Impact of adiposity on muscle function and clinical events among elders with dynapenia, presarcopenia and sarcopenia: a community-based cross-sectional study

Role of adipokines in sarcopenia

ABSTRACT

Sarcopenia is an age-related disease that mainly involves decreases in muscle mass, muscle strength and muscle function. At the same time, the body fat content increases with aging, especially the visceral fat content. Adipose tissue is an endocrine organ that secretes biologically active factors called adipokines, which act on local and distant tissues. Studies have revealed that some adipokines exert regulatory effects on muscle, such as higher serum leptin levels causing a decrease in muscle function and adiponectin inhibits the transcriptional activity of Forkhead box O3 (FoxO3) by activating peroxisome proliferators-activated receptor-γ coactivator -1α (PGC-1α) and sensitizing cells to insulin, thereby repressing atrophy-related genes (atrogin-1 and muscle RING finger 1 [MuRF1]) to prevent the loss of muscle mass. Here, we describe the effects on muscle of adipokines produced by adipose tissue, such as leptin, adiponectin, resistin, mucin and lipocalin-2, and discuss the importance of these adipokines for understanding the development of sarcopenia.

Association Between Handgrip Strength and Type 2 Diabetes: A Prospective Cohort Study and Systematic Review With Meta-analysis

BACKGROUND

Both absolute (kg) and relative (kg per kg of body weight) handgrip strength (HGS) have been used as indicators of HGS. Multiple studies have explored HGS associations with type 2 diabetes (T2DM); however, prognostic values were inconsistent. We aimed to examine the associations between both absolute and relative HGS and incident T2DM.

METHODS

A total of 12,957 participants aged 40 years and older (mean age 51.0 years, 58.4% men) were followed and enrolled in the Tianjin Chronic Low-grade Systemic Inflammation and Health (TCLSIH) Cohort Study. Cox proportional hazards regression models were used to examine the association of HGS with incident T2DM. Other prospective studies on HGS and risk of T2DM were identified by searching several electronic databases up to November 31, 2021. Meta-analysis was performed by combining the results from the TCLSIH study and previous prospective cohort studies.

RESULTS

From the TCLSIH Cohort study, after adjustment, relative HGS was inversely associated with T2DM (hazard ratio per 0.1 higher relative HGS 0.667, 95% confidence interval [CI] 0.616, 0.722). However, no significant association between absolute HGS and incident T2DM was found. The meta-analyses showed that per 5 kg higher HGS was associated with a 5% (95% CI 2%, 8%) lower risk of T2DM and each 0.1 higher relative HGS was associated with a 22% (95% CI 14%, 29%) lower risk of T2DM.

CONCLUSION

The results from our cohort study and meta-analysis suggest that relative HGS was better than absolute HGS in predicting incident T2DM. Adiposity was an important factor that mediates the association between HGS and T2DM.

Sarcopenia and Sarcopenic Obesity and Osteoarthritis: A Discussion among Muscles, Fat, Bones, and Aging

Aging is a physical procedure for people and nature. Our aging world is expanding because of the life span extension. Aging has a crucial relationship with our body composition (muscles, bones, and adipose tissue), which is characterized by an increase in fat mass and a gradual decrease in muscle mass and strength and bone density. These alterations affect physical performance and impact quality of life enhancing the risk for non-communicable diseases, immobilization, and disability. As far we know, osteoarthritis of lower limbs, sarcopenic obesity, and muscle mass and/or strength loss are treated separately. However, bones, muscles, adipose tissue, and aging appear to have an interconnection through a dialogue as they talk to each other. Health disorders are coming into the surface when this relationship is disrupted. The aim of our study is to search deeper into this interconnection, so that when adipose tissue increases, we have to take a look into the condition of muscle mass, bone, and connective tissue and vice versa, through the assessment of physical performance. Consequently, the triad muscle-bone-adipose tissue disorders by aging should be treated as a single entity.

Sleep duration affects the sequential change of body mass index and muscle strength: a contribution to dynapenic obesity

BACKGROUND

With aging, body mass index (BMI) increases and muscle strength declines, resulting in dynapenic obesity. It remains unknown whether and how sleep duration contributes to the sequence of BMI and muscle strength change in the progression of dynapenic obesity.

