Association between insulin resistance and low relative appendicular skeletal muscle mass: evidence from a cohort study in community-dwelling older men and women participants

Comparison of muscle and fat parameters measured by ultrasonography and dual-energy x-ray absorptiometry between older palliative care patients with and without type 2 diabetes mellitus

BACKGROUND AND AIMS

There are limited data on the comparison of body compositions between diabetic and non-diabetic patients. We aimed to compare the muscle mass and fat parameters measured by ultrasonography (USG) and dual-energy x-ray absorptiometry (DXA) between older palliative care patients with and without type 2 diabetes mellitus (DM).

METHODS

We conducted a prospective, cross-sectional study. We recorded the demographics, comorbidities, blood pressures, microvascular complications, pressure injuries, ambulation and nutritional status, and laboratory parameters. We measured the handgrip strength with a hand dynamometer and anthropometric parameters. We analyzed the subcutaneous fat thickness, muscle thickness (MT), and cross-sectional area (CSA) of the rectus femoris (RF) and biceps brachii muscles by USG and the total and regional muscle mass and fat parameters by DXA. We performed a regression analysis to examine the independently associated factors of DM.

RESULTS

We included 55 patients (mean age: 79.0 ± 8.0 years, 56.4%: female). 43.6% had type 2 DM. The patients with DM had significantly higher glucose and HbA1c levels and lower RFMT and RFCSA values than the patients without DM (p < 0.01, for all). The RFMT was independently associated with DM after adjusting age, sex, and body mass index (Odds ratio = 0.735, 95% confidence interval = 0.565-0.956, p = 0.022).

CONCLUSION

Our study demonstrated that the RFMT might be associated with type 2 DM. This was the first study comparing the body compositions measured by USG and DXA between older diabetic and non-diabetic palliative patients with a wide range of laboratory evaluations. Longitudinal, multi-center studies are warranted to understand the underlying mechanisms.

Exploring the hypoglycemic mechanism of chlorogenic acids from Pyrrosia petiolosa (Christ) Ching on type 2 diabetes mellitus based on network pharmacology and transcriptomics strategy

ETHNOPHARMACOLOGICAL RELEVANCE

Pyrrosia petiolosa (Christ) Ching (YBSW) is a Traditional Chinese medicine rich in chlorogenic acids. It is an important component in many Traditional Chinese medicinal hypoglycemic formulas and is commonly used by the Miao people to treat diabetes with good efficacy. Our previous research has suggested that chlorogenic acids may be the active ingredients in YBSW.

AIM OF THE STUDY

To explore the mechanisms underlying the anti-type 2 diabetes mellitus (T2DM) hypoglycemic effects of chlorogenic acids contained in YBSW.

MATERIALS AND METHODS

In vivo experiments, hematoxylin-eosin staining (HE) staining, and immunohistochemistry (IHC) were used to determine the effects of chlorogenic acids contained in YBSW in rats. mRNA expression profiling, microarray analysis, and network pharmacology were used to analyze the underlying mechanisms of the effects. Finally, apoptosis and changes in the related pathways were evaluated in vitro using a 3-(4,5-dimethyl-2-thia-zolyl)-2,5-diphenyl-2-H-tetrazolium bromide assay, quantitative real-time polymerase chain reaction, immunofluorescence (IF) assessment, and flow cytometry.

RESULTS

After the administration of isochlorogenic acid B, the levels of triglycerides, serum total cholesterol, and fasting blood glucose significantly decreased. HE and IHC staining revealed that isochlorogenic acid B significantly increased insulin expression in islet cells. Using network pharmacology and RNA-seq Kyoto Encyclopedia of Genes and Genomes pathway enrichment analysis, we screened the advanced glycation end products-receptor for advanced glycation end products (AGE-RAGE) signaling pathway. We also verified that YBSW and its chlorogenic acid can inhibit apoptosis and downregulate the expression of related mRNA in the AGE-RAGE pathway in RIN-m5f cells.

CONCLUSIONS

YBSW exhibits a significant hypoglycemic effect, with chlorogenic acid being an effective component. The therapeutic effect of chlorogenic acids contained in YBSW is mainly realized by promoting insulin secretion and pancreatic tissue repair. Moreover, YBSW substantially mitigates apoptosis via the AGE-RAGE pathway in T2DM.

Ketogenic diet preserves muscle mass and strength in a mouse model of type 2 diabetes

Diabetes is often associated with reduced muscle mass and function. The ketogenic diet (KD) may improve muscle mass and function via the induction of nutritional ketosis. To test whether the KD is able to preserve muscle mass and strength in a mouse model of type 2 diabetes (T2DM), C57BL/6J mice were assigned to lean control, diabetes control, and KD groups. The mice were fed a standard diet (10% kcal from fat) or a high-fat diet (HFD) (60% kcal from fat). The diabetic condition was induced by a single injection of streptozotocin (STZ; 100 mg/kg) and nicotinamide (NAM; 120 mg/kg) into HFD-fed mice. After 8-week HFD feeding, the KD (90% kcal from fat) was fed to the KD group for the following 6 weeks. After the 14-week experimental period, an oral glucose tolerance test and grip strength test were conducted. Type 2 diabetic condition induced by HFD feeding and STZ/NAM injection resulted in reduced muscle mass and grip strength, and smaller muscle fiber areas. The KD nutritional intervention improved these effects. Additionally, the KD altered the gene expression of nucleotide-binding and oligomerization domain-like receptor family pyrin domain-containing 3 (NLRP3) inflammasome- and endoplasmic reticulum (ER) stress-related markers in the muscles of diabetic mice. Collectively, KD improved muscle mass and function with alterations in NLRP3 inflammasome and ER stress.

The Correlation Between Leg Muscle Mass Index and Non-Alcoholic Fatty Liver Disease in Patients with Type 2 Diabetes Mellitus

Objective

To analyze the relationship between leg skeletal muscle mass index (LSMI) and non-alcoholic fatty liver disease (NAFLD) in patients with type 2 diabetes mellitus (T2DM) and the ability of LSMI to predict NAFLD.

Methods

Two hundred patients with T2DM and NAFLD treated at Changzhou Second People's Hospital Affiliated with Nanjing Medical University and the National Metabolic Management Center from June 2022 to June 2023 were divided into four LSMI quartiles. The clinical information from the four patient groups was compared, and the relationship between type 2 diabetes and LSMI and NAFLD was examined. We used receiver operating characteristic curves to determine how well the LSMI predicts NAFLD in T2DM.

Results

The lowest quartile (Q1) had a higher prevalence of NAFLD than group Q4 (P < 0.05). LSMI was negatively associated with body mass index, LS, CAP, and other markers (P < 0.05). Receiver operating characteristic curve analysis LSMI predicted NAFLD with an ideal critical value of 0.64 and an area under the curve of 70.9%. The combined predictive value of the LSMI and the appendicular skeletal muscle mass index was more significant.

Conclusion

Reduced LSMI is associated with NAFLD.

Calf circumference as a screening tool for low skeletal muscle mass: Cut-off values in independent Thai older adults

BACKGROUND

Calf circumference is recommended as a marker for low muscle mass and as a case finding in the diagnosis of sarcopenia. However, the cut-off value differed by ethic and region. Currently there is no study among Thai population. Therefore, we aimed to identify the optimal cutoff value of calf circumference as a screening tool for low skeletal muscle mass in independent Thai older adults. Subgroup analysis was performed for obesity and adults over 75 years.

METHODS

This cross-sectional cohort studied in an outpatient geriatric check-up clinic. Participants, aged 60 and above, needed to be independent in basic activities of daily living to meet the inclusion criteria. Exclusion criteria comprised active malignancy, cardiac, pulmonary, or neurovascular diseases necessitating hospitalization in the preceding three months, chronic renal diseases requiring renal replacement therapy, and unstable psychiatric disorders. We measured the maximum calf circumference and appendicular skeletal muscle mass (ASMI) using bioelectrical impedance analysis (BIA). Low muscle mass is defined according to the Asian Working Group of Sarcopenia (AWGS) 2019 consensus.

RESULTS

We enrolled 6,404 elderly adults (mean age 67.3 ± 5.1 years), with a 47% prevalence of low muscle mass in women and 25% in men. Lower muscle mass significantly correlated with reduced BMI and waist circumference in both genders (p < 0.001). Optimal cut-off values for low muscle mass screening were < 33 cm (sensitivity 80.1%, specificity 60.5%) for women and < 34 cm (sensitivity 85.4%, specificity 70.2%) for men. Subgroup analysis for those with BMI ≥ 25 kg/m² suggested raising the cut-off for women to < 34 cm (sensitivity 80.6%, specificity 54.0%) and for men to < 35 cm (sensitivity 88.7%, specificity 55.2%) to enhance specificity without substantial sensitivity loss. In the older-old adult subgroup (≥ 75 years), optimal cut-off values were < 33 cm (sensitivity 84.6%, specificity 79.9%) for women and < 34 cm (sensitivity 75.6%, specificity 87.0%) for men.

CONCLUSIONS

There is a strong correlation between calf circumference and ASMI in independent Thai older adults. Calf circumference can serve as a screening tool for identifying low muscle mass. The recommended cut-off values for men and women are 34 cm and 33 cm, respectively in alignment with AWGS 2019 recommendation. Incorporating a 1-cm higher cut-off value for obese older adults improves the accuracy of muscle mass screening.

