Neck Circumference Cut-Off Points for Identifying Adiposity: Association with Chronic Metabolic Diseases in Older People.

BACKGROUND: The leading cause of death in older people is cardiovascular diseases. Several studies have found that neck circumference (NC) is a simple anthropometric marker associated with adiposity. The aim of this study is to estimate and validate NC cut-off points as adiposity markers and analyze their association with cardiovascular and chronic metabolic diseases in older people. METHODS: A cross-sectional study in 358 non-disabled, community-dwelling older people (71.7 ± 3.9 years) living in Santiago de Chile and participating in the HTSMayor study was conducted. Measurements of body composition and cardiovascular risks were evaluated. Receiver operating characteristic (ROC) curves and multiple logistic regression models were used to evaluate the association of NC with cardiovascular and chronic metabolic diseases. NC cut-off points were obtained to predict obesity, abdominal obesity, and adiposity. RESULTS: The best performance values of neck circumference relative to obesity and adiposity were obtained with respect to abdominal obesity (40.6 cm in men and 34.2 cm in women). Higher NC values were associated with a higher area under the curve (AUC) for men and women (men: AUC = 0.84; women: AUC = 0.86). NC was significantly associated with a higher risk for diabetes mellitus (OR = 1.95), hypertension (OR = 2.42), acute myocardial infarction (OR = 4.36), and comorbidities (OR = 2.01), and a lower risk for sarcopenia (OR = 0.35). CONCLUSIONS: This study shows that NC is a useful tool for detecting abdominal obesity, obesity, and adiposity in older people and that a higher NC increases the risk of chronic diseases.

Social relationships and their association with the functional capacity of older Chilean adults: longitudinal evidence.

BACKGROUND: Functional capacity is recognized as a central factor for health in old age and not all studies that seek to clarify the role of social relationships in functional capacity are conclusive. The subject has only been studied in a limited way in Latin America, a region that is aging prematurely, with evidence primarily from developed countries, which have experienced a more gradual aging of their population. This longitudinal study aimed to determine how aspects of social relationships impact the functionality of older Chileans. METHODOLOGY: We conducted a cohort study of 2,265 people aged 60 years or older who lived in the community and resided in Greater Santiago, Chile. Five aspects of social relationships were considered at baseline (participation in groups, clubs, or organizations; number of people in the household; participation in recreational activities; perception of material support, help or advice, and marital status), from which a cluster analysis by conglomerate was performed and used as the exposure of interest. Functional limitation (FL) was the dependent variable, classified as a limitation in at least 1 basic activity of daily living or 1 instrumental activity or 2 advanced activities. The control variables considered were: sex, age, educational level, multimorbidity, depression and years of follow-up. Survival analyses using a Cox proportional hazard regression and multilevel logistic regressions (person level and follow-up wave level) were performed. RESULTS: The identified clusters were four: "without social participation and does not live alone"; "without a partner and without social participation"; "no perception of support and no social participation"; "with participation, partner and perception of support". Social relationship clusters predicted FL incidence and FL reporting during follow-up. Being in the clusters "without social participation and does not live alone" and "without partner and without social participation" were risk factors for incident FL and report of FL during follow-up, compared to being in the reference cluster "with participation, partner and perception of support. CONCLUSIONS: In summary, our study showed that participating in social organizations, not living alone and having a partner are protective factors for presenting and developing functional limitation in old age for community-living Chileans in an urban area.

Self-Reported Sleep Duration Is a Useful Tool to Predict Sarcopenia in Chilean Older Adults: Evidence from the ALEXANDROS Longitudinal Study.

