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Aim: Humans adjusted to ambient hypoxia via the alteration of chemoreceptor reflex sensitivity. However, it has not yet been established how we can measure it. Thus, the aim of this investigation is to propose a method how to measure it using a newly developed pulse oximetry monitor. Methods: We assessed it as a relation between a phasic change of hypoxemic condition and an alteration of heart rate. We planned two types of investigations. Effects of high altitude on pulse oximetry (SpO2) and heart rate (HR) were observed by 25-minute continuous monitoring of SpO2 and HR. The first study was done in 3 healthy subjects (29-year and 56-year women and a 59-year man) along with a trip for about 10 days from Japan to Himalayan valley. More than 6 times of measurement of SpO2 and HR were done before and during the trip. Another observation of the 25-minute continuous monitoring was done in 44 Ladakhi priests (17-90 years men, average 49.1 years of age) living at an altitude of 2, 500 to 3, 720 meters. Results: SpO2 and HR were simultaneously monitored each cardiac beat in each subject. As an index of chemoreceptor reflex sensitivity (CRS), we measured a slope of the fitting line, showing a correlation between a prominent decrease of SpO2 and a phasic increase in HR. First investigation showed CRS changed from 0 msec/% at Japan before a trip to 42.5 msec/% during a trip at Himalayan valley. The second investigation showed higher measures of CRS of the 44 priests, average 46.1 msec/%, ranged from 3.3 to 148.5 msec/%. People living at high altitude have a higher sensitivity of chemoreceptor reflex compared to the low-latitude peers, although it has been fully habituated and fully adapted. Conclusions: We need a glocal, i.e., global and local, comprehensive assessment (GCA), including a measurement of CRS, for a more fruitful treatment. Longitudinal observations of GCA should help us to prevent strokes and other cardiovascular events, especially at high-altitude.

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.

高所では, 低圧と低酸素の他に, 温度, 風, 日照, 紫外線の影響, 昼夜の温度差, 生活様式, その他不明の要因が, 複雑に交錯して, 生命予後・疾病予後に影響を及ぼし, 高所地域住民の寿命は60歳余りと短いとされている. そこで本研究では, 平地に住む高知県T 町ならびに北海道U 町の地域住民の調査結果と比較することにより, ヒマラヤ地域に住む高所住民の健康のあり方を考察した. 2004年8月-2008年7月の間に, ラダック(Ladakh)地域の41集落(標高3300m から4590m)地域住民946名(13-92 歳, 平均51.4 歳, 男453 名, 女493 名)を対象に, 総合的機能評価を行ない, 北海道U 町住民183名と, 高知県T 町住民311名の, フィールド医学調査と比較した. 冠動脈疾患とメタボリック症候群の頻度は, 各々, 2%, 3%と少なく, 心房細動例は認められなかった. 一方, 頭痛の訴えは32%と多かった, ラダック地域住民の睡眠時間は, U町住民よりも長かったが(p < 0.01), 就眠までの時間は, 短時間であった(25.6 vs. 15.5 分, p < 0.005). ラダック住民は, 歩く速さが遅く(Up & Go; 12.9 vs. 14.6sec, p < 0.0005), Functional Reach が短く(26.4 vs. 21.7cm, p < 0.05), ボタンつけはずしに長い時間を要した(p < 0.00001). SpO2 はT 町に比し低く(96.6 vs. 85.2%, p < 0.00001), 呼吸数は頻数であった(18.3 vs. 22.1回/分, p, This investigation was particularly focused on chronoecology in Ladakh, to study quality of health as a physiological system at high altitude, as a comparison with the chronoecological study in Japanese T-town, Kochi and U-town, Hokkaido. Effects of high altitude on life style and cardiovascular function were studied by glocal (i.e., global and local) comprehensive assessment, including a questionnaire on sleep habit, in 946 Ladakhis (from 13 to 92 years, average 51.4 years of age, 453 men and 493 women), living at altitudes of 3300 to 4590 m, and in Japanese residents of 183 U-town and 311 T-town. Residents in the high-altitude community of Ladakh had a less frequent suffering from coronary artery disease, atrial fibrillation and metabolic syndrome (3%, 0%, 3%, respectively), but a longer sleeping time (p