Search

Background: Among older persons, disability is often precipitated by intervening illnesses and injuries leading to hospitalization. In the Lifestyle Interventions and Independence for Elders (LIFE) Study, a structured moderate-intensity physical activity program, compared with a health education program, was shown to significantly reduce the amount of time spent with major mobility disability (MMD) over the course of 3.5 years. We aimed to determine whether the benefit of the physical activity program in promoting independent mobility was diminished in the setting of intervening hospitalizations.Methods: We analyzed data from a single-blinded, parallel group randomized trial (ClinicalTrials.gov: NCT01072500). In this trial, 1635 sedentary persons, aged 70-89 years, who had functional limitations but were able to walk 400 m, were randomized from eight US centers between February 2010 and December 2013: 818 to physical activity (800 received intervention) and 817 to health education (805 received intervention). Intervening hospitalizations and MMD, defined as the inability to walk 400 m, were assessed every 6 months for up to 3.5 years.Results: For both the physical activity and health education groups, intervening hospitalizations were strongly associated with the initial onset of MMD and inversely associated with recovery from MMD, defined as a transition from initial MMD onset to no MMD. The benefit of the physical activity intervention did not differ significantly based on hospital exposure. For onset of MMD, the hazard ratios (HR) were 0.79 (95% confidence interval [CI] 0.58-1.1) and 0.77 (0.62-0.95) in the presence and absence of intervening hospitalizations, respectively (P-interaction, 0.903). For recovery of MMD, the magnitude of effect was modestly greater among participants who were hospitalized (HR 1.5, 95% CI 0.71-3.0) than in those who were not hospitalized (HR 1.2, 95% CI 0.88-1.7), but this difference did not achieve statistical significance (P-interaction, 0.670).Conclusions: Intervening hospitalizations had strong deleterious effects on the onset of MMD and recovery from MMD, but did not diminish the beneficial effect of the LIFE physical activity intervention in promoting independent mobility. To achieve sustained benefits over time, structured physical activity programs should be designed to accommodate acute illnesses and injuries leading to hospitalizations given their high frequency in older persons with functional limitations.Trial Registration: ClinicalTrials.gov identifier NCT01072500 . [ABSTRACT FROM AUTHOR]

Background: The Long Life Family Study (LLFS) is an international study to identify the genetic components of various healthy aging phenotypes. We hypothesized that pedigree-specific rare variants at longevity-associated genes could have a similar functional impact on healthy phenotypes.Methods: We performed custom hybridization capture sequencing to identify the functional variants in 464 candidate genes for longevity or the major diseases of aging in 615 pedigrees (4,953 individuals) from the LLFS, using a multiplexed, custom hybridization capture. Variants were analyzed individually or as a group across an entire gene for association to aging phenotypes using family based tests.Results: We found significant associations to three genes and nine single variants. Most notably, we found a novel variant significantly associated with exceptional survival in the 3' UTR OBFC1 in 13 individuals from six pedigrees. OBFC1 (chromosome 10) is involved in telomere maintenance, and falls within a linkage peak recently reported from an analysis of telomere length in LLFS families. Two different algorithms for single gene associations identified three genes with an enrichment of variation that was significantly associated with three phenotypes (GSK3B with the Healthy Aging Index, NOTCH1 with diastolic blood pressure and TP53 with serum HDL).Conclusions: Sequencing analysis of family-based associations for age-related phenotypes can identify rare or novel variants. [ABSTRACT FROM AUTHOR]

Background: Preventive services offered to older Americans are currently under-utilized despite considerable evidence regarding their health and economic benefits. Individuals with low self-efficacy in accessing these services need to be identified and provided self-efficacy enhancing interventions. Scales measuring self-efficacy in the management of chronic diseases exist, but do not cover the broad spectrum of preventive services and behaviors that can improve the health of older adults, particularly older women who are vulnerable to poorer health and lesser utilization of preventive services. This study aimed to evaluate the psychometric properties of a new preventive services use self-efficacy scale, by measuring its internal consistency reliability, assessing internal construct validity by exploring factor structure, and examining differences in self-efficacy scores according to participant characteristics.Methods: The Preventive Services Use Self-Efficacy (PRESS) Scale was developed by an expert panel at the University of Pittsburgh Center for Aging and Population Health - Prevention Research Center. It was administered to 242 women participating in an ongoing trial and the data were analyzed to assess its psychometric properties. An exploratory factor analysis with a principal axis factoring approach and orthogonal varimax rotation was used to explore the underlying structure of the items in the scale. The internal consistency of the subscales was assessed using Cronbach's alpha coefficient.Results: The exploratory factor analysis defined five self-efficacy factors (self-efficacy for exercise, communication with physicians, self-management of chronic disease, obtaining screening tests, and getting vaccinations regularly) formed by 16 items from the scale. The internal consistency of the subscales ranged from .81 to .94. Participants who accessed a preventive service had higher self-efficacy scores in the corresponding sub-scale than those who did not.Conclusions: The 16-item PRESS scale demonstrates preliminary validity and reliability in measuring self-efficacy in the use of preventive services among older women. It can potentially be used to evaluate the impact of interventions designed to improve self-efficacy in the use of preventive services in community-dwelling older women. [ABSTRACT FROM AUTHOR]

Background: Obesity is an increasingly prevalent condition among older adults, yet relatively little is known about how built environment variables may be associated with obesity in older age groups. This is particularly the case for more vulnerable older adults already showing functional limitations associated with subsequent disability. Methods: The Lifestyle Interventions and Independence for Elders (LIFE) trial dataset (n= 1600) was used to explore the associations between perceived built environment variables and baseline obesity levels. Age-stratified recursive partitioning methods were applied to identify distinct subgroups with varying obesity prevalence. Results: Among participants aged 70-78 years, four distinct subgroups, defined by combinations of perceived environment and race-ethnicity variables, were identified. The subgroups with the lowest obesity prevalence (45.5-59.4 %) consisted of participants who reported living in neighborhoods with higher residential density. Among participants aged 79-89 years, the subgroup (of three distinct subgroups identified) with the lowest obesity prevalence (19.4 %) consisted of non-African American/Black participants who reported living in neighborhoods with friends or acquaintances similar in demographic characteristics to themselves. Overall support for the partitioned subgroupings was obtained using mixed model regression analysis. Conclusions: The results suggest that, in combination with race/ethnicity, features of the perceived neighborhood built and social environments differentiated distinct groups of vulnerable older adults from different age strata that differed in obesity prevalence. Pending further verification, the results may help to inform subsequent targeting of such subgroups for further investigation. Trial registration: Clinicaltrials.gov Identifier = NCT01072500 [ABSTRACT FROM AUTHOR]

Background: Very little is known about the longitudinal changes in energy requirements in late life. The purposes of this study were to: (1) determine the energy requirements in late life and how they changed during a 7 year time-span, (2) determine whether changes in fat free mass (FFM) were related to changes in resting metabolic rate (RMR), and (3) determine the accuracy of predicted total energy expenditure (TEE) to measured TEE. Methods: TEE was assessed via doubly labeled water (DLW) technique in older adults in both 1999 (n = 302; age: 74 ± 2.9 yrs) and again in 2006 (n = 87 age: 82 ± 3.1 yrs). RMR was measured with indirect calorimetry, and body composition was assessed with dual-energy x-ray absorptiometry. Results: The energy requirements in the 9th decade of life were 2208 ± 376 kcal/d for men and 1814 ± 337 kcal/d for women. This was a significant decrease from the energy requirements in the 8th decade of life in men (2482 ± 476 kcal/d vs. 2208 ± 376 kcal/d) but not in women (1892 ± 271 kcal/d vs. 1814 ± 337 kcal/d). In addition to TEE, RMR, and activity EE (AEE) also decreased in men, but not women, while FFM decreased in both men and women. The changes in FFM were correlated with changes in RMR for men (r = 0.49, p < 0.05) but not for women (r = -0.08, ns). Measured TEE was similar to Dietary Reference Intake (DRI) predicted TEE for men (2208 ± 56 vs. 2305 ± 35 kcal/d) and women (1814 ± 42 vs. 1781 ± 20 kcal/d). However, measured TEE was different than the World Health Organization (WHO) predicted TEE in men (2208 ± 56 vs. 2915 ± 31 kcal/d (p < 0.05)) and women (1814 ± 42 vs. 2315 ± 21 kcal/d (p < 0.05)). Conclusions: TEE, RMR and AEE decreased in men, but not women, from the 8th to 9th decade of life. The DRI equation to predict TEE was comparable to measured TEE, while the WHO equation over-predicted TEE in our elderly population. [ABSTRACT FROM AUTHOR]

