Correlates of Skeletal Muscle Mass and Differences Between Novel Subtypes in Recent-Onset Diabetes

CONTEXT

Low skeletal muscle mass (SMM) is associated with long-standing diabetes but little is known about SMM in newly diagnosed diabetes.

OBJECTIVE

We aimed to identify correlates of SMM in recent-onset diabetes and to compare SMM between novel diabetes subtypes.

METHODS

SMM was normalized to body mass index (SMM/BMI) in 842 participants with known diabetes duration of less than 1 year from the German Diabetes Study (GDS). Cross-sectional associations between clinical variables, 79 biomarkers of inflammation, and SMM/BMI were assessed, and differences in SMM/BMI between novel diabetes subtypes were analyzed with different degrees of adjustment for confounders.

RESULTS

Male sex and physical activity were positively associated with SMM/BMI, whereas associations of age, BMI, glycated hemoglobin A1c, homeostatic model assessment for β-cell function, and estimated glomerular filtration rate with SMM/BMI were inverse (all P < .05; model r2 = 0.82). Twenty-three biomarkers of inflammation showed correlations with SMM/BMI after adjustment for sex and multiple testing (all P < .0006), but BMI largely explained these correlations. In a sex-adjusted analysis, individuals with severe autoimmune diabetes had a higher SMM/BMI whereas individuals with severe insulin-resistant diabetes and mild obesity-related diabetes had a lower SMM/BMI than all other subtypes combined. However, differences were attenuated after adjustment for the clustering variables.

CONCLUSION

SMM/BMI differs between diabetes subtypes and may contribute to subtype differences in disease progression. Of note, clinical variables rather than biomarkers of inflammation explain most of the variation in SMM/BMI.

Prospective associations between changes in physical activity and sedentary time and subsequent lean muscle mass in older English adults: the EPIC-Norfolk cohort study

BACKGROUND

The longitudinal associations between physical behaviours and lean muscle mass indices need to be better understood to aid healthy ageing intervention development.

METHODS

We assessed physical behaviours (total physical activity, moderate-to-vigorous physical activity (MVPA), light physical activity, total sedentary time and prolonged sedentary bout time) for 7 days using hip-worn accelerometers. We also assessed domain-specific physical behaviours (walking, cycling, gardening and housework time) with self-report questionnaires at baseline (2006-2011) and follow-up (2012-2016) in the European Prospective Investigation into Cancer (EPIC)-Norfolk study. We assessed body composition using dual-energy X-ray absorptiometry (DEXA) at follow-up in 1535 participants (≥ 60 years at baseline). From this, we derived appendicular lean muscle mass (ALM) indices (% relative ALM = (ALM/total body weight)*100), body mass index (BMI)-scaled ALM (ALM/BMI, kg/kg/m2) and height-scaled ALM (ALM/height2, kg/m2)). We evaluated the prospective associations of both baseline and change in physical behaviours with follow-up muscle mass indices using multivariable linear regression.

RESULTS

Over 5.5 years (SD 14.8) follow-up, higher baseline accelerometer-measured physical activity and lower sedentary time were associated with higher subsequent relative ALM and BMI-scaled ALM, but not height-scaled ALM (e.g. 0.02% higher subsequent relative ALM per minute/day of baseline MVPA for men). Greater increases in physical activity and greater declines in sedentary time variables were associated with higher subsequent relative ALM and BMI-scaled ALM, but not height-scaled ALM (e.g. 0.001 kg/kg/m2 subsequent BMI-scaled ALM and 0.04% subsequent relative ALM per min/day/year increases in LPA over follow-up; 0.001 kg/kg/m2 subsequent BMI-scaled ALM and -0.03% subsequent relative ALM per min/day/year less of total sedentary time over follow-up). Greater increases in women's cycling and gardening over follow-up were associated with greater subsequent relative ALM (cycling 0.9% per hour/week/year; gardening 0.2% per hour/week/year) and BMI-scaled ALM (cycling 0.03 kg/kg/m2 per hour/week/year; gardening 0.004 kg/kg/m2 per hour/week/year).

CONCLUSION

Physical behaviours across all intensities, and in women more specifically cycling and gardening, may help prevent age-related declines in muscle mass.

