Frailty Index and Sex-Specific 6-Year Mortality in Community-Dwelling Older People: The ActiFE Study

Relationship between hemoglobin and grip strength in older adults: the ActiFE study

INTRODUCTION

Although anemia is associated with low muscle strength, hemoglobin has been rarely studied considering ferritin.

AIM

To analyze the association between hemoglobin and grip strength in community-dwelling older adults.

METHODS

We used data from a German cohort of adults ≥ 65 years, excluding those with CRP > 10 mg/L or taking iron supplements. Grip strength (kg) was measured using a Jamar dynamometer. Analysis was performed using multiple linear regression, adjusted for established confounders. Due to interaction, age-stratified (< 80, 80 +), further sex-stratified analysis in those < 80 years old and ferritin-stratified in men < 80 years were performed.

RESULTS

In total, 1294 participants were included in this analysis (mean age 75.5 years, 549 (42.3%) women, 910 (70.3%) < 80 years). On average, hemoglobin and grip strength were 14.9 g/dL and 41.3 kg for men, 13.9 g/dL and 25.1 kg for women. Hemoglobin was significantly positively associated with grip strength only among women < 80 years (β 0.923 [95% CI 0.196, 1.650]). For men < 80 years, the association was significant when ferritin was ≥ 300 µg/L (β 2.028 [95% CI 0.910, 3.146]). No association was detected among those participants 80 + .

DISCUSSION AND CONCLUSIONS

Our data show an association between hemoglobin and grip strength only in women < 80 years old. For men < 80 years, the association was only significant with ferritin levels ≥ 300 µg/L. Considering the decreasing levels of hemoglobin and grip strength and the high prevalence of iron deficiency in older adults further analyses investigating this relationship with more iron specific parameters such as transferrin saturation are warranted.

Preserving the discreteness of deficits during coding leads to a lower frailty index in individuals living in long-term care

This study assesses two coding approaches on the frailty index (FI). Two FI were calculated using 43 variables from 29,758 older adults (84.6 ± 8 years old; 64 % female) in long-term care. Scores were coded as 0, 0.5, or 1 regardless of the number of levels (grouped), or preserved (e.g., a 4 level variable was coded as 0, 0.33, 0.67, or 1; discrete). Grouped and discrete FI were compared with each ordinal variable removed but all other ordinal variables included. This was repeated until 28 unique (14 grouped, 14 discrete) FI had been constructed each with one ordinal variable removed per FI. FI was correlated to age and mortality separated by sex. The median grouped (0.302 (0.221-0.372)) was higher relative to the discrete (0.237 (0.170-0.307)) FI. The discrete (r = 0.91, r = 0.87) and grouped (r = 0.93, r = 0.87) FI showed similar relationships to age and mortality. Removal of any ordinal variable reduced grouped FI by 0.004 or 0.016, whereas removal led to both increases (range: 0.003-0.001) and reductions (range: 0.002-0.008) for discrete FI. A grouped approach inflates FI. A discrete approach provides a more accurate measure of frailty.

Mediating effects of cognitive reserve on the relationship between frailty and cognition in older people without dementia

PURPOSE

This study aimed to explore the potential mediating effects of cognitive reserve on the association between frailty and cognition in the older people without dementia.

METHODS

We performed a cross-sectional analysis of data from 3122 community-dwelling older adults (≥ 65-years-old) without dementia of the Cognitive Function and Ageing Study in Wales. A 31-item frailty index was used to assess frailty. A cognitive lifestyle score was constructed to evaluate cognitive reserve, which includes participants' educational level, occupational attainment, and engagement in social and cognitive activities in later life. Linear regression and mediation modeling were used to investigate the relationship between frailty and cognition and the mediating effects of cognitive reserve as well as social and cognitive activities, an alterable component of cognitive reserve for older adults.

RESULTS

Frailty was negatively associated with cognition. Cognitive reserve was a mediator of the association between frailty and global cognition (- 1.92; 95% CI: - 2.50, - 1.35), as well as individual cognitive domains, with indirect effects contributing to 13-59% of the total effects. Social and cognitive activities have smaller but similar mediating effects on these associations.

