The role of frailty in explaining the association between the metabolic syndrome and mortality in older adults

The association of multidimensional frailty with metabolic syndrome and low-grade inflammation in community-dwelling older adults in the Netherlands: a Lifelines cohort study

BACKGROUND

Preventing metabolic syndrome (MetS) and frailty in older adults is crucial for healthy aging. The association between MetS and physical frailty is well-documented, with low-grade inflammation as potential explanation. However, the association between MetS and frailty as a multidimensional concept, and the association of low-grade inflammation with presence of MetS and frailty, is yet unclear. Therefore, we examined these associations low-grade inflammation in a large cohort of community-dwelling older adults.

METHODS

This cross-sectional study was performed among adults aged ≥ 65 years enrolled in the Dutch Lifelines population cohort. MetS was defined according to the Joint Interim Statement of 2009. Frailty was measured by the Groningen Frailty Indicator (GFI), which consists of 15 self-reported items on both physical and psychosocial functioning, with a score ≥ 4 indicating presence of frailty. The association between MetS and its five components and frailty was assessed using logistic regression models. Low-grade inflammation was represented by high-sensitivity C-reactive protein (hsCRP) level. The association of hsCRP level with presence of MetS and frailty was assessed using multinomial logistic regression in a sub-cohort with available hsCRP measurements.

RESULTS

Of 11,552 adults (52.1% women) included, the prevalences of MetS and frailty were 28% and 15%, respectively. MetS was positively associated with frailty after adjusting for relevant covariates (OR: 1.37; 95% CI: 1.22-1.53). MetS components elevated blood pressure was most strongly associated with frailty. In the sub-cohort of 3896 participants, high hsCRP was associated with presence of MetS and frailty (OR: 1.31; 95% CI: 1.15-1.51), and MetS alone (OR: 1.44; 95% CI: 1.33-1.56), but not to frailty alone. A higher hsCRP level was associated with a higher score on the physical domain of frailty (b: 0.06; 95% CI: 0.03-0.08).

CONCLUSIONS

Presence of MetS is associated with presence of frailty indicated by a multidimensional index in a large group of Dutch older adults. Low-grade inflammation, indicated by plasma hsCRP level, was found to be associated with both presence of MetS and frailty and presence of MetS alone. Increased hsCRP levels were associated with the physical component of frailty, but not with frailty as a multidimensional concept.

The prevalence of frailty among patients with metabolic syndrome: a systematic review and meta-analysis

BACKGROUND

Growing evidence shows that metabolic syndrome and frailty are significantly associated. Screening and assessing frailty in patients with metabolic syndrome is important to help improve their clinical outcomes and quality of life. Therefore, understanding the prevalence of frailty in patients with metabolic syndrome is the first critical step, however, the prevalence reported in the literature varies widely.

AIM

To pool the overall prevalence of frailty among patients with metabolic syndrome.

DESIGN

Systematic review and meta-analysis.

METHODS

The Cochrane Library, PubMed, Web of Science, Embase, APA PsycINFO, Scopus, CINAHL Complete, CNKI, Wan Fang, SinoMed, and VIP databases were searched from the inception to March 6, 2024. Statistical analysis was performed using STATA15 software. The prevalence was pooled using the random-effects model. The sources of heterogeneity were investigated by using meta-regression and subgroup analyses.

RESULTS

A total of 22 original studies published between 2007 and 2023 were included in this systematic review and meta-analysis, involving 19,921 metabolic syndrome patients. The prevalence of frailty and pre-frailty among patients with metabolic syndrome was 20% (95% CI: 16% to 25%, I2 = 99.44%) and 45% (95% CI: 36% to 53%, I2 = 99.20%). Subgroup analyses revealed differences in prevalence by frailty instruments, geographic regions, study settings, publication years, study quality, study design, and different components of metabolic syndrome.

CONCLUSIONS

This systematic review and meta-analysis showed the high prevalence of frailty and pre-frailty in patients with metabolic syndrome. In the future, more high-quality longitudinal studies and exploration of other potential demographic characteristics that may influence frailty are needed to understand more information on frailty in patients with metabolic syndrome.

