BACKGROUND: Previous observational studies have revealed a potentially robust bidirectional relationship between frailty and low back pain (LBP). However, the precise causal relationship remains unclear.
METHODS: To examine the potential causal association between frailty and LBP, we conducted bidirectional two-sample Mendelian randomization analysis (MR) study. Genetic data on frailty index (FI) and LBP were acquired from publicly available genome-wide association studies (GWAS). Various MR methodologies were utilized, such as inverse variance weighting (IVW), weighted median, and MR-Egger, to evaluate causality. Additionally, sensitivity analyses were conducted to evaluate the robustness of the findings.
RESULTS: Genetically predicted higher FI (IVW, odds ratio [OR] = 1.66, 95% CI 1.17-2.36, p = 4.92E-03) was associated with a higher risk of LBP. As for the reverse direction, genetic liability to LBP showed consistent associations with a higher FI (IVW, OR = 1.13, 95% CI 1.07-1.19, p = 2.67E-05). The outcomes from various MR techniques and sensitivity analyses indicate the robustness of our findings.
CONCLUSIONS: Our research findings provide additional evidence bolstering the bidirectional causal relationship between frailty and LBP.

BACKGROUND: Frailty in older people is a rising global health concern; therefore, monitoring prevalence estimates and presenting projections of future frailty are important for healthcare planning.
OBJECTIVE: To present current prevalence estimates of frailty and pre-frailty and future projections according to both dominant frailty models in a large population-based observational study including adults ≥ 70 years in Norway.
METHODS: In this population-based observational study, we included 9956 participants from the HUNT4 70 + study, conducting assessments at field stations, homes, and nursing homes. Frailty was assessed using Fried criteria and a 35-item frailty index (HUNT4-FI). Inverse probability weighting and calibration using post-stratification weights and aggregated register data for Norway according to age, sex, and education ensured representativeness, and population projection models were used to estimate future prevalence.
RESULTS: According to Fried criteria, the current prevalence rates of frailty and pre-frailty in people ≥ 70 years were 10.6% and 41.9%, respectively, and for HUNT4-FI 35.8% and 33.2%, respectively. Compared to previous European estimates we identified higher overall frailty prevalence, but lower prevalence in younger age groups. Projections suggest the number of Norwegian older adults living with frailty will close to double by 2040.
CONCLUSIONS: Frailty in older people in Norway is more prevalent than previous European estimates, emphasising the imperative for effective interventions aimed to delay and postpone frailty and ensure healthcare system sustainability in an ageing population. Future planning should consider the great heterogeneity in health and functioning within the 70 + population.

OBJECTIVE: The aim was to predict the effectiveness of using frailty, defined by the frailty index (FI), for predicting recurrent pneumonia and death in patients over 50 years and older with vascular cognitive impairment (VCI) during long-term hospitalization.
METHODS: This retrospective cohort study was conducted at a teaching hospital in western China and included VCI patients aged ≥50 years undergoing long-term hospitalization. The relevant data were collected from the electronic medical record system. The FI was based on 31 parameters and groups were defined using a cutoff value (0.2) as robust (FI < 0.2) and FRAIL (≥0.2). The definition of recurrent pneumonia was a minimum of two episodes within a year, with the symptoms, signs, and imaging results of pneumonia disappearing completely between episodes, and a minimum interval between episodes of seven days. Death was recorded by the hospital as the result of cardiac and respiratory arrest and survival was defined as the interval between hospital admission and confirmed death. Logistic regression models were used to assess the association between FI and recurrent pneumonia, while associations between FI and death were assessed by Cox proportional hazards models.
RESULTS: A total of 252 long-term hospitalized VCI patients ≥50 years old were enrolled, of whom 115 were male (45.6 %). Ninety-seven patients (38.5 %) were defined as FRAIL. The median length of stay for hospitalized patients was 37 months. Overall, 215 patients developed pneumonia during hospitalization, which occurred an average of 14.5 months after admission, while 151 (59.9 %) had recurrent pneumonia, and 155 (61.5 %) died. Of these, 143 died in the hospital and 12 died after discharge. No significant differences were seen in the incidence of recurrent pneumonia between FRAIL and robust long-term hospitalized VCI patients (FRAIL vs. robust: 66.0 % vs. 56.1 %, P = 0.121) while FRAIL patients had a higher mortality rate than robust patients (FRAIL vs. robust: 71.1 % vs. 55.5 %, P = 0.013). After further Cox regression analysis and adjustment for possible confounders found to be significant in the univariate analysis (including age, sex, smoking history, and activities of daily living (ADL) score), FRAIL patients had a higher risk of death than healthy patients (HR = 1.595, 95 % CI: 1.149-2.213). In addition, based on Model 2, confounding variables that were not statistically significant in the univariate analysis but may have had an impact on the results (including marital status, educational level, drinking history, comorbidity and rehabilitation treatment) were incorporated into Model 3 for further correction. The result remained unchanged, namely, that compared with robust patients, FRAIL patients had a higher risk of death (HR = 1.771, 95 % CI: 1.228-2.554).
CONCLUSIONS: Frailty defined by the FI was effective for predicting the risk of mortality but not that of recurrent pneumonia in long-term hospitalized VCI patients aged 50 or older.