The Prevalence of Sarcopenia among Hunan Province Community-Dwelling Adults Aged 60 Years and Older and Its Relationship with Lifestyle: Diagnostic Criteria from the Asian Working Group for Sarcopenia 2019 Update

Background and Objectives: This study aims to detect the prevalence of sarcopenia in community-dwelling older adults in Hunan Province, discuss factors related to lifestyle, and provide a reliable basis for the prevention and treatment of sarcopenia. Materials and Methods: In this study, a total of 1040 community-dwelling adults ≥ 60 years were examined for sarcopenia using a cluster stratified random sampling method, which was defined using the diagnostic criteria recommended by the Asian Working Group for Sarcopenia (AWGS) from September 2019 to March 2020. Multivariate logistic regression analysis was applied to determine the correlation between sarcopenia and smoking, drinking, nutritional status, physical activity, and sleep quality. Results: A total of 27.1% of the older adults were diagnosed with sarcopenia, with rates of 26.2% in men and 25.2% in women. Multiple logistic regression showed that advanced age (OR = 2.480, 95% CI: 1.730, 3.553), the risk of malnutrition (OR = 2.085, 95% CI: 1.440, 3.019), and malnutrition (OR = 1.212, 95% CI: 0.304, 4.834) were risk factors for sarcopenia. No falls in the previous year (OR = 0.616, 95% CI: 1.885, 1.209), normal weight (OR = 0.228, 95% CI: 0.109, 0.475), overweight (OR = 0.030, 95% CI: 0.013, 0.069), moderate physical activity (OR = 0.593, 95% CI: 0.377, 0.933), or high physical activity (OR = 0.417, 95% CI: 0.230, 0.755) were identified as protective factors for sarcopenia. Conclusions: The prevalence of sarcopenia was high among older adults in the community in Hunan Province. In addition, we found that lifestyle is an important factor in sarcopenia.

Association between meal-specific daily protein intake and lean mass in older adults: results of the cross-sectional BASE-II study

BACKGROUND

Adequate total and meal-specific protein intake is considered an important prerequisite to preserve appendicular lean mass (ALM) in older adults and to prevent sarcopenia.

OBJECTIVES

We analyzed the meal-specific protein intake across the main meals between participants with normal vs. low ALM to BMI ratio (ALMBMI).

METHODS

782 participants [59.6% men; median 69 (IQR: 65, 71) y] of the Berlin Aging Study II have been included in this analysis. ALM was assessed by dual X-ray absorptiometry. Low lean mass was defined as ALMBMI using recommended sex-specific cut-offs. A 5-day nutritional protocol was used to assess total and meal-specific protein intake.

RESULTS

Median total protein intake was 0.89 (IQR: 0.74, 1.05) g/kg/d body weight (BW) in participants with low ALMBMI and 1.02 (IQR: 0.86, 1.21) g/kg BW in participants with normal ALMBMI (P < 0.001). Daily protein intake at breakfast was similar in both groups [0.23 (95% CI: 0.20, 0.26) vs. 0.24 (95% CI: 0.23, 0.26) g/kg BW; P = 0.245]. Subjects with low ALMBMI reported a lower protein intake at lunch and dinner compared with those with normal ALMBMI [0.29 (95% CI: 0.27, 0.32) vs. 0.35 (95% CI: 0.34, 0.36) g/kg BW; P = 0.001 and 0.32 (95% CI: 0.30, 0.35) vs. 0.36 (95% CI: 0.35, 0.37) g/kg BW; P = 0.027, respectively]. In a stepwise regression model, a higher total protein intake was positively associated with ALMBMI [ß = 0.10 (95% CI: 0.07, 0.13) P < 0.001]. The protein intake at dinner was positively associated with ALMBMI [ß = 0.14 (95% CI: 0.08, 0.19) P < 0.001] irrespective of protein intake at breakfast and lunch. This association disappeared after additional adjustment for total protein intake.

CONCLUSION

Our data highlight an association of total protein intake and ALMBMI in older adults. Although current data support an association of high ALMBMI with protein intake at dinner in particular, this was not independent from total protein intake and the findings do not allow a conclusion on causality.

Associations Between Serum GDF15 Concentrations, Muscle Mass, and Strength Show Sex-Specific Differences in Older Hospital Patients

Aging is accompanied by a progressive decline of muscle mass and strength and also higher levels of circulating cytokines such as growth differentiation factor 15 (GDF15). Studies evaluating the association of GDF15 with muscle mass and strength are rare. In this analysis, we investigated GDF15 concentrations and their relationship with muscle mass and strength in older men compared with women. GDF15 serum concentrations were measured in 103 (60 years and older) hospital patients and an age-matched control group with an immunosorbent assay. Skeletal muscle mass was determined with the bioelectrical impedance analysis. Grip strength and knee extension strength were assessed and normalized for height. Associations between GDF15 concentrations and muscle mass and strength were evaluated with general linear models. Male patients showed higher levels of GDF15 compared with female patients (p = 0.021). Elevated GDF15 concentrations were associated with lower measures of muscle mass, exclusively in men, after adjustment for age and number of drugs per day. Our results indicate sex differences between associations of GDF15 with muscle mass and strength parameters in a cohort of older hospital patients.

Longitudinal Changes of Body Composition Phenotypes and Their Association with Incident Type 2 Diabetes Mellitus during a 5-Year Follow-up in Koreans

BACKGROUND

To elucidate longitudinal changes of complex body composition phenotypes and their association with incident type 2 diabetes mellitus.

METHODS

A total of 17,280 (mean age, 48.1±8.2 years) Korean adults who underwent medical check-ups were included. The mean follow-up duration was 5.5±0.5 years. Body compositions were assessed using a bioelectrical impedance analysis. Four body composition phenotypes were defined using the median of appendicular skeletal muscle mass (ASM) index and fat mass index: low muscle/low fat (LM/LF); high muscle (HM)/LF; LM/high fat (HF); and HM/HF groups.

RESULTS

Of the individuals in the LM/LF or HM/HF groups, over 60% remained in the same group, and over 30% were moved to the LM/HF group. Most of the LM/HF group remained in this group. In the baseline HM/LF group, approximately 30% stayed in the group, and the remaining individuals transitioned to the three other groups in similar proportions. Incident diabetes was significantly lower in participants who remained in the HM/LF group than those who transitioned to the LM/LF or LM/HF group from the baseline HM/LF group in men. ASM index was significantly associated with a decreased risk for incident diabetes in men regardless of obesity status (adjusted odds ratio [OR], 0.71 per kg/m²; 95% confidence interval [CI], 0.52 to 0.97 in non-obese) (adjusted OR, 0.87; 95% CI, 0.77 to 0.98 in obese) after adjusting for other strong risk factors (e.g., baseline glycosylated hemoglobin and homeostasis model assessment of insulin resistance).

CONCLUSION

Maintenance of ASM may be protective against the development of type 2 diabetes mellitus in men, regardless of obesity status.

Association of Multiorgan Computed Tomographic Phenomap With Adverse Cardiovascular Health Outcomes: The Framingham Heart Study

Importance

Increased ability to quantify anatomical phenotypes across multiple organs provides the opportunity to assess their cumulative ability to identify individuals at greatest susceptibility for adverse outcomes.

Objective

To apply unsupervised machine learning to define the distribution and prognostic importance of computed tomography-based multiorgan phenotypes associated with adverse health outcomes.

Design, Setting, and Participants

This asymptomatic community-based cohort study included 2924 Framingham Heart Study participants between July 2002 and April 2005 undergoing computed tomographic imaging of the chest and abdomen. Participants are from the offspring and third-generation cohorts.

Exposures

Eleven computed tomography-based measures of valvular/vascular calcification, adiposity, and muscle attenuation.

Main Outcomes and Measures

All-cause mortality and cardiovascular disease (myocardial infarction, stroke, or cardiovascular death).