The intersection of frailty and metabolism

On average, aging is associated with unfavorable changes in cellular metabolism, which are the processes involved in the storage and expenditure of energy. However, metabolic dysregulation may not occur to the same extent in all older individuals as people age at different rates. Those who are aging rapidly are at increased risk of adverse health outcomes and are said to be "frail." Here, we explore the links between frailty and metabolism, including metabolic contributors and consequences of frailty. We examine how metabolic diseases may modify the degree of frailty in old age and suggest that frailty may predispose toward metabolic disease. Metabolic interventions that can mitigate the degree of frailty in people are reviewed. New treatment strategies developed in animal models that are poised for translation to humans are also considered. We suggest that maintaining a youthful metabolism into older age may be protective against frailty.

Inflammation and Oxidative Stress in Frailty and Metabolic Syndromes-Two Sides of the Same Coin

In developed countries, aging is often seen as typical, but it is made complicated by many disorders and co-morbidities. Insulin resistance seems to be an underlying pathomechanism in frailty and metabolic syndromes. The decline in insulin sensitivity leads to changes in the oxidant-antioxidant balance and an accelerated inflammatory response, especially by adipocytes and macrophages in adipose tissue, as well as muscle mass density. Thus, in the pathophysiology of syndemic disorders-the metabolic syndrome and frailty syndrome-an extremely important role may be played by increased oxidative stress and pro-inflammatory state. Papers included in this review explored available full texts and the reference lists of relevant studies from the last 20 years, before the end of 2022; we also investigated the PubMed and Google Scholar electronic databases. The online resources describing an elderly population (≥65 years old) published as full texts were searched for the following terms: "oxidative stress and/or inflammation", "frailty and/or metabolic syndrome". Then, all resources were analyzed and narratively described in the context of oxidative stress and/or inflammation markers which underlie pathomechanisms of frailty and/or metabolic syndromes in elderly patients. So far, different metabolic pathways discussed in this review show that a similar pathogenesis underlies the development of the metabolic as well as frailty syndromes in the context of increased oxidative stress and acceleration of inflammation. Thus, we argue that the syndemia of the syndromes represents two sides of the same coin.

The Association between Metabolic Syndrome, Frailty and Disability-Free Survival in Healthy Community-dwelling Older Adults

OBJECTIVES

To examine the association between metabolic syndrome (MetS) and frailty, and determine whether co-existent MetS and frailty affect disability-free survival (DFS), assessed through a composite of death, dementia or physical disability.

DESIGN

Longitudinal study.

SETTING AND PARTICIPANTS

Community-dwelling older adults from Australia and the United States (n=18,264) from "ASPirin in Reducing Events in the Elderly" (ASPREE) study.

MEASUREMENTS

MetS was defined according to American College of Cardiology/American Heart Association Task Force on Clinical Practice Guidelines (2018). A modified Fried phenotype and a deficit accumulation Frailty Index (FI) were used to assess frailty. Association between MetS and frailty was examined using multinomial logistic regression. Cox regression was used to analyze the association between MetS, frailty and DFS over a median follow-up of 4.7 years.

RESULTS

Among 18,264 participants, 49.9% met the criteria for MetS at baseline. Participants with Mets were more likely to be pre-frail [Relative Risk Ratio (RRR): 1.22; 95%Confidence Interval (CI): 1.14, 1.30)] or frail (RRR: 1.66; 95%CI: 1.32, 2.08) than those without MetS. MetS alone did not shorten DFS while pre-frailty or frailty alone did [Hazard Ratio (HR): 1.68; 95%CI: 1.45, 1.94; HR: 2.65; 95%CI:1.92, 3.66, respectively]. Co-existent MetS with pre-frailty/frailty did not change the risk of shortened DFS.

CONCLUSIONS

MetS was associated with pre-frailty or frailty in community-dwelling older individuals. Pre-frailty or frailty increased the risk of reduced DFS but presence of MetS did not change this risk. Assessment of frailty may be more important than MetS in predicting survival free of dementia or physical disability.