METHODS

Data were derived from the first two waves of China Health and Retirement Longitudinal Study. Sleep duration was self-reported. BMI was calculated and grip strength (GS) was measured to reflect muscle strength. The effect of baseline sleep duration on the sequential change of BMI and GS was assessed using two mediation models considering the nonlinear associations between them. The moderating effect of metabolic disorder was also tested.

RESULTS

Totally 4986 participants aged ≥ 50 years (50.8% females) with complete information on variables were included. Baseline BMI fully mediated the nonlinear association between sleep duration and follow-up GS change, but baseline GS did not mediate between sleep duration and follow-up BMI change for older men and women. Short sleep duration positively affected BMI-induced GS change (β = 0.038; 95%CI, 0.015-0.074), while this favorable effect became nonsignificant for moderate sleep duration (β = 0.008; 95% CI, -0.003-0.024) and turned negative with prolonged sleep duration (β =  - 0.022; 95%CI, - 0.051 to - 0.003). This nonlinear mediation effect was more pronounced in older women who are relatively metabolically healthy at baseline.

CONCLUSION

For older adults in China, the influence of sleep duration on BMI-induced GS change but not the GS-induced BMI change suggested the contribution of sleep duration to the sequential course in the progression of dynapenic obesity. Sleep duration deviated either above or below normal range may confer adverse impact on GS through BMI. Strategies addressing sleep and obesity jointly to improve muscle function and delay the progression of dynapenic obesity are required.

Hand Grip Strength Relative to Waist Circumference as a Means to Identify Men and Women Possessing Intact Mobility in a Cohort of Older Adults with Type 2 Diabetes

Possessing intact mobility in older adults assures their continued independence. The early identification of reduced mobility in older adults with type 2 diabetes (T2DM) is paramount for preventing their future physical deterioration. Hand grip strength (HGS), relative to body size, is associated with mobility in older T2DM patients. This study aims to identify an HGS index that best identifies mobilityintact older T2DM patients, along with its optimal cut-off point. The baseline data are from a cohort of 122 older T2DM patients (59% women) (mean age of 70.2 ± 4.4 years). Three mobility tests encompassing three main mobility domains were measured, including usual gait speed (UGS), timed up and go (TUG), and a two-minute walk test (2MWT). Passing scores were defined as those either above the established cut-off points or above the 25th percentile of population norms. Passing all three tests was considered as possessing intact mobility. Receiver operating characteristic (ROC) curves of the most relevant HGS indices were constructed to determine the area under the curve (AUC) that best identifies patients with intact mobility. In a sample of 122 older adults with T2DM, 63.9% of women and 60% of men were found to possess intact mobility. HGS relative to waist circumference (WC) was found to have the strongest association with intact mobility, presenting the highest AUC in both men (0.78) and women (0.72) for discriminating mobility status, with an optimal cut-off of 0.355 (kg/cm) and 0.245 (kg/cm) in men and women, respectively. HGS relative to WC best differentiated between mobility-intact older adults with T2DM and those with mobility limitations, especially in men. Using HGS/WC as a simple and safe screening mode for mobility in a clinical setting could potentially identify older patients with T2DM that require therapeutic interventions.

Association between body fat and sarcopenia in older adults with type 2 diabetes mellitus: A cross-sectional study

OBJECTIVES

To investigate the association between body fat (BF%) and sarcopenia in older adults with type 2 diabetes mellitus (T2DM) and potential link with increased levels of inflammatory indicators and insulin resistance.

METHODS

A total of 543 older adults with T2DM were included in this cross-sectional study. Appendicular skeletal muscle (ASM), handgrip strength and gait speed were measured to diagnose sarcopenia according to the updated Asian Working Group for Sarcopenia (AWGS) 2019 criteria. Body composition data were tested using dual-energy X-ray absorptiometry (DEXA). Levels of serum high-sensitive C-reactive protein (hs-CRP), interleukin-6, fasting blood insulin (FINS), hemoglobin A1c (HbA1c), 25-hydroxyvitamin D₃ [25(OH) D₃] were also determined.

