcopenia and its adverse health outcomes. Thus, further well-designed and well-conducted studies on sarcopenia are needed.

Skeletal muscle mass is associated with higher dietary protein intake and lower body fat in postmenopausal women: a cross-sectional study

OBJECTIVE

We investigated the association between skeletal muscle mass and dietary protein intake, habitual physical activity, body composition, and metabolic variables.

METHODS

One hundred three healthy postmenopausal women from southern Brazil (age 55.2 ± 4.9 y, body mass index 27.2 ± 4.6 kg/m) were enrolled. Bone mineral density, %body fat, %trunk fat mass, and appendicular lean mass were assessed by dual-energy x-ray absorptiometry, resting metabolic rate by indirect calorimetry, and habitual physical activity by pedometer. Skeletal muscle mass index (SMI) was expressed as appendicular lean mass standardized to body mass index. The cutoff for low lean mass was <0.512. Protein intake was measured by a validated food frequency questionnaire and categorized into tertiles: ≤0.93 g/kg body weight (BW), 0.94 to 1.29 g/kg BW, and ≥1.3 g protein/kg BW.

RESULTS

The prevalence of low lean mass (SMI <0.512) was 7%. Waist circumference, %body fat, trunk fat mass, and diastolic blood pressure were higher, whereas SMI and mean daily steps were lower in women with protein intake ≤0.93 g/kg BW. SMI was positively correlated with physical activity (r = 0.205, P = 0.038) and protein intake (r = 0.334, P = 0.001), and negatively correlated with waist circumference (r = -0.505, P < 0.001) and %body fat (r = 0.808, P < 0.001). Linear regression analysis adjusted for age, time since menopause, previous smoking behavior, and energy intake showed an independent, positive contribution of protein intake (mean difference 0.007, 95% CI, 0.001-0.014, P = 0.044) and an independent, negative contribution of %body fat (mean difference -0.010, 95%CI, -0.011 to -0.008, P < 0.001) to SMI.

CONCLUSIONS

In our healthy postmenopausal women, SMI was positively associated with protein intake and negatively associated with %body fat.

Reduced dietary intake of micronutrients with antioxidant properties negatively impacts muscle health in aged mice

BACKGROUND

Inadequate intake of micronutrients with antioxidant properties is common among older adults and has been associated with higher risk of frailty, adverse functional outcome, and impaired muscle health. However, a causal relationship is less well known. The aim was to determine in old mice the impact of reduced dietary intake of vitamins A/E/B6/B12/folate, selenium, and zinc on muscle mass, oxidative capacity, strength, and physical activity (PA) over time.

METHODS

Twenty-one-month-old male mice were fed either AIN-93-M (control) or a diet low in micronutrients with antioxidant properties (=LOWOX-B: 50% of mouse recommended daily intake of vitamins A, E, B6, and B12, folate, selenium, and zinc) for 4 months. Muscle mass, grip strength, physical activity (PA), and general oxidative status were assessed. Moreover, muscle fatigue was measured of m. extensor digitorum longus (EDL) during an ex vivo moderate exercise protocol. Effects on oxidative capacity [succinate dehydrogenase (SDH) activity], muscle fibre type, number, and fibre cross-sectional area (fCSA) were assessed on m. plantaris (PL) using histochemistry.

RESULTS

After 2 months on the diet, bodyweight of LOWOX-B mice was lower compared with control (P < 0.0001), mainly due to lower fat mass (P < 0.0001), without significant differences in food intake. After 4 months, oxidative status of LOWOX-B mice was lower, demonstrated by decreased vitamin E plasma levels (P < 0.05) and increased liver malondialdehyde levels (P = 0.018). PA was lower in LOWOX-B mice (P < 0.001 vs. control). Muscle mass was not affected, although PL-fCSA was decreased (~16%; P = 0.028 vs. control). SDH activity and muscle fibre type distribution remained unaffected. In LOWOX-B mice, EDL force production was decreased by 49.7% at lower stimulation frequencies (P = 0.038), and fatigue resistance was diminished (P = 0.023) compared with control.

CONCLUSIONS

Reduced dietary intake of vitamins A, E, B6, and B12, folate, selenium, and zinc resulted in a lower oxidative capacity and has major impact on muscle health as shown by decreased force production and PA, without effects on muscle mass. The reduced fCSA in combination with similar SDH activity per fibre might explain the reduced oxidative capacity resulting in the increased fatigue after exercise in LOWOX-B mice.

Relationship between serum selenium, sociodemographic variables, other trace elements and lipid profile in an adult Spanish population

INTRODUCTION

Several studies have shown an inverse relationship between selenium status and cardiovascular health, although epidemiologic evidence yielded by the randomized trials did not find a beneficial effect of selenium administration. The aim of this study was to analyze the association between serum selenium levels and lipid profile adjusted by age, sex and other associated factors among a general adult population in Spain.