TRIAL REGISTRATION

Thai clinical trial registry: TCTR20200511003.

The associations of erythrocyte membrane polyunsaturated fatty acids with skeletal muscle loss: A prospective cohort study

BACKGROUND & AIMS

Polyunsaturated fatty acids (PUFAs) may play a vital role in maintaining skeletal muscle mass in the aged population. This study investigated the longitudinal relationship between the concentrations of erythrocyte membrane PUFAs and age-related changes in skeletal muscle mass over an average 6.5 years of follow-up in a Chinese middle-aged and older adult population.

METHODS

A total of 1494 participants aged 57.4 ± 4.7 years were included in this study. Skeletal muscle mass was determined using dual-energy X-ray absorptiometry. Per year percent changes in the skeletal muscle index (Δ% SMI), appendicular skeletal muscle index (Δ% ASMI), and total body lean mass index (Δ% TBLMI) from baseline were calculated. Concentrations of total and individual cis-n-3 and cis-n-6 PUFAs of the erythrocyte membrane were determined using gas-liquid chromatography.

RESULTS

Fully adjusted linear regression models showed that per unit increases in the concentrations of C18:2 n-6, C20:4 n-6, C22:4 n-6, and total n-6 PUFAs resulted in increases of 0.022%-0.155 % in the Δ% SMI (P for linearity: <0.001-0.006). Restricted cubic spline analysis revealed an inverted U-shaped relationship between the concentrations of C20:2 n-6, C22:5 n-3, C22:6 n-3, and total n-3 PUFAs and the Δ% SMI (P for non-linearity: <0.001-0.036). In addition, an inverted U-shaped curve was also detected for the relationships of the linoleic acid/α-linolenic acid ratio (P for non-linearity = 0.010) and n-6/n-3 PUFA ratio (P for non-linearity = 0.013) with the Δ% SMI, with the Δ% SMI peaking at respective ratios of 124.96 and 3.69. Similar associations were revealed by the Bayesian kernel machine regression model. No interaction effect was detected between the individual PUFAs for the Δ% SMI in the bivariate exposure-response analysis. Overall, similar results were observed for the Δ% ASMI and Δ% TBLMI.

CONCLUSIONS

The associations between different individual PUFAs and age-related muscle loss in middle-aged and older adults may be different. Our results suggest that high concentrations of erythrocyte membrane n-6 PUFAs may be correlated with less skeletal muscle mass loss, whereas extremely high concentrations of n-3 PUFAs may be correlated with more muscle loss.

Establishing reference values for percentage of appendicular skeletal muscle mass and their association with metabolic syndrome in Korean adolescents

PURPOSE

The association between appendicular skeletal muscle mass (ASM) and cardiometabolic risk has been emphasized. We estimated reference values of the percentage of ASM (PASM) and investigated their association with metabolic syndrome (MS) in Korean adolescents.

METHODS

Data from the Korea National Health and Nutrition Examination Survey performed between 2009 and 2011 were used. Tables and graphs of reference PASM were generated using 1,522 subjects, 807 of whom were boys aged 10 to 18. The relationship between PASM and each component of MS in adolescents was further analyzed in 1,174 subjects, 613 of whom were boys. Moreover, the pediatric simple MS score (PsiMS), the homeostasis model assessment of insulin resistance (HOMA-IR), and the triglyceride-glucose (TyG) index were analyzed. Multivariate linear and logistic regressions adjusting for age, sex, household income, and daily energy intake were performed.

RESULTS

In boys, PASM increased with age; the trend was different in girls, in whom PASM declined with age. PsiMS, HOMA-IR, and TyG index showed inverse associations with PASM (PsiMS, β=-0.105, P<0.001; HOMA-IR, β=-0.104, P<0.001; and TyG index, β=-0.013, P<0.001). PASM z-score was negatively associated with obesity (adjusted odds ratio [aOR], 0.22; 95% CI, 0.17-0.30), abdominal obesity (aOR, 0.27; 95% CI, 0.20-0.36), hypertension (aOR, 0.65; 95% CI, 0.52-0.80), and elevated triglycerides (aOR, 0.67; 95% CI, 0.56-0.79).

CONCLUSION

The probability of acquiring MS and insulin resistance decreased as PASM values increased. The reference range may offer clinicians information to aid in the effective management of patients. We urge clinicians to monitor body composition using standard reference databases.

Association between Sarcopenia and Poor Glycemic Control in Older Adults with Type 2 Diabetes Mellitus

BACKGROUND

Aging is associated with a decrease in muscle mass. Insulin resistance and hyperglycemia accelerate muscle loss, leading to a deterioration in strength, muscle mass, and physical capacity in older adults. This study was conducted to determine the association between sarcopenia and poor glycemic control in older adults with type 2 diabetes mellitus (T2D).

METHODS

A cross-sectional study was carried out in older adults with T2D in geriatric outpatient clinics. Sarcopenia was diagnosed as per the European Working Group on Sarcopenia in Older People 2 (EWGSOP2) criteria. According to glycosylated hemoglobin (HbA1c) levels, participants were classified into glycemic control (HbA1c ≤ 7.5%) and poor glycemic control (HbA1c ≥ 7.5%) groups.

RESULTS

Older adults with sarcopenia were found to have poor glycemic control compared to adults without sarcopenia (62.3% vs. 47.9%, p = 0.007). Logistic regression analysis showed an association between poor glycemic control and the presence of sarcopenia (odds ratio (OR): 1.79, 95% confidence interval (CI): 1.17-2.75) and low muscle mass (OR: 1.73, 95% CI: 1.07-2.73).

CONCLUSIONS

Poor glycemic control is associated with the presence of sarcopenia and low muscle mass, which highlights the need to implement better treatment strategies in order to reduce the loss of muscle mass.

Nativity differences in the relationship between handgrip strength and cognitive impairment in older Mexican Americans over 20 years of follow-up

PURPOSE

To examine nativity differences in the relationship between handgrip strength (HGS) and cognitive impairment among Mexican Americans aged ≥ 65 years with normal or high cognitive function at baseline over a 20-year period.

METHODS

Prospective cohort study of 2,155 non-institutionalized Mexican Americans aged ≥ 65 years from the Hispanic Established Population for the Epidemiological Study of the Elderly) who scored ≥ 21 in the Mini Mental State Examination (MMSE) at baseline. Measures included socio-demographics, body mass index, medical conditions, depressive symptoms, physical function, disability, HGS quartiles (sex-adjusted), and MMSE. We used generalized estimating equation models to estimate the odds ratio (OR) and 95% Confidence Interval (CI) of cognitive impairment (MMSE < 21) as a function of HGS quartile by nativity and adjusted for covariates.

RESULTS

US-born and foreign-born participants in the 4th quartile (highest) of HGS at baseline had lower odds of cognitive impairment over time compared with those in the 1st (lowest) HGS quartile (OR=0.95, 95% CI=0.90-0.99 and OR=0.93, 95% CI=0.89-0.98, respectively), after controlling for all covariates. When we analyzed HGS quartiles as time-varying, we found that US-born participants in the 3rd and 4th HGS quartile had 25% and 30% lower odds of cognitive impairment, respectively, while foreign-born participants in the 3rd and 4th HGS quartile had 27% and 49% lower odds of cognitive impairment over time, respectively, after controlling for all covariates.

CONCLUSION

Foreign-born older Mexican Americans who performed high in HGS experienced 7% lower odds of cognitive impairment over time compared with US-born older Mexican Americans.

Gender Differences in Relation to Body Composition, Insulin Resistance, and Islet Beta Cell Function in Newly Diagnosed Diabetic or Pre-Diabetic Patients

OBJECTIVE

To assess the correlation between body components with insulin resistance (IR) and islet beta cell function in patients with newly diagnosed type 2 diabetes mellitus (T2DM) or pre-diabetes mellitus (pre-DM) and to explore whether this correlation differs in males and females.

METHODS

111 newly diagnosed diabetic or pre-diabetic patients were recruited in this cross-sectional study. 75g oral glucose tolerance test was used to determine the diagnosis of DM or pre-DM. Homeostasis model assessment of insulin resistance (HOMA-IR) and glucose disposition index (DI₃₀) was calculated to assess IR and islet beta cell function, respectively. Whole-body and regional lean mass (LM) and fat mass (FM) were obtained by dual-energy X-ray absorptiometry (DEXA). Partial correlation and multiple linear regression analyses were used to determine the associations between body composition, IR, and islet beta cell function.

RESULTS

More body fat and appendicular fat was observed in female patients than in male, though with similar BMI. Legs fat % was negatively correlated with HOMA-IR, whereas legs lean % was positively associated with HOMA-IR in females (r = -0.673, p = 0.017; r =0.664, p = 0.018, respectively). The regression analysis showed that legs LM was positively correlated with HOMA-IR in females. However, in male patients, android FM was positively correlated with HOMA-IR (r = 0.462, p = 0.007), and trunk LM was negatively associated with DI₃₀ (r = -0.458, p = 0.007). Nevertheless, no significant correlation was observed between body composition and islet beta cell function in female patients.