The association between metabolic syndrome and presence of frailty: a systematic review and meta-analysis

BACKGROUND

Frailty represents a progressive deterioration in multi-system of the body and could increase vulnerability to stressors. Recently, several studies found that metabolic syndrome was significantly associated with frailty and emphasized its role in assessing and preventing frailty. However, these conclusions are controversial. We conducted this systematic review and meta-analysis to evaluate the association between metabolic syndrome and frailty.

METHODS

Databases including Pubmed, Embase, Web of Science, CINAHL Complete, China National Knowledge Infrastructure (CNKI) and Wanfang Data Knowledge Service Platform were searched for studies on the association between metabolic syndrome and frailty, from inception to 17th June 2022. Two researchers independently screened the literature, extracted the data and evaluated the quality. Stata/SE 15.0 software was used to perform the statistical analysis.

RESULTS

Eleven studies were included in this review and eight studies were included in the meta-analysis, involving one prospective cohort studies and ten cross-sectional studies with 12,640 participants. The pooled results indicated that metabolic syndrome was significantly associated with frailty (OR = 1.82, 95% CI = 1.46-2.27) with a low heterogeneity (I² = 32.1%), and there were significant associations between MetS and weakness (OR = 1.35, 95% CI = 1.15-1.58, I² = 0.0%), slow gait speed (OR = 1.80, 95% CI = 1.51-2.14, I² = 93.4%), weight loss (OR = 1.77, 95% CI = 1.36-2.29, I² = 0.0%) and decreased physical activity (OR = 1.87, 95% CI = 1.49-2.35, I² = 39.7%).

CONCLUSIONS

The findings of this systematic review and meta-analysis suggested that metabolic syndrome could be significantly associated with the presence of frailly. Future studies need to further consider the effects of measurement tools, age and specific disease status in this association. Furthermore, the casual relationship between them is to be determined.

The Relationship between Metabolic Syndrome and Frailty in Older People: A Systematic Review and Meta-Analysis

AIMS

Both metabolic syndrome (MetS) and frailty are associated with increased all-cause mortality, yet the complex interplay between these two conditions has not adequately been elucidated. We aim to analyse the relationship between MetS and frailty through a systematic review of the literature with meta-analyses.

METHODS

A literature search was conducted via MEDLINE and EMBASE. Studies were included if validated frameworks for defining frailty and MetS (presence of at least 3 out of the five constitutive components: abdominal obesity, high fasting blood glucose, hypertension, hypertriglyceridaemia, and low high-density lipoprotein level) were utilised, in addition to the inclusion of participants aged 60 or older.

RESULTS

Eleven studies were included, all observational. All were in community-dwelling older people, 9 cross-sectional and 2 longitudinal. Most of the studies used Fried's frailty phenotype. The prevalence of frailty ranged from 0.9% to 14.8% in population-based studies and 35.6% in the outpatient clinic setting. The prevalence of MetS was also higher in the outpatient clinic setting at 47.5%, compared to 17.5-41.0% in the community-dwelling populations. The meta-analysis of 11 studies showed that MetS was associated with an increased risk of frailty (pooled OR 1.73, 95% CI, 1.41-2.13).

CONCLUSION

This systematic review and meta-analysis suggest that frailty was more prevalent in older people with MetS compared to older people without MetS. The study findings suggest the importance of frailty screening in older people with MetS and a distinct role of managing MetS in preventing frailty in older people.

Do changes in frailty, physical functioning, and cognitive functioning predict mortality in old age? Results from the Longitudinal Aging Study Amsterdam

Background

The ability to accurately predict survival in older adults is crucial as it guides clinical decision making. The added value of using various health indicators as well as changes in these indicators for predicting mortality remains unclear. The aim of this study was to investigate whether changes in health indicators such as frailty and physical performance improve mortality predictions in old age.

Methods

This is a population based prospective cohort study on 995 community-dwelling people aged 68–92 years from the Longitudinal Aging Study Amsterdam. Two measurements at a three-year interval (1995/1996 and 1998/1999) were available for the frailty index, frailty phenotype, grip strength, walking speed, and Mini-Mental State Examination (MMSE). Cox regression was used to analyze mortality risks associated with the current health status and changes in health, with mortality data up to 2017. The extent to which these health indicators improved mortality predictions compared to models with age and sex only was assessed by the area under the receiver operating characteristic curve (AUC).