MATERIALS AND METHODS

We recruited 372 hospital employee volunteers (60 men and 312 women) with a mean age of 47 (SD: 10.9), whom were given a standardized questionnaire. Serum selenium concentration was measured by electrothermal atomization atomic absorption spectrometry. Serum copper and zinc concentrations were measured using flame atomic absorption spectrometry.

RESULTS

The mean of serum selenium was 79.5μg/L (SD: 11.7) with no sex-dependent differences. In the multivariate linear regression analysis, the associated factors with the mean levels of selenium were: age (β=0.223; CI 95%: 0.101-0.345), p<0.001; widowhood (β=-9.668; CI 95%: -17.234 to -2.102), p=0.012; calcium supplements (β=3.949; CI 95%: 0.059-7.838), p=0.047; zinc (β=0.126; CI 95%: 0.013-0.238), p=0.028 and glucose (β=0.172; CI 95%: 0.062- 0.281), p=0.002; Participants with serum selenium≥79.5μg/L were 1.98 (OR=1.98; CI 95% 1.17-3.35; p=0.011) and 2.04 times (OR=2.04; CI 95% 1.06-3.97; p=0.034) more likely to have cholesterol ≥200mg/dL and LDL-c ≥100mg/dL respectively than those with serum selenium <79.5μg/L.

CONCLUSIONS

Higher selenium was positively associated with increased total and LDL cholesterol but not with HDL-c and triglycerides. More studies are needed in order to confirm the lower serum selenium findings in widows.

Frailty and nutrition: From epidemiological and clinical evidence to potential mechanisms

Frailty is a geriatric condition characterized by unintentional weight loss, low muscle strength, feeling of exhaustion, reduced physical activity capacity and slow walking speed. Theoretically, nutrition is a factor closely related to the frailty syndrome: all frailty criteria are more or less affected by poor eating habits, whereas frailty itself may have a negative effect on eating and, thus, on the nutritional status. Indeed, research data suggest an association between frailty and specific constituents of diet, namely protein and energy intake, as well as intakes of specific micronutrients. Furthermore, healthy dietary patterns, such as the Mediterranean diet, have been linked to the frailty prevention. In the present narrative review, we critically evaluate cross-sectional, prospective and intervention studies examining the relationship between diet and frailty development and prevention. Potential mechanisms linking nutrition and frailty as well as directions for future research are discussed.

Protective effect of Dunaliella sp., lipid extract rich in polyunsaturated fatty acids, on hepatic and renal toxicity induced by nickel in rats

AIMS

The present study was undertaken to investigate the protective effect of lipid extract of Dunaliella sp. (LE) rich in polyunsaturated fatty acids (PUFA), against oxidative stress induced by nickel in experimental rats.

METHODS

Our investigation evaluated the antioxidant activity of LE using both DPPH and NBT assays. Twenty female albino Wistar rats, randomly allocated into four experimental groups, namely (C): control, (Nit): nickel-treated rats with 5 mg/kg/d of NiCl2 during 30 days, (LEa): lipid extract-administered rats with 5  mg/kg BW/d during 30 days and (Nit + LEa): rats treated with Ni and LE-administered during 30 days.

RESULTS

The in vitro antioxidant activity demonstrated that LE presents an important antioxidant potential. In vivo, the (Nit + LEa) cotreatment decreased the level of malondialdehyde and restored the antioxidant enzyme activities (superoxide dismutase, catalase and glutathione peroxidase) in livers and kidneys in comparison with those treated with Ni only. LE administration to rats treated with Ni also ameliorated biochemical and histological parameters as compared to only Ni-treated group. LE of Dunaliella sp., rich in polyunsaturated fatty acids showed a significant hepato- and reno-protective effect against metal-induced toxicity.

CONCLUSION

LE of Dunaliella sp., rich in PUFA has been proven to be effective in protection against Ni-induced toxicity.

Differences in Nutrient Intake and Biochemical Nutrient Status Between Sarcopenic and Nonsarcopenic Older Adults-Results From the Maastricht Sarcopenia Study

BACKGROUND

There is growing evidence of a relationship between nutrients and muscle mass, strength, and physical performance. Although nutrition is seen as an important pillar of treating sarcopenia, data on the nutritional intake of sarcopenic older adults are limited.

OBJECTIVE

To investigate potential nutritional gaps in the sarcopenic population, the present study compared nutrient intake and biochemical nutrient status between sarcopenic and nonsarcopenic older adults.