Age-related sleep disorders share common pathways with sarcopenia. Prospective data from Latin American populations are scarce, and the association between sleep disorders and sarcopenia in Chileans remains unknown. Thus, we aimed to study the longitudinal association between sleep disorders and sarcopenia in a cohort study of 1116 community-dwelling Chilean older people ≥60 years old from the ALEXANDROS cohorts. After the exclusion criteria, 318 subjects were followed. Sociodemographic data, self-reported chronic diseases, sedentarism, sleep characteristics, anthropometric measurements, handgrip strength, and muscle performance were assessed. Results indicated that at baseline, the prevalence of sarcopenia was 24.10% without gender differences, and the prevalence of self-reported sleep problems was 23.3%, higher in women (26.46% versus 17.15% in men). The adjusted Cox regression models for sarcopenia showed an association between sarcopenia, sleep disorders (HR = 2.08, 95% IC 1.14-3.80), and long sleep duration (HR = 2.42, 95% IC 1.20-4.91). After 8.24 years of follow-up, there were 2.2 cases of sarcopenia per 100 person-years. This study demonstrates that sleep disorders are an independent risk factor for sarcopenia in Chilean older people. The identification of sleep disorders through self-reported data provides an opportunity for early identification of risk and cost-effective sarcopenia prevention.

Decreased mitochondrial respiration associates with frailty in community-dwelling older adults.

Aging population has led to an increased prevalence of chronic and degenerative pathologies. A manifestation of unhealthy aging is frailty, a geriatric syndrome that implies a non-specific state of greater vulnerability. Currently, methods for frailty diagnosis are based exclusively on clinical observation. The aim of this study is to determine whether the bioenergetic capacity defined as mitochondrial oxygen consumption rate (OCR) of peripheral circulation mononuclear cells (PBMC) associates with the frailty phenotype in older adults and with their nutritional status. This is a cross-sectional analytic study of 58 participants 70 years and older, 18 frail and 40 non-frail adults, from the ALEXANDROS cohort study, previously described. Participants were characterized through sociodemographic and anthropometric assessments. Frail individuals displayed a higher frequency of osteoporosis and depression. The mean age of the participants was 80.2 ± 5.2 years, similar in both groups of men and women. Regarding the nutritional status defined as the body mass index, most non-frail individuals were normal or overweight, while frail participants were mostly overweight or obese. We observed that OCR was significantly decreased in frail men (p < 0.01). Age was also associated with significant differences in oxygen consumption in frail patients, with lower oxygen consumption being observed in those over 80 years of age. Therefore, the use of PBMC can result in an accessible fingerprint that may identify initial stages of frailty in a minimally invasive way.

Ethnic differences in disability-free life expectancy and disabled life expectancy in older adults in Chile.

BACKGROUND: Although about 10% of the Latin American population is indigenous, ethnic differences in disability-free life expectancy (DFLE) and life expectancy with disability (DLE) are unknown. OBJECTIVE: To estimate disability-free life expectancy and disabled life expectancy among Mapuche (the largest indigenous group) and non-indigenous older adults aged 60 years or more in Chile. METHOD: Disability was measured following a methodology that combines limitations of daily living, cognitive impairment and dependence previously validated in Chile. Finally, the DFLE was estimated using Sullivan's method combining life tables by ethnicity and disability proportions from the EDES survey designed for the study of ethnic differentials in health and longevity in Chile. RESULTS: Non-Indigenous people have a higher total and Disability-free life expectancy compared to Mapuche people at all ages. While at age 60 a Mapuche expects to live 18.9 years, of which 9.4 are disability-free, a non-Indigenous expects to live 26.4 years, of which 14 are disability-free. In addition, although the length of life with disability increases with age for both populations, Mapuche who survive to age 80 or 90 expect to live 84% and 91% of their remaining life with disability, higher proportions compared to non-indigenous people (62.9% and 75%, respectively). CONCLUSIONS: This is the first study addressing inequities in DFLE between the Mapuche and non-Indigenous population, reflected in lower total life expectancy, lower DFLE and higher DLE in Mapuche compared to the non-Indigenous population. Our results underscore the need for increased capacity to monitor mortality risks among older people, considering ethnic differences.

The first genome-wide association study in the Argentinian and Chilean populations identifies shared genetics with Europeans in Alzheimer's disease.