RESULTS

The prevalence of sarcopenia in all participants was 8.84%, of which 11.90% were male and 5.84% females. The Pearson's correlation analysis revealed that BF% was negatively correlated with gait speed in men and women (R =-0.195, P=0.001; R = -0.136, P =0.025, respectively). After adjusting for all potential confounders, sarcopenia was positive associated with BF% (male, OR: 1.38, 95% CI: 1.15-1.65, P< 0.001; female, OR: 1.30, 95% CI: 1.07-1.56, P=0.007), and negatively associated with body mass index (BMI) (male, OR: 0.57, 95% CI: 0.44-0.73, P<0.001; female, OR: 0.48, 95% CI: 0.33-0.70, P<0.001). No significant differences were found in hs-CRP, interleukin-6, and insulin resistance between older T2DM adults with and without sarcopenia.

CONCLUSION

Higher BF% was linked to an increased risk of sarcopenia in older adults with T2DM, suggesting the importance of assessing BF% rather than BMI alone to manage sarcopenia.

Gait Characteristics of Dynapenia, Sarcopenia, and Presarcopenia in Community-Dwelling Japanese Older Women: A Cross-Sectional Study

Age-related decline in skeletal muscle mass and function are risk factors for reduced walking ability. This study aimed to understand the characteristic gait parameters of presarcopenia (low muscle mass only), dynapenia (low muscle function only), and sarcopenia (low muscle mass and function), which have differing skeletal muscle characteristics. Skeletal muscle mass, grip strength, and gait parameters (walking speed, cadence, step length, step width, gait angle, foot angle, stance time, swing time, and double stance time) were evaluated in 307 older Japanese women. Low muscle function was determined by grip strength and normal walking speed. Participants were assessed and divided into the normal (60.9%, n = 187), presarcopenia (25.7%, n = 79), dynapenia (5.2%, n = 16), and sarcopenia (8.1%, n = 25) groups. When compared to the normal group, the sarcopenia group had significantly slower walking speed and shorter step length (p < 0.05); the dynapenia group had significantly slower walking speed, smaller cadence, shorter step length, wider step width, and longer stance time (p < 0.05); and the presarcopenia group showed no differences. Skeletal muscle function may therefore be more strongly related to reduced walking function in older adults than body composition factors. The decrease in walking function was most pronounced in older women with dynapenia.

Association between the visceral adiposity index and risks of all-cause and cause-specific mortalities in a large cohort: Findings from the UK biobank

BACKGROUND AND AIMS

The visceral adiposity index (VAI) has been recently established as a measure of visceral fat distribution and is shown to be associated with a wide range of adverse health events. However, the precise associations between the VAI score and all-cause and cause-specific mortalities in the general population remain undetermined.

METHODS AND RESULTS

In this large-scale prospective epidemiological study, 357,457 participants (aged 38-73 years) were selected from the UK Biobank. We used Cox competing risk regression models to estimate the association between the VAI score and all-cause, cardiovascular disease (CVD), cancer, and other mortalities. The VAI score was significantly correlated with an increased risk of all-cause mortality (hazard ratio [HR], 1.200; 95% confidence interval [CI], 1.148-1.255; P < 0.0001), cancer mortality (HR, 1.224; 95% CI, 1.150-1.303; P < 0.0001), CVD mortality (HR, 1.459; 95% CI, 1.148-1.255; P < 0.0001), and other mortalities (HR, 1.200; 95% CI, 1.148-1.255; P < 0.0001) after adjusting for a series of confounders. In addition, the subgroup analyses showed that HRs were significantly higher in participants who were male, aged below 65 years, and body mass index less than 25.

CONCLUSION

In summary, VAI was positively associated with an increased risk of all-cause and cause-specific mortalities in a nationwide, well-characterised population identified in a UK Biobank. The VAI score might be a complementary traditional predictive indicator for evaluating the risk of adverse health events in the population of Western adults aged 38 years and older.