DESIGN

The Maastricht Sarcopenia Study included 227 community-dwelling older adults (≥65 years) from Maastricht, 53 of whom were sarcopenic based on the European Working Group on Sarcopenia in Older People algorithm. Habitual dietary intake was assessed with a food frequency questionnaire and data on dietary supplement use were collected. In addition, serum 25-hydroxyvitamin D, magnesium and α-tocopherol/cholesterol, plasma homocysteine and red blood cell n-3, and n-6 fatty acids profiles were assessed. Nutrient intake and biochemical nutrient status of the sarcopenic groups were compared with those of the nonsarcopenic groups. The robustness of these results was tested with a multiple regression analysis, taking into account between-group differences in characteristics.

RESULTS

Sarcopenic older adults had a 10%-18% lower intake of 5 nutrients (n-3 fatty acids, vitamin B6, folic acid, vitamin E, magnesium) compared with nonsarcopenic older adults (P < .05). When taking into account dietary supplement intake, a 19% difference remained for n-3 fatty acids intake (P = .005). For the 2 biochemical status markers, linoleic acid and homocysteine, a 7% and 27% difference was observed, respectively (P < .05). The higher homocysteine level confirmed the observed lower vitamin B intake in the sarcopenic group. Observed differences in eicosapentaenoic acid and 25-hydroxyvitamin D between the groups were related to differences in age and living situation.

CONCLUSIONS

Sarcopenic older adults differed in certain nutritional intakes and biochemical nutrient status compared with nonsarcopenic older adults. Dietary supplement intake reduced the gap for some of these nutrients. Targeted nutritional intervention may therefore improve the nutritional intake and biochemical status of sarcopenic older adults.

Understanding the gastrointestinal tract of the elderly to develop dietary solutions that prevent malnutrition

Although the prevalence of malnutrition in the old age is increasing worldwide a synthetic understanding of the impact of aging on the intake, digestion, and absorption of nutrients is still lacking. This review article aims at filling the gap in knowledge between the functional decline of the aging gastrointestinal tract (GIT) and the consequences of malnutrition on the health status of elderly. Changes in the aging GIT include the mechanical disintegration of food, gastrointestinal motor function, food transit, chemical food digestion, and functionality of the intestinal wall. These alterations progressively decrease the ability of the GIT to provide the aging organism with adequate levels of nutrients, what contributes to the development of malnutrition. Malnutrition, in turn, increases the risks for the development of a range of pathologies associated with most organ systems, in particular the nervous-, muscoskeletal-, cardiovascular-, immune-, and skin systems. In addition to psychological, economics, and societal factors, dietary solutions preventing malnutrition should thus propose dietary guidelines and food products that integrate knowledge on the functionality of the aging GIT and the nutritional status of the elderly. Achieving this goal will request the identification, validation, and correlative analysis of biomarkers of food intake, nutrient bioavailability, and malnutrition.

Frailty and nutrition: searching for evidence

Frailty is a geriatric syndrome that predicts disability, morbidity and mortality in the elderly. Poor nutritional status is one of the main risk factors for frailty. Macronutrients and micronutrients deficiencies are associated with frailty. Recent studies suggest that improving nutritional status for macronutrients and micronutrients may reduce the risk of frailty. Specific diets such as the Mediterranean diet rich in anti-oxidants, is currently investigated in the prevention of frailty. The aim of this paper is to summarize the current body of knowledge on the relations between nutrition and frailty, and provide recommendations for future nutritional research on the field of frailty.

Low serum selenium level is associated with low muscle mass in the community-dwelling elderly

OBJECTIVES

Elderly persons with low muscle mass (LMM) or sarcopenia are prone to frailty and functional decline. This study aimed to investigate the relationship between serum selenium level and skeletal muscle mass in community-dwelling elderly.

DESIGN

Cross-sectional observational study.

SETTING AND PARTICIPANTS

A total of 327 elderly Taipei citizens (mean age 71.5 ± 4.7 years) were recruited from the community.

MEASUREMENTS

Skeletal muscle mass was measured by bioelectrical impedance analysis. LMM was defined by low skeletal muscle index (SMI: muscle mass (kg)/[height (m)](2)). All participants were further divided into quartiles by serum selenium level and the risk for LMM among these quartiles was examined using multivariate logistic regression analyses. Estimated serum selenium levels for the LMM group vs the normal group and estimated SMI in the quartiles of serum selenium were computed by least square method in linear regression models.

