Graded association between kidney function and impaired orthostatic blood pressure stabilization in older adults

Background- impaired orthostatic blood pressure (bp) stabilization is highly prevalent in older adults and is a predictor of endorgan injury,falls,and mortality. we sought to characterize the relationship between postural bp responses and the kidney. methods and results- we performed a cross-sectional analysis of 4204 participants from the irish longitudinal study on ageing,a national cohort of community-dwelling adults aged ≥50 years. beat-to-beat systolic and diastolic bp were measured during a 2-minute active stand test. the primary predictor was cystatin c estimated glomerular filtration rate (egfr) categorized as follows (ml/min per 1.73 m2): ≥90 (reference,n=1414); 75 to 89 (n=1379); 60 to 74 (n=942); 45 to 59 (n=337); < 45 (n=132). we examined the association between egfr categories and (1) sustained orthostatic hypotension,defined as a bp drop exceeding consensus thresholds (systolic bp drop ≥20 mm hg±diastolic bp drop ≥10 mm hg) at each 10-second interval from 60 to 110 seconds inclusive; (2) pattern of bp stabilization,characterized as the difference from baseline in mean systolic bp/diastolic bp at 10-second intervals. the mean age of subjects was 61.6 years; 47% of subjects were male,and the median egfr was 82 ml/min per 1.73 m2. after multivariable adjustment,participants with egfr < 60 ml/min per 1.73 m2 were approximately twice as likely to have sustained orthostatic hypotension (p=0.008 for trend across egfr categories). we observed a graded association between egfr categories and impaired orthostatic bp stabilization,particularly within the first minute of standing. conclusions- we report a novel,graded relationship between diminished egfr and impaired orthostatic bp stabilization. mapping the postural bp response merits further study in kidney disease as a potential means of identifying those at risk of hypotensionrelated events. © 2017 the authors.