Results

The median age of the participants was 50 years (interquartile range, 43-60 years), and 1422 (48.6%) were men. Principal component analysis identified 3 major anatomic axes: (1) global calcification (defined by aortic, thoracic, coronary, and valvular calcification); (2) adiposity (defined by pericardial, visceral, hepatic, and intrathoracic fat); and (3) muscle attenuation that explained 65.7% of the population variation. Principal components showed different evolution with age (continuous increase in global calcification, decrease in muscle attenuation, and U-shaped association with adiposity) but similar patterns in men and women. Using unsupervised clustering approaches in the offspring cohort (n = 1150), we identified a cohort (n = 232; 20.2%) with an unfavorable multiorgan phenotype across all 3 anatomic axes as compared with a favorable multiorgan phenotype. Membership in the unfavorable phenotypic cluster was associated with a greater prevalence of cardiovascular disease risk factors and with increased all-cause mortality (hazard ratio, 2.61; 95% CI, 1.74-3.92; P < .001), independent of coronary artery calcium score, visceral adipose tissue, and 10-year global cardiovascular disease Framingham risk, and it provided improvement in metrics of discrimination and reclassification.

Conclusions and Relevance

This proof-of-concept analysis demonstrates that unsupervised machine learning, in an asymptomatic community cohort, identifies an unfavorable multiorgan phenotype associated with adverse health outcomes, especially in elderly American adults. Future investigations in larger populations are required not only to validate the present results, but also to harness clinical, biochemical, imaging, and genetic markers to increase our understanding of healthy cardiovascular aging.

Meridian Cuffing Exercises Improved Functional Fitness and Cardiopulmonary Functioning of Community Older Adults

This study was aimed to test the effects of a meridian cuffing exercise, the Healthy Beat Acupunch (HBA) regimen, on the functional fitness and cardiopulmonary functioning of community older adults. A single-blind, cluster randomized controlled trial was conducted. We randomly allocated eight community care centers to the intervention or control group and recruited 228 participants who completed the study (intervention: four centers, n = 111; control: four centers, n = 117). The intervention group underwent a 40-min session of HBA regimen 3 times per week for 6 months. Functional fitness and cardiopulmonary functioning were assessed at baseline, 3 months, and 6 months of the intervention. The intervention group demonstrated significantly greater improvements in functional fitness and cardiopulmonary functioning than the control group between baseline and either 3 months or 6 months. We suggest that activities designed to promote health among community older adults include acupunch exercises.

Polypharmacy as a Risk Factor for Clinically Relevant Sarcopenia: Results From the Berlin Aging Study II

Background

Sarcopenia affects more than 10% of older adults. Next to age-associated physiologic changes, diseases like diabetes or inflammatory, neurological, malignant and endocrine disorders may contribute to the development of sarcopenia. Likewise, polypharmacy, i.e., multiple drug use, is common among older adults. Although the two conditions frequently co-occur, the association of polypharmacy with sarcopenia has not yet been examined. We investigated the association of polypharmacy and sarcopenia in a large cohort of community-dwelling older adults (60-84 years).

Methods

Thousand five hundred and two participants from the Berlin Aging Study II were included. Polypharmacy was defined as concurrent use of 5 or more drugs (prescription and nonprescription). Body composition was assessed with dual-energy X-ray absorptiometry, and appendicular lean mass (ALM) was calculated as sum of the four limbs' lean mass. Sarcopenia was defined as low ALM-to-body mass index (BMI)-ratio using validated sex-specific cutoffs.

Results

Mean age was 68.7 ± 3.7 years, 50.7% were female. The median (interquartile range) number of drugs was 2 (1-4); 21.1% of subjects reported regular use of ≥5 drugs. Subjects with polypharmacy were more often sarcopenic according to the applied ALM/BMI-cutoffs (16.3% vs 6.9%, p < 0.001), with a higher BMI (p < 0.001) and lower ALM/BMI (p < 0.001), but no significant difference in mean ALM. Notably, polypharmacy was also associated with higher rates of reduced gait speed and exhaustion. Even after multivariable adjustment (sex, age, comorbid conditions and physical activity) polypharmacy was consistently associated with a significantly increased likelihood of sarcopenia (odds ratio = 2.24, 95% confidence interval [CI] = 1.33-3.75).

Conclusion

Polypharmacy is associated with clinically relevant sarcopenia, as assessed by a low ALM/BMI.