INTRODUCTION: Genome-wide association studies (GWAS) are fundamental for identifying loci associated with diseases. However, they require replication in other ethnicities. METHODS: We performed GWAS on sporadic Alzheimer's disease (AD) including 539 patients and 854 controls from Argentina and Chile. We combined our results with those from the European Alzheimer and Dementia Biobank (EADB) in a meta-analysis and tested their genetic risk score (GRS) performance in this admixed population. RESULTS: We detected apolipoprotein E ε4 as the single genome-wide significant signal (odds ratio  = 2.93 [2.37-3.63], P = 2.6 × 10-23 ). The meta-analysis with EADB summary statistics revealed four new loci reaching GWAS significance. Functional annotations of these loci implicated endosome/lysosomal function. Finally, the AD-GRS presented a similar performance in these populations, despite the score diminished when the Native American ancestry rose. DISCUSSION: We report the first GWAS on AD in a population from South America. It shows shared genetics modulating AD risk between the European and these admixed populations. HIGHLIGHTS: This is the first genome-wide association study on Alzheimer's disease (AD) in a population sample from Argentina and Chile. Trans-ethnic meta-analysis reveals four new loci involving lysosomal function in AD. This is the first independent replication for TREM2L, IGH-gene-cluster, and ADAM17 loci. A genetic risk score (GRS) developed in Europeans performed well in this population. The higher the Native American ancestry the lower the GRS values.

Life expectancy by ethnic origin in Chile.

Background: Ethnic and racial differences in life expectancy have been well established in different societies. However, even though an important part of the population of Latin America is Indigenous, there is little knowledge about them. Objective: Determine if there are ethnic differences in life expectancy at birth and at 60 years in Chile, and if the Mapuche (largest Indigenous ethnic group) have similar life expectancy to other Indigenous peoples. Method: Life tables for the Mapuche and other Indigenous groups and non-Indigenous people were built using the 2017 census. Specifically, we used the questions of the number of live children born and the number of surviving children. With this information, using the indirect method of own children we determined infantile mortality. Then, using the relational logit model and the model life table (west), we estimated the survival function for all ages. Results: Indigenous Chileans have seven years lower life expectancy at birth than the non-Indigenous population (76.2 vs. 83.2 years). The differential at age 60 is 6 years (20.3 vs. 26.4 years). We also found that Mapuche have an even greater disadvantage in survival than other ethnic groups. This is reflected in 2 years less life expectancy, both at birth and at 60 years. Discussion: Our results ratify the existence of marked ethnic-racial inequality in the extension of life in Chile and demonstrate a greater disadvantage in terms of survival of the Mapuche compared to other Indigenous and non-Indigenous groups. It is thus of great relevance to design policies that would decrease the existing inequalities in lifespan.

The impacts of social determinants of health and cardiometabolic factors on cognitive and functional aging in Colombian underserved populations.

Global initiatives call for further understanding of the impact of inequity on aging across underserved populations. Previous research in low- and middle-income countries (LMICs) presents limitations in assessing combined sources of inequity and outcomes (i.e., cognition and functionality). In this study, we assessed how social determinants of health (SDH), cardiometabolic factors (CMFs), and other medical/social factors predict cognition and functionality in an aging Colombian population. We ran a cross-sectional study that combined theory- (structural equation models) and data-driven (machine learning) approaches in a population-based study (N = 23,694; M = 69.8 years) to assess the best predictors of cognition and functionality. We found that a combination of SDH and CMF accurately predicted cognition and functionality, although SDH was the stronger predictor. Cognition was predicted with the highest accuracy by SDH, followed by demographics, CMF, and other factors. A combination of SDH, age, CMF, and additional physical/psychological factors were the best predictors of functional status. Results highlight the role of inequity in predicting brain health and advancing solutions to reduce the cognitive and functional decline in LMICs.

Grip Strength Trajectories and Cognition in English and Chilean Older Adults: A Cross-Cohort Study.