CONCLUSIONS

Negative effect of frailty on cognition was partially mediated by a reduction in cognitive reserve. Our results support the possibility that enhancing cognitive reserve, especially engagement in social and cognitive activities may protect cognitive health against frailty.

Frailty and risks of all-cause and cause-specific death in community-dwelling adults: a systematic review and meta-analysis

BACKGROUND

The associations of frailty with all-cause and cause-specific mortality remain unclear. Therefore, we performed this meta-analysis to fill this gap.

METHODS

We searched the PubMed and Embase databases through June 2022. Prospective cohort studies or clinical trials examining frailty were evaluated, and the multiple adjusted risk estimates of all-cause and cause-specific mortality, such as death from cardiovascular disease (CVD), cancer, respiratory illness, dementia, infection, and coronavirus disease 2019 (COVID-19), were included. A random effects model was used to calculate the summary hazard ratio (HR).

RESULTS

Fifty-eight studies were included for the qualitative systematic review, of which fifty-six studies were eligible for the quantitative meta-analysis, and the studies included a total of 1,852,951 individuals and more than 145,276 deaths. Compared with healthy adults, frail adults had a significantly higher risk of mortality from all causes (HR 2.40; 95% CI 2.17-2.65), CVD (HR 2.64; 95% CI 2.20-3.17), respiratory illness (HR 4.91; 95% CI 2.97-8.12), and cancer (HR 1.97; 95% CI 1.50-2.57). Similar results were found for the association between prefrail adults and mortality risk. In addition, based on the studies that have reported the HRs of the mortality risk per 0.1 and per 0.01 increase in the frailty index, we obtained consistent results.

CONCLUSIONS

The present study demonstrated that frailty was not only significantly related to an increased risk of all-cause mortality but was also a strong predictor of cause-specific mortality from CVD, cancer, and respiratory illness in community-dwelling adults. More studies are warranted to clarify the relationship between frailty and cause-specific mortality from dementia, infection, and COVID-19.

TRIAL REGISTRATION

PROSPERO (CRD42021276021).

Association Between Changes in Frailty Index and Clinical Outcomes: An Observational Cohort Study

Purpose

Although the association between a single assessment of frailty index (FI) and clinical outcomes has been revealed in prior studies, there is a lack of knowledge about the prognostic value of FI at different time points and the changes in repeated measurements of FI. Hence, we sought to determine the clinically meaningful changes in FI and reveal the association with the changes and a composite outcome of mortality and institutionalization.

Participants and Methods

This study was based on a longitudinal study of the Pyeongchang Rural Area cohort that included people aged 65 years or older, ambulatory and living at home. Individuals were divided into the worsened group (changes in FI ≥ 0.03 during 2 years) and the stable group (changes in FI < 0.03 during 2 years). The incidence of a composite outcome was compared between the two groups and the relationship was adjusted for age, sex, baseline FI, and follow-up FI.

Results

Of the 953 participants, 403 (42.3%) and 550 (57.7%) were included in the worsened group and the stable group, respectively. The worsened group had a significantly higher risk of the composite outcome than the stable group (HR, 2.37 [95% CI, 1.54-3.67]; p < 0.001). Although the higher risk remained significant after adjusting for age, sex, and baseline FI, the statistical significance disappeared after adjusting for follow-up FI (p = 0.614). The aggravation of FI in the worsened group was predominantly due to aggravation of FI domains, such as activities in daily living, cognitive function and mood, and mobility rather than comorbidity burden.

Conclusion

Aggravation of FI was associated with a composite outcome regardless of baseline FI, and the association was significantly reflected in the follow-up measurement of FI. The worsening FI was mainly attributable to functional geriatric domains.

Prevalence of Prefrailty and Frailty Among Older Adults in Germany: A Systematic Review, Meta-Analysis and Meta-Regression

Background

Various studies have identified the prevalence of prefrailty and frailty among older adults in Germany. Nevertheless, there is no review systematically synthesizing these studies. Thus, our aim was to close this gap in knowledge. Moreover, another aim was to perform a meta-analysis to synthesize the pooled prevalence of prefrailty and frailty. A further aim was to explore potential sources of heterogeneity based on a meta-regression.

