ヒマラヤ地域住民の生活習慣の調査と、心血管系機能の高所適応に見られる男女差

Abstract

Aim: Numerous physiologic studies attempted to explain the effects of ambient hypoxia on humans, and now we know how humans adapted to it through changes in the expression of hypoxia-related genes. However, little is investigated about the gender difference from a view point of glocal (combined global and local) comprehensive assessment. Methods: We studied the effects of high altitude on pulse oximetry (SpO2), blood pressure (BP), heart rate (HR), aortic stiffness of cardio-ankle vascular index (CAVI). Subjects were 1, 858 Ladakhis (777 men and 1081 women). We investigated the gender difference of compensatory mechanisms by comparing the cardiovascular functions among 3 groups of high altitudes, i.e., from 2500 to 3000 m, from 3200 to 3720 m, and from 3800 to 4590m. Results: There observed no significant differences of the cardiovascular function among the three altitudes in men, but in women systolic BP became higher along with the altitudes and incidences of ECG findings, including 1st degree of AV block, ST depression and abnormal Q waves, became more frequent along with altitude. In addition, Ladakhi women showed steeper negative slope of the regression line between SpO2 and age, and larger slope of the regression line between systolic and diastolic BPs and age, compared with Ladakhi men. Conclusions: Our study indicates an existence of gender difference of adaptation to ambient hypoxia especially on cardiovascular functions, which suggests a need for the glocal comprehensive assessment for the better diagnosis and for the more fruitful treatment in community dwellers, especially at higher altitude.