[Show abstract][Hide abstract] ABSTRACT: As the number of older adults in the United States rises, maintaining functional independence among older Americans has emerged as a major clinical and public health priority. Older people who lose mobility are less likely to remain in the community; demonstrate higher rates of morbidity, mortality, and hospitalizations; and experience a poorer quality of life. Several studies have shown that regular physical activity improves functional limitations and intermediate functional outcomes, but definitive evidence showing that major mobility disability can be prevented is lacking. A Phase 3 randomized controlled trial is needed to fill this evidence gap.
The Lifestyle Interventions and Independence for Elders (LIFE) Study is a Phase 3 multicenter randomized controlled trial designed to compare a supervised moderate-intensity physical activity program with a successful aging health education program in 1,600 sedentary older persons followed for an average of 2.7 years.
LIFE's primary outcome is major mobility disability, defined as the inability to walk 400 m. Secondary outcomes include cognitive function, serious fall injuries, persistent mobility disability, the combined outcome of major mobility disability or death, disability in activities of daily living, and cost-effectiveness.
Results of this study are expected to have important public health implications for the large and growing population of older sedentary men and women.
The Journals of Gerontology Series A Biological Sciences and Medical Sciences 08/2011; 66(11):1226-37. · 4.31 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Decreases in levels of sex hormones occur with aging. Observational studies have found associations of low testosterone concentrations in older men with adverse symptoms; however, these associations do not prove causality. Therefore, the question arises whether to treat older men whose serum testosterone is low. In 2009, the Testosterone Trial (T Trial) was funded to examine the efficacy of therapy in 800 elderly men with low testosterone levels; potentially associated symptoms; and abnormalities in physical, sexual, or cognitive function or vitality.
[Show abstract][Hide abstract] ABSTRACT: In a robust and consistent manner, sustained caloric restriction (CR) has been shown to retard the aging process in a variety of animal species. Nonhuman primate studies suggest that CR may have similar effects in longer-lived species. The CALERIE (Comprehensive Assessment of the Long-term Effects of Reducing Intake of Energy) research program is the first systematic investigation of CR in nonobese human beings. In the phase 2 study, it is hypothesized that 2 years of sustained CR, involving a 25% reduction of ad libitum energy intake, results in beneficial effects similar to those observed in animal studies. This article presents the design and implementation of this study.
The study is a multicenter, parallel-group, randomized controlled trial. A sample of 225 participants (22.0 ≤ body mass index [BMI] < 28.0 kg/m(2)) is being enrolled with 2:1 allocation to CR.
An intensive dietary and behavioral intervention was developed to achieve 25% CR and sustain it over the 2 years. Adherence is monitored using a doubly labeled water technique. Primary outcomes are resting metabolic rate and core temperature, and are assessed at baseline and at 6-month intervals. Secondary outcomes address oxyradical formation, cardiovascular risk markers, insulin sensitivity and secretion, immune function, neuroendocrine function, quality of life and cognitive function. Biologic materials are stored in a central repository.
An intricate protocol has been developed to conduct this study. Procedures have been implemented to safeguard the integrity of the data and the conclusions drawn. The results will provide insight into the detrimental changes associated with the human aging process and how CR mitigates these effects.
The Journals of Gerontology Series A Biological Sciences and Medical Sciences 10/2010; 66(1):97-108. · 4.31 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The Short Physical Performance Battery (SPPB), which includes walking, balance, and chair stands tests, independently predicts mobility disability and activities of daily living disability. To date, however, there is no definitive evidence from randomized controlled trials that SPPB scores can be improved. Our objective was to assess the effect of a comprehensive physical activity (PA) intervention on the SPPB and other physical performance measures.
A total of 424 sedentary persons at risk for disability (ages 70-89 years) were randomized to a moderate-intensity PA intervention or a successful aging (SA) health education intervention and were followed for an average of 1.2 years.
The mean baseline SPPB score on a scale of 0-12, with 12 corresponding to highest performance, was 7.5. At 6 and 12 months, the PA versus SA group adjusted SPPB (+/- standard error) scores were 8.7 +/- 0.1 versus 8.0 +/- 0.1, and 8.5 +/- 0.1 versus 7.9 +/- 0.2, respectively (p < .001). The 400-meter walking speed was also significantly improved in the PA group. The PA group had a lower incidence of major mobility disability defined as incapacity to complete a 400-meter walk (hazard ratio = 0.71, 95% confidence interval = 0.44-1.20).
A structured PA intervention improved the SPPB score and other measures of physical performance. An intervention that improves the SPPB performance may also offer benefit on more distal health outcomes, such as mobility disability.
The Journals of Gerontology Series A Biological Sciences and Medical Sciences 12/2006; 61(11):1157-65. · 4.31 Impact Factor