CONCLUSION

Android FM was positively correlated with IR only in male patients but not in females. Besides, relative legs fat and LM were independently associated with IR in female patients but not in males. Further studies are needed to explore the underlying mechanism.

Lower insulin level is associated with sarcopenia in community-dwelling frail and non-frail older adults

BACKGROUND

Sarcopenia is common among older individuals with and without type 2 diabetes mellitus (T2DM). There are conflicting evidence in support of the role of insulin in the development of age-related and T2DM-related sarcopenia. We investigated the relationships between the levels of fasting insulin and other blood biomarkers related to insulin or lipid metabolism with the presence of sarcopenia in two independent studies.

MATERIALS AND METHODS

In 246 pre-frail frail older individuals with (n = 41) and without T2DM (n = 205) in the Singapore Frailty Interventional Trial, sarcopenia was defined by low appendicular lean mass (ALM) relative to total body mass (skeletal muscle index, SMI = ALM/height2) and low lower limb strength or gait speed according to the Asian Working Group for Sarcopenia (AWGS) criteria released in 2019, and related to levels of fasting insulin and glucose, C-peptide, IGF-1, leptin, and active ghrelin. This investigation was validated in another independent study sample of 189 robust and pre-frail frail elderly in the Singapore Longitudinal Aging Study Wave 2 (SLAS-2).

RESULTS

Compared to non-sarcopenic individuals, those with sarcopenia and possible sarcopenia showed significantly lower fasting insulin (p < 0.05) in pre-frail/frail and non-frail older individuals. Consistent trends of relationships were observed for serum levels of C-peptide, IGF-1, leptin, and active ghrelin. In multivariable logistic regression models, sarcopenia was independently associated with low insulin (p < 0.05). Levels of fasting insulin, C-peptide, and leptin were also significantly associated with BMI, SMI, knee extension strength, gait speed, and physical activity score.

CONCLUSION

Dysregulated insulin secretion in diabetic and non-diabetic older individuals may play an important role in age-related and diabetes-related sarcopenia.

Association between ALT/AST and Muscle Mass in Patients with Type 2 Diabetes Mellitus

Objective

The alanine aminotransferase/aspartate aminotransferase (ALT/AST) ratio is thought to be related to metabolic disorders and insulin resistance. Type 2 diabetes mellitus (T2DM) is a high-risk population for low muscle mass. This study was performed to evaluate the association between ALT/AST and muscle mass in subjects with T2DM.

Method

This cross-sectional study enrolled 1068 subjects (566 males and 502 females) with T2DM. General information, medical history, and blood samples were collected. Skeletal muscle index (SMI) was detected using dual-energy X-ray absorptiometry. Logistic regression analysis was utilized to determine the correlation of ALT/AST and low muscle mass in subjects with T2DM. Multiple linear regression analysis was utilized to evaluate the association between ALT/AST, SMI and other metabolic characteristics.

Result

Of all subjects, 115 men (20.3%) and 71 women (14.1%) presented low muscle mass. ALT/AST was related to an increased risk for low muscle mass in both genders. Multiple linear regression analysis displayed that SMI was negatively associated with ALT/AST, age, glycosylated hemoglobin (HbA1c), and high-density lipoprotein cholesterol (HDL) in male group. While in female group, SMI was positively associated with systolic blood pressure (SBP) and negatively associated with ALT/AST and age. Furthermore, ALT/AST was associated with age and BMI in both genders.

Conclusion

ALT/AST was negatively associated with muscle mass in subjects with T2DM.

Dietary patterns and sarcopenia in elderly adults: the Tianjin Chronic Low-grade Systemic Inflammation and Health (TCLSIH) study

Sarcopenia is a core contributor to several health consequences, including falls, fractures, physical limitations and disability. The pathophysiological processes of sarcopenia may be counteracted with the proper diet, delaying sarcopenia onset. Dietary pattern analysis is a whole diet approach used to investigate the relationship between diet and sarcopenia. Here, we aimed to investigate this relationship in an elderly Chinese population. A cross-sectional study with 2423 participants aged more than 60 years was performed. Sarcopenia was defined based on the guidelines of the Asian Working Group for Sarcopenia, composed of low muscle mass plus low grip strength and/or low gait speed. Dietary data were collected using a FFQ that included questions on 100 food items along with their specified serving sizes. Three dietary patterns were derived by factor analysis: sweet pattern, vegetable pattern and animal food pattern. The prevalence of sarcopenia was 16·1 %. The higher vegetable pattern score and animal food pattern score were related to lower prevalence of sarcopenia (P_trend = 0·006 and < 0·001, respectively); the multivariate-adjusted OR of the prevalence of sarcopenia in the highest v. lowest quartiles were 0·54 (95 % CI 0·34, 0·86) and 0·50 (95 % CI 0·33, 0·74), separately. The sweet pattern score was not significantly related to the prevalence of sarcopenia. The present study showed that vegetable pattern and animal food pattern were related to a lower prevalence of sarcopenia in Chinese older adults. Further studies are required to clarify these findings.

The Positive Association between Muscle Mass and Bone Status Is Conserved in Men with Diabetes: A Retrospective Cross-Sectional and Longitudinal Study

Bone and muscle are known to be correlated and interact chemically each other. Diabetes affects the health status of these two types of organ. There has been lack of studies of men on this topic. This study aims to investigate the relationship between bone and muscle status in men with and without diabetes. This study enrolled 318 and 88 men with and without diabetes, respectively, between April 2007 and December 2017. The appendicular skeletal muscle index (ASMI) was correlated with femoral neck bone mineral density (BMD), total hip BMD, and the trabecular bone score (TBS) in both groups (p < 0.001−0.008). In analysis of the changes in muscle mass and bone-related parameters over the 3 years, the ASMI was correlated with total hip BMD only in diabetes group (p = 0.016) and the TBS in both groups (p < 0.001−0.046). This study showed that the positive correlation between muscle mass and bone status was largely conserved in diabetic group in men. Moreover, in a long-term perspective, muscle mass might be more correlated with the bone microarchitecture or bone quality than bone density, and the association between muscle mass and total hip BMD could be stronger in the diabetic group.

Association between dietary inflammatory index score and muscle mass and strength in older adults: a study from National Health and Nutrition Examination Survey (NHANES) 1999-2002

PURPOSE

Chronic low-grade systemic inflammation affects muscle protein metabolism. The dietary inflammatory index (DII®) is a tool designed to assess the inflammatory potential of the diet. The available data on the association between DII and sarcopenia are limited. We aimed to investigate the association of the DII with components of sarcopenia in individuals over 50 years of age.

METHODS

This cross-sectional study used the National Health and Nutrition Examination Survey (NHANES) 1999-2002 dataset. Body composition was measured, and isokinetic strength of the knee extensors (peak force) was evaluated. Low muscle mass and strength were defined using sex-specific thresholds. Energy-adjusted DII (E-DII™) scores were calculated using 24-h dietary recall data. Regression models were fit to evaluate the association between E-DII scores and low muscle mass and low muscle strength, alone and combined.

RESULTS

Mean age of study participants was 62.1 ± 9.5 years, and 138 participants (7.4%) belonged to the combination group of low muscle mass and low muscle strength. In multivariable-adjusted regression models, higher E-DII score was associated with lower appendicular skeletal muscle index (ASMI) (β =  - 0.03, P  < 0.001, P trend <0.001), and lower peak force (β =  -2.15, P  = 0.04, P trend = 0.01) and higher likelihood for these components combined (OR = 1.12, 95% CI 1.01-1.25, P = 0.03).

CONCLUSION

Higher E-DII score is associated with lower muscle mass and muscle strength, and increased likelihood for the combination of low muscle mass and low muscle strength in older adults. This has important implications for healthy aging.

Body composition and risk factors associated with sarcopenia in post-COVID patients after moderate or severe COVID-19 infections

Background

Post-COVID-19 syndrome is characterized by diverse symptoms and abnormalities that persist beyond 12 weeks from the onset of acute COVID-19. Severity disease has been associated with more musculoskeletal alterations such as muscle weakness, dyspnea, and distance walking. The aim was to evaluate the impact of invasive mechanical ventilation (IMV) on body composition and investigate risk factors associated with sarcopenia in post-COVID-19 patients three months after moderate or severe COVID-19 infections.

Methods

Cross-sectional study. 530 patients with PCR-confirmed diagnoses of moderate to severe COVID-19, > 18 years old, oxygen saturation ≤ 93%, PaO₂/FiO₂ ratio < 300, who required hospitalization and were discharged were included. We excluded those who died before the follow-up visit, declined to participate, or could not be contacted.

Results

The mean age was 53.79 ± 12.90 years. IMV subjects had lower phase angle and handgrip strength and higher impedance index, frequency of low muscle mass, and low muscle strength than those without IMV. The risk factors of sarcopenia were > 60 years of age, diabetes, obesity, IMV, and prolonged hospital stay. The multivariate model showed that age > 60 years (OR: 4.91, 95% CI: 2.26–10.63), obesity (OR: 3.73, 95% CI: 1.21–11.54), and interaction between prolonged length of hospital stay and IMV (OR: 2.92; 95% CI: 1.21–7.02) were related to a higher risk of sarcopenia.

Conclusion

Obesity and the interaction between prolonged length of hospital stay and IMV are associated with a higher risk of sarcopenia at 3 months after severe or moderate COVID-19 infection.

