Dysregulation of the hypothalamic pituitary adrenal (HPA) axis and physical performance at older ages: an individual participant meta-analysis.

"details of the cohorts are given in supplementary data 1 2 2 2 2 1 chair rising ability was assessed in hcs lasa and nshd.; we undertook a series of sensitivity analyses using: (a) the 30 min post-waking rather than mean morning cortisol level (b) salivary or serum cortisol from lasa (c) less than 5 s as the criteria for poor balance (d) maximum grip strength for the lasa cohort (e) inclusion of subjects with no data due to inability to undertake the test and (f) for hcs using the 3 m walk test rather than the tug test for walking speed (see supplementary data 2 ) 3 descriptive characteristics of the participants in the six studies are shown in table 1 .; there was weak evidence to suggest that the associations were stronger in non-obese than obese participants for morning cortisol and walking speed but this could have been due to chance ( p (heterogeneity) = 0 10) 3 3 we found little effect on the meta-analyses for a wide range of sensitivity analyses (see supplemental data 2 ) 4 the results of these meta-analyses showed that more dynamic activity of the hpa axis i e greater decline was associated with better physical performance for most of our outcomes and that there were no interactions with age gender or bmi."

"Conflict of interest The authors have no conflicts of interest to declare."

"HALCyon is funded by the New Dynamics of Ageing (RES-353-25-0001) and MG and RC are receiving support from this grant. The Boyd Orr cohort has received funding from the Medical Research Council, the World Cancer Research Fund, Research into Ageing, United Kingdom Survivors, the Economic and Social Research Council, the Wellcome Trust and the British Heart Foundation. The Boyd Orr follow-up clinics in 2002 were funded within a Wellcome Research Training Fellowship in Clinical Epidemiology to RMM (GR063779FR). The Caerphilly Prospective Study was undertaken by the former MRC Epidemiology Unit (South Wales) and the School of Social and Community Medicine, University of Bristol acts as the data custodian. The Hertfordshire Cohort Study was funded by the UK Medical Research Council, the Wellcome Trust, Arthritis Research UK and the University of Southampton. The NSHD is funded by the UK Medical Research Council. The WHII study has been supported by grants from the UK Medical Research Council; British Heart Foundation; National Heart Lung and Blood Institute and National Institute on Aging, US, NIH. The Longitudinal Aging Study Amsterdam (LASA) is financially supported by the Dutch Ministry of Public Health, Welfare and Sports. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript."