Köchli Sabrina, Schutte Aletta E, Botha-Le Roux Shani, Gafane-Matemane Lebo F, Smith Wayne, van Rooyen Johannes M, Mokwatsi Gontse G, Kruger Ruan
Hypertension in Africa Research Team (HART), North-West University, Potchefstroom, South Africa.
Hypertension in Africa Research Team (HART), North-West University, Potchefstroom, South Africa; Medical Research Council: Unit for Hypertension and Cardiovascular Disease, Faculty of Health Sciences, North-West University, Potchefstroom, South Africa; School of Population Health, University of New South Wales, The George Institute for Global Health, Sydney, Australia.
Nutr Metab Cardiovasc Dis. 2021 Apr 9;31(4):1071-1080. doi: 10.1016/j.numecd.2020.12.021. Epub 2020 Dec 24.
Heart rate variability (HRV) is a main determinant of autonomic function and related to the development of hypertension and cardiovascular (CV) disease. Hypertension develops in black populations at an earlier age, which could be due to differences in the autonomic nervous system activity and sodium/potassium handling in black and white populations. We investigated whether HRV is associated with 24 h urinary sodium and potassium excretion and blood pressure (BP) in a young bi-ethnic cohort.
We examined 423 black and 483 white healthy adults (aged 24.5 ± 3.1 years) for 24 h HRV, including standard deviation of normal RR intervals (SDNN) reflecting autonomic variations over time, and root mean square of successive differences (RMSSD) reflecting parasympathetic activity. We measured 24 h urinary sodium and potassium concentration and BP. The black group had lower SDNN and potassium excretion as well as higher RMSSD, sodium and Na/k ratio compared to the white group (all p < 0.05). Only in black individuals, urinary potassium excretion was independently and negatively associated with SDNN (β[95% CI];-0.26[-0.50;-0.02]ms) and RMSSD (-0.14[-0.27;-0.01]ms, p < 0.05). One unit increase in sodium/potassium (Na/K) ratio was associated with higher SDNN (β[95% CI]; 3.04[0.89; 5.19]ms) and RMSSD (1.60[0.41; 2.78]ms) in the black cohort only (both p < 0.001). In both groups elevated 24 h diastolic BP was associated with lower RMSSD (p < 0.05).
Lower potassium excretion and higher Na/K ratio related independently to higher HRV in young and healthy black adults. A better ethnic-specific understanding of sodium and potassium handling is required as part of preventive cardiology, especially in black individuals.
ClinicalTrials.gov Identifier: NCT03292094; URL: https://clinicaltrials.gov/ct2/show/NCT03292094.
心率变异性（HRV）是自主神经功能的主要决定因素，与高血压及心血管疾病的发生发展相关。高血压在黑人人群中发病年龄较早，这可能是由于黑人和白人在自主神经系统活动以及钠/钾代谢方面存在差异。我们在一个年轻的双种族队列中研究了HRV是否与24小时尿钠和钾排泄以及血压（BP）相关。
我们对423名黑人及483名白人健康成年人（年龄24.5±3.1岁）进行了24小时HRV检测，包括反映自主神经随时间变化的正常RR间期标准差（SDNN），以及反映副交感神经活动的相邻RR间期差值的均方根（RMSSD）。我们测量了24小时尿钠和钾浓度以及血压。与白人组相比，黑人组的SDNN和钾排泄较低，而RMSSD、钠及钠/钾比值较高（均p<0.05）。仅在黑人个体中，尿钾排泄与SDNN（β[95%CI]；-0.26[-0.50；-0.02]ms）和RMSSD（-0.14[-0.27；-0.01]ms，p<0.05）独立且呈负相关。仅在黑人队列中，钠/钾（Na/K）比值每增加一个单位与更高的SDNN（β[95%CI]；3.04[0.89；5.19]ms）和RMSSD（1.60[0.41；2.78]ms）相关（均p<0.001）。在两组中，24小时舒张压升高均与较低的RMSSD相关（p<0.05）。
在年轻健康的黑人成年人中，较低的钾排泄和较高的钠/钾比值独立地与较高的HRV相关。作为预防心脏病学的一部分，需要更好地针对不同种族了解钠和钾的代谢情况，尤其是在黑人个体中。
ClinicalTrials.gov标识符：NCT03292094；网址：https://clinicaltrials.gov/ct2/show/NCT03292094 。
