Graded Association Between Kidney Function and Impaired Orthostatic Blood Pressure Stabilization in Older Adults

• Published in: Journal of the American Heart Association Vol. 6; no. 5
• Main Authors: Canney, Mark, O'Connell, Matthew D. L., Sexton, Donal J., O'Leary, Neil, Kenny, Rose Anne, Little, Mark A., O'Seaghdha, Conall M.
• Format: Journal Article
• Language: English
• Published: England John Wiley and Sons Inc 01.05.2017; Wiley
• Subjects: Age Factors; Aged; Biomarkers - blood; Blood Pressure; blood pressure measurement/monitoring; Chi-Square Distribution; cystatin C; Cystatin C - blood; Female; Glomerular Filtration Rate; Humans; hypotension; Hypotension, Orthostatic - diagnosis; Hypotension, Orthostatic - epidemiology; Hypotension, Orthostatic - physiopathology; Ireland - epidemiology; kidney; Kidney - physiopathology; Linear Models; Logistic Models; low blood pressure; Male; Middle Aged; Multivariate Analysis; Odds Ratio; Original Research; orthostatic hypotension; Posture; Risk Factors; Time Factors; hypotension; cystatin C; kidney; orthostatic hypotension; glomerular filtration rate; blood pressure measurement/monitoring; low blood pressure
• ISSN: 2047-9980; 2047-9980
• DOI: 10.1161/JAHA.117.005661

Background Impaired orthostatic blood pressure (BP) stabilization is highly prevalent in older adults and is a predictor of end‐organ 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 hypotension‐related events.