Abstract 3942: Blood Pressure Response to Cold Pressor Predicts Salt-Sensitivity in the GenSalt Study
We examined the association between blood pressure (BP) responses to a cold pressor test and to dietary sodium and potassium interventions among 1,813 GenSalt study participants in rural China. BP was measured prior to and at 0, 60, 120, and 240 seconds after the participants immersed their hand in the ice water (3oC to 5oC) for 1 minute at baseline visits. The dietary intervention included a 7-day low sodium-feeding (51.3 mmol/day), a 7-day high sodium-feeding (307.8 mmol/day), and a 7-day oral potassium supplementation (60 mmol/day). A total of nine BPs were measured during the 3-day baseline observation and the last 3 days of each intervention phase using a random-zero sphygmomanometer. High salt-sensitivity or potassium-sensitivity was defined as BP changes in the top 30th percentile among all study participants. The BP response to cold pressor was highly significantly associated with BP changes during sodium and potassium interventions (all p<0.0001). Compared to the lowest quartile of BP responses to the cold pressor test, systolic BP changes (95% CI) during low-salt intervention were -2.02 (-2.87 to -1.16), -3.17 (-4.05 to -2.28), and -5.98 (-6.89 to -5.08) mm Hg for the top 3 quartiles, respectively. The corresponding systolic BP changes during high salt intervention were 0.40 (-0.36 to 1.16), 0.44 (-0.35 to 1.22), and 2.30 (1.50 to 3.10) mm Hg, and systolic BP changes during potassium supplementation were -0.26 (-0.99 to 0.46), -0.95 (-1.70 to -0.20), and -1.59 (-2.36 to -0.83) mm Hg, respectively. Similarly, compared to the lowest quartile of BP responses to the cold pressor test, the odds ratios (95% CI) of high salt-sensitivity were 2.23 (1.56–3.19), 3.17 (2.22–4.52), and 5.54 (3.89–7.90) during low-sodium intervention, 1.27 (0.92–1.74), 1.57 (1.14–2.16), and 2.26 (1.64–3.10), during high-sodium intervention, and 1.07 (0.78–1.45), 1.55 (1.14–2.11), and 1.56 (1.14–2.13) during potassium supplementation, for the top 3 quartiles, respectively. These results suggest that BP response to cold pressor predicts salt-sensitivity. Furthermore, BP responses to cold pressor and to dietary sodium and potassium intervention might share the same underlying physiological pathway.