A Narrative Review of Non-Pharmacological Strategies for Managing Sarcopenia in Older Adults with Cardiovascular and Metabolic Diseases

Impact of diet and exercise on mitochondrial quality and mitophagy in Alzheimer's disease

Alzheimer's disease (AD) is a devastating neurodegenerative disorder that affects millions of people worldwide. It is characterized by the accumulation of beta-amyloid and phosphorylated tau, synaptic damage, and mitochondrial abnormalities in the brain, leading to the progressive loss of cognitive function and memory. In AD, emerging research suggests that lifestyle factors such as a healthy diet and regular exercise may play a significant role in delaying the onset and progression of the disease. Mitochondria are often referred to as the powerhouse of the cell, as they are responsible for producing the energy to cells, including neurons to maintain cognitive function. Our article elaborates on how mitochondrial quality and function decline with age and AD, leading to an increase in oxidative stress and a decrease in ATP production. Decline in mitochondrial quality can impair cellular functions contributing to the development and progression of disease with the loss of neuronal functions in AD. This article also covered mitophagy, the process by which damaged or dysfunctional mitochondria are selectively removed from the cell to maintain cellular homeostasis. Impaired mitophagy has been implicated in the progression and pathogenesis of AD. We also discussed the impact of impaired mitophagy implicated in AD, as the accumulation of damaged mitochondria can lead to increased oxidative stress. We expounded how dietary interventions and exercise can help to improve mitochondrial quality, and mitochondrial function and enhance mitophagy in AD. A diet rich in antioxidants, polyphenols, and mitochondria-targeted small molecules has been shown to enhance mitochondrial function and protect against oxidative stress, particularly in neurons with aged and mild cognitively impaired subjects and AD patients. Promoting a healthy lifestyle, mainly balanced diet and regular exercise that support mitochondrial health, in an individual can potentially delay the onset and progression of AD. In conclusion, a healthy diet and regular exercise play a crucial role in maintaining mitochondrial quality and mitochondrial function, in turn, enhancing mitophagy and synaptic activities that delay AD in the elderly populations.

Time Allocation to Physical Activity and Sedentary Behaviour and Its Impact on Sarcopenia Risk: A Systematic Review and Meta-Analysis

AIM

To evaluate the relationship between time spent in sedentary behaviour and physical activity and sarcopenia in older adults, and to analyse the effect of reallocating time between different intensities of activities on sarcopenia.

DESIGN

Systematic review and meta-analysis.

METHODS

Following PRISMA guidelines, data were synthesised using a random-effects model, with heterogeneity assessed via Cochran's Q test and the I2 statistic. Study quality was evaluated using the Newcastle-Ottawa Scale by two independent reviewers.

DATA SOURCES

A comprehensive search was conducted in PubMed, Web of Science, Embase, CINAHL and Cochrane databases for studies published up to November 5, 2024, with no language or date restrictions. Relevant reference lists were also manually screened.

RESULTS

The present review included six studies involving 9914 older adults. Three studies suggested that older adults without sarcopenia spent more time performing light physical activities (SMD: 0.35; 95% CI: 0.24-0.45) and moderate to vigorous physical activity (SMD: 0.61; 95% CI: 0.49-0.74) and had less sedentary behaviour (SMD: -0.34; 95% CI: -0.51 to -0.16) than did older adults with sarcopenia. Replacing sedentary behaviour with an equivalent amount of moderate to vigorous physical activity (10, 30, or 60 min) each day can reduce the risk of sarcopenia, with 30 min showing the best preventive effect. However, research findings on the relationship between substituting sedentary behaviour time with light physical activities and sarcopenia are inconsistent.

IMPLICATIONS FOR THE PROFESSION

Encouraging older adults to engage in moderate to vigorous physical activity, even in short bouts of 10 min, can significantly reduce the risk of sarcopenia. Healthcare professionals should tailor activity recommendations to individual preferences and physical conditions to promote overall health and reduce sedentary behaviour.

PATIENT AND PUBLIC CONTRIBUTION

No Patient or Public Contribution.

TRIAL REGISTRATION

CRD42023416166.

