Association of midlife body composition with old-age health-related quality of life, mortality, and reaching 90 years of age: a 32-year follow-up of a male cohort

Nutrition as the foundation for successful aging: a focus on dietary protein and omega-3 polyunsaturated fatty acids

Skeletal muscle plays a critical role throughout the aging process. People living with sarcopenia, a progressive and generalized loss of skeletal muscle mass and function, often experience diminished quality of life, which can be attributed to a long period of decline and disability. Therefore, it is important to identify modifiable factors that preserve skeletal muscle and promote successful aging (SA). In this review, SA was defined as (1) low cardiometabolic risk, (2) preservation of physical function, and (3) positive state of wellbeing, with nutrition as an integral component. Several studies identify nutrition, specifically high-quality protein (eg, containing all essential amino acids), and long-chain omega-3 polyunsaturated fatty acids (n-3 PUFAs), eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA), as positive regulators of SA. Recently, an additive anabolic effect of protein and n-3 PUFAs has been identified in skeletal muscle of older adults. Evidence further suggests that the additive effect of protein and n-3 PUFAs may project beyond skeletal muscle anabolism and promote SA. The key mechanism(s) behind the enhanced effects of intake of protein and n-3 PUFAs needs to be defined. The first objective of this review is to evaluate skeletal muscle as a driver of cardiometabolic health, physical function, and wellbeing to promote SA. The second objective is to examine observational and interventional evidence of protein and n-3 PUFAs on skeletal muscle to promote SA. The final objective is to propose mechanisms by which combined optimal intake of high-quality protein and n-3 PUFAs likely play a key role in SA. Current evidence suggests that increased intake of protein above the Recommended Dietary Allowance and n-3 PUFAs above the Dietary Guidelines for Americans recommendations for late middle-aged and older adults is required to maintain skeletal muscle mass and to promote SA, potentially through the mechanistical target of rapamycin complex 1 (mTORC1).

Health-related quality of life and mortality in the 'Seguimiento Universidad de Navarra' prospective cohort study

OBJECTIVE

To study the association between health-related quality of life (HRQoL) and all-cause mortality in a healthy middle-aged Mediterranean cohort.

METHODS

We included 15,390 participants -mean age 42.8 years at first HRQoL ascertainment, all university graduates-. HRQoL was assessed with the self-administered Medical Outcomes Study Short Form-36 (SF-36) twice, with a 4-year gap. We used multivariable-adjusted Cox regression models to address the relation between self-reported health and Physical or Mental Component Summary (PCS-36 or MCS-36) and mortality, and their interaction with prior comorbidities or adherence to the Mediterranean diet (MedDiet).

RESULTS

Over 8.7 years of median follow-up time, 266 deaths were identified. Hazard ratio (HR) for the excellent vs. poor/fair category in self-reported health was 0.30 (95 % confidence interval (CI), 0.16-0.57) in the model with repeated measurements of HRQoL. Both the PCS-36 (HRquartile4(Q4)vs.Q1 0.57 [95%CI, 0.36-0.90], ptrend < 0.001; HRper+10points: 0.64 [95%CI, 0.54-0.75]) and the MCS-36 (HRQ4vs.Q1 0.67 [95%CI, 0.46-0.97], ptrend = 0.025; HRper+10points: 0.86 [95%CI, 0.74-0.99]) were inversely associated with mortality in the model with repeated measurements of HRQoL. Previous comorbidities or adherence to the MedDiet did not modify these associations.

CONCLUSIONS

Self-reported HRQoL -assessed as self-reported health, PCS-36 and MCS-36- obtained with the Spanish version of the SF-36 were inversely associated with mortality risk, regardless of the presence of previous comorbidities or adherence to the MedDiet.

