Orthostatic change in systolic blood pressure associated with cold pressor reflection and heart rate variability in the elderly

Abstract

ABSTRACTBackground: Impaired orthostatic blood pressure (BP) response is a frequent finding in the elderly. The goal of the study was to investigate the association of variability of supine-to-orthostatic BP with cold pressor reflection and heart rate variability in the elderly.Methods: From June 2010 to September 2013, 287 elderly aged ≥ 60 years were enrolled in Jinan area, China. The elderly were classified into lower (n = 96), intermediate (n = 95), and higher (n = 96) tertile groups according to the tertile of the percentage change of supine-to-orthostatic systolic BP.Results: There were significant increasing trends in systolic BP response to the CPT at 0 and 60 sec; the plasma levels of epinephrine, norepinephrine, and angiotensin II; and decreasing trends in DNN, SDNN index, and SDANN from the lower to the higher tertile group, and differences between any two groups were significant (P < .05). The percentage change of supine-to-orthostatic systolic BP was positively correlated with systolic BP response to CPT at 0 and 60 sec, VLF, epinephrine, norepinephrine, and angiotensin II (P < .001) and negatively correlated with SDNN, SDNN index, SDANN, rMSSD, pNN50, LF, and ratio of LF/HF (P < .001). The BP response to CPT, parameters of HRV, and the plasma levels of norepinephrine and angiotensin II were independently associated with the percentage change of supine-to-orthostatic systolic BP after adjustment for confounders.Conclusion: Aggressive variability of supine-to-orthostatic systolic BP might be significantly associated with the imbalance of sympathetic and parasympathetic activity, especially high sensitivity sympathetic response in the elderly.Abbreviations: BP: blood pressure; BMI: body mass index; CPT: cold pressor test; HRV: heart rate variability; SDNN: standard deviation of all normal-to-normal R-R intervals; SDNN index: mean of the standard deviations of all 5-min normal-to-normal R-R intervals of the entire recording; SDANN: standard deviation of the averages of normal-to-normal R-R intervals during all 5-min periods of the entire recording; rMSSD: square root of the mean squared differences between successive normal R-R intervals; pNN50: number of adjacent normal R-R intervals differing by more than 50 ms; VLF: very low frequency; LF: low frequency; HF: high frequency; TCHO: total cholesterol; HDL-c: high-density lipoprotein cholesterol; LDL-c: low-density lipoprotein cholesterol; FPG: fasting plasma glucose; SD: standard deviation.