ASSOCIATION OF LIVER STIFFNESS BY TRANSIENT ELASTOGRAPHY WITH MOBILITY DIFFICULTY IN OLDER ADULTS WITH NO CIRRHOSIS

Growing experience with non-invasive ultrasound transient elastography (TE) offers now a major opportunity to improve understanding about the functional impact of non-advanced, asymptomatic liver dysfunction. We assessed the relationship of liver stiffness measurement (LSM) and controlled attenuation parameter (CAP) obtained by TE, surrogates for liver fibrosis and steatosis, respectively, with mobility difficulty, an early stage of the disablement process. Cross-sectional study utilizing National Health and Nutrition Examination Survey 2017-2018 data. Analytic sample (n=1,203) included participants aged 60 years and older without known cirrhosis with available LSM and CAP. Logistic regression assessed the odds of mobility difficulty (walking ¼ mile or climbing stairs) according to LSM and/or CAP, with adjustment for demographics, diseases, metabolic syndrome, body mass index, aminotransferases, gamma-glutamyl transferases, albumin, and platelets. LSM and CAP were linearly, positively associated with the probability of mobility difficulty. In the fully adjusted model, LSM, though not CAP, remained strongly associated with mobility difficulty. Those with LSM in the top (>7 kilopascals [kPa]) and intermediate quintiles (4-7 KPa) had higher odds of mobility difficulty; i.e., odds ratio (OR): 1.81; 95% confidence interval (CI): 1.15-2.86; p=0.01) and OR:1.45; 95%CI: 1.01-2.08; p=.046), respectively. LSM was independently associated with early mobility disability in older adults without known cirrhosis. A direct effect through sarcopenia promotion pathways might be speculated. Whether TE screening could be useful to identify adults with non-advanced liver fibrosis who might benefit from preventive interventions – e.g., diet and exercise for non-alcoholic fatty liver disease patients vis-à-vis mobility disability prevention remains to be tested.

Pooled Cohort Probability Score for Subclinical Airflow Obstruction

Rationale: Early detection of chronic obstructive pulmonary disease (COPD) is a public health priority. Airflow obstruction is the single most important risk factor for adverse COPD outcomes, but spirometry is not routinely recommended for screening. Objectives: To describe the burden of subclinical airflow obstruction (SAO) and to develop a probability score for SAO to inform potential detection and prevention programs. Methods: Lung function and clinical data were harmonized and pooled across nine U.S. general population cohorts. Adults with respiratory symptoms, inhaler use, or prior diagnosis of COPD or asthma were excluded. A probability score for prevalent SAO (forced expiratory volume in 1 second/forced vital capacity < 0.70) was developed via hierarchical group-lasso regularization from clinical variables in strata of sex and smoking status, and its discriminative accuracy for SAO was assessed in the pooled cohort as well as in an external validation cohort (NHANES [National Health and Nutrition Examination Survey] 2011-2012). Incident hospitalizations and deaths due to COPD (respiratory events) were defined by adjudication or administrative criteria in four of nine cohorts. Results: Of 33,546 participants (mean age 52 yr, 54% female, 44% non-Hispanic White), 4,424 (13.2%) had prevalent SAO. The incidence of respiratory events (Nat-risk = 14,024) was threefold higher in participants with SAO versus those without (152 vs. 39 events/10,000 person-years). The probability score, which was based on six commonly available variables (age, sex, race and/or ethnicity, body mass index, smoking status, and smoking pack-years) was well calibrated and showed excellent discrimination in both the testing sample (C-statistic, 0.81; 95% confidence interval [CI], 0.80-0.82) and in NHANES (C-statistic, 0.83; 95% CI, 0.80-0.86). Among participants with predicted probabilities ⩾ 15%, 3.2 would need to undergo spirometry to detect one case of SAO. Conclusions: Adults with SAO demonstrate excess respiratory hospitalization and mortality. A probability score for SAO using commonly available clinical risk factors may be suitable for targeting screening and primary prevention strategies.

SCREENING FOR LOW SHORT PHYSICAL PERFORMANCE BATTERY SCORES: CAN GRIP STRENGTH AND SINGLE CHAIR STAND BE USEFUL?

The clinical value of low Short Physical Performance Battery (SPPB) scores for identification of older adults at-disability-risk who may benefit from structured intervention is well-established. Feasibility concerns – e.g., time, space constraints – are factors that often preclude SPPB implementation in clinical settings. We assessed whether grip strength (GS) and/or single chair stand (SCS), simple and highly feasible tests, could be useful for clinical identification of older adults with poor SPPB performance. Cross-sectional study using most recent data (Round 7) from the National Health and Aging Trends Study, which enrolled a large U.S. representative sample of Medicare beneficiaries 65 years and older (baseline round: 2011; yearly follow-ups). Nursing home residents were excluded. Sample size was 4,612. Outcome: poor SPPB performance (score <8). Low GS: <20 Kg (women) or <30 Kg (men), and able to do a SCS without use of arm (yes/no) were predictors. Logistic regression, areas under the curves (AUC), and accuracy statistics were computed. AUC for low GS was 0.66, and SCS inability was 0.68; when both tests were considered together, AUC increased significantly: 0.76. Among those SCS-unable (n=752), 95.6% had SPPB<8. A two-stage screening approach; i.e., detection of SCS inability first, followed by low GS in those SCS-able resulted in a net-sensitivity of 75.3%, and net-specificity of 83.5%. Sequential screening with SCS and GS testing might offer a case finding screening approach appealing to busy clinical settings from feasibility, accuracy, and/or efficiency perspectives for identification of older adults with low SPPB who may benefit from established interventions.

Discriminative Accuracy of FEV1:FVC Thresholds for COPD-Related Hospitalization and Mortality

IMPORTANCE

According to numerous current guidelines, the diagnosis of chronic obstructive pulmonary disease (COPD) requires a ratio of the forced expiratory volume in the first second to the forced vital capacity (FEV1:FVC) of less than 0.70, yet this fixed threshold is based on expert opinion and remains controversial.

OBJECTIVE

To determine the discriminative accuracy of various FEV1:FVC fixed thresholds for predicting COPD-related hospitalization and mortality.

DESIGN, SETTING, AND PARTICIPANTS

The National Heart, Lung, and Blood Institute (NHLBI) Pooled Cohorts Study harmonized and pooled data from 4 US general population-based cohorts (Atherosclerosis Risk in Communities Study; Cardiovascular Health Study; Health, Aging, and Body Composition Study; and Multi-Ethnic Study of Atherosclerosis). Participants aged 45 to 102 years were enrolled from 1987 to 2000 and received follow-up longitudinally through 2016.

EXPOSURES

Presence of airflow obstruction, which was defined by a baseline FEV1:FVC less than a range of fixed thresholds (0.75 to 0.65) or less than the lower limit of normal as defined by Global Lung Initiative reference equations (LLN).

MAIN OUTCOMES AND MEASURES

The primary outcome was a composite of COPD hospitalization and COPD-related mortality, defined by adjudication or administrative criteria. The optimal fixed FEV1:FVC threshold was defined by the best discrimination for these COPD-related events as indexed using the Harrell C statistic from unadjusted Cox proportional hazards models. Differences in C statistics were compared with respect to less than 0.70 and less than LLN thresholds using a nonparametric approach.

RESULTS

Among 24 207 adults in the pooled cohort (mean [SD] age at enrollment, 63 [10.5] years; 12 990 [54%] women; 16 794 [69%] non-Hispanic white; 15 181 [63%] ever smokers), complete follow-up was available for 11 077 (77%) at 15 years. During a median follow-up of 15 years, 3925 participants experienced COPD-related events over 340 757 person-years of follow-up (incidence density rate, 11.5 per 1000 person-years), including 3563 COPD-related hospitalizations and 447 COPD-related deaths. With respect to discrimination of COPD-related events, the optimal fixed threshold (0.71; C statistic for optimal fixed threshold, 0.696) was not significantly different from the 0.70 threshold (difference, 0.001 [95% CI, -0.002 to 0.004]) but was more accurate than the LLN threshold (difference, 0.034 [95% CI, 0.028 to 0.041]). The 0.70 threshold provided optimal discrimination in the subgroup analysis of ever smokers and in adjusted models.

CONCLUSIONS AND RELEVANCE

Defining airflow obstruction as FEV1:FVC less than 0.70 provided discrimination of COPD-related hospitalization and mortality that was not significantly different or was more accurate than other fixed thresholds and the LLN. These results support the use of FEV1:FVC less than 0.70 to identify individuals at risk of clinically significant COPD.

Concurrent change in dehydroepiandrosterone sulfate and functional performance in the oldest old: results from the Cardiovascular Health Study All Stars study

INTRODUCTION

The correlation between dehydroepiandrosterone sulfate (DHEAS) decline and age led to the hypothesis that DHEAS might be a marker of primary aging, though conflicting data from observational studies of mortality do not support this. We evaluated concurrent DHEAS and functional decline in a very old cohort to test if DHEAS change tracks with functional change during aging.

METHODS

DHEAS and functional performance (gait speed, grip strength, Modified Mini-Mental State Examination [3MSE] score, and digit symbol substitution test [DSST] score) were measured in 1996-1997 and 2005-2006 in 989 participants in the Cardiovascular Health Study All Stars study (mean age 85.2 years in 2005-2006, 63.5% women and 16.5% African American). We used multivariable linear regression to test the association of DHEAS decline with functional decline.

