Interaction of Skeletal and Left Ventricular Mass in Older Adults with Low Muscle Performance

Differences in sarcopenia status and mortality according to physical activity: results from the Korean Longitudinal Study on Health and Aging (KLoSHA)

PURPOSE

There is increasing evidence that promoting physical activity can prevent sarcopenia. However, physical activity (PA) decreases with age, and the impact of PA intensity on health is unclear. This study investigated the relationship between the level of PA and sarcopenia, and the association between PA levels and mortality in patients with and without sarcopenia.

METHODS

Data were derived from the Korean Longitudinal Study on Health and Aging. PA was classified as sedentary behavior, light PA, or moderate-to-vigorous PA. Each PA level was subdivided based on the median time spent engaged in that activity, yielding eight PA profiles. Logistic regression and Cox proportional hazard models were used to investigate the association between PA level and sarcopenia, and between PA profiles and mortality.

RESULTS

This study included 620 participants (50.2% women; mean age 75.7 ± 7.5 years), of whom 130 (21.0%) participants were identified sarcopenia. During follow-up (mean 10.9 ± 4.1 years), 264 (42.6%) participants died. Overall, sarcopenic participants were less physically active than non-sarcopenic participants. After multivariate adjustment, more sedentary behavior and less moderate-to-vigorous PA were associated with sarcopenia and all related variables, except muscle mass. Compared with the reference, non-sarcopenic participants with lower sedentary behavior and concomitantly higher moderate-to-vigorous PA had significantly lower hazard ratios for mortality, while higher light PA reduced mortality in sarcopenic participants regardless of time spent engaged in sedentary behavior or moderate-to-vigorous PA.

CONCLUSIONS

PA, especially sedentary behavior and moderate-to-vigorous PA, was associated with sarcopenia and related variables, but the level of PA that prevented death differed according to sarcopenia status. Our findings may help determine the optimal intensity and amount of PA.

Cross-sectional and longitudinal association between atrial fibrillation and sarcopenia: Findings from the Korean frailty and aging cohort study

BACKGROUND

Sarcopenia is commonly observed in patients with cardiovascular diseases. However, studies on the association between sarcopenia and atrial fibrillation and their causal relationships are limited. We performed cross-sectional and longitudinal analyses to investigate the association between sarcopenia and atrial fibrillation among community-dwelling older adults.

METHODS

A total of 2225 participants from the Korean Frailty and Aging Cohort Study (KFACS) from 2016 to 2017 were included in this cross-sectional analysis. Sarcopenia was defined according to the Asian Working Group for Sarcopenia 2019 consensus. Atrial fibrillation was diagnosed on the basis of electrocardiographic findings. We investigated whether atrial fibrillation increased the risk of incident sarcopenia 2 years later and whether sarcopenia, in turn, increased the 2-year risk of developing atrial fibrillation using KFACS data from 2018 to 2019.

RESULTS

Of the 2225 participants (54.2% women; mean age 76.0 ± 3.9 years), 509 (22.9%) had sarcopenia at baseline. In the cross-sectional analysis, sarcopenia was associated with atrial fibrillation after multivariate adjustment [odd ratio (OR), 2.127; 95% confidence interval (CI), 1.240-3.648; P = 0.006]. Among the sarcopenia components, low physical performance was associated with atrial fibrillation (OR, 1.872; 95% CI, 1.123-3.120; P = 0.016). During the 2-year follow-up period, atrial fibrillation was not associated with new-onset of sarcopenia (OR, 1.483; 95% CI, 0.597-3.685; P = 0.396), and sarcopenia also did not significantly increase the risk of incident atrial fibrillation (OR, 1.120; 95% CI, 0.384-3.264; P = 0.836).

CONCLUSIONS

Although we found a significant association between sarcopenia and atrial fibrillation in a cross-sectional analysis, we could not establish a causal relationship between the two based on 2 years of follow-up. Further research with long-term follow-up is required to identify causal relationship between atrial fibrillation and sarcopenia.