A longitudinal analysis of serum adiponectin levels and bone mineral density in postmenopausal women in Taiwan

Since bone and fat mass are derived from mesenchyme in early development, adipokines secreted by adipose tissue may have an effect on bone metabolism. The relationship between adiponectin and bone mineral density (BMD) has been inconsistent in previous reports, with results being dependent on age, gender, menopausal status and bone sites. We investigated the relationship between serum adiponectin levels and the BMD of proximal femur and vertebrae bones in a 96-week longitudinal study of post-menopausal women with repeated measures of both. Linear regression models were used to determine the relation between adiponectin and BMD at each time point cross-sectionally, and a generalized estimating equation (GEE) model was used to investigate the longitudinal trends. Among 431 subjects, 376 (87%) provided baseline adiponectin measurements and 373 provided more than two measurements for longitudinal analysis. The means of serum adiponectin and BMD decreased with time. In linear regression models, adiponectin at baseline, the 48th week and the 96th week appeared to be inversely associated with BMD of proximal femur bone, but not lumbar spine after adjusting for age and various confounders. However, they all turn insignificant with further adjustment of body mass index. The inverse association between adiponectin and BMD of proximal femur is substantiated by all generalized equation models. Before adding the BMI in the model, the increase of 1 mg/dL of adiponectin can accelerate the decrease of proximal femur BMD by 0.001 (SE = 0.0004, p = 0.008). With BMI in the model, the drop rate was 0.0008 (SE = 0.0004, p = 0.026) and remained similar with further adjustment of two bone turnover markers. In this longitudinal analysis with both adiponectin and BMD measured at three time points, we demonstrate that with the increase of adiponectin level, the decline of proximal femur BMD in postmenopausal women accelerated during a period of 96 weeks.

Body Composition Characteristics of Community-Dwelling Older Adults With Dynapenia or Sarcopenia

This study aimed to determine the differences in muscle and fat masses of the arm and leg between older adults with dynapenia, sarcopenia, or presarcopenia and normal individuals. The percent body fat, lean body mass, and skeletal mass index were measured with bioelectrical impedance analysis. Muscle function was evaluated using grip strength and walking speed. Participants were classified into four categories. Dynapenia was defined as low muscle function with normal muscle mass. Sarcopenia was defined as the presence of both low muscle mass and low muscle function. Presarcopenia was defined as low muscle mass with normal muscle function. Control was defined as normal muscle mass and function. Multivariate analyses of variance were performed separately for women and men to test the main effect of sarcopenia category on body composition. Among the 356 enrolled participants, 270 were women, and 86 were men. In older women, the dynapenia and sarcopenia groups had significantly less muscle mass in the leg than the control group. In older men, the dynapenia group demonstrated a higher body fat mass in the leg than the control group. These results suggest that different strategies are necessary to prevent dynapenia in women and men.

The Association Between Depressive Symptoms and Sarcopenia Among Community-Dwelling Older Adults: A Cross-Sectional Study

Purpose

To evaluate the relationship between depressive symptoms and sarcopenia among older adults.

Materials and Methods

This is a cross-sectional study. A total of 700 community-dwelling older persons enrolled in this study. Sarcopenia is defined according to the Asian Working Group for Sarcopenia 2019 (AWGS 2019). The bioelectrical impedance analysis assessed muscle mass while a digital dynamometer quantified muscle strength. Furthermore, a 6-meter gait speed test measured physical performance. The Geriatric Depression Scale (GDS-30) screened for depressive symptoms. Data collected include those of socio-demographic, lifestyle, and comorbidity.

Results

The sample comprised 700 participants (455 women) with a mean age of 70.4±6.8 years. 21.5% had sarcopenia, among them, 5.6% at severe stage, while depressive symptoms were present in 8.1% (57/700). After adjusting for the potential confounders of age, sex, marital status, living status, hypertension, body mass index, and physical activity, the depressive symptoms that were found were not associated with sarcopenia but, instead, low gait speed. However, severe sarcopenia significantly impacted the risk of depressive symptoms, particularly in females.

Conclusion

Depressive symptoms are not associated with sarcopenia, but severe sarcopenia increases the risk of depressive symptoms in females, according to updated AWGS 2019 criteria. Gait speed is independently associated with depressive symptoms. The finding highlights that older people with sarcopenia should be screened for depressive symptoms, especially females. Future studies should evaluate the value of gait speed interventions for depressive symptoms among older adults.