OBJECTIVE: To investigate the association between five dietary trajectories over 21 years and frailty in Norwegian older adults.
METHODS: This study used data from three surveys of the Tromsø Study. Diet was measured using food frequency questionnaires at baseline (Tromsø4, 1994-95), after 7 years (Tromsø5, 2001) and at the end of follow-up (Tromsø7, 2015-16). Survey-specific diet scores were constructed based on the Nordic Nutrition Recommendations 2023 and group-based trajectory modelling was used to derive dietary trajectories. At follow-up, frailty was assessed with a 41-item frailty index. Linear regression analysis was performed to assess the associations between dietary trajectories and frailty, adjusted for baseline variables.
RESULTS: Among the 715 participants, 55% were women, with an average age of 54 years at baseline and 74 years at follow-up. The dietary trajectories \'moderately healthy\' and \'healthy increase\' were associated with a lower frailty index score at follow-up (β = -0.02, 95% confidence interval (CI) = -0.04, -0.002, β = -0.03, 95% CI = -0.06, -0.007), compared with the \'unhealthy\' trajectory.
CONCLUSIONS: Our findings suggest that maintaining a moderately healthy to very healthy diet from mid-life into older age is associated with a lower risk of frailty and supports the promotion of a healthy diet from adulthood to facilitate healthy ageing.

UNASSIGNED: Frailty is common among patients entering cardiac rehabilitation (CR). Frailty is associated with poor health outcomes; however, it is unclear if frailty influences achieving goals in CR.
UNASSIGNED: We report a secondary analysis of participants who were referred to an exercise and education-based CR program from 2005 to 2015. Frailty was measured by a 25-item accumulation of deficits frailty index (FI) ranging from 0 to 1; higher scores indicate higher frailty. Participants were categorized by admission frailty levels (FI scores: < 0.20, 0.20-0.29, 0.30-0.39, > 0.40). CR goals were determined with shared decision-making between CR staff and the patients. We conducted logistic regression analyses to examine the odds of goal attainment by CR completion, adjusting for age, sex, education, marital status, and referring diagnosis. Analyses were performed using baseline frailty as a categorical and continuous outcome, and frailty change as a continuous outcome in separate models.
UNASSIGNED: Of 759 eligible participants (age: 59.5 ± 9.8, 24% female), 607 (80%) participants achieved a CR goal at graduation. CR goals were categorized into similar themes: control or lose weight (n = 381, 50%), improve physical activity behaviour and fitness (n = 228, 30%), and improve cardiovascular profile (n = 150, 20%). Compared to the most severe frailty group (FI >0.40), lower levels of frailty at baseline were associated with achieving a goal at CR completion [FI < 0.20: OR = 4.733 (95% CI: 2.197, 10.194), p < .001; FI 0.20-0.29: OR = 2.116 (1.269-3.528), p = .004]. Every 1% increase in the FI was associated with a 3.5% reduction in the odds of achieving a CR goal [OR = 0.965 (0.95, 0.979), p < .001]. Participants who reduced their frailty by a minimally clinically important difference of at least 0.03 (n = 209, 27.5%) were twice as likely to achieve their CR goal [OR = 2.111 (1.262, 3.532), p = .004] than participants who increased their frailty by at least 0.03 (n = 82, 10.8%). Every 1% improvement in the FI from baseline to follow up was associated with a 2.7% increase in the likelihood of CR goal achievement [OR = 1.027 (1.005, 1.048), p = .014].
UNASSIGNED: Lower admission frailty was associated with a greater likelihood of achieving CR goals. Frailty improvements were associated with CR goal achievement, highlighting the influence of frailty on goal attainment.