Growing evidence about the link between cognitive and physical decline suggests the early changes in physical functioning as a potential biomarker for cognitive impairment. Thus, we compared grip-strength trajectories over 12-16 years in three groups classified according to their cognitive status (two stable patterns, normal and impaired cognitive performance, and a declining pattern) in two representative UK and Chilean older adult samples. The samples consisted of 7069 UK (ELSA) and 1363 Chilean participants (ALEXANDROS). Linear Mixed models were performed. Adjustments included socio-demographics and health variables. The Declined and Impaired group had significantly lower grip-strength at baseline when compared to the Non-Impaired. In ELSA, the Declined and Impaired showed a faster decline in their grip strength compared to the Non-Impaired group but differences disappeared in the fully adjusted models. In ALEXANDROS, the differences were only found between the Declined and Non-Impaired and they were partially attenuated by covariates. Our study provides robust evidence of the association between grip strength and cognitive performance and how socio-economic factors might be key to understanding this association and their variability across countries. This has implications for future epidemiological research, as hand-grip strength measurements have the potential to be used as an indicator of cognitive performance.

Fuerza de prensión manual. Un sencillo, pero fuerte predictor de salud en población adulta y personas mayores / Handgrip strength as a predictor of adverse health outcomes

Muscle strength can be measured through different methods and handgrip strength is one of the most used techniques in epidemiological studies. Given its easy application, high reliability, and low cost, it is considered an important health biomarker. Handgrip strength is associated with adverse health outcomes such as mortality and risk of developing chronic diseases, cardiovascular, respiratory, cancer and dementia. There is a paucity of evidence in Chile about the association of handgrip strength with these health outcomes limiting its visibility and implementation in clinical settings. Therefore, this narrative review summarizes the scientific evidence about the association of grip strength with non-communicable chronic diseases and mortality in middle age and older adults.

Subjective Assessments of Quality of Life Are Independently Associated with Depressive Symptoms among Older Adults Enrolled in Primary Care in Chile.

In Chile, depressive symptoms are highly prevalent among Chilean older adults, and research that examines the factors associated with them is scarce. This study aimed to determine if subjective assessments of quality of life are associated with positive screen for depressive symptoms among older adults enrolled in primary care in Chile. The participants of the study were people aged 70 years or more enrolled in primary care centers in three Chilean cities. The 15-item Geriatric Depression Scale was used to determine depressive symptoms. Multivariate logistic models were used to determine the associations. Overall, 17.28% men, and 26.47% women (p = 0.003) screened positive for depression. Subjective assessments of quality of life, including self-perceived health, memory, quality of life, and pain, were associated with a positive screen for depression. Only 17.65% of men and 43.55% of women who screened positive for depressive symptoms reported a diagnosis of depression. Assessments of quality of life in health checks of older adults in primary care could contribute to narrow the diagnosis and treatment gap by improving the ability to identify those who are more likely to experience depressive symptoms.

Exploring the Association between Vitamin D and Changes in Cognitive Function in Chilean Older Adults: Evidence from the ALEXANDROS Cohort Study.

Background: The increasing aging of the population with the consequent increase of age-associated cognitive disorders pose the challenge of controlling its preventable risk factors, among which vitamin D deficit is a putative factor. Thus, our objective is to explore the association between vitamin D and cognitive performance in a cohort study of community-dwelling Chilean older people. Material and Methods: Cohort study of 955 (69.7% female), community-dwelling older Chileans free of cognitive impairment from the Alexandros cohorts, with 25(OH)D measurement at baseline. Cognitive Function was evaluated with the Mini Mental State Examination (MMSE) short-form questionnaire. Plasma levels of 25(OH)D were classified as Normal > 30 ng/mL Insufficiency 20−29 ng/mL, Deficiency 20−12 ng/mL and Severe Deficiency < 12 ng/mL. Penalized regressions models were made to assess associations. Results: Mean age of the sample was 66.6 + 4.5 years, with 8.5 + 4.7 years of education. After a mean follow-up of 9.6 years, 54 new cases of Mild Cognitive Impairment (MCI)were identified (Incidence density rate = 5.9 per 1000 person/years). Mean vitamin D plasma levels were lower in people with MCI than in the normal cognitive ones (23.0 + 12.75 vs. 28.35 + 15.17 ng/mL, p < 0.01). In the fully adjusted model only severe deficiency of vitamin D was associated with MCI (RR = 2.33; 95% CI: (1.03−5.26). Conclusions: In this longitudinal study, our results confirm that low Vitamin D is a risk factor for MCI, and that people with severe deficiency have more than double the risk of MCI people with normal Vitamin D levels. Considering the high frequency of vitamin D deficiency in older people, and its preventability, these results are very valuable for future public health programmes.