Obesity and myosteatosis: the two characteristics of dynapenia in patients with cirrhosis

OBJECTIVE

In patients with liver cirrhosis, the clinical characteristics of dynapenia, a condition in which skeletal muscle mass is maintained but muscle strength is reduced, are not yet known. This study aimed to clarify the characteristics of dynapenia and its impact on quality of life (QOL) in patients with liver cirrhosis.

METHODS

We retrospectively analyzed 116 patients with cirrhosis. Based on grip strength and skeletal muscle mass measured by the bioelectrical impedance analysis method, patients were divided into four groups: normal muscle status, dynapenia, pre-sarcopenia (a condition involving only low muscle mass), and sarcopenia. The characteristics of dynapenia and its influence on QOL were examined.

RESULTS

Fourteen patients had dynapenia. Liver function did not differ among the four groups. In patients with dynapenia, BMI was highest and computed tomography attenuation of skeletal muscle at the third lumbar spine vertebra was lowest among the four groups. The percentage of patients with both BMI ≥25 kg/m2 and myosteatosis was significantly higher in patients with dynapenia [9/14 (64.3%)] than in those with sarcopenia [2/23 (8.7%), P = 0.004] and pre-sarcopenia [0/18 (0%), P < 0.001] and tended to be higher than those with normal muscle status [16/61 (26.2%), P = 0.065]. The physical QOL in patients with dynapenia was as low as that in those with sarcopenia and significantly lower than that in those with normal muscle status.

CONCLUSION

Cirrhotic patients with dynapenia had high BMI and myosteatosis, and impaired physical QOL.

Higher Serum Leptin Levels are Associated with a Reduced Risk of Sarcopenia but a Higher Risk of Dynapenia Among Older Adults

Background

Leptin plays an important role in regulating the energy homeostasis of fat and muscle. Paradoxical findings existed between serum leptin levels and muscle health conditions. Here, we aimed to investigate the relationship between serum leptin levels and the risk of sarcopenia or dynapenia among older adults.

Methods

Adults aged 65 and older living in the community were recruited at annual health checkups. Body composition, gait speed, and handgrip strength were examined. The cutoff values of muscle mass and strength to define sarcopenia and dynapenia were based on the consensus by the Asia Working Group of Sarcopenia in 2019. Serum leptin level was measured by an immunoassay.

Results

Four hundred sixty participants (55.65% females) were enrolled. There were 16.08% and 23.91% with sarcopenia and dynapenia, respectively. Higher serum leptin levels were positively associated with muscle and fat mass but negatively associated with handgrip strength and gait speed for both sexes. In the logistic regression models adjusted for various confounders, a higher serum leptin level was associated with an increased risk of dynapenia with dose-response effects among both male and female participants (odds ratio [OR]=3.74, 95% confidence interval [CI]= 0.99–14.17; OR= 3.32, 95% CI=1.03–10.74, respectively), and a positive trend existed in both genders (p for trend=0.040 and 0.042, respectively). In contrast, a higher leptin level was associated with a reduced risk of sarcopenia with dose-response trends for both sexes (OR= 0.06, 95% CI=0.01–0.48; OR= 0.26, 95% CI=0.06–1.17, respectively) in models of multivariate logistic regression analyses, and a negative trend existed in both genders (p for trend = 0.002 and 0.023, respectively).

Conclusion

A positive trend existed between the serum leptin level and the dynapenia risk, whereas it revealed a negative trend in the serum leptin level and sarcopenia risk in both male and female elderly individuals. The biological mechanisms underlying its negative association with muscle strength but its positive association with muscle mass warrants further investigation.

Fibro-Adipogenic Progenitors: Versatile keepers of skeletal muscle homeostasis, beyond the response to myotrauma

While Fibro-Adipogenic Progenitors (FAPs) have been originally identified as muscle-interstitial mesenchymal cells activated in response to muscle injury and endowed with inducible fibrogenic and adipogenic potential, subsequent studies have expanded their phenotypic and functional repertoire and revealed their contribution to skeletal muscle response to a vast range of perturbations. Here we review the emerging contribution of FAPs to skeletal muscle responses to motor neuron injuries and to systemic physiological (e.g., exercise) or pathological metabolic (e.g., diabetes) perturbations. We also provide an initial blueprint of discrete sub-clusters of FAPs that are activated by specific perturbations and discuss their role in muscle adaptation to these conditions.