UNASSIGNED: The emergence of obstructive sleep apnea (OSA) is marked by a growing trend towards younger individuals, while its developmental trajectory remains shrouded in uncertainty, accompanied by intricate prognostic implications. While frailty and sleep problems often coexist, the relationship between them remains unclear. Hence, this study aims to utilize the National Health and Nutrition Examination Survey (NHANES) database from 2005 to 2008 to analyze and explore the relationship between the level of frailty index (FI) and the risk of OSA incidence and survival outcomes.
UNASSIGNED: Specialized weighted complex survey design analysis software was employed for data analysis. Multivariate logistic regression models and restricted cubic splines (RCS) were utilized to assess the association between FI and OSA incidence in all participants. Additionally, a Cox proportional hazards model was established to estimate the association between FI and the hazard ratios (HRs) for all-cause mortality and cardiovascular disease (CVD) mortality.
UNASSIGNED: A total of 8524 participants were included in this study. Compared to the Non-frail group (FI ≤ 0.1), OSA risk increased with higher FI levels. In Model 3, adjusted for multiple covariates, the Pro-frail group (0.1 0.3) [OR = 2.32, 95 % CI (1.55, 3.48)] exhibited an average 31 %, 62 %, and 132 % increase in OSA risk, respectively. RCS results demonstrated a nonlinear dose-response relationship between OSA risk and FI levels, with an increasing trend (P = 0.004). The Cox model indicated that, except for the Pro-frail group, OSA-related mortality risk also increased with higher FI levels, with a more pronounced effect on CVD-related mortality.
UNASSIGNED: This study supports the hypothesis that FI may be associated with an increased risk of OSA, with a higher emphasis on OSA-related mortality risk in Mildly frail and Moderately/Severely frail populations.

UNASSIGNED: Frailty is a severe, common co-morbidity associated with congestive heart failure (CHF). This retrospective cohort study assesses the association between frailty and the risk of mortality in critically ill CHF patients.
UNASSIGNED: Eligible patients with CHF from the Medical Information Base for Intensive Care IV database were retrospectively analyzed. The frailty index based on laboratory tests (FI_Lab) index was calculated using 33 variables to assess frailty status. The primary outcomes were in-hospital mortality and one-year mortality. The secondary outcomes were the incidence of acute kidney injury (AKI) and the administration of renal replacement therapy (RRT) in patients with concurrent AKI. Survival disparities among the FI_Lab subgroups were estimated with Kaplan-Meier survival analysis. The association between the FI_Lab index and mortality was examined with Cox proportional risk modeling.
UNASSIGNED: A total of 3273 adult patients aged 18 years and older were enrolled in the study, with 1820 men and 1453 women included. The incidence rates of in-hospital mortality and one-year mortality rate were 0.96 per 1,000 person-days and 263.8 per 1,000 person-years, respectively. Multivariable regression analysis identified baseline FI_Lab > 0.45 as an independent risk factor predicting in-hospital mortality (odds ratio = 3.221, 95% CI 2.341-4.432, p < 0.001) and one-year mortality (hazard ratio=2.152, 95% CI: 1.730-2.678, p < 0.001). In terms of predicting mortality, adding FI_Lab to the six disease severity scores significantly improved the overall performance of the model (all p < 0.001).
UNASSIGNED: We established a positive correlation between the baseline FI_Lab and the likelihood of adverse outcomes in critical CHF patients. Given its potential as a reliable prognostic tool for such patients, further validation of FI_Lab across multiple centers is recommended for future research.

BACKGROUND: Uric acid (UA), the terminal breakdown product of purine metabolism, possesses contradictory roles, functioning both as an inflammatory mediator and as an antioxidant. Its clinical relevance, particularly in geriatric populations, remains a topic of ongoing debate. Aiming to elucidate whether circulating UA is detrimental or beneficial to human health, we investigate the association between serum UA concentrations and the frailty index-a comprehensive measure of biological aging in a nationally representative cohort of community-dwelling older adults.
METHODS: We conducted a population-based, cross-sectional study utilizing data from the Korea National Health and Nutrition Examination Survey. The sample included 4268 participants aged 65 years and above. A deficit accumulation frailty index (FI) was constructed using 38 items that assess physical, cognitive, psychological, and social domains. Based on the FI, participants were categorized into non-frail (FI ≤ 0.15), pre-frail (0.15 < FI ≤ 0.25), or frail (FI > 0.25). Serum UA levels were quantified through a colorimetric enzymatic assay.
RESULTS: After controlling for confounders such as age, sex, socioeconomic status (including income and education level), lifestyle factors (smoking status), and medical history (hypertension, diabetes, dyslipidemia, stroke, cardiovascular diseases), and body mass index, serum UA levels were observed to be significantly higher in frail participants compared with their non-frail counterparts (P < 0.001). Furthermore, serum UA concentrations demonstrated a positive correlation with the FI (P < 0.001), and the odds ratio for frailty per 1 mg/dL increase in serum UA was 1.22 (P < 0.001). Additionally, older adults in the highest quartile of UA levels exhibited a significantly higher FI and 1.66-fold increased odds of frailty compared with those in the lowest quartile (P = 0.011 and P = 0.005, respectively).
CONCLUSIONS: These findings suggest that elevated circulating UA levels may act as a pro-aging factor rather than an anti-aging one in older adults, highlighting its potential role in accelerating biological aging. The data further support the utility of serum UA as a potential blood-based biomarker for frailty in this demographic, contributing to the expanding evidence on its significance in geriatric health assessments.

