Prevalence and clinical peculiarities of essential hypertension in a population living at high altitude.

Screening examinations were performed in ethnically related populations of men aged 30-59 years, living in high mountain regions of Tien-Shan and Pamir (2800-3600 m above sea level) and in the lowlands (800-900 m). The incidence of borderline hypertension (BH) and essential hypertension (EH) was statistically significantly higher among the inhabitants of lowland regions: EH was recorded among them in 15.4%, vs. 4.2% among men living at high altitude; BH was present among the male lowland population (LL) in 10.6% vs. 6.0% among highlanders (HL). The main characteristic clinico-functional feature of EH in HL was its frequent association with high-altitude pulmonary hypertension and right ventricular hypertrophy. Aldosterone excretion was in HL with EH substantially lower, and sodium excretion higher, than in a comparable group of lowland inhabitants.