Beneficial Effect of H2S-Releasing Molecules in an In Vitro Model of Sarcopenia: Relevance of Glucoraphanin

Sarcopenia is a gradual and generalized skeletal muscle (SKM) syndrome, characterized by the impairment of muscle components and functionality. Hydrogen sulfide (H₂S), endogenously formed within the body from the activity of cystathionine-γ-lyase (CSE), cystathionine- β-synthase (CBS), and mercaptopyruvate sulfurtransferase, is involved in SKM function. Here, in an in vitro model of sarcopenia based on damage induced by dexamethasone (DEX, 1 μM, 48 h treatment) in C2C12-derived myotubes, we investigated the protective potential of exogenous and endogenous sources of H₂S, i.e., glucoraphanin (30 μM), L-cysteine (150 μM), and 3-mercaptopyruvate (150 μM). DEX impaired the H₂S signalling in terms of a reduction in CBS and CSE expression and H₂S biosynthesis. Glucoraphanin and 3-mercaptopyruvate but not L-cysteine prevented the apoptotic process induced by DEX. In parallel, the H₂S-releasing molecules reduced the oxidative unbalance evoked by DEX, reducing catalase activity, O₂⁻ levels, and protein carbonylation. Glucoraphanin, 3-mercaptopyruvate, and L-cysteine avoided the changes in myotubes morphology and morphometrics after DEX treatment. In conclusion, in an in vitro model of sarcopenia, an impairment in CBS/CSE/H₂S signalling occurs, whereas glucoraphanin, a natural H₂S-releasing molecule, appears more effective for preventing the SKM damage. Therefore, glucoraphanin supplementation could be an innovative therapeutic approach in the management of sarcopenia.

Diabetes mellitus is associated with declines in physical function among men with and without HIV

OBJECTIVE

To determine the longitudinal relationships between abnormal glucose metabolism and physical function in persons with HIV (PWH) and without HIV.

DESIGN

Prospective cohort study of men with or at risk for HIV in four United States cities between 2006 and 2018.

METHODS

Men with or at risk for HIV from the Multicenter AIDS Cohort Study (MACS) had semi-annual assessments of glycemic status, grip strength, and gait speed. We used linear mixed models with random intercept to assess associations between glycemic status and physical function. Glycemic status was categorized as normal, impaired fasting glucose (IFG), controlled diabetes mellitus [hemoglobin A1C (HbA1C) <7.5%], or uncontrolled diabetes mellitus (HbA1C ≥ 7.5%).

RESULTS

Of 2240 men, 52% were PWH. Diabetes mellitus was similar among PWH (7.7%) vs. persons without HIV (6.7%, P = 0.36) at baseline. PWH had slower gait speed (1.17 vs. 1.20 m/s, P < 0.01) but similar grip strength (40.1 vs. 39.8 kg, P = 0.76) compared with persons without HIV at baseline. In multivariate models, gait speed decline was greater with controlled diabetes mellitus [-0.018 m/s (-0.032 to -0.005), P = 0.01] and grip strength decline was greater with controlled [-0.560 kg (-1.096 to -0.024), P = 0.04] and uncontrolled diabetes mellitus [-0.937 kg (-1.684 to -0.190), P = 0.01), regardless of HIV serostatus compared with normoglycemic individuals.

DISCUSSION

Abnormal glucose metabolism was associated with declines in gait speed and grip strength regardless of HIV serostatus. These data suggest that improvement in glucose control should be investigated as an intervenable target to prevent progression of physical function limitations among PWH.

Large mid-upper arm circumference is associated with reduced insulin resistance independent of BMI and waist circumference: A cross-sectional study in the Chinese population

BACKGROUND

Body mass index (BMI) is a common indicator in clinical practice, but it is not sufficient to predict insulin resistance (IR). Other anthropometric methods supplement BMI in the assessment of body composition, which can be predicted more accurately. This cross-sectional study aimed to evaluate the association between mid-upper arm circumference (MUAC), triceps skinfold (TSF) thickness, mid-arm muscle circumference (MAMC) and IR in Chinese adults.

METHODS

This cross-sectional study analyzed data from the 2009 China Health and Nutrition Survey database. The study population was divided into four groups according to the MUAC quartiles, and the homeostasis mode assessment was used to evaluate the degree of IR. Logistic regression analysis was performed to calculate odds ratios (ORs) with 95% confidence intervals (CIs), with adjustments for multiple covariates. Subgroup analyses stratified by age, sex, BMI, waist circumference (WC), smoking status, and alcohol consumption were performed.

RESULTS

In total, 8,070 participants were included in the analysis. As MUAC increased, BMI, TSF thickness, MAMC, and the proportion of IR tended to increase. However, we found that there was a significant negative association between MUAC and MAMC and IR in the logistic regression analysis, independent of BMI and WC, the ORs for the highest quartiles compared with the lowest quartiles were 0.662 (95%CI: 0.540-0.811) and 0.723 (95%CI: 0.609-0.860), respectively. There was no significant association was observed between the TSF thickness and IR (OR=1.035 [95%CI: 0.870-1.231]). The inverse associations were more pronounced among participants with lower BMI and WC. No significant age-specific differences were observed (P-heterogeneity > 0.05).

CONCLUSIONS

After adjusting for BMI and WC, MUAC was negatively associated with IR in Chinese adults, and the association between MUAC and IR was derived from arm muscle instead of subcutaneous fat. MUAC could be an additional predictor of IR besides BMI and WC in clinical practice.

Prevalence of obesity and diabetes in older people with sarcopenia defined according to EWGSOP2 and FNHI criteria

Background

Although the prevalence of sarcopenic obesity is increasing, nowadays a universally accepted definition still does not exist. Because, this clinical entity is defined as the combination of obesity and sarcopenia, the diagnosis appears to be strictly linked to criteria used for sarcopenia and the available prevalence data are not uniform. To investigate the prevalence of sarcopenic obesity in older persons according to EWGSOP2 and FNIH criteria. Second, to evaluate the prevalence of diabetes in patients with sarcopenia diagnosed by the two definitions.

Methods

Observational multicenter study performed in 2014 on older patients admitted to 12 Italian hospitals (GLISTEN Study). Data were collected through standardized questionnaires, which assessed: socio-demographic data, cognitive status, functional abilities, pharmacological therapy, comorbidities, and blood tests. Moreover, muscle mass and strength and physical performance were evaluated.

Results

Six hundred and ten were included in the analyses. Among sarcopenic patients, the prevalence of sarcopenic obesity was 30.8% with FNIH and 0% with EWGSOP2 criteria. According to EWGSOP2 criteria, 23.7% of sarcopenic and 30.8% of non-sarcopenic patients were affected by diabetes (p = 0.101); otherwise, using FNIH criteria, 36.3% of sarcopenic and 26.9% of non-sarcopenic patients were diabetic (p = 0.030). After adjustment for potential confounders, diabetic patients had a 73% higher probability of being sarcopenic according to FNIH criteria (OR 1.73; 95% CI 1.13–2.64).

Conclusions

The EWGSOP2 and FNIH sarcopenia criteria are differently related to the prevalence of obesity and diabetes. The EWGSOP2 criteria seem to be not suitable to identify people with sarcopenic obesity.

Midlife and late-life diabetes and sarcopenia in a general older Japanese population: The Hisayama Study

AIMS/INTRODUCTION

To investigate the association between midlife or late-life diabetes and the development of sarcopenia in an older Japanese population.

MATERIALS AND METHODS

A total of 824 Japanese residents aged 65 to 84 years without sarcopenia were followed up from 2012 to 2017. Sarcopenia was determined following the Asian Working Group for Sarcopenia definition. The time of diabetes diagnosis was classified as midlife or late-life diabetes by the age at first diagnosis of diabetes (< 65 or ≥ 65 years) based on annual health checkups data over the past 24 years. The duration of diabetes was categorized into three groups of < 10, 10-15, and > 15 years. The odds ratios of incident sarcopenia according to the diabetic status were estimated using a logistic regression analysis.

RESULTS

During follow-up, 47 subjects developed sarcopenia. The multivariable-adjusted odds ratio for incident sarcopenia was significantly greater in subjects with diabetes at baseline than in those without it (odds ratio 2.51, 95% confidence interval 1.26-5.00). Subjects with midlife diabetes had a significantly greater risk of incident sarcopenia, whereas no significant association between late-life diabetes and incident sarcopenia was observed. With a longer duration of diabetes, the risk of incident sarcopenia increased significantly (P for trend = 0.002).

CONCLUSIONS

The present study suggests that midlife diabetes and a longer duration of diabetes are significant risk factors for incident sarcopenia in the older population. Preventing diabetes in midlife may reduce the risk of the development of sarcopenia in later life.

Prevalence of Musculoskeletal Disorders in Patients with Coronary Artery Disease

Aim. To study the prevalence of musculoskeletal disorders in patients with stable coronary artery disease (CAD).