Frailty in Aging and the Search for the Optimal Biomarker: A Review.

In the context of accelerated aging of the population worldwide, frailty has emerged as one of the main risk factors that can lead to loss of self-sufficiency in older people. This syndrome is defined as a reduced state of physiological reserve and functional capacity. The main diagnostic tools for frailty are based on scales that show deficits compared to their clinical application, such as the Fried frailty phenotype, among others. In this context, it is important to have one or more biomarkers with clinical applicability that can objectively and precisely determine the degree or risk of frailty in older people. The objective of this review was to analyze the biomarkers associated with frailty, classified according to the pathophysiological components of this syndrome (inflammation, coagulation, antioxidants, and liver function, among others). The evidence demonstrates that biomarkers associated with inflammation, oxidative stress, skeletal/cardiac muscle function, and platelet function represent the most promising markers of frailty due to their pathophysiological association with this syndrome. To a lesser extent but with the possibility of greater innovation, biomarkers associated with growth factors, vitamins, amino acids, and miRNAs represent alternatives as markers of this geriatric syndrome. Likewise, the incorporation of artificial intelligence represents an interesting approach to strengthening the diagnosis of frailty by biomarkers.

Characterization by Gender of Frailty Syndrome in Elderly People according to Frail Trait Scale and Fried Frailty Phenotype.

Background: Frailty has emerged as one of the main geriatric syndromes to be prevented in order to improve quality of health and life in the elderly. In this sense, the characterization of this syndrome through reliable and feasible diagnostic tools for clinical use, such as the Frail Trait Scale 5 (FTS-5) and Frail Trait Scale 3 (FTS-3), represents the basis for this objective. Objectives: To characterize the frailty syndrome in a population of older adults using FTS-5, FTS-3, and Fried phenotype (FP) as frailty diagnostic tools. Design: Cross-sectional study. Participants: 300 adults ≥65 years recruited from different Family Health Centers and community groups of older people in Talca, Chile. Methods: The diagnosis of frailty was made according to FP, FTS-5, and FTS-3 tools. Data about sociodemographic characteristics and anthropometric measurements were collected by a clinical interview by a previously trained health professional. Results: A total prevalence of frailty according to the FP of 19.7% was observed; while in the group of women and men it was 21.4% and 15.0%, respectively. Concerning the FTS-5 tool, the total prevalence of frailty was 18%, while in the group of women and men was 18.0% and 17.5%, respectively. The FTS-3 tool shows a total prevalence of frailty of 23.3%, while in the group of women and men a prevalence of 22.7% and 25.0%, respectively. A significant difference is observed with respect to the presence of the Fried criteria of "weakness" (women: 21.4%, men: 38.8%) and "weight loss" (women: 16.8%, men: 7.5%; p < 0.05). A significant difference is observed concerning the average score of "Handgrip" criteria, "walking time", and "Physical Activity Scale for the Elderly" (PASE) between the group of women and men. Frailty, diagnosed by FTS-3, is significantly associated with the risk factors of overweight (body mass index ≥ 25) (OR: 10.225, 95% CI: 1.297−80.617) and advanced age (age ≥ 75 years) (OR: 1.839, 95% CI: 1.040−3.250). Conclusion: The prevalence of frailty observed with the FTS-5 (18%) and FTS-3 (23.3%) tools are similar to the prevalence observed through the FP (19.7%) and those reported in other observational studies. Considering the similar prevalence of frailty diagnosed with the three tools, FTS-3 should be a valuable tool for the screening of frailty in the community.

Social participation and 5-year all-cause mortality in older Chilean people.

We aimed to examine the degree to which social participation is associated with mortality risk in older adults in Chile. We used the Chilean National Survey on Elderly Dependency, which is linked to vital statistics, in order to obtain death records. Four proportional risk regression models were estimated. Even with controlled sociodemographic, economic, family, and health variables, older adults who participate in social activities had a 22% lower risk of death than those who do not participate. We concluded that social participation is a strong and significant protective factor for mortality in Chilean older adults. Social participation should thus be promoted from a life course perspective considering its effect on mortality in older adults who maintained an active social life.