Association between sarcopenia with lifestyle and family function among community-dwelling Chinese aged 60 years and older

Background

Sarcopenia is defined as the age-related decline in skeletal muscle mass and function. The risk factors and causes of sarcopenia must be identified to develop prevention and treatment strategies for this syndrome. Our aim was to examine the association between sarcopenia with lifestyle and family function among community-dwelling Chinese people aged 60 years and older.

Methods

We conducted this study to evaluate sarcopenia among 834 community-dwelling Chinese individuals aged ≥60 years using the Asian Working Group for Sarcopenia (AWGS) criteria. The sociodemographic characteristics, food consumption patterns, habits of smoking, and alcohol consumption of the participants were collected using a general questionnaire, whereas physical activity was assessed using the International Physical Activity Questionnaire (IPAQ; long-form version). Family function was assessed using the Family APGAR scale. In addition, the association of sarcopenia with lifestyle and family function was examined using univariate and multivariate analyses.

Results

The total prevalence rate of sarcopenia was 10.6%. Female participants with sarcopenia had a lower frequency per week of nut consumption than those without sarcopenia (p < 0.05), whereas, for male participants, the differences in food consumption patterns of those with sarcopenia versus those without sarcopenia were not significant. Among the participants, the mean Family APGAR score was 8 (standard deviation [SD] = 0.92). For both sexes, participants with sarcopenia had lower family function scores than those without sarcopenia. In the multivariate model, after adjustment for all covariates, frequency per week of nut consumption (adjusted OR 0.724, 95% CI 0.532–0.985, P < 0.05) and Family APGAR score (adjusted OR 0.683, 95% CI 0.496–0.940, P = 0.019) were statistically significantly associated with sarcopenia. The relationship between other lifestyle habits and sarcopenia was not significant.

Conclusion

There was significant association between sarcopenia with intake of nuts and family function. Further studies should evaluate if adequate intake of nuts and a well-functioning family may be effective in lowering the risk of sarcopenia.

The association of lean and fat mass with all-cause mortality in older adults: The Cardiovascular Health Study

BACKGROUND AND AIMS

Understanding contributions of lean and fat tissue to cardiovascular and non-cardiovascular mortality may help clarify areas of prevention in older adults. We aimed to define distributions of lean and fat tissue in older adults and their contributions to cause-specific mortality.

METHODS AND RESULTS

A total of 1335 participants of the Cardiovascular Health Study (CHS) who underwent dual-energy x-ray absorptiometry (DEXA) scans were included. We used principal components analysis (PCA) to define two independent sources of variation in DEXA-derived body composition, corresponding to principal components composed of lean ("lean PC") and fat ("fat PC") tissue. We used Cox proportional hazards regression using these PCs to investigate the relationship between body composition with cardiovascular and non-cardiovascular mortality. Mean age was 76.2 ± 4.8 years (56% women) with mean body mass index 27.1 ± 4.4 kg/m². A greater lean PC was associated with lower all-cause (HR = 0.91, 95% CI 0.84-0.98, P = 0.01) and cardiovascular mortality (HR = 0.84, 95% CI 0.74-0.95, P = 0.005). The lowest quartile of the fat PC (least adiposity) was associated with a greater hazard of all-cause mortality (HR = 1.24, 95% CI 1.04-1.48, P = 0.02) relative to fat PCs between the 25th-75th percentile, but the highest quartile did not have a significantly greater hazard (P = 0.70).

CONCLUSION

Greater lean tissue mass is associated with improved cardiovascular and overall mortality in the elderly. The lowest levels of fat tissue mass are linked with adverse prognosis, but the highest levels show no significant mortality protection. Prevention efforts in the elderly frail may be best targeted toward improvements in lean muscle mass.