Results

The AUC of age and sex for five-year mortality was 72.8% (95% CI 69.0 – 76.5) and was the lowest in the oldest old (age > 80.5 years). The added AUC of the current status of health indicators ranged from 0.7 to 3.3%. The added AUC of the three-year change was lower, ranging from -0.0 to 1.1%, whereas the added AUC of three-year change and current status combined was similar to current status alone, ranging from 0.6 to 3.2%. Across age, the added AUC of current status was highest in the oldest old, however there was no such pattern using three-year change. Overall, the frailty index appeared to improve mortality predictions the most, followed by the frailty phenotype, MMSE, grip strength, and walking speed.

Conclusions

Current health status improved mortality predictions better than changes in health. Its contribution was highest in the oldest old, but the added value to models with age and sex only was limited.

Association between serum lactate dehydrogenase and frailty among individuals with metabolic syndrome

While metabolic syndrome (MetS) is associated with frailty, the correlation of serum lactate dehydrogenase (sLDH) and frailty with MetS remain uncertain. To investigate the relationship between sLDH and frail components in the US with MetS. A total of 4,066 participants aged 40-90 years were assessed from the database of the third National Health and Nutrition Examination Survey, 1988-1994. The participants were classified into MetS and non-MetS groups. Multivariate logistic regression analysis with four models were performed to assess the odds ratio (OR) of the divided tertiles of sLDH levels with frailty, and frail components including slow walking (SW), weakness, exhaustion, low physical activity (LPA), and low body weight (LBW). Higher sLDH levels were positively associated with frailty in the MetS group (p = 0.024) but not in non-MetS group (p = 0.102). After covariate adjustments, the OR of frailty in the upper two tertiles compared to the lowest tertile and revealed statistical significance (p < 0.05). Frail components of SW, weakness, exhaustion, and LPA were associated with higher sLDH (p < 0.05) except for LBW in MetS and non-MetS groups. The results demonstrated the strong association of higher sLDH levels and frailty among US individuals with MetS.

Cognitive frailty predicting death and disability in Chinese elderly

OBJECTIVE

Cognitive frailty (CF) is associated with adverse health outcomes, but different CF models have been proposed in the literature. We explored whether cognitive impairment (CoI) assessed by the Revised Hasegawa dementia scale (HDS-R) and physical frailty (PF) assessed by the modified Frailty Phenotype can be combined to predict risks of adverse outcomes in elderly Chinese subjects.

METHODS

The data collected in the Rugao Longevity and Aging Study were used. PF was assessed by the modified Frailty phenotype. CoI was defined as the lowest 20% of the HDS-R score. CF was defined as the co-existence of physical frailty and CoI, excluding those with severe CoI(HDR-S ≤ 10). The date and cause of death were acquired from the Death registry of Rugao's Civil Affairs Bureau. Disability was measured using the activities of daily living (ADL) scale.

RESULTS

The prevalence of CF was 2.9% at baseline. During 3-year follow-up, 130 (8.1%) of the 1607 elderly subjects died. The highest mortality risk was observed among subjects with CF (hazard ratio [HR] = 2.94, 95% confidence interval [CI] = 1.28-6.78). Fully adjusted survival plots showed that CF was associated with the highest risk for 3-year mortality. The incidence of ADL disability was 6.0% after 3 years. Compared with the robust and non-CoI elderly, CF was associated with a 10.48-fold (95% CI 2.98-36.80) higher risk of ADL disability.

CONCLUSIONS

The CF model defined as a combination of HDS-R and Frail Phenotypes showed predictive validity for all-cause death and new-onset ADL disability 3 years later.