Material and methods. Patients with stable CAD (n=387) were included in the study. The subjects were admitted to the hospital for planned myocardial revascularization (ages of 50-82). The median age was 65 [59;69] years. Most of the sample consisted of males - 283 (73.1%). 323 (83.5%) patients had arterial hypertension (AH), 57.1% - history of myocardial infarction, and a quarter of the patients had type 2 diabetes mellitus (DM). The study of musculoskeletal system included the identification of sarcopenia in accordance with The European Working Group on Sarcopenia in Older People (EWGSOP, 2019); verification of osteopenia/osteoporosis according to the WHO criteria (2008); diagnosing osteosarcopenia in case of sarcopenia and osteopenia/osteoporosis coexistence.

Results. At the initial screening of sarcopenia in accordance with EWGSOP, clinical signs (according to the Strength, assistance with walking, rising from a chair, climbing stairs, and falls (SARC-F) questionnaire) were detected in 41.3% of cases, but further examination (dynamometry, quantitative assessment of skeletal muscle) confirmed this diagnosis only in 19.9% of patients with CAD. Among the examined patients with CAD a low T-score according to DEXA was found in 53 (13.7%) of cases, and osteopenia was diagnosed 10 times more often than osteoporosis (90.6% vs. 9.4%). Furthermore, due to combination of low bone density (osteopenia/osteoporosis) and reduced muscle mass and strength (sarcopenia), osteosarcopenia was verified in one patient. Thus, the study revealed the prevalence of particular types of musculoskeletal disorders in 105 (27.1%) patients with stable CAD. The most common type of musculoskeletal disorder was sarcopenia - 52 cases (13.4%); osteopenia/osteoporosis was detected in 28 patients (7.2%), osteosarcopenia in 25 (6.5%). The most pronounced clinical manifestation of sarcopenia and osteopenia/osteoporosis, reflected by a higher score on the SARC-F questionnaire, low handgrip strength, small area of muscle tissue, low musculoskeletal index, as well as low values of bone mineral density, were observed in patients with osteosarcopenia. Patients with osteopenia/osteoporosis did not differ significantly from patients without musculoskeletal conditions in most parameters, with the exception of the T-score, the average SARC-F score, and muscle strength in men. The conducted correlation analysis revealed not only the relationship between the parameters of musculoskeletal function, but also their association with age, duration of AH, CAD, and type 2 DM.

Conclusion. Several types of musculoskeletal disorders were found in a third of patients with CAD. Sarcopenia was revealed to be the most frequent type of musculoskeletal disorder.

Dual effects of insulin resistance on mortality and function in non-diabetic older adults: findings from the Toledo Study of Healthy Aging

Insulin signalling declines with increasing age and impacts skeletal muscle function and longevity in animal models. Our aim was to assess the relationships between insulin resistance (IR) and frailty and mortality in a unique community-dwelling cohort of older people. 991 non-diabetic subjects from the Toledo Study of Healthy Ageing (TSHA) cohort were included. IR was estimated by the homeostasis model assessment index (HOMA-IR) at baseline while frailty was determined by frailty phenotype (FP) and Frailty Trait Scale (FTS) at baseline and after 5-year follow-up. Deaths were also determined. Multivariate regression models were used to analyze the effects of HOMA-IR on outcomes. Age, gender, BMI, education level, cardio- and cerebro-vascular disease, glomerular filtration rate, and disability were included as potential confounding variables in progressive adjustment models. IR determined as increasing log HOMA-IR was inversely associated with risk of mortality. The association remained significant for all adjustment models (HR: 0.64-0.69). When we analyzed survival curves, the higher the HOMA-IR tertile, the lower the mortality rate (highest vs lowest tertile, p = 0.0082). In contrast, IR increased the risk of incident frailty determined by FP (OR 1.81 [1.14-2.87]) as well as deterioration of frailty status determined by worsening in FTS score (OR 1.28 [1.01-1.63]) at 5-year follow-up. In non-diabetic older subjects, IR significantly increases the risk for frailty and functional decline but decreased the risk of death at 5-year follow-up. This finding raises the need of assessing the effect of biomarkers on different outcomes before establishing their role as biomarkers of aging.

Effects of resistance training using elastic bands on muscle strength with or without a leucine supplement for 48 weeks in elderly patients with type 2 diabetes

Type 2 diabetes is associated with sarcopenia. Resistance training and appropriate nutritional therapy are reported to be effective for muscle strength and mass. This study aimed to evaluate the effect of resistance training using elastic bands at home combined with a leucine-rich amino acid supplement on muscle strength, physical function, and muscle mass in elderly type 2 diabetes. We conducted a 48-week prospective single-center randomized controlled trial in 60 patients who were randomly allocated to one of three groups: control (C), resistance exercise (R), and resistance exercise plus supplement (RL). R and RL groups performed daily bodyweight resistance training with elastic bands exercises at home, and the RL group also took 6 g of a leucine-rich amino acid supplement daily. Knee extension strength (muscle strength), grip strength, usual gait speed (physical function), muscle mass, and cognitive function were assessed at 0 and 48 weeks. Although the change in knee extension strength from baseline was significantly increased by 6.4 Nm (95% CI 1.0, 11.7) in the RL group (p = 0.036), no significant difference was observed among the three groups (p = 0.090). Physical function, muscle mass, and cognitive function also had no changes during the study period among the three groups. No additive effect of a leucine-rich amino acid supplement on muscle strength or mass was observed. Although a post hoc analysis comparing with or without resistance training (C group vs. R + RL group) found that knee extension strength was significantly increased (p = 0.028), and cognitive decline was less (p = 0.046) than in the C group.

Decreased Appendicular Skeletal Muscle Mass is Associated with Poor Outcomes after ST-Segment Elevation Myocardial Infarction

AIM

The importance of sarcopenia in cardiovascular diseases has been recently demonstrated. This study aims to examine whether skeletal muscle mass (SMM), an important component of sarcopenia, is associated with an increased risk of poor outcome in patients after ST-segment elevation myocardial infarction (STEMI).

METHODS

We measured SMM in 387 patients with STEMI using dual-energy X-ray absorptiometry. Patients were divided into low- and high-appendicular skeletal mass index (ASMI: appendicular SMM divided by height squared (kg/m²)) groups using the first quartile of ASMI (≤ 6.64 kg/m² for men and ≤ 5.06 kg/m² for women). All patients were followed up for the primary composite outcome of all-cause death, nonfatal myocardial infarction, nonfatal ischemic stroke, hospitalization for congestive heart failure, and unplanned revascularization.

RESULTS

Low-ASMI group was older and had a more complex coronary lesion, a lower left ventricular ejection fraction, and a higher prevalence of Killip classification ≥ 2 than high-ASMI group. During a median follow-up of 33 months, the event rate was significantly higher in low-ASMI group than in high-ASMI group (24.7% vs 13.4%, log-rank p=0.001). Even after adjustment for patients' background, low ASMI was independently associated with the high risk of primary composite events (adjusted hazard ratio 2.06, 95% confidence interval 1.01- 4.19, p=0.04). In the subgroup analyses of male patients (n=315), the optimal cutoff point of ASMI for predicting primary composite outcome was 6.75 kg/m², which was close to its first quartile value.

CONCLUSIONS

Low ASMI is independently associated with poor outcome in patients with STEMI.

Association between the Thigh Muscle and Insulin Resistance According to Body Mass Index in Middle-Aged Korean Adults

BACKGROUND

We examined the associations between thigh muscle area (TMA) and insulin resistance (IR) according to body mass index (BMI) in middle-aged Korean general population.

METHODS

TMA was measured using quantitative computed tomography and corrected by body weight (TMA/Wt) in 1,263 men, 788 premenopausal women, and 1,476 postmenopausal women all aged 30 to 64 years. The tertiles of TMA/Wt were calculated separately for men and for premenopausal and postmenopausal women. Homeostatic model assessment for insulin resistance (HOMA-IR) was performed using fasting blood glucose and insulin levels, and increased IR was defined according to sex-specific, top quartiles of HOMA-IR. Associations between the TMA/Wt tertiles and increased IR according to the BMI categories (<25 and ≥25 kg/m²) were assessed using multivariable logistic regression analysis.

RESULTS

In men with higher BMIs, but not in those with lower BMIs, the presence of an increased IR had significantly higher odds ratios in the lower TMA/Wt tertiles, even after adjustment for visceral fat area. However, in premenopausal and postmenopausal women, there was no significant inverse association between TMA/Wt tertiles and increased IR, regardless of BMI category.

CONCLUSION

Our findings suggest that the thigh muscle is inversely associated with IR in men, particularly in those with higher BMIs.

Low skeletal muscle mass is associated with arterial stiffness in community-dwelling Chinese aged 45 years and older

Background

Evidence suggests that body composition has impact on arterial stiffness. However, evidence in Chinese are limited, and results remain controversial. The aim of our study is to investigate whether skeletal muscle mass is associated with arterial stiffness in Chinese community-dwelling men and women aged 45 years and older.

Methods

In this cross-sectional study, 20,477 participants (age range: 45–80 years, 68.8% women) were included in the analysis. Brachial-ankle pulse wave velocity (baPWV), an indicator of arterial stiffness was measured using a waveform device. Total muscle mass and muscle mass of arm, leg and trunk were measured by bioelectrical impedance analysis. Height and weight were measured and appendicular skeletal muscle mass index (ASMI) was calculated as appendicular skeletal muscle mass (sum of arm and leg muscle mass) divided by height square.