Forecasting Healthy Life Expectancy Among Chilean Community-Dwelling Older Adults With and Without Sarcopenia.

BACKGROUND: Sarcopenia is an important risk factor for disability and dependency at old age. The prevalence of sarcopenia among the Chilean older population is high. OBJECTIVE: To estimate life expectancy, healthy life expectancy and unhealthy life expectancy among sarcopenic and non-sarcopenic older adults from Santiago, Chile. METHODS: A sample of 1,897 community-dwelling older adults aged 60 years or more, living in Santiago, was observed between 5-15 years. Disability was defined as the unhealthy state, assessed through self-reported difficulties in activities of daily living. Sarcopenia was determined via HTSMayor software. Total and marginal life expectancies were estimated using the Interpolated Markov Chain method "IMaCh". RESULTS: At 60 years, estimated life expectancy for sarcopenic and non-sarcopenic older adults was similar (22.7 and 22.5 years, respectively). The proportion of years to be lived with disability was three times greater in sarcopenic adults, compared to non-sarcopenic people. This difference was observed up to 80 years. Non-sarcopenic women had a higher proportion of years to be lived with disabilities compared to non-sarcopenic men of the same age, but this proportion was higher among sarcopenic men, compared to sarcopenic women until 70 years of age. DISCUSSION: People with sarcopenia expect to live a higher proportion of years with disabilities. Sarcopenic men until 70 years expected to live a higher proportion of years with disability, compared to sarcopenic women. Monitoring sarcopenia among older people may help to identify individuals with higher risk of disability onset. Future research should focus on disentangling the mechanisms explaining sex differences.

Dynamic relationships between body fat and circulating adipokine levels from adolescence to young adulthood: The Santiago Longitudinal Study.

BACKGROUND AND AIMS: Adipose tissue secretes adipokines such as adiponectin and leptin, playing important roles in energy metabolism. The longitudinal associations between such adipokines and body fat accumulation have not been established, especially during adolescence and young adulthood and in diverse populations. The study aims to assess the longitudinal association between body fat measured with dual X-ray absorptiometry and plasma adipokines from adolescence to young adulthood. METHODS AND RESULTS: Among Hispanic/Latino participants (N = 537) aged 16.8 (SD: 0.3) years of the Santiago Longitudinal Study, we implemented structural equation modeling to estimate the sex-specific associations between adiposity (body fat percent (BF%) and proportion of trunk fat (PTF)) and adipokines (adiponectin and leptin levels) during adolescence (16 y) and these values after 6 years of follow-up (22 y). In addition, we further investigated whether the associations differed by baseline insulin resistance (IR) status. We found evidence for associations between 16 y BF% and 22 y leptin levels (ß (SE): 0.58 (0.06) for females; 0.53 (0.05) for males), between 16 y PTF and 22 y adiponectin levels (ß (SE): -0.31 (0.06) for females; -0.18 (0.06) for males) and between 16 y adiponectin levels and 22 y BF% (ß (SE): 0.12 (0.04) for both females and males). CONCLUSION: We observed dynamic relationships between adiposity and adipokines levels from late adolescence to young adulthood in a Hispanic/Latino population further demonstrating the importance of this period of the life course in the development of obesity.

[Handgrip strength as a predictor of adverse health outcomes]. / Fuerza de prensión manual. Un sencillo, pero fuerte predictor de salud en población adulta y personas mayores.

Muscle strength can be measured through different methods and handgrip strength is one of the most used techniques in epidemiological studies. Given its easy application, high reliability, and low cost, it is considered an important health biomarker. Handgrip strength is associated with adverse health outcomes such as mortality and risk of developing chronic diseases, cardiovascular, respiratory, cancer and dementia. There is a paucity of evidence in Chile about the association of handgrip strength with these health outcomes limiting its visibility and implementation in clinical settings. Therefore, this narrative review summarizes the scientific evidence about the association of grip strength with non-communicable chronic diseases and mortality in middle age and older adults.