Dual effects of insulin resistance on mortality and function in non-diabetic older adults: findings from the Toledo Study of Healthy Aging

Insulin signalling declines with increasing age and impacts skeletal muscle function and longevity in animal models. Our aim was to assess the relationships between insulin resistance (IR) and frailty and mortality in a unique community-dwelling cohort of older people. 991 non-diabetic subjects from the Toledo Study of Healthy Ageing (TSHA) cohort were included. IR was estimated by the homeostasis model assessment index (HOMA-IR) at baseline while frailty was determined by frailty phenotype (FP) and Frailty Trait Scale (FTS) at baseline and after 5-year follow-up. Deaths were also determined. Multivariate regression models were used to analyze the effects of HOMA-IR on outcomes. Age, gender, BMI, education level, cardio- and cerebro-vascular disease, glomerular filtration rate, and disability were included as potential confounding variables in progressive adjustment models. IR determined as increasing log HOMA-IR was inversely associated with risk of mortality. The association remained significant for all adjustment models (HR: 0.64-0.69). When we analyzed survival curves, the higher the HOMA-IR tertile, the lower the mortality rate (highest vs lowest tertile, p = 0.0082). In contrast, IR increased the risk of incident frailty determined by FP (OR 1.81 [1.14-2.87]) as well as deterioration of frailty status determined by worsening in FTS score (OR 1.28 [1.01-1.63]) at 5-year follow-up. In non-diabetic older subjects, IR significantly increases the risk for frailty and functional decline but decreased the risk of death at 5-year follow-up. This finding raises the need of assessing the effect of biomarkers on different outcomes before establishing their role as biomarkers of aging.

Advanced Age and Chronic Kidney Disease Modify the Association Between Metabolic Syndrome and Frailty Among Community-Dwelling Elderly

Metabolic syndrome (MetS) predisposes older adults to the development of frailty. However, previous studies have not explored factors that may influence the association between MetS and the risk of frailty in this population. Community-dwelling older adults (≥65 years of age) were prospectively identified and enrolled between 2013 and 2016. MetS and frailty were defined based on the American Association of Clinical Endocrinologists and Study of Osteoporotic Fractures criteria, respectively. Multiple logistic regression with frailty/prefrailty as the dependent variable was used to examine the relationship between MetS and frailty/prefrailty, supplemented by subgroup analyses of the influence of aging and chronic kidney disease (CKD). Among 2862 elderly (73.4 ± 6.7 years), 17.5% and 17.3%, respectively, had MetS and frailty/prefrailty, among whom 74 (2.6%) and 420 (14.7%) had frailty and prefrailty. The presence of MetS (odds ratio [OR] 2.53, p < 0.001), higher age (OR 1.05, p < 0.001), and CKD (OR 1.42, p = 0.006) were associated with a significantly higher risk of frailty/prefrailty. Furthermore, among those ≥80 years of age, the association between MetS and frailty/prefrailty disappeared (p = 0.329). Among those with CKD, the presence of MetS was significantly associated with a progressively higher risk of frailty/prefrailty (for stage 3 or higher and for stage 3b or higher, OR 6.4 and 12.4, p < 0.001 and = 0.009, respectively). In conclusion, aging and CKD modified the association between MetS and frailty. These findings may assist in devising case-specific care plans for elderly with MetS by refocusing our attention on those at high risk of developing frailty/prefrailty.

The Longitudinal Aging Study Amsterdam: cohort update 2019 and additional data collections

The Longitudinal Aging Study Amsterdam (LASA) is a prospective cohort study of older adults in the Netherlands, initially based on a nationally representative sample of people aged 55-84 years. The study has been ongoing since 1992, and focuses on the determinants, trajectories and consequences of physical, cognitive, emotional and social functioning. Strengths of the LASA study include its multidisciplinary character, the availability of over 25 years of follow-up, and the cohort-sequential design that allows investigations of longitudinal changes, cohort differences and time trends in functioning. The findings from LASA have been reported in over 600 publications so far (see www.lasa-vu.nl). This article provides an update of the design of the LASA study and its methods, on the basis of recent developments. We describe additional data collections, such as additional nine-monthly measurements in-between the regular three-yearly waves that have been conducted among the oldest old during 2016-2019, and the inclusion of a cohort of older Turkish and Moroccan migrants.