BACKGROUND: Insulin resistance is linked to an increased risk of frailty, yet the comprehensive relationship between the triglyceride glucose-body mass index (TyG-BMI), which reflects weight, and frailty, remains unclear. This relationship is investigated in this study.
METHODS: Data from 9135 participants in the China Health and Retirement Longitudinal Study (2011-2020) were analysed. Baseline TyG-BMI, changes in the TyG-BMI and cumulative TyG-BMI between baseline and 2015, along with the frailty index (FI) over nine years, were calculated. Participants were grouped into different categories based on TyG-BMI changes using K-means clustering. FI trajectories were assessed using a group-based trajectory model. Logistic and Cox regression models were used to analyse the associations between the TyG-BMI and FI trajectory and frail incidence. Nonlinear relationships were explored using restricted cubic splines, and a linear mixed-effects model was used to evaluate FI development speed. Weighted quantile regression was used to identify the primary contributing factors.
RESULTS: Four classes of changes in the TyG-BMI and two FI trajectories were identified. Individuals in the third (OR = 1.25, 95% CI: 1.10-1.42) and fourth (OR = 1.83, 95% CI: 1.61-2.09) quartiles of baseline TyG-BMI, those with consistently second to highest (OR = 1.49, 95% CI: 1.32-1.70) and the highest (OR = 2.17, 95% CI: 1.84-2.56) TyG-BMI changes, and those in the third (OR = 1.20, 95% CI: 1.05-1.36) and fourth (OR = 1.94, 95% CI: 1.70-2.22) quartiles of the cumulative TyG-BMI had greater odds of experiencing a rapid FI trajectory. Higher frail risk was noted in those in the fourth quartile of baseline TyG-BMI (HR = 1.42, 95% CI: 1.28-1.58), with consistently second to highest (HR = 1.23, 95% CI: 1.12-1.34) and the highest TyG-BMI changes (HR = 1.58, 95% CI: 1.42-1.77), and those in the third (HR = 1.10, 95% CI: 1.00-1.21) and fourth quartile of cumulative TyG-BMI (HR = 1.46, 95% CI: 1.33-1.60). Participants with persistently second-lowest to the highest TyG-BMI changes (β = 0.15, 0.38 and 0.76 respectively) and those experiencing the third to fourth cumulative TyG-BMI (β = 0.25 and 0.56, respectively) demonstrated accelerated FI progression. A U-shaped association was observed between TyG-BMI levels and both rapid FI trajectory and higher frail risk, with BMI being the primary factor.
CONCLUSIONS: A higher TyG-BMI is associated with the rapid development of FI trajectory and a greater frail risk. However, excessively low TyG-BMI levels also appear to contribute to frail development. Maintaining a healthy TyG-BMI, especially a healthy BMI, may help prevent or delay the frail onset.

BACKGROUND: Exploring the association between Childhood Emotional Support (CES) and the mechanisms of aging is pivotal for understanding its potential to lessen the incidence of age-related pathologies and promote a milieu for healthy aging.
METHODS: Utilizing data from the UK Biobank comprising nearly 160,000 individuals, comprehensive analyses were conducted to explore associations between CES levels and age-related diseases, biological age and aging hallmarks. Cox proportional hazards regression models were used to investigate the relationship between CES and the risk of hospitalization for age-related diseases. Linear regression models were employed to explore the associations between CES and the frailty index (FI), Klemera-Doubal method (KDM) biological age acceleration, homeostatic dysregulation (HD), C-reactive protein (CRP), white blood cell (WBC) count, and telomere length.
RESULTS: The analyses revealed a significant association between higher CES levels and a decreased risk of hospitalization for age-related diseases in later life. After adjustments for covariates, the hazard ratio for age-related diseases was 0.87 (95 % confidence interval, 0.83-0.91, p < 0.001) in those with the highest CES level compared to those with the lowest CES level. Participants with the highest CES level exhibited lower FI scores (coefficient = -0.033, p < 0.001), reduced CRP level (coefficient = -0.097, p < 0.05) and lower WBC counts (coefficient = -0.034, p < 0.05). Stratified analyses based on genetic susceptibility further elucidated the protective role of CES against age-related diseases.
CONCLUSIONS: These findings underscore the potential of early interventions targeting CES to promote healthy aging and alleviating the burden of age-related diseases.