Methods

A number of three electronic databases (PubMed, PsycINFO, and CINAHL) were searched (plus an additional hand search). The observational studies that determine the prevalence of frailty among older adults aged 65 years and above in Germany were included, whereas disease-specific samples were excluded. Data extraction included the description of the sample, operationalization of frailty, statistical analysis, sample characteristics and main findings. The established Joanna Briggs Institute (JBI) standardized critical appraisal instrument for prevalence studies was used for evaluating the quality of the studies. Important steps were performed by two reviewers.

Results

In sum, a number of 12 studies were included. The prevalence of frailty varied from about 2.4 to 25.6%. The pooled prevalence of frailty was 13.7% (95% CI: 9.0 to 18.5%). There was a significant heterogeneity among the studies (I² = 98.9%, p < 0.001). The pooled prevalence of prefrailty was 40.2% (95% CI: 28.3 to 52.1%; I² = 99.6%, p < 0.001). Some evidence of a publication bias exists. Meta-regressions showed that some of the heterogeneity was explained by the tool to quantify frailty and the average age of the respective sample.

Conclusion

Particularly, the high prevalence of prefrailty should be highlighted since it is important to prevent individuals in old age from developing to frail status. This knowledge is important for the German society as a whole and for relevant stakeholders.

Systematic Review Registration

PROSPERO, identifier: CRD42021293648.

Prevalence of Undernutrition, Frailty and Sarcopenia in Community-Dwelling People Aged 50 Years and Above: Systematic Review and Meta-Analysis

The world’s population aged ≥65 is expected to rise from one in eleven in 2019 to one in six by 2050. People aged ≥65 are at a risk of undernutrition, frailty, and sarcopenia. The association between these conditions is investigated in a hospital setting. However, there is little understanding about the overlap and adverse health outcomes of these conditions in community-dwelling people. This systematic review aims to quantify the reported prevalence and incidence of undernutrition, frailty, and sarcopenia among older people aged ≥50 living in community dwellings. Searches were conducted using six databases (AMED, CENTRAL, EMBASE, Web of Science, MEDLINE, and CINAHL), and 37 studies were included. Meta-analyses produced weighted combined estimates of prevalence for each condition (Metaprop, Stata V16/MP). The combined undernutrition prevalence was 17% (95% CI 0.01, 0.46, studies n = 5; participants = 4214), frailty was 13% (95% CI 0.11, 0.17 studies n = 28; participants = 95,036), and sarcopenia was 14% (95% CI 0.09, 0.20, studies n = 9; participants = 7656). Four studies reported incidence rates, of which three included data on frailty. Nearly one in five of those aged ≥50 was considered either undernourished, frail, or sarcopenic, with a higher occurrence in women, which may reflect a longer life expectancy generally observed in females. Few studies measured incidence rates. Further work is required to understand population characteristics with these conditions and the overlap between them. PROSPERO registration No. CRD42019153806.

Systolic Blood Pressure and Mortality in Community-Dwelling Older Adults: The Role of Frailty

OBJECTIVES

To investigate whether frailty modifies the association of systolic blood pressure (SBP) with cardiovascular mortality and all-cause mortality in community-dwelling older adults.

DESIGN

A prospective cohort study.

SETTING

A population-based study of nationally representative older Chinese adults in a community setting.

PARTICIPANTS

This study included participants aged 65 years or older from the Chinese Longitudinal Healthy Longevity Survey 2002-2014 and followed up to 2018.

MEASUREMENTS

Participants were divided into two groups according to a frailty index based on the accumulation of a 44-items deficits model. The association between SBP and mortality was analyzed using multivariable-adjusted Cox proportional hazards models.

RESULTS

Among 18,503 participants included, the mean age was 87.2 years and the overall median follow-up time was 42.7 months. We identified 7808 (42.2%) frail participants (mean frailty index=0.33), in which 7533 (96.5%) died during the follow-up. Effect modification by frailty was detected (P for interaction=0.032). Among frail participants, a U-shaped association was found with hazard ratios of 1.16 (95% CI, 1.02-1.32) for SBP < 100 mmHg, and 1.11 (95% CI, 1.00-1.24) for SBP ≥ 150 mmHg compared with SBP 120-130 mmHg. For non-frail older adults, a tendency toward higher risk among those with SBP ≥ 130 mmHg was observed. The analyses towards cardiovascular mortality showed similar results.

