PP.34.31

Abstract

Objective: To correlate cognitive performance with heart rate variability (HRV) in elderly normotensives and hypertensives. Design and method: Global cognition was assessed by CAMCOG-R summation score in elderly normotensives [NTN; n = 20 (7 women); 68 ± 1yo; 131 ± 3mmHg; 66 ± 2bpm; education = 11 ± 1y] and hypertensives [HTN; n = 42 (26 women); 68 ± 1yo; 149 ± 3mmHg; 68 ± 2bpm; education = 8 ± 1y]. Executive function (EF) was assessed by an EF score (EFS) derived from CAMCOG-R and WAIS-III. The domains in these tests that showed a correlation coefficient > 0.4 and p-value < 0.01 with the EF domain of CAMCOG-R were added to create the EFS. Thus, the EFS was the arithmetic sum of EF, language expression, verbal fluency, remote memory, learning, attention, praxis and perception domains in CAMCOG-R, and the raw scores of digits, comprehension, vocabulary, codes and symbols domains in WAIS-III. Depression was assessed by Beck Depression Inventory. We continuously measured supine HR for 15 min and during a 30-min head-up tilt with Finometer. Supine (S) and orthostatic (O) autonomic modulation of HR was assessed through the ratio of spectral analysis of HRV in the low and high frequency (LF/HF) bands. The LF/HR is a non-dimensional index of the balance between the sympathetic and parasympathetic output to the heart. Results: The CAMCOG-R summation score and EFS were greater in NTN (87 ± 2 vs. 77 ± 1, p < 0.001 and 237 ± 6 vs. 189 ± 7, p < 0.001), respectively. Supine LF/HF were similar in NTN and HTN (1.5 ± 0.2 vs. 1.4 ± 0.2, p = 0.8) whereas O-LF/HF was greater in NTN (2.5 ± 0.5 vs. 1.5 ± 0.2, p = 0.04). In linear multivariable regression models controlled for sex and depression, hypertension and less education were independent adverse predictors of CAMCOG-R summation score and EFS whereas a lower O-LF/HF was an adverse predictor of EFS (Table). Conclusions: Normotensives exhibited better global cognition and executive function than hypertensives. In line with literature, we showed that both hypertension and less education are associated with lower global cognition and executive function. Notably, altered O-LF/HF does not impact global cognition but may impair executive function. Our results suggest that autonomic modulation of HR is not correlated with global cognition but may modulate executive function in elderly hypertensives.