Results

After adjustment for age, body fat percentage, systolic blood pressure and diastolic blood pressure, ASMI was negatively associated with baPWV [β (SE) for men: − 0.208 (0.016), p < 0.0001; for women: − 0.245 (0.012), p < 0.0001]. High ASMI was a protective factor for the presence of arterial stiffness (defined as baPWV) [OR (95%CI) for men: 0.730 (0.682, 0.782), p < 0.0001; women: 0.634 (0.593, 0.677), p < 0.0001]. Similar associations were found between quantity of muscle mass (total and appendicular muscle mass, muscle mass of arm, leg and trunk) and arterial stiffness in men and women after further adjustment for height (all p < 0.0001).

Conclusion

Low skeletal muscle mass is associated with increased risk of arterial stiffness in Chinese community-dwelling adults aged 45 years and older.

A cross-sectional study: Associations between sarcopenia and clinical characteristics of patients with type 2 diabetes

Sarcopenia is a geriatric syndrome and it impairs physical function. Patients with type 2 diabetes mellitus (T2DM) are at a higher risk of sarcopenia. The purpose of this study is to explore characteristics of general information and metabolic factors of sarcopenia in patients with T2DM in the northeast of China, and provide information for the prevention and treatment of sarcopenia in clinical practice.Patients with T2DM aged ≥65 were recruited in Changchun from March 2017 to February 2018. Questionnaires of general information, physical examination, laboratory and imaging examination were conducted. The patients were assigned into sarcopenia group and non-sarcopenia group according to the diagnostic criteria proposed by Asian working group for sarcopenia (AWGS), and the differences between 2 groups were analyzed.A total of 132 participants were included in this study, of which, 38 (28.8%) were diagnosed with sarcopenia. 94 (71.2%) were with no sarcopenia. Logistic regression analysis showed that age (OR: 1.182, 95%CI: 1.038-1.346), trunk fat mass (TFM) (OR: 1.499, 95%CI: 1.146-1.960) and free thyroxine (FT4) (OR: 1.342, 95%CI: 1.102-1.635) were independent risk factors for sarcopenia. BMI (body mass index) (OR: 0.365, 95%CI: 0.236-0.661), exercise (OR: 0.016, 95%CI: 0.001-0.169), female (OR: 0.000, 95%CI: 0.00-0.012), metformin (OR: 0.159, 95%CI: 0.026-0.967) and TSM (trunk skeletal muscle mass) (OR: 0.395, 95%CI: 0.236-0.661) were protective factors for sarcopenia.Sarcopenia in patients with T2DM is associated with increased age, increased TFM and increased FT4 level. Regular exercise, female, metformin administrations, high BMI and increased TSM are associated with lower risk of sarcopenia.

Risk Assessment of Sarcopenia in Patients With Type 2 Diabetes Mellitus Using Data Mining Methods

Purpose: Sarcopenia is a geriatric syndrome, and it is closely related to the prevalence of type 2 diabetes mellitus (T2DM). Until now, the diagnosis of sarcopenia requires Dual Energy X-ray Absorptiometry (DXA) scanning. This study aims to make risk assessment of sarcopenia with support vector machine (SVM) and random forest (RF) when DXA is not available. Methods: Firstly, we recruited 132 patients aged over 65 and diagnosed with T2DM in Changchun, China. Clinical data were collected for predicting sarcopenia. Secondly, we selected 3, 5, and 7 features out of over 40 features of patient's data with backward selection, respectively, to train SVM and RF classification models and regression models. Finally, to evaluate the performance of the models, we performed leave one out and 5-fold cross validation. Results: When training the model with 5 features, the sensitivity, specificity, negative predictive value (NPV) and positive predictive value (PPV) were favorable, and it was better than the models trained with 3 features and 7 features. Area under the receiver operating characteristic (ROC) curve (AUC) were over 0.7, and the mean AUC of SVM models was higher than that of RF. Conclusions: Using SVM and RF to make risk assessment of sarcopenia in the elderly is an option in clinical setting. Only 5 features are needed to input into the software to run the algorithm for a primary assessment. It cannot replace DXA to diagnose sarcopenia, but is a good tool to evaluate sarcopenia.

Effect of Insulin Resistance on BMD and Fracture Risk in Older Adults

CONTEXT

Adults with type 2 diabetes (T2D) have higher fracture risk compared with nondiabetics, despite having higher bone mineral density (BMD). Insulin resistance (IR) has been associated with increased BMD. It is not known if IR increases fracture risk.

OBJECTIVE

We investigated the relationship among IR HOMA-IR, BMD, and incident nonspine fractures in nondiabetic individuals.

DESIGN

Participants included 2398 community-dwelling, nondiabetic older adults (age 74 ± 3 years, 53% women, 38% black) in the Health, Aging and Body Composition Prospective Cohort Study [median follow-up: 12 (interquartile range: 6) years].

RESULTS

The cut-off values for the HOMA-IR quartiles were 1.05, 1.54, and 2.33. Total hip BMD was 0.104 g/cm2 higher in the fourth vs the first HOMA-IR quartile (P < 0.001). This difference was attenuated after adjustment for BMI (adjusted mean difference 0.007 g/cm2; P = 0.371). In unadjusted models, fracture risk was lower in those with higher HOMA-IR [hazard ratio (HR) 0.86 (95% CI 0.73 to 1.01) and 0.65 (95% CI 0.47 to 0.89) for the third and fourth quartile, respectively, vs the first quartile]. However, after adjustment for BMD and BMI, fracture risk was significantly higher in the third quartile (HR 1.19, 95% CI 1.00 to 1.41) and tended to be increased in the fourth quartile (HR 1.12, 95% CI 0.87 to 1.46) vs the first quartile.

CONCLUSIONS

Greater IR is associated with higher BMD in nondiabetic older adults. In contrast to the relationship between T2D and fracture risk, we did not find consistent evidence that greater IR is associated with increased fracture risk after adjustment for BMI and BMD.

Dietary Patterns, Skeletal Muscle Health, and Sarcopenia in Older Adults

In recent decades, the significance of diet and dietary patterns (DPs) for skeletal muscle health has been gaining attention in ageing and nutritional research. Sarcopenia, a muscle disease characterised by low muscle strength, mass, and function is associated with an increased risk of functional decline, frailty, hospitalization, and death. The prevalence of sarcopenia increases with age and leads to high personal, social, and economic costs. Finding adequate nutritional measures to maintain muscle health, preserve function, and independence for the growing population of older adults would have important scientific and societal implications. Two main approaches have been employed to study the role of diet/DPs as a modifiable lifestyle factor in sarcopenia. An a priori or hypothesis-driven approach examines the adherence to pre-defined dietary indices such as the Mediterranean diet (MED) and Healthy Eating Index (HEI)—measures of diet quality—in relation to muscle health outcomes. A posteriori or data-driven approaches have used statistical tools—dimension reduction methods or clustering—to study DP-muscle health relationships. Both approaches recognise the importance of the whole diet and potential cumulative, synergistic, and antagonistic effects of foods and nutrients on ageing muscle. In this review, we have aimed to (i) summarise nutritional epidemiology evidence from four recent systematic reviews with updates from new primary studies about the role of DPs in muscle health, sarcopenia, and its components; (ii) hypothesise about the potential mechanisms of ‘myoprotective’ diets, with the MED as an example, and (iii) discuss the challenges facing nutritional epidemiology to produce the higher level evidence needed to understand the relationships between whole diets and healthy muscle ageing.

Fish protein supplementation in older nursing home residents: a randomised, double-blind, pilot study

Background

Age-related loss of muscle mass and function is common in older adults, and studies investigating if dietary proteins may protect and possibly build lean body mass are needed. We assessed the feasibility of conducting a nutritional intervention study in older nursing home residents to investigate the effects of fish protein supplementation on markers of glucose metabolism and inflammation.

Methods

This was a double-blind randomised controlled pilot study. Twenty-four nursing home residents, without major cognitive impairment, received a daily oral nutritional supplement containing 5.2 g of fish protein or placebo for 6 weeks. Anthropometric measurements were conducted at baseline. Participants were screened for nutritional risk using the Mini Nutritional Assessment and activities of daily living using the Barthel index and dietary intake was registered. Hand grip strength was measured and fasting blood samples collected at baseline and endpoint.

Results

Compliance was high and dropout was low, but participant recruitment was challenging. Serum concentrations of monocyte chemoattractant protein-1 decreased, and C-reactive protein increased in the intervention group compared to control, with no changes in markers of glucose metabolism between groups.

Conclusion

Conducting a nutritional intervention using fish protein supplementation in older nursing home residents is feasible but should be conducted as a multi-centre study to account for the low recruitment rate observed in the present study. A full-scale study is needed to gain more knowledge on the potential effects of fish proteins on markers of glucose metabolism and inflammation in relation to the age-related loss of muscle mass and function.