Association of muscle wasting with mortality risk among adults: A systematic review and meta-analysis of prospective studies

The relationship between muscle wasting and mortality risk in the general population remains unclear. Our study was conducted to examine and quantify the associations between muscle wasting and all-cause and cause-specific mortality risks. PubMed, Web of Science and Cochrane Library were searched until 22 March 2023 for main data sources and references of retrieved relevant articles. Prospective studies investigating the associations of muscle wasting with risks of all-cause and cause-specific mortality in the general population were eligible. A random-effect model was used to calculate the pooled relative risk (RR) and 95% confidence intervals (CIs) for the lowest versus normal categories of muscle mass. Subgroup analyses and meta-regression were performed to investigate the potential sources of heterogeneities among studies. Dose-response analyses were conducted to evaluate the relationship between muscle mass and mortality risk. Forty-nine prospective studies were included in the meta-analysis. A total of 61 055 deaths were ascertained among 878 349 participants during the 2.5- to 32-year follow-up. Muscle wasting was associated with higher mortality risks of all causes (RR = 1.36, 95% CI, 1.28 to 1.44, I²  = 94.9%, 49 studies), cardiovascular disease (CVD) (RR = 1.29, 95% CI, 1.05 to 1.58, I²  = 88.1%, 8 studies), cancer (RR = 1.14, 95% CI, 1.02 to 1.27, I²  = 38.7%, 3 studies) and respiratory disease (RR = 1.36, 95% CI, 1.11 to 1.67, I²  = 62.8%, 3 studies). Subgroup analyses revealed that muscle wasting, regardless of muscle strength, was significantly associated with a higher all-cause mortality risk. Meta-regression showed that risks of muscle wasting-related all-cause mortality (P = 0.06) and CVD mortality (P = 0.09) were lower in studies with longer follow-ups. An approximately inverse linear dose-response relationship was observed between mid-arm muscle circumference and all-cause mortality risk (P < 0.01 for non-linearity). Muscle wasting was associated with higher mortality risks of all causes, CVD, cancer and respiratory disease in the general population. Early detection and treatment for muscle wasting might be crucial for reducing mortality risk and promoting healthy longevity.

Handgrip strength is positively associated with successful aging in older adults: A national cross-sectional study in China

OBJECTIVES

Muscle strength gradually decreases with advancing age. This study aimed to explore the relationship between handgrip strength and successful aging and its specific dimensions in older adults using a nationally representative sample.

METHODS

A total of 5269 adults aged 60 and older were included in this study. Handgrip strength was measured using a dynamometer and was organized into quartiles by sex. Successful aging was defined by Rowe and Kahn's conceptual model including the following five dimensions: (a) no major diseases; (b) freedom from disability; (c) high cognitive function; (d) good psychological status; and (e) active social engagement in life. Logistic regression models were used to examine the association between handgrip strength and successful aging and its specific dimensions.

RESULTS

The prevalence of successful aging was found to be 35.1 % in Chinese older adults. Compared to older adults with handgrip strength in the first quartile, those with handgrip strength in the second quartile, third quartile, and fourth quartile had a higher probability of successful aging (adjusted odds ratio (OR): 1.40 (95 % CI: 1.16, 1.69) to 2.06 (95 % CI: 1.70, 2.50)). We further found that the association between handgrip strength and successful aging was related to different ages.

CONCLUSION

This study suggested that there is a close association between handgrip strength and successful aging. Older adults who have greater handgrip strength can successfully deal with the challenges of aging. For older people, keeping a high level of muscle strength in late life may be helpful to the constant successful aging.

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.

Gender difference in appendicular muscle strength: determinant of the quality of life in the older Taiwanese

Background: The loss of skeletal muscle mass by aging determines the health status and the quality of life (QoL).

Objective: To examine the relationships between appendicular muscle strength and the QoL of elderly adults in gender difference.

Methods: This was a cross-sectional study, in which 690 subjects who participated in older adults health examination in the health management center of Tri-Service General Hospital from 2018 to 2021. A structured questionnaire was used to collect basic demographic data. The 12-Item Short Form Survey (SF-12) was used to evaluate the QoL of subjects. Their grip strength and gait speed were measured, and Dual-energy X-ray absorptiometry was used to measure muscle mass and other body composition data. Multivariate regression analysis was used to examine the relationships between upper and lower limb muscle strength and the QoL of older adults.

