Salivary cortisol and frailty syndrome in elderly residents of long-stay institutions: a cross-sectional study.

Analyze the relationship between frailty and cortisol in elderly residents of long-stay institutions. A cross-sectional study was conducted in the city of João Pessoa-PB-Brazil, on a sample of residents of long-stay institutions. Data were collected on frailty phenotype (weight loss, fatigue, slowness, weakness and low physical activity) and salivary cortisol (first measurement between 6 and 7a.m.; second measurement between 11 and 12a.m.; third measurement between 4 and 5p.m.). Statistical analysis applied Pearson's correlation test, Chi-square test, ANOVA and linear regression. The sample was composed of 69 elderly subjects, 37.7% men and 62.3% women, with a mean age of 77.5 (±7.8) years. The percentage of frail elderly was 45.8%. Frail aged subjects achieved higher cortisol values on the third measurement (p=0.04) and frailty load was significantly associated to the first measurement (r=0.25, p=0.04). Simple linear regression analysis showed a rate of determination (R(2)=0.05) between frailty load and the first cortisol measurement. Greater cortisol values in the morning and before bed among frail aged individuals suggest a positive correlation may exist between cortisol levels and frailty in elderly residents of long-stay institutions.