Trial registration

ClinicalTrials.gov NCT03529344 18.05.2018 (retrospectively registered)

Evaluation of skeletal muscle mass indices, assessed by bioelectrical impedance, as indicators of insulin resistance in patients with type 2 diabetes

[Purpose] This study aimed to investigate the association between two skeletal muscle mass indices and insulin resistance, and to determine the skeletal muscle mass index that is beneficial in evaluating insulin resistance in patients with type 2 diabetes mellitus. [Participants and Methods] This study evaluated 136 male and 100 female patients with type 2 diabetes mellitus. The skeletal muscle mass was evaluated by bioelectrical impedance analysis. Two skeletal muscle mass indices were investigated as the appendicular skeletal muscle mass index (appendicular skeletal muscle mass divided by the square of height) and relative total skeletal muscle mass (total skeletal muscle mass as a percent of body weight). The homeostasis model assessment of insulin resistance was used as a marker of insulin resistance. Associations were investigated by grouping the participants according to gender and age (<60 or ≥60 years). [Results] The appendicular skeletal muscle mass index was positively associated with the homeostasis model assessment of insulin resistance, except in male patients aged ≥60 years, whereas the relative total skeletal muscle mass was significantly inversely associated with the homeostasis model assessment of insulin resistance, in all patient groups. The cutoff values of the relative total skeletal muscle mass for the presence of insulin resistance were 37.9% and 32.5% in male and female patients, respectively. [Conclusion] This finding suggests that relative total skeletal muscle mass may be a better indicator of insulin resistance than appendicular skeletal muscle mass index is, in patients with type 2 diabetes mellitus.

Physical Activity Earlier in Life Is Inversely Associated With Insulin Resistance Among Adults in Japan

Background

It is known that physical activity affects glucose metabolism. However, there have been no reports on the influence of physical activity earlier in life on subsequent glucose metabolism. Therefore, we analyzed the influence of physical activity in earlier decades of life on insulin resistance in middle aged and older residents in Japan.

Methods

The subjects were 6,883 residents of Okazaki City between the ages of 40 and 79 years who underwent physical examinations at the Okazaki City Medical Association Public Health Center from April 2007 through August 2011. They gave informed consent for participation in the study. Data on individual characteristics were collected via a questionnaire and from the health examination records. Fasting blood glucose and insulin levels were used to calculate the homeostatic model assessment of insulin resistance (HOMA-IR). HOMA-IR >1.6 was considered to indicate insulin resistance for the purpose of logistic regression models.

Results

The study sample included 3,683 men and 3,200 women for whom complete information was available. For those who exercised regularly throughout their teens to their 30s–40s, the odds ratio for having insulin resistance was 0.75 (95% confidence interval [CI], 0.58–0.96) for men and 0.76 (95% CI, 0.58–0.99) for women after adjusting for other variables, including age, body mass index, and present physical activity. A linear trend was also observed in both men and women.

Conclusions

Subjects who have exercised regularly in the early decades of life are less likely to have insulin resistance later in life.

Eccentric Training Improves Body Composition by Inducing Mechanical and Metabolic Adaptations: A Promising Approach for Overweight and Obese Individuals

Skeletal muscle generates force by either shortening (concentrically) or lengthening (eccentrically). Eccentric (ECC) exercise is characterized by a lower metabolic demand and requires less muscle activity than concentric (CON) exercise at the same level of exerted force. However, the specific effect of ECC training vs. CON training on lean and fat mass remains underexplored. The first aim of this paper was to review the available evidence regarding the effects of ECC training on whole body and segmental lean and fat mass and, when possible, compare these with the effects of CON training. The second aim was to provide some insights into the main mechanical, physiological, and metabolic adaptations of ECC training that contribute to its effects on body composition. The third aim was to determine the beneficial effects of ECC exercise on health-related parameters in overweight and obese patients. ECC training is an effective modality to improve lean mass, but when matched for load or work, the difference between ECC and CON trainings seems unclear. A few studies reported that ECC training is also efficient at reducing fat mass. By increasing post-exercise resting energy expenditure, modifying metabolic substrate, and improving both blood lipid profile and insulin resistance, ECC training is a potential exercise modality for individuals with chronic conditions such as those who are overweight and obese. Further investigations using standardized experimental conditions, examining not only segmental but also whole body composition, are required to compare ECC and CON trainings.

Testosterone Therapy and Glucose Homeostasis in Men with Testosterone Deficiency (Hypogonadism)

Since the early 1990s, it has been recognized that testosterone (T) levels are lower in men with type 2 diabetes mellitus (T2DM) compared with nondiabetic men (controls). Hypogonadism has been reported in approximately 50% of men with T2DM with robust correlations with measures of obesity, such as waist circumference and body mass index (BMI). In longitudinal studies, hypogonadism has been identified as a predictor of incident T2DM. Experimental withdrawal of T led to acute decreased insulin sensitivity, which can be reversed by normalization of T concentrations. Androgen deprivation therapy, commonly used in men with advanced prostate cancer, increases the risk of incident T2DM significantly.While short-term studies of T therapy in hypogonadal men with T2DM show only minor effects, long-term administration of T leads to meaningful and sustained improvements of glycemic control with parallel reductions in body weight and waist circumference. The more insulin-resistant and obese a patient is at the time of initiation of T therapy, the more improvements are noted. The observed effects are likely mediated by the increase in lean body mass invariably achieved by T therapy, as well as the improvement in energy and motivation, referred to as the psychotropic effects of T. As recommended by various guidelines, measuring T levels and, if indicated, restoring men's T levels into the normal physiological range can have a substantial impact on ameliorating T2DM in hypogonadal men.

Psoas and paraspinous muscle index as a predictor of mortality in African American men with type 2 diabetes mellitus

AIM

Recent studies revealed a correlation between skeletal muscle mass index and density with longevity; these studies largely evaluated appendicular skeletal muscles in older Caucasians. This retrospective cohort study assessed the association between axial skeletal muscles size and density with survival in African Americans with type 2 diabetes mellitus.

METHODS

Psoas and paraspinous muscle mass index (cross sectional area/height²) and radiographic density (in Hounsfield Units) were measured using computed tomography in African American-Diabetes Heart Study participants, 314 women and 256 men, with median (25th, 75th quartile) age 55.0(48.0, 62.0) and 57.0(50.0, 64.0) years, respectively. Covariates in fully-adjusted model included age, sex, BMI, smoking, hormone replacement therapy (women), cardiovascular disease, hypertension, coronary artery calcified plaque mass, carotid artery calcified plaque mass, and African ancestry proportion.

RESULTS

After median of 7.1(5.9, 8.2) years follow-up, 30(9.6%) of women and 49(19.1%) of men were deceased. In fully-adjusted models, psoas muscle mass index and paraspinous muscle mass index were inversely associated with mortality in men (psoas muscle mass index, hazard ratio [HR] = 0.61, P = 0.004; paraspinous muscle mass index, HR = 0.64, P = 0.004), but not in women. Psoas and paraspinous muscle densities did not associate with all-cause mortality. A penalized Cox regression that involved all covariates and predictors associated with mortality showed that only paraspinous muscle mass index remained a significant predictor of mortality (HR = 0.65, P = 0.02).

CONCLUSION

Independent from established risk factors for mortality, higher psoas and paraspinous muscle index associate with reduced all-cause mortality in middle-aged African American men with type 2 diabetes mellitus.

Frailty and sarcopenia - newly emerging and high impact complications of diabetes

Diabetes increases the risk of physical dysfunction and disability. Diabetes-related complications and coexisting morbidities partially explain the deterioration in physical function. The decline in muscle mass, strength and function associated with diabetes leads to sarcopenia, frailty and eventually disability. Frailty acts as a mediator in the pathogenesis of disability in older people with diabetes and its measurement in routine daily practice is recommended. Frailty is a dynamic process which progresses from a robust condition to a pre-frail stage then frailty and eventually disability. Therefore, a multimodal intervention which includes adequate nutrition, exercise training, good glycaemic control and the use of appropriate hypoglycemic medications may help delay or prevent the progression to disability.

Mitochondria and endoplasmic reticulum: Targets for a better insulin sensitivity in skeletal muscle?

Obesity and its associated metabolic disorders represent a major health burden, with economic and social consequences. Although adapted lifestyle and bariatric surgery are effective in reducing body weight, obesity prevalence is still rising. Obese individuals often become insulin-resistant. Obesity impacts on insulin responsive organs, such as the liver, adipose tissue and skeletal muscle, and increases the risk of cardiovascular diseases, type 2 diabetes and cancer. In this review, we discuss the effects of obesity and insulin resistance on skeletal muscle, an important organ for the control of postprandial glucose. The roles of mitochondria and the endoplasmic reticulum in insulin signaling are highlighted and potential innovative research and treatment perspectives are proposed.

Relationship between sleep parameters, insulin resistance and age-adjusted insulin like growth factor-1 score in non diabetic older patients

BACKGROUND

Sleep complaints are prevalent in older patients. Sleepiness, short or long sleep duration and obstructive sleep apnea (OSA) are associated with insulin resistance (IR). These parameters have not yet been considered together in the same study exploring the possible association between IR and sleep in older patients. IR is involved in cardiovascular and metabolic diseases, pathologies which are highly prevalent in older patients. Here we assess, in older non-diabetic patients with sleep complaints, the associations between IR and sleep parameters objectively recorded by polysomnography (PSG) rather than self-report. The Growth Hormone/Insulin like growth factor-1 axis could play a role in the development of IR during sleep disorders. The second objective of this study was to analyze the association between sleep parameters and age-adjusted IGF-1 score, which could explain the association between OSA and IR.