Results: In men, legs muscle mass percentage (LegsMM%) (β = 3.67; 95% CI: 0.64–6.69; p = 0.018) and gait speed (β = 6.09; 95% CI: 3.88–8.30; p < 0.001) were positively associated with physical component summary (PCS) scores, and gait speed (β = 4.63; 95% CI: 2.66–6.60; p < 0.001) was also related to an improvement mental component summary (MCS) scores. In women, arms muscle mass percentage (ArmsMM%) (β = 6.50; 95% CI: 2.34–10.66; p = 0.002) and grip strength (β = 10.54; 95% CI: 6.27–14.81; p < 0.001) had the greatest effect on improving PCS scores, whereas grip strength (β = 7.58; 95% CI 4.00–11.17; p < 0.001) was also found to help improve MCS scores.

Conclusions: Men should focus on lower limb training, whereas females should focus on upper limb training to effectively improve their QoL. Appropriate exercise interventions should be designed for different genders for the promotion of the healthy aging policy.

An examination of the relationship among plasma brain derived neurotropic factor, peripheral vascular function, and body composition with cognition in midlife African Americans/Black individuals

African American/Black individuals have been excluded from several lines of prominent neuroscience research, despite exhibiting disproportionately higher risk factors associated with the onset and magnitude of neurodegeneration. Therefore, the objective of the current investigation was to examine potential relationships among brain derived neurotropic factor (BDNF), peripheral vascular function, and body composition with cognition in a sample of midlife, African American/Black individuals. Midlife adults (men: n = 3, 60 ± 4 years; women: n = 9, 58 ± 5 years) were invited to complete two baseline visits separated by 4 weeks. Peripheral vascular function was determined by venous occlusion plethysmography, a dual-energy X-ray absorptiometry was used to determine body composition, and plasma was collected to quantify BDNF levels. The CNS Vital Signs computer-based test was used to provide scores on numerous cognitive domains. The principal results included that complex attention (r = 0.629) and processing speed (r = 0.734) were significantly (p < 0.05) related to the plasma BDNF values. However, there was no significant (p > 0.05) relationship between any vascular measure and any cognitive domain or BDNF value. Secondary findings included the relationship between lean mass and peak hyperemia (r = 0.758) as well as total hyperemia (r = 0.855). The major conclusion derived from these results was that there is rationale for future clinical trials to use interventions targeting increasing BDNF to potentially improve cognition. Additionally, these results strongly suggest that clinicians aiming to improve cognitive health via improvements in the known risk factor of vascular function should consider interventions capable of promoting the size and function of skeletal muscle, especially in the African American/Black population.

Body fat and risk of all-cause mortality: a systematic review and dose-response meta-analysis of prospective cohort studies

BACKGROUND/OBJECTIVES

We aimed to evaluate the relationships between body fat percentage (BF%), fat mass (FM), fat mass index (FMI) and visceral (VAT) and subcutaneous adipose tissue (SAT) with risk of all-cause mortality.

METHODS

We did a systematic search in PubMed, Scopus, and Web of Science to June 2021. We selected prospective cohorts of the relationship between body fat with risk of all-cause mortality in the general population. We applied random-effects models to calculate the relative risks (RRs) and 95%CIs.

RESULTS

A total of 35 prospective cohort studies with 923,295 participants and 68,389 deaths were identified. The HRs of all-cause mortality for a 10% increment in BF were 1.11 (95%CI: 1.02, 1.20; I² = 93%, n = 11) in the general adult populations, and 0.92 (95%CI: 0.79, 1.06; I² = 76%, n = 7) in adults older than 60 years. The HRs were 1.06 (95%CI: 1.01, 1.12; I² = 86%, n = 10) for a 5 kg increment in FM, 1.11 (95%CI: 1.06, 1.16; I² = 79%, n = 7) for a 2 kg/m² increment in FMI, and 1.17 (95%CI: 1.03, 1.33; I² = 72%, n = 8) and 0.81 (0.66, 0.99; I² = 59%, n = 6) for a 1-SD increment in VAT and SAT, respectively. There was a J shaped association between BF% and FM and all-cause mortality risk, with the lowest risk at BF% of 25% and FM of 20 kg. In subgroup analyses, although there was little evidence of between-subgroup heterogeneity, the observed positive associations were more pronounced in studies which had a longer duration, excluded participants with prevalent cardiovascular disease and cancer at baseline, with adjustment for smoking or restricted to never smokers, and less pronounced in studies which adjusted for potential intermediates, suggesting an impact of reverse causation, confounding and over-adjustment in some of the studies.

