The functional consequences of the age-associated decline in IGF-I are unknown. We hypothesized that low IGF-I levels in older women would be associated with poor muscle strength and mobility. We assessed this question in a population representative of the full spectrum of health in the community, obtaining serum IGF-I levels from women aged 70–79 yr, enrolled in the Women's Health and Aging Study I or II. Cross-sectional analyses were performed using 617 women with IGF-I levels drawn within 90 d of measurement of outcomes. After adjustment for age, there was an association between IGF-I and knee extensor strength (P = 0.004), but not anthropometry or other strength measures. We found a positive relationship between IGF-I levels and walking speed for IGF-I levels below 50 μg/liter (P < 0.001), but no relationship above this threshold. A decline in IGF-I level was associated with self-reported difficulty in mobility tasks. All findings were attenuated after multivariate adjustment. In summary, in a study population including frail and healthy older women, low IGF-I levels were associated with poor knee extensor muscle strength, slow walking speed, and self-reported difficulty with mobility tasks. These findings suggest a role for IGF-I in disability as well as a potential target population for interventions to raise IGF-I levels.
Background. Understanding points of onset of the frailty syndrome is vital to early identification of at-risk individuals and to targeting intervention efforts to those components that are first affected, when reversal may be most possible. This study aims to characterize natural history by which commonly used frailty criteria manifest and to assess whether the rate of progression to frailty depends on initial manifestations. Methods. The investigation was based on a 7.5-year observational study of 420 community-dwelling women aged 70–79 years who were not frail at baseline, with frailty defined as meeting ≥3 of 5 criteria: weight loss, slow walking speed, weakness, exhaustion, and low physical activity level. Results. The 7.5-year incidence of frailty was 9% among women who were nonfrail at baseline. Despite significant heterogeneity, weakness was the most common first manifestation, and occurrence of weakness, slowness, and low physical activity preceded exhaustion and weight loss in 76% of the women who were nonfrail at baseline. Women with exhaustion or weight loss as initial presenting symptoms were 3–5 times more likely to become frail than were women without any criterion (p <.05). Conclusions. Our findings suggest that weakness may serve as a warning sign of increasing vulnerability in early frailty development, and weight loss and exhaustion may help to identify women most at risk for rapid adverse progression.
Introduction: Among older adults with diabetes, cognitive dysfunction is of particular concern as it has implications for treatment adherence and diabetes self-management. The prevalence of cognitive dysfunction has not been well characterized in this population. Methods: We conducted a cross-sectional analysis of 5509 participants (1815 with diabetes) from visit 5 (2011-2013) of the ARIC Study. Diabetes was defined based on self-reported physician diagnosis, diabetes medication use, or HbA1c ≥ 6.5%. Cognitive function was measured using 8 neuropsychological tests, which were grouped into three cognitive domains representing memory, executive function, and language. Participants were categorized as having cognitive dysfunction if test scores were more than 1.5 standard deviations below age-, race-, and education-adjusted scores derived from a cognitively healthy population. We calculated crude prevalence estimates and used Poisson regression to estimate adjusted prevalence ratios (PRs), comparing cognitive dysfunction in persons with and without diabetes. We adjusted for demographic and clinical characteristics. Results: The mean age of participants was 75 years, 59% were female, 79% were white, and 33% had diabetes. In each domain, the prevalence of cognitive dysfunction among persons with diabetes ranged from 14% to 27%. Persons with diabetes were more likely than persons without diabetes to have dysfunction in multiple domains (PR = 1.29, 95% CI: 1.12, 1.49). Prevalence of cognitive dysfunction was significantly higher in persons with versus without diabetes for memory (PR=1.13, 95% CI: 1.02, 1.25), language (PR=1.24, 95% CI: 1.09, 1.45), and executive function (PR=1.10, 95% CI: 1.00, 1.22)(Figure). PRs were similar in crude models. Conclusions: The prevalence of cognitive dysfunction among older adults with diabetes is high. These results have implications for how physicians educate patients in appropriate self-management practices and for the prevention of diabetes-related complications.
Symptoms of dry eye and dry mouth are common in the elderly and are often debilitating. Previous research on small populations has been inconsistent regarding the contribution to sicca symptoms of autoimmune markers, medication use, and other factors. The objective of this study was to determine the population prevalence of symptoms of dry eye and dry mouth and to evaluate possible risk factors.This is a population-based study of 2481 individuals, aged 65 to 84 years, residing in Salisbury, Md, and identified by the Health Care Financing Medicare database. The main outcome measures included information on sicca symptoms, medical history, medication use, and joint examination results collected in a standardized manner. Autoimmune status was assessed in 1200 individuals by measuring antinuclear antibody, rheumatoid factor, and autoantibodies to the soluble nuclear antigens Ro/SS-A and La/SS-B by double immunodiffusion.Approximately 27% of the population reported dry eye or dry mouth symptoms to be present often or all the time and 4.4% reported both. The prevalence of dry mouth (but not dry eye) symptoms increased with age, female sex, and white race. No association of sicca symptoms was found with rheumatoid arthritis, smoking, alcohol consumption, reproductive hormonal status, or the presence of autoantibodies. A strong, dose-response relationship was observed between sicca symptoms and the use of certain medication classes. The proportion of the population prevalence of sicca symptoms attributable to the use of drying medications was estimated at 62% for dry eye and dry mouth and 38% for dry eye or dry mouth symptoms.Sicca symptoms are common in the elderly, and medication side effects appear to be a major underlying factor. Our results do not indicate an association between autoimmune status and sicca symptoms and do not support immunologic testing in persons with sicca symptoms in the absence of other important systemic features.
Abstract Physical resilience – rebound in relevant functioning and biomarkers following a health stressor – is hypothesized to be rooted in the level of fitness of stress-response physiology defining one’s “physiological resilience capacity” (PRC). This physiology forms a dynamical system comprising specific modules (the individual stress response systems and their underlying components) and their dynamic interactions with each other via feedback and other protocols. Such a system can be modeled using differential equations whose parameters may then define the PRC. We do not yet know how to measure these parameters directly, however. Rather, they are conceptually defined “constructs” which must be inferred using indirect measures—ideally, stimulus response data probing multiple aspects of the relevant physiology. Latent variable models are ideally suited to this setting. Two challenges for their application in studies of resilience are presented: (1) Integrating specific scientific knowledge on the dynamical systems in modeling the co-distribution of the indirect measures. (2) Synergizing such models’ advantages for construct measurement with advantages of machine learning approaches to optimize accuracy for predicting resilient outcomes by inferred PRC. Challenges and their proposed solutions are illustrated using multifaceted stimulus response data being collected in an ongoing investigation on the physiological basis of resilience to clinical stressors in older adults, the Study of Physical Resilience in agING. The work aims to produce physiologically rooted measures providing effective risk predictors for older adults facing impending stressors as well as intervention candidates by which to promote PRC in the longer term.
Predicting the clinical trajectory of individual patients hospitalized with coronavirus disease 2019 (COVID-19) is challenging but necessary to inform clinical care. The majority of COVID-19 prognostic tools use only data present upon admission and do not incorporate changes occurring after admission.
