チベット高所住民における低酸素と耐糖能異常 : 「糖尿病アクセル仮説」の検証に関する Review

Abstract

本稿は, 高所プロジェクトの提唱してきた「糖尿病アクセル仮説」の一部について検証した科学論文 (Glucose intolerance associated with hypoxia in people living at high altitudes in the Tibetan highland. BMJ open 2016) のレビューである。耐糖能障害がライフスタイルと低酸素血症といかに関連するかを, 中国からインドにわたるチベット高原 (2900-4800m) の1258人の住民において研究された。社会経済的要因, 高度3500m 以上在住, および低酸素血症が, 高所住民の耐糖能異常の増加に大きく関与していることが報告された。低酸素血症, 多血症, 耐糖能異常の3者には密接な関係があり, 加齢とライフスタイル変化がその関係を促進している (糖尿病アクセル仮説) ことが検証された。

The association between glucose intolerance and high altitudes (2900-4900m) was clarified in Tibetan highlanders. The hypothesis was verified that dwelling at high altitudes have vulnerability to diabetes accelerated by lifestyle change or aging. 1258 subjects (40-87 years) were examined; farmers in Domkhar (2900-3800m), nomads in Haiyan, Ryuho, and Changthang (3000-4800m), and urban dwellers in Leh and Jiegu (3300-3700m). The prevalence of glucose intolerance was higher in urban dwellers and in farmers compared with nomads. Dwelling at a higher altitude was significantly associated with fasting hyperglycemia (odds ratios for >4500 and 3500-3999m were 3. 59 and 2. 07 vs 1.0 ; <3500m) by multiple logistic regression analysis with adjustment of age, sex, and confounding factors. Further hypoxemia and polycythemia were closely associated with glucose intolerance. Socioeconomic factors, hypoxemia, and the effects of altitudes over 3500m play a major role in the high prevalence of glucose intolerance in highlanders. Tibetan highlanders may be vulnerable to glucose intolerance, with polycythemia as a sign of poor hypoxic adaptation, accelerated by lifestyle change and aging.