CONCLUSIONS

Higher body fat content was related to a higher risk of mortality in a J shaped manner. Any future studies should further assess the impact of reverse causation and residual confounding on these associations.

REGISTRATION

PROSPERO (CRD42021240743).

The Benefits of Utilizing Total Body Composition as a Predictor of Cardiorespiratory Fitness Based on Age: A Pilot Study

Maximal oxygen consumption (VO2max) has been associated with body fat percentage (%BF) or fat free mass. However, most analyses do not consider total body composition (TBC) as defined by %BF, fat free mass index (FFMI—a height-adjusted measure of muscle mass), visceral adipose tissue, and bone mineral content (BMC). The aim of this study was to determine if TBC predicts cardiorespiratory fitness in healthy adults and if a relationship exists in young and older adults. Sixty healthy individuals (age group 1 (AG1, ≤35 years), n = 35; age group 2 (AG2, >35 years), n = 25) were screened in a cross-sectional study and retrospectively examined. All participants completed a full body DEXA scan and a standardized multistage treadmill test to determine VO2max. A multiple linear regression analysis was performed to examine the relationship between TBC and VO2max. The multiple regression model showed an overall significant effect for TBC (p < 0.001, R2 = 0.282). When analyzed by age group, the regression model of TBC was not significant in young adults (AG1, p = 0.319, R2 = 0.141), but significant in older adults (AG2, p < 0.001, R2 = 0.683). Significant predictors of VO2max in the older cohort were %BF (β = −0.748, p = 0.001) and BMC (β = 0.014, p = 0.002). Total body composition predicted VO2max in a small cohort of healthy adults. This study highlights the importance of TBC for cardiovascular health, especially in mid-to later-life individuals.

Potential Utility of Electrical Impedance Myography in Evaluating Age-Related Skeletal Muscle Function Deficits

Skeletal muscle function deficits associated with advancing age are due to several physiological and morphological changes including loss of muscle size and quality (conceptualized as a reduction in the intrinsic force-generating capacity of a muscle when adjusted for muscle size). Several factors can contribute to loss of muscle quality, including denervation, excitation-contraction uncoupling, increased fibrosis, and myosteatosis (excessive levels of inter- and intramuscular adipose tissue and intramyocellular lipids). These factors also adversely affect metabolic function. There is a major unmet need for tools to rapidly and easily assess muscle mass and quality in clinical settings with minimal patient and provider burden. Herein, we discuss the potential for electrical impedance myography (EIM) as a tool to evaluate muscle mass and quality in older adults. EIM applies weak, non-detectible (e.g., 400 μA), mutifrequency (e.g., 1 kHz–1 MHz) electrical currents to a muscle (or muscle group) through two excitation electrodes, and resulting voltages are measured via two sense electrodes. Measurements are fast (~5 s/muscle), simple to perform, and unaffected by factors such as hydration that may affect other simple measures of muscle status. After nearly 2 decades of study, EIM has been shown to reflect muscle health status, including the presence of atrophy, fibrosis, and fatty infiltration, in a variety of conditions (e.g., developmental growth and maturation, conditioning/deconditioning, and obesity) and neuromuscular diseases states [e.g., amyotrophic lateral sclerosis (ALS) and muscular dystrophies]. In this article, we describe prior work and current evidence of EIM’s potential utility as a measure of muscle health in aging and geriatric medicine.