Effect of Short-Term Cold Exposure on Central Aortic Blood Pressure in Patients with CKD

Abstract

Objectives: Study determined effects of arterial hypertension and impaired kidney function on acute cold exposure induced changes in peripheral and central aortic blood pressure (BP). Methods: Five-six subjects were divided into 3 groups including 20 hypertensive patients with normal kidney function (AH-non-CKD), 20 patients with hypertension and CKD (AH-CKD) stage 3b–4 and 16 healthy normotensive subjects (C). Baseline BP, central BP, and central pulse pressure, unadjusted augmentation index (AI) and central augmented pressure were assessed by applanation tonometry (SphygmoCor) before entering the room with constant temperature −10°C (°C), after 10 min in the cold room and in same conditions in room temperature. Results: Cold exposure led to significant increase of central aortic, systolic, and diastolic BP in both AH-non-CKD (p < 0.01) and AH-CKD (p < 0.001). The central aortic BP did not change in healthy subjects. The increase of central aortic systolic blood pressure was significantly larger in AH-CKD compared to AH-non-CKD group (p = 0.0002). Increase of aortic central and brachial systolic and diastolic BP was significantly larger in AH-CKD and AH-non-CKD patients than in controls. AI increased and subendocardial viability ratio and heart rate decreased after cold exposure in all groups. Central aortic and brachial rate pressure product increased by approximately 2,300 bpm × mm Hg (p < 0.001) and 1,600 bpm × mm Hg (p < 0.001), respectively, in the AH-CKD group and by 1,000 bpm × mm Hg (p = 0.007) and 500 bpm × mm Hg (p = 0.19) in AH-non-CKD group after cold exposure. Conclusion: Short-term cold exposure induces larger increase of brachial and central aortic BP in patients with arterial hypertension than in healthy subjects. The changes in central aortic pressure are augmented in hypertensive patients with impaired kidney function.