METHODS

72 non-diabetic older patients, mean age 74.5 ± 7.8 years, were included in this observational study. We evaluated anthropometric measures, subjective and objective sleepiness, polysomnography, Homeostatic Model Assessment for IR (HOMA-IR) and age-adjusted IGF-1 score. A multivariate regression was used to determine factors associated with HOMA-IR.

RESULTS

The 47 OSA patients were over-weight but not obese and had higher IR than the non-OSA patients. In multilinear regression analysis, apnea-hypopnea index was independently associated with IR after adjustment for several confounding factors. Neither IGF-1 level nor IGF-1 score were different in the two groups.

CONCLUSIONS

We demonstrate that in non-diabetic older patients with sleep complaints, OSA is independently associated with IR, regardless of anthropometric measurements and sleep parameters (sleep duration/sleepiness/arousals). Targeting OSA to reduce IR could be useful in the elderly, although further exploration is required.

Low Relative Lean Mass is Associated with Increased Likelihood of Abdominal Aortic Calcification in Community-Dwelling Older Australians

Age-related loss of skeletal muscle is associated with increased risk of functional limitation and cardiovascular (CV) mortality. In the elderly abdominal aortic calcification (AAC) can increase CV risk by altering aortic properties which may raise blood pressure and increase cardiac workload. This study investigated the association between low muscle mass and AAC in community-dwelling older Australians. Data for this cross-sectional analysis were drawn from a 2010 sub-study of the Melbourne Collaborative Cohort Study in the setting of community-dwelling older adults. Three hundred and twenty-seven participants [mean age = 71 ± 6 years; mean BMI = 28 ± 5 kg/m(2); females n = 199 (62 %)] had body composition determined by dual-energy x-ray absorptiometry (DXA) and AAC determined by radiography. Participants were stratified into tertiles of sex-specific BMI-normalised appendicular lean mass (ALM). Those in the lowest tertile were considered to have low relative muscle mass. Aortic calcification score (ACS) was determined visually as the extent of calcification on the aortic walls between L1 and L4 vertebrae (range: 0-24). Severe AAC was defined as ACS ≥ 6. Prevalence of any AAC was highest in participants with low relative muscle mass (74 %) compared to the middle (65 %) and upper (53 %) tertiles (p trend = 0.006). The lower ALM/BMI tertile had increased odds (Odds ratio = 2.3; 95 % confidence interval: 1.1-4.6; p = 0.021) of having any AAC; and having more severe AAC (2.2; 1.2-4.0; p = 0.009) independent of CV risk factors, serum calcium and physical activity. AAC is more prevalent and severe in community-dwelling older adults with low relative muscle mass. Maintaining muscle mass could form part of a broader primary prevention strategy in reducing AAC.

Frailty and sarcopenia as the basis for the phenotypic manifestation of chronic diseases in older adults

Frailty is a functional status that precedes disability and is characterized by decreased functional reserve and increased vulnerability. In addition to disability, the frailty phenotype predicts falls, institutionalization, hospitalization and mortality. Frailty is the consequence of the interaction between the aging process and some chronic diseases and conditions that compromise functional systems and finally produce sarcopenia. Many of the clinical manifestations of frailty are explained by sarcopenia which is closely related to poor physical performance. Reduced regenerative capacity, malperfusion, oxidative stress, mitochondrial dysfunction and inflammation compose the sarcopenic skeletal muscle alterations associated to the frailty phenotype. Inflammation appears as a common determinant for chronic diseases, sarcopenia and frailty. The strategies to prevent the frailty phenotype include an adequate amount of physical activity and exercise as well as pharmacological interventions such as myostatin inhibitors and specific androgen receptor modulators. Cell response to stress pathways such as Nrf2, sirtuins and klotho could be considered as future therapeutic interventions for the management of frailty phenotype and aging-related chronic diseases.

Sarcopenic Obesity and Metabolic Syndrome in Adult Caucasian Subjects

OBJECTIVES

Recently metabolic aspects linked to sarcopenic obesity (SO) were investigated. Extant studies involved especially older people from Asian or White-mixed American cohorts.

THE AIMS OF OUR STUDY WERE

to explore the prevalence of sarcopenia in Caucasian adult obese subjects using two different indices of sarcopenia, and to investigate the relationship among SO, metabolic syndrome (MS), inflammation, and serum albumin concentrations.

DESIGN

Cross- sectional study.

SUBJECTS/METHODS

The study was performed from 2011 to 2014 in a hospitalized care setting. Inclusion criteria were: age>18 and <65 years, BMI≥30 Kg/m2. Fat mass (FM) and fat-free mass (FFM) were assessed by DXA. Appendicular skeletal muscle mass (ASMM) was calculated. Sarcopenia was defined as ASMM/height2 or ASMM/weight <2SD than the sex-specific mean of a young population. The cutoffs were ASMM/h2<6.54 Kg/m2 for men and 4.82 Kg/m2 for women, and ASMM/weight<0.2827 for men and 0.2347 for women. ISI-Matsuda was calculated. MS was diagnosed (NCEP-ATPIII).

RESULTS

727 subjects (age: 45.72±13.56 years, BMI: 37.74±5.82 kg/m2) were enrolled. The prevalence of SO was 1.0% or 34.8% in men and 0.6% or 50.1% in women, using ASMM/height2 ratio or ASMM/weight. Subjects with SO based on ASMM/height2 were scarce, only data relying on ASMM/weight were considered. Subjects with SO had higher BMI, waist circumference, FM, and lower FFM and ASMM than nonsarcopenic obese individuals (all p<0.05). ISI-Matsuda was lower and hs-CRP levels were higher in subjects with SO (all p<0.05). MS was more prevalent in subjects with SO than nonsarcopenic obese subjects (47.6% vs 34.3%, p<0.001). ASMM/weight was decreased in subjects with MS (0.2522±0.0410 vs 0.2423±0.0352, p=0.001).

CONCLUSION

SO is associated with MS and low- grade inflammation in adult Caucasian subjects. Metabolic profile evaluation should be recommended in subjects with SO.

Weight lifting and appendicular skeletal muscle mass among breast cancer survivors: a randomized controlled trial

Low appendicular skeletal muscle mass (ASMM) is associated with premature mortality, hyperinsulinemia, frailty, disability, and low bone mineral density. We explored the potential efficacy of slowly progressive weight lifting to attenuate the decline of ASMM among breast cancer survivors by conducting a post hoc analysis of data from the Physical Activity and Lymphedema trial. Between October 2005 and August 2008, we conducted a single-blind, randomized controlled trial of twice weekly slowly progressive weight lifting or standard care among 295 non-metastatic breast cancer survivors. ASMM was quantified using dual-energy X-ray absorptiometry. Changes in ASMM were evaluated from baseline to 12 months between the weight lifting and control groups using repeated measures linear mixed effects regression models. Over 12 months, participants in the weight lifting group experienced attenuated declines in muscle mass compared to the control group, as reflected by relative ASMM (-0.01 ± 0.02 kg/m(2) vs -0.08 ± 0.03 kg/m(2); P = 0.041) and absolute ASMM (-0.02 ± 0.06 kg vs -0.22 ± 0.07 kg; P = 0.038), respectively. Weight lifting did not alter other body composition outcomes including body mass index, total body mass, body fat percentage, and fat mass compared to the control group. Weight lifting significantly increased upper and lower body muscle strength compared to the control group. The intervention was well tolerated with no serious adverse events related to weight lifting. Slowly progressive weight lifting attenuated the decline of ASMM among breast cancer survivors compared to standard care over 12 months. These data are hypothesis generating. Future studies should examine the efficacy of weight lifting to improve distal health outcomes among breast cancer survivors.

Appendicular skeletal muscle mass and insulin resistance in an elderly korean population: the korean social life, health and aging project-health examination cohort

BACKGROUND

Increasing evidence supports an association between age-related loss of muscle mass and insulin resistance. However, the association has not been fully investigated in the general population. Thus, we investigated the association between appendicular skeletal muscle mass (ASM) and insulin resistance in an elderly Korean population.

METHODS

This cross-sectional study included 158 men (mean age, 71.8) and 241 women (mean age, 70.6) from the Korean Social Life, Health and Aging Project, which started in 2011. In this study, ASM was measured by bioelectrical impedance analysis and was analyzed in three forms: ASM (kg), ASM/height(2) (kg/m(2)), and ASM/weight (%). The homeostasis model assessment of insulin resistance (HOMA-IR) was used as a measure of insulin resistance. The relationships between the ASM values and the HOMA-IR were investigated by multiple linear regression models.

RESULTS

The HOMA-IR was positively associated with ASM (β=0.43, P<0.0001) and ASM/height(2) (β=0.36, P<0.0001) when adjusted for sex and age. However, after additional adjustment for body weight, HOMA-IR was inversely associated with ASM (β=-0.43, P<0.001) and ASM/height(2) (β=-0.30, P=0.001). Adjustment for other potential confounders did not change these associations. Conversely, HOMA-IR was consistently and inversely associated with ASM/weight before and after adjustment for other potential confounders.

CONCLUSION

Our results support the idea that lower skeletal muscle mass is independently associated with insulin resistance in older adults. When evaluating sarcopenia or muscle-related conditions in older adults, their whole body sizes also need to be considered.