A new physical-cognitive scale for assessment of frailty in Chinese Han elderly

Objective: To develop a physical- cognitive scale for assessment of frailty and compare the clinical features between the new scale and the conventional Fried criteria. Methods: 1757 individuals aged 70-84 were analyzed. Participants reporting three or more Fried phenotypes were grouped as frail patients (FP) whereas others as non-frail (NF). A score of Hasegawa's dementia scale (HDS-R) higher than 21.5 were classified as non-cognitive impairment group (NCI) group. By combining the cognitive and frailty criteria, participants manifesting three or more positive components out of the six were categorized into the Physical-cognitive frailty group (Pc-F) while others into non- Pc-F (Pc-NF). Results: Of all the participants, 46.7% (820) were males and 53.3% (937) were females. The mean age was 75.33 ± 3.90. 10.1% (178/1757) were evaluated as FP patients. The prevalence of CI was 53.2%; CI was much higher in the frail group (77.0%) than in the non-frail group (50.5%). Based on the new Pc-F scale, 163 out of 1579 NF participants were identified as Pc-F, and the prevalence of Pc-F reached 19.4% (341/1757). In the Pc-F group, there are more females, patients of advanced age, diabetes, stroke, CHD, CKD, metabolic syndrome, and high hs-CRP. Within the Pc-F group, patients with CI showed a higher incidence of exhaustion, low activity, weakness, and slowness than those without CI. Conclusions: Our study revealed a significantly worse status in frail participants with CI than without. Our new scale shows a stronger correlation between frailty and complications than the classic phenotype.

Frailty as a Predictor of All-Cause Mortality Among Older Nursing Home Residents: A Systematic Review and Meta-analysis

OBJECTIVES

We performed a meta-analysis based on prospective cohort studies to synthesize the pooled risk effect and to determine whether frailty is a predictor of all-cause mortality.

DESIGN

Systematic review and meta-analysis.

SETTING

PubMed, EMBASE, and the Cochrane Library were systematically searched in October 2018. A random effects model was applied to combine the results according to the heterogeneity of the included studies.

PARTICIPANTS

Older nursing home residents.

MEASUREMENTS

Mortality risk due to frailty.

RESULTS

Fourteen studies (9076 participants) were included in this meta-analysis. Pooled results demonstrated that nursing home residents with frailty were at an increased risk of mortality [pooled hazards ratio (HR) = 1.88, 95% confidence interval (CI) = 1.57, 2.25, I² = 47.8%, P < .001] compared to those without frailty. Results of subgroup analyses showed that frailty was significantly associated with the risk of mortality among older nursing home residents when using FRAIL-NH (pooled HR = 2.10, 95% CI = 1.60-2.77, P < .001) and Frailty Index (pooled HR = 1.74, 95% CI = 1.40-2.18, P < .001) to define frail people, whereas when using the diagnosis criteria of CSHA-CFS for frailty, the pooled HR was 2.82 (95% CI = 0.79-10.10, P = .111). In addition, the subgroup analysis for length of follow-up showed that studies with a follow-up period of 1 year or more (pooled HR = 1.83, 95% CI = 1.52, 2.21, P < .001) reported a significantly higher rate of mortality among individuals with frailty, compared to those without frailty. Similar results were also found in studies with a follow-up period of less than 1 year (pooled HR = 2.67, 95% CI = 1.43, 5.00, P = .002).

CONCLUSIONS AND IMPLICATIONS

Frailty is a significant predictor of all-cause mortality in older nursing home residents. Therefore, there is an urgent need to screen for frailty in nursing home residents and carry out appropriate multidisciplinary intervention strategies to prevent poor outcomes and reduce the rate of mortality among older nursing home residents.

Disability, quality of life and all-cause mortality in older Mexican adults: association with multimorbidity and frailty

BACKGROUND

Multimorbidity and frailty are relevant conditions among older adult population. There is growing evidence about their association with poor health outcomes like disability, worst quality of life, and death. Nonetheless, the independent associations of both conditions have been studied, and few evidence exists about an interaction between them. Our aims were to assess the association of frailty and multimorbidity with the disability, quality of life and all-cause mortality as well as to analyze a potential interaction between these conditions.

METHODS

Analytical samples included 1410 respondents for disability and quality of life, and 1792 for mortality. We performed a longitudinal analysis with older Mexican adults aged 50, using data collected from the WHO's Study on global AGEing and Adult Health Waves 1 and 2. Disability was measured using the World Health Organization Disability Assessment Schedule (WHODAS 2.0), and quality of life using the WHOQOL (WHO Quality of Life) instrument. All-cause mortality was determined by reviewing death certificates. Associations of frailty and multimorbidity with disability, quality of life and mortality were estimated using linear regression and Cox proportional hazards models.