The effect of resistance training on patients with secondary sarcopenia: a systematic review and meta-analysis

To analyse the effectiveness of resistance training on secondary sarcopenia, we conducted a meta-analysis to elucidate the effects of resistance training (RT) on muscle strength (handgrip strength [HGS]), muscle mass (Skeletal muscle mass index [SMI]), and physical function (Gait speed [GS]) in patients with secondary sarcopenia. All studies published between 2015 and January 2024 on the effects of resistance training on patients with secondary sarcopenia were retrieved from 6 electronic databases: PubMed, Web of Science Core Collection, Embase, the Cochrane Library, the China National Knowledge Infrastructure (CNKI) Core journals and the Wanfang Database. Two researchers independently extracted and evaluated studies that met the inclusion and exclusion criteria. Finally, 12 randomized controlled trials were included. Pooled analyses of baseline data and results were performed using Review Manager 5.3 with standardized mean variance (SMD) and random effects model. The study included 12 randomized controlled trials involving 639 patients (mean age 57.28 ± 2.66 to 79.6 ± 5.4 years). There are five types of complications among the patients: obesity, type 2 diabetes, Alzheimer's disease, hemodiaysis, and pancreatic cancer. Compared with the control group, RT effectively improved HGS [SMD = 2.47, 95% CI (1.50, 3.43), p < 0.01, I2 = 94%]; SMI [SMD = 0.94, 95% CI (0.52, 1.36), p < 0.01, I2 = 56%]; and GS [SMD = 2.18, 95% CI (-0.01, 4.37), p ≥ 0.05, I2 = 97%]. Further subgroup analysis of the results showed that the intervention effect on grip strength was greater for non-elastic band resistance [SMD = 2.40, 95% CI (1.05, 3.75), p < 0.01, I2 = 94%] than for elastic band resistance (EBRT) [SMD = 1.22, 95% CI (-0.14, 2.58), p < 0.01, I2 = 95%]. The intervention effect of RT on grip strength is more significant in patients with T2D [SMD = 0.59, 95%CI (0.26-0.93, p < 0.01, I2 = 27%] and obesity [SMD = 0.74, 95%CI (0.32-1.15, p < 0.01, I2 = 0%]. For patients with secondary sarcopenia, Resistance training (RT) can effectively enhance muscle strength and muscle mass; however, it does not significantly improve physical function. Different RT intervention methods have different effects on patients, such as elastic band training and non-elastic band training (bounce ball RT; equipment RT, etc.). Different types of complications may influence the effectiveness of RT intervention.

Vascular Impairment, Muscle Atrophy, and Cognitive Decline: Critical Age-Related Conditions

The triad of vascular impairment, muscle atrophy, and cognitive decline represents critical age-related conditions that significantly impact health. Vascular impairment disrupts blood flow, precipitating the muscle mass reduction seen in sarcopenia and the decline in neuronal function characteristic of neurodegeneration. Our limited understanding of the intricate relationships within this triad hinders accurate diagnosis and effective treatment strategies. This review analyzes the interrelated mechanisms that contribute to these conditions, with a specific focus on oxidative stress, chronic inflammation, and impaired nutrient delivery. The aim is to understand the common pathways involved and to suggest comprehensive therapeutic approaches. Vascular dysfunctions hinder the circulation of blood and the transportation of nutrients, resulting in sarcopenia characterized by muscle atrophy and weakness. Vascular dysfunction and sarcopenia have a negative impact on physical function and quality of life. Neurodegenerative diseases exhibit comparable pathophysiological mechanisms that affect cognitive and motor functions. Preventive and therapeutic approaches encompass lifestyle adjustments, addressing oxidative stress, inflammation, and integrated therapies that focus on improving vascular and muscular well-being. Better understanding of these links can refine therapeutic strategies and yield better patient outcomes. This study emphasizes the complex interplay between vascular dysfunction, muscle degeneration, and cognitive decline, highlighting the necessity for multidisciplinary treatment approaches. Advances in this domain promise improved diagnostic accuracy, more effective therapeutic options, and enhanced preventive measures, all contributing to a higher quality of life for the elderly population.

Association of a Combination of Sarcopenia and Type 2 Diabetes with Blood Parameters, Nutrient Intake, and Physical Activity: A Nationwide Population-Based Study

This study aimed to investigate the association of sarcopenia and type 2 diabetes (T2D) with blood parameters, nutrient intake, and physical activity in older Korean adults. We divided 2952 participants into four groups: sarcopenic diabetes (SD), sarcopenia alone (S), diabetes alone (D), and non-sarcopenia and non-diabetes (NSND). Sarcopenia was defined by the appendicular skeletal muscle mass index, and T2D by fasting glucose levels or ongoing treatment. Blood samples were collected after an 8-h fast. Nutrient intake was assessed using a 24-h recall; physical activity was evaluated using a questionnaire. Compared with those in the other groups, the men in the S and SD groups showed significantly lower hemoglobin and hematocrit levels; vitamin D levels in men and parathyroid hormone levels in women were significantly lower in the SD group. Total energy, protein, and carbohydrate intakes were significantly lower in the SD and S groups than those in the D and NSND groups. Physical inactivity was significantly more common in the SD group (men: odds ratio, 1.61; women: odds ratio, 2.37) than in the NSND group. A combination of sarcopenia and diabetes as well as sarcopenia alone was associated with low levels of blood parameters, poor nutrient intake, and low physical activity.