Association between skeletal muscle and left ventricular mass in patients with hyperthyroidism

Objective

This study aims to investigate the relationship between skeletal muscle and left ventricular mass (LVM) in patients with hyperthyroidism, providing theoretical and data-based foundations for further research on the interaction between secondary muscle atrophy and cardiac remodeling.

Methods

A retrospective data collection was conducted, including 136 patients with hyperthyroidism (Study group) and 50 healthy participants (control group). The Study group was further divided into Group A (high LVM) and Group B (low LVM) based on LVM size. Multiple linear regression analysis was performed to examine the correlation between skeletal muscle and LVM, with model evaluation. Based on the results, further nonlinear regression analysis was conducted to explore the detailed relationship between skeletal muscle and LVM.

Results

Compared to the control group, the Study group exhibited significantly lower LVM, skeletal muscle mass index (SMI), and skeletal muscle mass (SMM) (P<0.05). Within the subgroups, Group A had significantly higher SMI, SMM, and hand grip strength compared to Group B (P<0.05). The results of the multiple linear regression showed a certain correlation between SMI (β=0.60, P=0.042, 95% CI=0.02~1.17) and hand grip strength (β=0.34, P=0.045, 95% CI=0.01~0.67) with LVM. However, the residuals of the multiple regression did not follow a normal distribution (K-S=2.50, P<0.01). Further results from a generalized linear model and structural equation modeling regression also demonstrated a correlation between SMI (β=0.60, P=0.040, 95% CI=0.03~1.17) (β=0.60, P=0.042, 95% CI=0.02~1.17) and hand grip strength (β=0.34, P=0.043, 95% CI=0.01~0.67) (β=0.34, P=0.045, 95% CI=0.01~0.67) with LVM.

Conclusion

Patients with hyperthyroidism may exhibit simultaneous decreases in LVM, SMM, and SMI. The LVM in patients is correlated with SMM and hand grip strength, highlighting the need for further exploration of the causal relationship and underlying mechanisms. These findings provide a basis for the prevention and treatment of secondary sarcopenia and cardiac pathology in patients with hyperthyroidism.

Haemodynamic Parameters Underlying the Relationship between Sarcopenia and Blood Pressure Recovery on Standing

BACKGROUND

Sarcopenia, delayed blood pressure (BP) recovery following standing, and orthostatic hypotension (OH) pose significant clinical challenges associated with ageing. While prior studies have established a link between sarcopenia and impaired BP recovery and OH, the underlying haemodynamic mechanisms remain unclear.

METHODS

We enrolled 107 participants aged 50 and above from a falls and syncope clinic, conducting an active stand test with continuous non-invasive haemodynamic measurements. Hand grip strength and five-chair stand time were evaluated, and muscle mass was estimated using bioelectrical impedance analysis. Participants were categorised as non-sarcopenic or sarcopenic. Employing mixed-effects linear regression, we modelled the effect of sarcopenia on mean arterial pressure and heart rate after standing, as well as Modelflow®-derived parameters such as cardiac output, total peripheral resistance, and stroke volume, while adjusting for potential confounders.

RESULTS

Sarcopenia was associated with diminished recovery of mean arterial pressure during the 10-20 s period post-standing (β -0.67, p < 0.001). It also resulted in a reduced ascent to peak (0-10 s) and recovery from peak (10-20 s) of cardiac output (β -0.05, p < 0.001; β 0.06, p < 0.001). Furthermore, sarcopenia was associated with attenuated recovery (10-20 s) of total peripheral resistance from nadir (β -0.02, p < 0.001) and diminished recovery from peak (10-20 s) of stroke volume (β 0.54, p < 0.001). Notably, heart rate did not exhibit a significant association with sarcopenia status at any time interval post-standing.

