Zuheng Cheng

Urinary electrolytes and hypertension in elderly Kazakhs

AbstractBackground. Deficiency of potassium (K) intake is associated with hypertension, and high dietary K intake may have a preventive effect. The prevalence of hypertension and incidence of stroke are higher in Kazakhs than in other ethnic groups in the Peoples Republic of China (PRC). The Barkol area in the Xinjiang region in PRC is an area with a high population of Kazakhs. We carried out a study in this region that involved blood pressure monitoring and the examination of serum and urinary electrolytes in the Kazakh and Han populations of the area. Methods. Twenty-four-hour ambulatory blood pressure monitoring and urine collections were performed for each study subject. In each subject, urine was collected simultaneously for 24 h during the blood pressure monitoring. Serum and urinary electrolytes were measured. Results. The prevalence of hypertension was higher in the Kazakh population than in the Han (men, 53%; women, 43% in the Kazakhs; men, 40%; women, 30% in the Han; P < 0.001). Urinary excretion of potassium was lower in Kazakhs than in Han (Kazakh, 18.9 ± 8.7 mmol/day; Han, 36.5 ± 11.3 mmol/day; P < 0.001). Urinary excretion of sodium was lower in Kazakhs than in Han (Kazakhs, 181.4 ± 77.6 mmol/day; Han, 194.1 ± 75.9 mmol/day; P < 0.001). Mean 24-h blood pressure was higher in Kazaks than in Han, and this value correlated positively with the urinary sodium/potassium ratio (r = 0.39; P < 0.001). Conclusions. The prevalence of hypertension was higher in Kazakhs than in Han in the Barkol area in the Xinjiang region. Kazakhs had a low intake of potassium. The sodium/potassium ratio was higher in Kazakhs than in Han. A high Na/K ratio, together with low intake of potassium, may be a factor in Kazakh hypertension.