Chronoecological health watch of arterial stiffness and neuro-cardio-pulmonary function in elderly community at high altitude (3524 m), compared with Japanese town

Abstract

Effects of high altitude on arterial stiffness and neuro-cardio-pulmonary function were studied. Blood pressure (BP) and heart rate (HR) were measured in a sitting position on resting Ladakhis, living at an altitude of 3250-4647 m (Phey village, 3250 m: 17 men and 55 women; Chumathang village, 4193 m: 29 men and 47 women; Sumdo village, 4540 m: 38 men and 57 women; and Korzok village, 4647 m: 84 men and 70 women). The neuro-cardio-pulmonary function, including the Kohs block design test, the Up and Go, the Functional Reach and the Button tests, was examined in 40 elderly subjects (19 men and 21 women, mean age: 74.7 ± 3.3 years) in Leh, Ladakh (altitude: 3524 m), for comparison with 324 elderly citizens (97 men and 227 women, mean age: 80.7 ± 4.7 years) of Tosa, Japan (altitude: 250 m). Cardio-Ankle Vascular Index (CAVI) was measured as the heart-ankle pulse wave velocity (PWV) in these subjects using a VaSera CAVI instrument (Fukuda Denshi, Tokyo).SpO 2 decreased while Hb and diastolic BP increased with increasing altitude. At higher altitude, residents were younger and leaner. Women in Leh vs. Tosa had a poorer cognitive function, estimated by the Kohs block design test (3.7 ± 3.6 vs. 16.4 ± 9.6 points, P < 0.0001) and poorer ADL functions NIH-PA Author ManuscriptNIH-PA Author Manuscript NIH-PA Author Manuscript (Functional Reach: 13.7 ± 7.0 cm vs. 25.3 ± 8.7 cm, P < 0.0001; Button test: 22.5 ± 4.8 vs. 14.8 ± 5.7 s, P < 0.0001). Time estimation was shorter at high altitude (60-s estimation with counting: 41.1% shorter in men and 23.0% shorter in women).A higher voltage of the QRS complex was observed in the ECG of Leh residents, but two times measurement of CAVI showed no statistically significant differences between Leh and Tosa (two times of CAVI measures; 9.49 vs. 10.01 rn/s and 9.41 vs. 10.05 m/s, respectively), suggesting that most residents succeed to adapt sufficiently to the high-altitude environment. However, correlation of CAVI with age shows several cases who show an extreme increase in CAVI. Thus, for the prevention of stroke and other adverse cardiovascular outcomes, including dementia, CAVI may be very useful, especially at high altitude.In conclusion, elderly people living at high altitude have a higher risk of cardiovascular disease than low-latitude 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-cardio-pulmonary function.

Comparative study of the cardio-ankle vascular index and ankle–brachial index between young Japanese and Mongolian subjects

“…Importantly, one study has suggested that CAVI levels are higher in residents living at high altitude than those at sea level, and increases in hematocrit and oxidative stress by hypoxia are speculated as the causes. 21 In fact, the increased hematocrit levels in Mongolian subjects have already been reported. 20 Therefore, the results of higher CAVI levels in the Mongolian subjects may be partly due to such hypoxia-related factors.…”

“…As a possible mechanism, the residential altitude is very different between Japanese and Mongolian people and it has been documented that the altitude can contribute to circulatory characteristics such as HR and BP. 20,21 The mean altitude of JMU (Tochigi prefecture) is approximately 50 m (165 feet) and that of Ulaanbaatar is 1350 m (4429 feet) above sea level. In our study, the higher levels in HR and BP in the Mongolian subjects may be explained by the earlier study results that HR and BP (DBP in particular) increased with rising altitude levels.…”

“…In our study, the higher levels in HR and BP in the Mongolian subjects may be explained by the earlier study results that HR and BP (DBP in particular) increased with rising altitude levels. 20,21 However, basically CAVI is independent of BP (at least, the direct causes of increases in BP cannot necessarily be similar to those in CAVI). Importantly, one study has suggested that CAVI levels are higher in residents living at high altitude than those at sea level, and increases in hematocrit and oxidative stress by hypoxia are speculated as the causes.…”

Comparative Study of Atherosclerotic Parameters in Mongolian and Japanese Patients with Hypertension and Diabetes Mellitus

“…One possible explanation for this may be the existence of differences in environmental factors. The enhanced effect of high altitude on not only blood pressure 22) but CAVI 5,23) in Mongolia has been reported. The lowered effect of high altitude on plasma glucose has also been reported 24) , and in fact our studied Mongolian DM patients had lower glucose levels.…”

Glocalization of Social and Environmental Determinants of Health

“…These behavioral risk factors may be also called primary risk factors of NCDs [11]. Apart from these social determinants of health, high altitude, geomagnetic activity, and sleep disruption are other environmental factors which can predispose circadian variability in biological functions resulting in NCDs [13][14][15][16]. In high income countries, many experts believe that poverty is the major cause of deaths and disability due to NCDs [1][2][3].…”