CONCLUSION

The compromised BP recovery observed in sarcopenia appears to be driven by an initial reduction in the peak of cardiac output, followed by attenuated recovery of cardiac output from its peak and total peripheral resistance from its nadir. This cardiac output finding seems to be influenced by stroke volume rather than heart rate. Possible mechanisms for these findings include cardio-sarcopenia, the impact of sarcopenia on the autonomic nervous system, and/or the skeletal muscle pump.

Cardio-sarcopenia: A syndrome of concern in aging

Cardiac alterations in structure and function, namely, the left ventricle, have been intensely studied for decades, in association with aging. In recent times, there has been keen interest in describing myocardial changes that accompany skeletal muscle changes in older adults. Initially described as a cardio-sarcopenia syndrome where alterations in myocardial structure were observed particularly among older adults with skeletal muscle sarcopenia, investigations into this syndrome have spurred a fresh level of interest in the cardiac-skeletal muscle axis. The purpose of this perspective is to summarize the background for this "syndrome of concern," review the body of work generated by various human aging cohorts, and to explore future directions and opportunities for understanding this syndrome.

Mitophagy: At the heart of mitochondrial quality control in cardiac aging and frailty

Cardiovascular disease is highly prevalent among older adults and poses a huge burden on morbidity, disability, and mortality. The age-related increased vulnerability of the cardiovascular system towards stressors is a pathophysiological trait of cardiovascular disease. This has been associated with a progressive deterioration of blood vessels and decline in heart function during aging. Cardiomyocytes rely mostly on oxidative metabolism for deploying their activities and mitochondrial metabolism is crucial to this purpose. Dysmorphic, inefficient, and oxidant-producing mitochondria have been identified in aged cardiomyocytes in association with cardiac structural and functional alterations. These aberrant organelles are thought to arise from inefficient mitochondrial quality control, which has therefore been place in the spotlight as a relevant mechanism of cardiac aging. As a result of alterations in mitochondrial quality control and redox dyshomeostasis, mitochondrial damage accumulates and contributes to cardiac frailty. Herein, we discuss the contribution of defective mitochondrial quality control pathways to cardiac frailty. Emerging findings pointing towards the exploitation of these pathways as therapeutic targets against cardiac aging and cardiovascular disease will also be illustrated.

Determinants of cardiac structure in frail and sarcopenic elderly adults

BACKGROUND

Cardiac structure and function change with age. The higher prevalence of left ventricular hypertrophy (LVH) with concentric remodeling is indicative of a typical geometric pattern of aging associated with a higher cardiovascular (CV) risk and diseases. The recent associations found between low left ventricular and skeletal mass in older patients with frailty and sarcopenia have raised great interest in investigating cardiac characteristics and determinants of left ventricular mass (LVM) in this population.

DESIGN

Cross-sectional study.

METHODS

We evaluated 100 sarcopenic and physically frail outpatients, 33 men (M), 67 women (F), aged ≥70 years (mean age 79 ± 5) and enrolled in the Parma site of European multicenter SPRINTT population.

RESULTS

All male and female participants showed LVH, assessed as indexed LVM to body surface area (LVM/BSA) (M = 128 ± 39 g/m²; F = 104 ± 26 g/m²), and were more prone to have concentric geometry, as demonstrated by relative wall thickness value (0.41 in both sexes). After backward regression analysis, including covariates such as age, sex, office or ABPM systolic blood pressure (SBP), heart rate, BSA, use of β blockers, ACE-inhibitors, angiotensin receptor blockers, calcium channel blockers, diuretics, physical activity, hemoglobin level, and Mini Mental State examination - the most powerful determinants of LVM were clinical SBP (β = 1.51 ± 0.31, p = 0.0005), BSA (β = 165.9 ± 41.4, p = 0.0001), while less powerful determinants were 24 h, daily and nightly SBP (p = 0.02, p = 0.002, p = 0.004 respectively).

CONCLUSIONS

Older sarcopenic and physically frail patients showed LVH with a tendency towards concentric geometry. The main determinant of LVM was SBP, highlighting the key role that hemodynamic condition plays in determining LVH in this population.