Methodological considerations in the analysis of fecal glucocorticoid metabolites in tufted capuchins (Cebus apella)

Analysis of fecal glucocorticoid (GC) metabolites has recently become the standard method to monitor adrenocortical activity in primates noninvasively. However, given variation in the production, metabolism, and excretion of GCs across species and even between sexes, there are no standard methods that are universally applicable. In particular, it is important to validate assays intended to measure GC production, test extraction and storage procedures, and consider the time course of GC metabolite excretion relative to the production and circulation of the native hormones. This study examines these four methodological aspects of fecal GC metabolite analysis in tufted capuchins (Cebus apella). Specifically, we conducted an adrenocorticotrophic hormone (ACTH) challenge on one male and one female capuchin to test the validity of four GC enzyme immunoassays (EIAs) and document the time course characterizing GC me- tabolite excretion in this species. In addition, we compare a common field-friendly technique for extracting fecal GC metabolites to an established laboratory extraction methodology and test for effects of storing “field extracts” for up to 1 yr. Results suggest that a corticosterone EIA is most sensitive to changes in GC production, provides reliable measures when extracted according to the field method, and measures GC metabolites which remain highly stable after even 12 mo of storage. Further, the time course of GC metabolite excretion is shorter than that described yet for any primate taxa. These results provide guidelines for studies of GCs in tufted capuchins, and underscore the importance of validating methods for fecal hormone analysis for each species of interest

A snapshot of the prevalence of physical activity amongst older, community dwelling people in Victoria, Australia: patterns across the 'young-old' and 'old-old'

BACKGROUND: Physical activity has a range of health benefits for older people. The aim of this study was to determine physical activity prevalence and attitudes amongst respondents to a trial screening survey. METHODS: A cross-sectional survey was conducted. Subjects were community dwelling older people aged ≥ 65 years, recruited via general practices in Victoria, Australia. Participants completed a mailed screening tool containing the Geriatric Depression Scale, the Active Australia survey and the Physical Activity Readiness Questionnaire. RESULTS: Of 330 participants, 20% were ≥ 80 years. Activity levels were similar to those reported in population studies. The proportion of participants reporting physical activity was greatest for the walking category, but decreased across categories of physical activity intensity. The oldest-old were represented at all physical activity intensity levels. Over half reported exercising at levels that, according to national criteria are, 'sufficient to attain health benefit'. A greater proportion of participants aged 85 years and older were unaware of key physical activity messages, compared to participants aged less than 85 years. CONCLUSION: Most population surveys do not provide details of older people across age categories. This survey provided information on the physical activity of people up to 91 years old. Physical activity promotion strategies should be tailored according to the individual's needs. A better understanding of the determinants of physical activity behaviour amongst older sub-groups is needed to tailor and target physical activity promotion strategies and programs to maximise physical activity related health outcomes for older people