RESULTS

Multimorbidity assessed through three patterns (cardiopulmonary, vascular-metabolic, and mental-musculoskeletal) was associated with the three outcomes in this study. Cardiopulmonary and mental-musculoskeletal patterns increased the WHODAS mean score (β = 5.05; p < 0.01 and β = 5.10; p < 0.01, respectively) and decreased WHOQOL score (β = - 1.81; p < 0.01 and β = - 2.99; p < 0.01, respectively). Vascular-metabolic was associated with mortality (HR = 1.47; p = 0.04), disability (β = 3.27; p < 0.01) and quality of life (β = - 1.30; p = 0.02). Frailty was associated with mortality (pre-frail: HR = 1.48; p = 0.02 and frail: HR = 1.68; p = 0.03), disability (pre-frail: β = 5.02; p < 0.01; frail: β = 13.29; p < 0.01) and quality of life (pre-frail: β = - 2.23; p < 0.01; frail: β = - 4.38; p < 0.01). Interaction terms of frailty and multimorbidity were not statistically significant.

CONCLUSIONS

Multimorbidity and frailty are important predictors of poor health outcomes. These results highlight the importance of carrying out health promotion and prevention actions as well as specific interventions aimed at older adults who suffer from multimorbidity and frailty, in such a way that deleterious effects on health can be avoided.

Frailty and the endocrine system

Frailty is a condition characterised by loss of biological reserves, failure of homoeostatic mechanisms, and vulnerability to adverse outcomes. The endocrine system is considered particularly important in frailty, because of its complex inter-relationships with the brain, immune system, and skeletal muscle. This Review summarises evidence indicating a key role for the hypothalamic-pituitary axis in the pathogenesis of frailty through aberrant regulation of glucocorticoid secretion, insulin-like growth factor signalling, and androgen production. Evidence also indicates a potential role for vitamin D and insulin resistance in the pathogenesis of frailty. The role of thyroid hormones in the pathogenesis of frailty remains uncertain. Key convergent pathological effects of frailty include loss of muscle mass and strength, with consequent impact on mobility and activities of daily living. Future translational research should focus on the understanding of endocrine mechanisms, to identify potential biomarkers of the condition, modifiable targets for treatment, and novel pharmacological drugs targeted at the endocrine components of frailty.

Association of metabolic syndrome and its components with all-cause and cardiovascular mortality in the elderly: A meta-analysis of prospective cohort studies

There is increasing evidence regarding the relationship between metabolic syndrome and mortality. However, previous research examining metabolic syndrome and mortality in older populations has produced mixed results. In addition, there is a clear need to identify and manage individual components of metabolic syndrome to decrease cardiovascular disease (CVD) mortality. In this meta-analysis, we searched the MEDLINE databases using PubMed, Cochrane Library, and EMBASE databases. Based on 20 prospective cohort studies, metabolic syndrome was associated with a higher risk of all-cause mortality [relative risk (RR), 1.23; 95% confidence interval (CI), 1.15-1.32; I = 55.9%] and CVD mortality (RR, 1.24; 95% CI, 1.11-1.39; I = 58.1%). The risk estimates of all-cause mortality for single components of metabolic syndrome were significant for higher values of waist circumference or body mass index (RR, 0.94; 95% CI, 0.88-1.00), higher values of blood glucose (RR, 1.19; 95% CI, 1.05-1.34), and lower values of high-density lipoprotein (HDL) cholesterol (RR, 1.11; 95% CI, 1.02-1.21). In the elderly population, metabolic syndrome was associated with an increased risk of all-cause and CVD mortality. Among the individual components of metabolic syndrome, increased blood glucose and HDL cholesterol levels were significantly associated with increased mortality. However, older obese or overweight individuals may have a decreased mortality risk. Thus, the findings of the current meta-analysis raise questions about the utility of the definition of metabolic syndrome in predicting all-cause mortality and CVD mortality in the elderly population.