The fatter, the better in old age: the current understanding of a difficult relationship

Biological basis and treatment of frailty and sarcopenia

In an ageing society, the importance of maintaining healthy life expectancy has been emphasized. As a result of age-related decline in functional reserve, frailty is a state of increased vulnerability and susceptibility to adverse health outcomes with a serious impact on healthy life expectancy. The decline in skeletal muscle mass and function, also known as sarcopenia, is key in the development of physical frailty. Both frailty and sarcopenia are highly prevalent in patients not only with advanced age but also in patients with illnesses that exacerbate their progression like heart failure (HF), cancer, or dementia, with the prevalence of frailty and sarcopenia in HF patients reaching up to 50-75% and 19.5-47.3%, respectively, resulting in 1.5-3 times higher 1-year mortality. The biological mechanisms of frailty and sarcopenia are multifactorial, complex, and not yet fully elucidated, ranging from DNA damage, proteostasis impairment, and epigenetic changes to mitochondrial dysfunction, cellular senescence, and environmental factors, many of which are further linked to cardiac disease. Currently, there is no gold standard for the treatment of frailty and sarcopenia, however, growing evidence supports that a combination of exercise training and nutritional supplement improves skeletal muscle function and frailty, with a variety of other therapies being devised based on the underlying pathophysiology. In this review, we address the involvement of frailty and sarcopenia in cardiac disease and describe the latest insights into their biological mechanisms as well as the potential for intervention through exercise, diet, and specific therapies.

ALM/BMI: A Clinically Superior Index for Identifying Skeletal Muscle Dysfunction in Patients With Heart Failure

BACKGROUND

Skeletal muscle wasting is critical in patients with heart failure (HF). Whereas prior studies have employed appendicular lean mass (ALM) normalized by height squared to identify low skeletal muscle mass, the potential of ALM normalized to body mass index (ALM/BMI) remains unexplored in patients with HF. In this study, we compared the use of 2 skeletal muscle mass indices in patients with HF to examine their sex-specific correlations with measures of physical capacity, quality of life, and daily physical activity.

METHODS AND RESULTS

A total of 111 patients with HF underwent dual x-ray absorptiometry, physical capacity tests, and accelerometry and answered a quality-of-life questionnaire. ALM normalized by height squared and ALM/BMI indices disagreed in classifying low muscle mass (Cohen's κ, -0.008 [95% CI, -0.094 to 0.177]; P=0.93). ALM/BMI correlated well with 6-minute walking distance in women and men (R=0.67 and 0.49; P<0.001), with maximal oxygen uptake in women and men (R=0.41 and 0.48; P<0.05), and with maximal muscle strength in women and men (R=0.54 and 0.43; P<0.01). Inversely, ALM normalized by height squared did not correlate significantly with 6-minute walking distance or maximal oxygen uptake and correlated with maximal muscle strength only in men (R=0.43; P<0.001). Only ALM/BMI allowed for identification of a low-muscle-mass group characterized by poor quality of life (Minnesota Living With Heart Failure Questionnaire score of 33±21 versus 25±16; P=0.027) and less daily time spent in moderate to vigorous physical activity (8 [3-17] versus 15 [9-37] minutes; P<0.001).

CONCLUSIONS

ALM/BMI was superior for identifying clinically significant muscle dysfunction in both female and male patients with HF.

Obesity and Aging

The obesity epidemic in aging populations poses significant public health concerns for greater morbidity and mortality risk. Age-related increased adiposity is multifactorial and often associated with reduced lean body mass. The criteria used to define obesity by body mass index in younger adults may not appropriately reflect age-related body composition changes. No consensus has been reached on the definition of sarcopenic obesity in older adults. Lifestyle interventions are generally recommended as initial therapy; however, these approaches have limitations in older adults. Similar benefits in older compared with younger adults are reported with pharmacotherapy, however, large randomized clinical trials in geriatric populations are lacking.