RESULTS

After adjustment, each standard deviation decrease in DHEAS was associated with greater declines in gait speed (0.12 m/s, p = .01), grip strength (0.09 kg, p = .03), 3MSE score (0.13 points, p < .001), and DSST score (0.14 points, p = .001) in women only. Additional adjustment for baseline DHEAS attenuated the association with grip strength but did not alter other estimates appreciably, and baseline DHEAS was unassociated with functional decline.

CONCLUSIONS

In this cohort of very old individuals, DHEAS decline tracked with declines in gait speed, 3MSE score, and DSST score, but not grip strength, in women independent of baseline DHEAS level. DHEAS decline might be a marker for age-associated performance decline, but its relevance is specific to women.

Predicting the risk of mobility difficulty in older women with screening nomograms: the Women's Health and Aging Study II

BACKGROUND

A major obstacle to screening for early mobility disability (ie, mobility difficulty), a major public health concern, is the lack of a method that identifies those who are at high risk. The goal of this study was to develop easy-to-use clinical nomograms for estimation of the probability of incident mobility difficulty.

METHODS

We conducted a population-based prospective study using data from 266 high physically and cognitively functioning older women, aged 70 to 80 years, who were free of mobility disability at the baseline evaluation of the Women's Health and Aging Study II. The outcome measure was incident mobility disability within 18 months, defined as self-reported difficulty walking 0.8 km, climbing 10 steps, or transferring from or into a car or bus. Logistic regression and receiver operating characteristic curve analyses were used for evaluation of the optimal combination of self-reported and performance-based mobility measures. Bootstrap sampling and estimation was used for validation.

RESULTS

Predictive nomograms were developed based on a final model that included 3 simple-to-obtain measures of preclinical disability: self-report of modification in mobility tasks without having difficulty with them, one-leg stance balance, and time to walk 1 m at a usual pace. Final model accuracy (as estimated by the area under the receiver operating characteristic curve) was 73% (SE = 0.04). Validation analysis confirmed the high accuracy of these nomograms.

CONCLUSIONS

An original tool was developed for assessment of the risk of mobility difficulty in older women that can be used to assist physicians and researchers in deciding which women to target for preventive interventions.

Preclinical mobility disability predicts incident mobility disability in older women

BACKGROUND

Physical disability and dependency are serious, and frequent, adverse health outcomes associated with aging and resulting from chronic disease. Reasoning has suggested that there might be a preclinical, intermediate phase of disablement which might develop in parallel with progression of underlying disease and precede and predict disability. Definition of this stage could provide a basis for screening and early intervention to prevent disability. The objective of this study was to determine preclinical functional predictors of incident mobility difficulty and provide evidence for a preclinical stage of disability.

METHODS

A prospective, population-based cohort study was carried out in Baltimore, Maryland, with two evaluations 18 months apart. The participants were 436 community-dwelling women, 70-80 years of age at baseline, not cognitively impaired, and reporting difficulty in no areas, or only one area, of physical function (primarily mobility), who were participating in the Women's Health and Aging Study II. Participants were recruited from a population-based, age-stratified random sample. Incident mobility disability was studied in the subset without such disability at baseline. The main outcome measure was self-reported incident difficulty walking 1/2 mile or climbing up 10 steps.

RESULTS

At baseline, 69.3% of the cohort reported no difficulty with mobility. After 18 months, 16.0 and 11.7% of this group reported incident difficulty walking 1/2 mile or climbing up 10 steps, respectively. Those reporting baseline task modification due to underlying health problems, our measure of preclinical disability, were at three- to fourfold higher odds of progressing to difficulty than were those without such modification. In multivariate logistic regression analyses, this self-report measure, task modification without difficulty, and objective measures of performance were independently and jointly predictive of incident mobility difficulty. Specifically, for incident difficulty walking 1/2 mile, self-reported task modification odds ratio (OR) = 3.67, walking speed (.5 m/s difference) OR = 2.16; for incident difficulty climbing up 10 stairs, OR for task modification = 3.84, for stair climb speed (1/3 step/s difference) = 2.08 (95% CI did not include 1 for any). Covariates, age, living alone, number of chronic diseases, depression score, knee strength, and balance by functional reach, were not significant predictors in either model.

CONCLUSIONS

Two indicators of functional changes in older women without mobility difficulty, self-report of modification of method of doing a task in the absence of difficulty and performance measures, are independent and strong predictors of risk of incident mobility disability. The self-report measure provides substantial strength in predicting risk of incident disability across the full range of performance, and may identify a vulnerable point at which other risk factors act to cause transitions to disability. Together, the preclinical indicators identify a subset of high-functioning older women who are at high risk of mobility disability, and provide a potential basis for screening for disability risk and targeting interventions to prevent mobility disability.