CONCLUSION

Our results suggest the presence of effect modification by frailty indicating a possible negative effect for elevated SBP in non-frail older adults and a U-shaped relationship of SBP in frail older adults with respect to mortality even after adjusting for diastolic blood pressure.

Impact of Multidomain Lifestyle Intervention on Frailty Through the Lens of Deficit Accumulation in Adults with Type 2 Diabetes Mellitus

BACKGROUND

Type 2 diabetes and obesity increase the accumulation of health deficits and may accelerate biological aging. Multidomain lifestyle interventions may mitigate against this.

METHODS

Within a large, randomized clinical trial of intensive lifestyle intervention including caloric restriction, increased physical activity, dietary counseling, and risk factor monitoring compared with diabetes support and education, we examined the accumulation of health deficits across 8 years. We used two complementary frailty indices (FIs) based on deficit accumulation, one modeled on work in the Systolic Blood Pressure Intervention Trial and the other including additional deficits related to obesity and type 2 diabetes mellitus. Differences between intervention groups and their consistency among subgroups were assessed with re-randomization tests.

RESULTS

Data from 4,859 adults (45-76 years at baseline, 59% female) were analyzed. Random assignment to intensive lifestyle intervention was associated with lower FI scores throughout follow-up as captured by areas under curves traced by longitudinal means (p ≤ .001), over which time mean (SE) differences between intervention groups averaged 5.8% (0.9%) and 5.4% (0.9%) for the two indices. At year 8, the percentage of participants classified as frail (FI > 0.21) was lower among intensive lifestyle intervention (39.8% and 54.5%) compared with diabetes support and education (42.7% and 60.9%) for both FIs (both p < .001). Intervention benefits were relatively greater for participants who were older, not obese, and without history of cardiovascular disease at baseline.

CONCLUSIONS

Eight years of multidomain lifestyle intervention create a buffer against the accumulation of age-related health deficits in overweight or obese adults with type 2 diabetes.ClinicalTrials.gov Identifier: NCT00017953.

Biomarkers for Aging Identified in Cross-sectional Studies Tend to Be Non-causative

Biomarkers are important tools for diagnosis, prognosis, and identification of the causal factors of physiological conditions. Biomarkers are typically identified by correlating biological measurements with the status of a condition in a sample of subjects. Cross-sectional studies sample subjects at a single timepoint, whereas longitudinal studies follow a cohort through time. Identifying biomarkers of aging is subject to unique challenges. Individuals who age faster have intrinsically higher mortality rates and so are preferentially lost over time, in a phenomenon known as cohort selection. In this article, we use simulations to show that cohort selection biases cross-sectional analysis away from identifying causal loci of aging, to the point where cross-sectional studies are less likely to identify loci that cause aging than if loci had been chosen at random. We go on to show this bias can be corrected by incorporating correlates of mortality identified from longitudinal studies, allowing cross-sectional studies to effectively identify the causal factors of aging.

Association of lung function with overall mortality is independent of inflammatory, cardiac, and functional biomarkers in older adults: the ActiFE-study

Reduced lung function is associated with overall and cardiovascular mortality. Chronic low grade systemic inflammation is linked to impaired lung function and cardiovascular outcomes. We assessed the association of lung function with overall 8-year mortality in 867 individuals of the Activity and Function in the Elderly study using confounder-adjusted Cox proportional hazards models (including gait speed and daily walking time as measures of physical function) without and with adjustment for inflammatory and cardiac markers. Forced expiratory volume in 1 s/forced vital capacity (FEV₁/FVC) but not FVC was related to mortality after adjustment for physical function and other confounders. Additional adjustment for inflammatory and cardiac markers did not change the hazard ratios (HR) markedly, e.g. for a FEV₁/FVC below 0.7 from 1.55 [95% confidence-interval (CI) 1.14-2.11] to 1.49 (95% CI 1.09-2.03). These independent associations were also observed in the apparently lung healthy subpopulation with even higher HRs up to 2.76 (95% CI 1.52-4.93). A measure of airflow limitation but not vital capacity was associated with overall mortality in this community-dwelling older population and in the subgroup classified as lung healthy. These associations were independent of adjustment for inflammatory and cardiac markers and support the role of airflow limitation as independent predictor of mortality in older adults.