The impact of BMI on psychological health in oldest old individuals-Are there differences between women and men?

OBJECTIVE

The aim of this study was to determine the association of mental health issues associated with BMI and gender in the oldest old population (secondary data analyses).

METHOD

The data were taken from the second follow-up of a long-term study investigating the impact of the COVID-19 pandemic on health in oldest old individuals (range: 77-96 years). The response rate was 80.0%. Apart from sociodemographic characteristics (age, gender, weight and height); anxiety, depression, somatic complaints and social support were assessed in this survey.

RESULTS

Analyses revealed gender-specific differences, indicating that male participants with excess weight show more complaints compared to their counterparts without excess weight. According to regression results, BMI was associated with somatization, but not depression or anxiety.

CONCLUSION

High BMI contributed to more somatic complaints and men may be affected differently by BMI regarding their mental well-being. Longitudinal results are needed in order to confirm these findings and develop suitable interventions based on individual needs of the oldest old.

Obesity in Caucasian Seniors on the Rise: Is It Truly Harmful? Results of the PolSenior2 Study

Obesity is associated with an increased risk of morbidity and mortality; however, data suggest that in old age, obesity is not detrimental. The study’s objective was to verify whether obesity frequency still increases in Polish Caucasian seniors and to verify the “obesity paradox”. Five thousand and fifty-seven community-dwelling individuals aged ≥ 65 years completed a detailed medical questionnaire, underwent measurements of the body mass index (BMI) and the waist circumference (WC), and an evaluation of physical and cognitive performances. Over a decade, general obesity increased by 2.1%, mostly due to a 3.9% increase in men. Abdominal obesity increased by 1.0%, mainly due to males, in whom it increased by 3.9%. Obesity increased the risk of several aging-related diseases, but this effect was less pronounced in the oldest-old. Obesity did not adversely affect the physical and cognitive functioning or mortality. Through a multivariable analysis, the BMI and WC remained the independent predictors of the Katz Activities of Daily Living score (p < 0.001 and p < 0.05, respectively) and Mini-Mental State Examination score (both p < 0.001). The Kaplan−Meier survival curves revealed that overweight and obesity classes 1 and 2 were associated with the lowest mortality. Through a multivariable analysis, overweight, class 1 obesity, and abdominal obesity remained the independent predictors of a decreased mortality (all p < 0.001). In conclusion, we found that overweight and obesity are not detrimental in seniors, including the oldest-old. We suggest that the anthropometric values defining obesity should be modified for age-advanced people.

The Relaxin-3 Receptor, RXFP3, Is a Modulator of Aging-Related Disease

During the aging process our body becomes less well equipped to deal with cellular stress, resulting in an increase in unrepaired damage. This causes varying degrees of impaired functionality and an increased risk of mortality. One of the most effective anti-aging strategies involves interventions that combine simultaneous glucometabolic support with augmented DNA damage protection/repair. Thus, it seems prudent to develop therapeutic strategies that target this combinatorial approach. Studies have shown that the ADP-ribosylation factor (ARF) GTPase activating protein GIT2 (GIT2) acts as a keystone protein in the aging process. GIT2 can control both DNA repair and glucose metabolism. Through in vivo co-regulation analyses it was found that GIT2 forms a close coexpression-based relationship with the relaxin-3 receptor (RXFP3). Cellular RXFP3 expression is directly affected by DNA damage and oxidative stress. Overexpression or stimulation of this receptor, by its endogenous ligand relaxin 3 (RLN3), can regulate the DNA damage response and repair processes. Interestingly, RLN3 is an insulin-like peptide and has been shown to control multiple disease processes linked to aging mechanisms, e.g., anxiety, depression, memory dysfunction, appetite, and anti-apoptotic mechanisms. Here we discuss the molecular mechanisms underlying the various roles of RXFP3/RLN3 signaling in aging and age-related disorders.