Background: Decreased gait speed and increased stride time, stride length, double support time, and stance time variability have consistently been associated with falling whereas step width variability has not been strongly related to falls. The purpose was to examine the linear and nonlinear associations between gait variability and fall history in older persons and to examine the influence of gait speed. Methods: Gait characteristics and fall history were obtained in 503 older adults (mean age = 79; 61% female) participating in the Cardiovascular Health Study who could ambulate independently. Gait characteristics were recorded from two trials on a 4 meter computerized walkway at the subject's self-selected walking speed. Gait variability was calculated as the coefficient of variation. The presence of a fall in the past 12 months was determined by interview. The nonlinear association between gait variability and fall history was examined using a simple three level classification derived from the distribution of the data and from literature based cut-points. Multivariate logistic regression was used to examine the association between step width variability (extreme or moderate) and fall history stratifying by gait speed (1.0 m/s) and controlling for age and gender. Results: Step length, stance time, and step time variability did not differ with respect to fall history (p > .33). Individuals with extreme step width variability (either low or high step width variability) were more likely to report a fall in the past year than individuals with moderate step width variability. In individuals who walked ≥ 1.0 m/s (n = 281), after controlling for age, gender, and gait speed, compared to individuals with moderate step width variability individuals with either low or high step width variability were more likely to have fallen in the past year (OR and 95% CI 4.38 [1.79-10.72]). The association between step width variability and fall history was not significant in individuals who walked < 1.0 m/s (n = 224). Conclusion: Extreme (either too little or too much) step width variability is associated with falls in the past year in older persons who walk at or near normal gait speed and not in older persons who walk slowly (<1.0 m/s). [ABSTRACT FROM AUTHOR]

Background: Whether physical activity can reduce cognitive frailty-a relatively new "compound" phenotype proposed in 2013-and whether the effect of physical activity differs based on levels of inflammation are unknown. Therefore, this study aimed to evaluate the effect of physical activity on cognitive frailty and whether baseline interleukin-6 (IL-6) levels modified this effect.Methods: We used data from the Lifestyle Interventions and Independence for Elders (LIFE) Study, a multicenter, single-blinded randomized trial conducted at eight US field centers between February 2010 and December 2013. The main outcome was cognitive frailty at 24 months, expressed as an ordinal variable based on the six combinations of its two components: frailty (non-frail, pre-frail, and frail) and mild cognitive impairment (yes, no). Frailty and cognition were assessed by the Study of Osteoporotic Fractures (SOF) index and the Modified Mini-Mental State Examination (3MSE) scale, respectively. Plasma IL-6 was measured at baseline. Of the 1635 original randomized sedentary participants (70-89 years), this study included 1298 participants with data on both cognitive frailty and IL-6 assessments at baseline.Results: After adjusting for field center, sex, and baseline levels of cognitive frailty, the ordinal logistic regression model revealed that participants in the physical activity group had 21% lower odds (odds ratio, 0.79; 95% confidence interval, 0.64-0.98) of worsening cognitive frailty over 24 months than those in the health education group. The effect of physical activity on cognitive frailty did not differ according to baseline IL-6 levels (P for interaction = 0.919). The results did not change after additional adjustment for IL-6 subgroups and the inverse probability of remaining in the study. Comparable results were observed according to age, sex, ethnicity/race, and short physical performance battery score (P for interaction = 0.835, 0.536, 0.934, and 0.458, respectively).Conclusions: A 24-month structured, moderate-intensity physical activity program reduced cognitive frailty compared with a health education program in sedentary older persons, and this beneficial effect did not differ according to baseline levels of inflammatory biomarker IL-6. These findings suggest that the new cognitive frailty construct is modifiable and highlight the potential of targeting cognitive frailty for promoting healthy aging.Trial Registration: Clinicaltrials.gov, NCT01072500. [ABSTRACT FROM AUTHOR]

Background: Choosing cost-effective strategies for improving the health of the public is difficult because the relative effects of different types of interventions are not well understood. The benefits of one-shot interventions may be different from the benefits of interventions that permanently change the probability of getting sick, recovering, or dying. Here, we compare the benefits of such types of public health interventions., Methods: We used multi-state life table methods to estimate the impact of five types of interventions on mortality, morbidity (years of life in fair or poor health), and years of healthy life (years in excellent, very good, or good health)., Results: A one-shot intervention that makes all the sick persons healthy at baseline would increase life expectancy by 3 months and increase years of healthy life by 6 months, in a cohort beginning at age 65. An equivalent amount of improvement can be obtained from an intervention that either decreases the probability of getting sick each year by 12%, increases the probability of a sick person recovering by 16%, decreases the probability that a sick person dies by 15%, or decreases the probability that a healthy person dies by 14%. Interventions aimed at keeping persons healthy increased longevity and years of healthy life, while decreasing morbidity and medical expenditures. Interventions focused on preventing mortality had a greater effect on longevity, but had higher future morbidity and medical expenditures. Results differed for older and younger cohorts and depended on the value to society of an additional year of sick life., Conclusion: Interventions that promote health and prevent disease performed well, but other types of intervention were sometimes better. The value to society of interventions that increase longevity but also increase morbidity needs further research. More comprehensive screening and treatment of new Medicare enrollees might improve their health and longevity without increasing future medical expenditures.