RESULTS

The estimated mean (±standard deviation) of serum selenium level was significantly lower in the LMM group compared with the normal group after adjusting for confounders (1.01 ± 0.03 μmol/L vs 1.14 ± 0.02 μmol/L, P < .001). After adjusting for age, sex, lifestyle, and physical and metabolic factors, the odds ratios (95% confidence interval, P value) of LMM in the bottom, second, and third selenium quartile groups were 4.62 (95% CI 2.11-10.10, P < .001), 2.30 (95% CI 1.05-5.03, P < .05) and 1.51 (95% CI 0.66-3.46, P = .327), respectively, compared with the top quartile group of serum selenium level. The least square mean of SMI increased with the quartiles of serum selenium (P < .001).

CONCLUSIONS

This is the first study to demonstrate that low serum selenium is independently associated with low muscle mass in the elderly. The causality and underlying mechanism between selenium and low muscle mass or sarcopenia warrant further research.

The combined effects of diet quality and physical activity on maintenance of muscle strength among diabetic older adults from the NuAge cohort

Diabetic older adults are at a higher risk of muscle strength (MS) decline than their non-diabetic counterparts. Adequate protein and energy intakes and physical activity (PA) may preserve MS during aging. However, the role of diet quality (DQ) in MS maintenance is still unknown. This study aimed to determine the association between DQ - alone or combined with PA - and changes in MS over 3 years in diabetic participants aged 67 to 84 years at recruitment in a secondary analysis of the longitudinal observational NuAge study. Changes in handgrip, knee extensor and elbow flexor strengths were calculated as the difference between recruitment (T1) and after 3 years (T4) in 156 diabetic older adults. Baseline DQ was calculated from 3 non-consecutive 24-hour dietary recalls collected at T1 using the validated Canadian Healthy Eating Index (C-HEI). Change in PA was calculated from Physical Activity Scale for the Elderly (PASE) as PASE T4-PASE T1. Four combinations of variables were created: C-HEI<70 with PASE change either < or > median and C-HEI ≥ 70 with PASE change either < or > median. The association between these four categories and MS maintenance was evaluated using General Linear Modeling (GLM). Analyses were stratified by sex and controlled for covariates. Baseline DQ alone was not associated with MS maintenance. Baseline DQ combined with PASE change showed associations with crude and baseline adjusted handgrip strength (p=0.031, p=0.018) and crude and baseline adjusted elbow flexor change (p=0.028, p=0.017) in males only; no significant results were found for knee extensor strength in either males or females. While findings for females were inconclusive, results demonstrate that better adherence to dietary guidelines combined with a more active lifestyle may prevent MS decline among diabetic older males. Additional research is needed on a larger sample since generalization of these results is limited by the small sample size.

Nutritional influences on age-related skeletal muscle loss

Age-related muscle loss impacts on whole-body metabolism and leads to frailty and sarcopenia, which are risk factors for fractures and mortality. Although nutrients are integral to muscle metabolism the relationship between nutrition and muscle loss has only been extensively investigated for protein and amino acids. The objective of the present paper is to describe other aspects of nutrition and their association with skeletal muscle mass. Mechanisms for muscle loss relate to imbalance in protein turnover with a number of anabolic pathways of which the mechanistic TOR pathway and the IGF-1–Akt–FoxO pathways are the most characterised. In terms of catabolism the ubiquitin proteasome system, apoptosis, autophagy, inflammation, oxidation and insulin resistance are among the major mechanisms proposed. The limited research associating vitamin D, alcohol, dietary acid–base load, dietary fat and anti-oxidant nutrients with age-related muscle loss is described. Vitamin D may be protective for muscle loss; a more alkalinogenic diet and diets higher in the anti-oxidant nutrients vitamin C and vitamin E may also prevent muscle loss. Although present recommendations for prevention of sarcopenia focus on protein, and to some extent on vitamin D, other aspects of the diet including fruits and vegetables should be considered. Clearly, more research into other aspects of nutrition and their role in prevention of muscle loss is required.

IGF-1, the cross road of the nutritional, inflammatory and hormonal pathways to frailty

The decline in functional capacity is a heterogeneous phenomenon in the elderly. An accelerated ageing determines a frail status. It results in an increased vulnerability to stressors for decreased physiological reserves. The early identification of a frail status is essential for preventing loss of functional capacity, and its clinical consequences. Frailty and mobility limitation result from an interplay of different pathways including multiple anabolic deficiency, inflammation, oxidative stress, and a poor nutritional status. However, the age-related decline in insulin-like growth factor 1 (IGF-1) bioactivity deserves special attention as it could represent the ideal crossroad of endocrine, inflammatory, and nutritional pathways to frailty. Several minerals, namely magnesium, selenium, and zinc, appear to be important determinants of IGF-1 bioactivity. This review aims to provide an overview of the potential usefulness of nutrients modulating IGF-1 as potential therapeutic targets in the prevention of mobility limitation occurring in frail older subjects.