高所地域Ladakh 住民に観察された認知機能の低下と、動脈硬化度の亢進 : 平地(日本)住民(25,211例)と高所地域Ladakh 住民(1,376例)の比較

Abstract

This investigation was particularly focused on chronoecology in Ladakh, to study circulation as a physiological system at high altitude, as a comparison with the chronoecological study in several Japanese towns. Aortic stiffness of cardio-ankle vascular index (CAVI) was measured using a VaSera instrument (Fukuda Denshi, Tokyo) in 25, 211 Japanese (13, 366 men and 11, 845 women) and in 1, 336 Ladakhis (561 men and 815 women), living at an altitude of 3250 to 4647 m. Effects of high altitude on neuro-cardiovascular function were studied by glocal (i.e., global and local) comprehensive assessment, including the Kohs block design test, the Up & Go, the Functional Reach and the Button tests, in Japanese T-town (80.7 years, 97 men and 227 women), in Japanese U-town (79.9 years, 47 men and 70 women), and in Leh, Ladakh (74.7 years, 19 men and 21 women) at an altitude of 3250 m. Residents in the highaltitude community of Leh had a poorer cognitive function, estimated by the Kohs block design test (9.0 vs. 16.4 points, p<0.0001) and poorer ADL functions (Functional Reach: 18.1 cm vs. 25.7 cm, p<0.0001). Time estimation of 10-sec was shorter at high altitude (8.5 vs. 16.4 sec, p<0.0001). A higher voltage of the QRS complex (SV1+RV5) was observed in the ECG of Leh residents (29.0 vs. 24.7 mm, p<0.05). Japanese and Ladakhi subjects, investigated CAVI, were classified into 13 age-groups every 5-year from under 25-year to over 80-year. CAVI values increased along with age in both Ladakhi and Japanese people. Highland people showed a higher CAVI values than the lowland people, and high-altitude Ladakhi people showed higher systolic and diastolic BP values than Japanese people at low-altitude, most of the 13 age-groups both in men and women. In conclusion, people living at high altitude have a higher risk of cardiovascular disease than low-altitude peers. To determine how these indices are associated with maintained cognitive function deserves further study by the longitudinal follow-up of these communities in terms of longevity and aging in relation to their neuro-cardiopulmonary function. Our data indicate the need for a more comprehensive cardiovascular assessment for a better diagnosis and a more fruitful treatment. Longitudinal observations of effects of socio-ecologic factors on the cardiovascular system should help prevent strokes and other cardiovascular events, especially at high-altitude.