Cross-sectional associations of objectively measured physical activity and sedentary time with sarcopenia and sarcopenic obesity in older men

This study investigated associations between objectively measured physical activity (PA) with sarcopenia and sarcopenic obesity in older British men. Participants were men aged 70-92years (n=1286) recruited from UK Primary Care Centres. Outcomes included (i) sarcopenia, defined as low muscle mass (lowest two fifths of the mid-upper arm muscle circumference distribution) accompanied by low muscular strength (hand grip strength <30kg) or low physical performance (gait speed≤0.8m/s); (ii) severe sarcopenia, required all three conditions; (iii) sarcopenic obesity defined as sarcopenia or severe sarcopenia and a waist circumference of >102cm. Independent variables included time spent in PA intensities measured by GT3x accelerometers, worn during one week in 2010-12. Multinomial regression models were used for cross-sectional analyses relating PA and sarcopenia. In total, 14.2% (n=183) of men had sarcopenia and a further 5.4% (n=70) had severe sarcopenia. 25.3% of sarcopenic or severely sarcopenic men were obese. Each extra 30min per day of moderate-to-vigorous PA (MVPA) was associated with a reduced risk of severe sarcopenia (relative risk [RR] 0.53, 95% confidence interval [CI] 0.30, 0.93) and sarcopenic obesity (RR 0.47 [95% CI 0.27, 0.84]). Light PA (LPA) and sedentary breaks were marginally associated with a reduced risk of sarcopenic obesity. Sedentary time was marginally associated with an increased risk of sarcopenic obesity independent of MVPA (RR 1.18 [95% CI 0.99, 1.40]). MVPA may reduce the risk of severe sarcopenia and sarcopenic obesity among older men. Reducing sedentary time and increasing LPA and sedentary breaks may also protect against sarcopenic obesity.

Neuromuscular junction degeneration in muscle wasting

PURPOSE OF REVIEW

Denervation is a hallmark of age-related and other types of muscle wasting. This review focuses on recent insights and current viewpoints regarding the mechanisms and clinical relevance of maintaining the neuromuscular junction to counteract muscle wasting resulting from aging or neural disease/damage.

RECENT FINDINGS

Activity-dependent regulation of autophagy, the agrin-muscle specific kinase-Lrp4 signaling axis, and sympathetic modulation are principal mechanisms involved in stabilizing the neuromuscular junction. These findings are derived from several animal models and were largely confirmed by human gene expression analysis as well as insights from rare neuromuscular diseases such as amyotrophic lateral sclerosis and congenital myasthenic syndromes. Based on these insights, agrin-derived fragments are currently being evaluated as biomarkers for age-related muscle wasting. Tuning of autophagy, of the agrin pathway, and of sympathetic input are being studied as clinical treatment of muscle wasting disorders.

SUMMARY

Basic research has revealed that maintenance of neuromuscular junctions and a few signaling pathways are important in the context of age-dependent and other forms of muscle wasting. These findings have recently started to enter clinical practice, but further research needs to substantiate and refine our knowledge.

Adherence to a Mediterranean-Style Diet and Appendicular Lean Mass in Community-Dwelling Older People: Results From the Berlin Aging Study II

BACKGROUND

Selected nutrients or food groups have often been studied with regard to long-term mortality and cardiovascular disease, whereas the relation between diet quality and appendicular lean mass (ALM) has rarely been researched.

OBJECTIVE

The aim of this study was to explore the association between a Mediterranean-style diet and ALM in community-dwelling older people.

METHODS

Cross-sectional data from the Berlin Aging Study II were available for 1,509 participants (51% women, 68.2±3.7 years). Nutrient intake was assessed using the European Prospective Investigation into Cancer and Nutrition Food Frequency Questionnaire. Adherence to a Mediterranean-style diet was evaluated with the modified Mediterranean-type diet score (mMedTypeDiet). ALM was determined by dual-energy X-ray absorptiometry and related to body mass index (ALM/BMI). A general linear regression model was carried out to assess the association between mMedTypeDiet score groups and ALM/BMI.

RESULTS

ALM/BMI was higher in women with a higher adherence to the mMedTypeDiet (0.64±0.1 vs 0.62±0.1 and 0.61±0.1 in low and medium adherence, retrospectively, p = .004). In the risk factor-adjusted general linear regression analysis, a higher adherence to the mMedTypeDiet was associated with higher ALM/BMI in women and better ALM/fat mass ratio when compared to a medium and a low diet quality. No significant associations were seen in men.

CONCLUSIONS

Higher adherence to a Mediterranean-style diet was associated with a positive effect on ALM/BMI in women.