Comprehensive geriatric assessment of elderly highlanders in Qinghai, China II: the association of polycythemia with lifestyle-related diseases among the three ethnicities.

AIM: The objective of this study is to disclose the association of polycythemia with lifestyle-related diseases (hypertension, obesity and glucose intolerance) among the three ethnicities in Qinghai, China. METHODS: The subjects were 393 elderly people (247 Han, 97 Tibetan and 49 Mongolian) aged 60 years and more living in Qinghai (3000 m a.s.l.) in China. The associated factors with polycythemia were analyzed in the subjects. Excessive polycythemia was defined as hemoglobin concentration over 20 mg/dL. RESULTS: Polycythemia was associated with men, hypoxemia, obesity and high diastolic blood pressure (DBP) in the elderly in Qinghai. Male sex was associated with polycythemia in all ethnicities. Obesity was associated with Han and Tibetan men. Glucose intolerance and activities of daily living were not directly associated with polycythemia after adjustment for sex. There were 7.9% with excessive polycythemia. Independently-associated factors for excessive polycythemia were male sex, body mass index of 25 or more, SpO(2) of less than 85%, DBP of 85 mmHg or more and Han ethnicity (vs Tibetan) by multiple logistic regression. CONCLUSION: There was a close association of polycythemia with diastolic hypertension and obesity in lifestyle-related diseases in high-altitude elderly people. Han people had a higher hemoglobin concentration after adjustment of lifestyle-related diseases compared with Tibetan people. The difference of hemoglobin concentration may be due to Tibetans undergoing a much longer period of adaptation than Han people. Further study is needed to disclose the association between the difference of hypoxic adaptation, lifestyle-related diseases and chronic mountain sickness for their prevention.

Comprehensive geriatric assessment of elderly highlanders in Qinghai, China, III: oxidative stress and aging in Tibetan and Han elderly highlanders.

BACKGROUND: Although there are several factors which may contribute to oxidative stress at high altitude, little is known about the association between oxidative stress and aging in the community-dwelling elderly in the Tibetan Plateau. METHODS: Reactive oxygen species (ROS) and comprehensive geriatric functions were examined among 235 community-dwelling elderly subjects aged 60 years or more (146 Hans and 89 Tibetans). As a marker of ROS, the levels of reactive oxygen metabolites (ROM) were measured using the d-ROM test. RESULTS: The rate of dependence of basic activities of daily living (basic ADL) among Tibetan elderly highlanders was significantly higher than that among Han elderly highlanders. The d-ROM level was higher among the Tibetan elderly than those among the Han elderly (Tibetan 465.6 +/- 97.9 Carr U, Han 415.3 +/- 72.0 Carr U, P = 0.003). The ROM level was higher among women than those among men. Stepwise multiple regression analysis showed that being Tibetan, female, and oxygen saturation were independent predictors of increasing d-ROM level (Tibetan beta, 0.241; female beta, 0.206; oxygen saturation beta, 0.218). The high levels of ROM (d-ROM >500 Carr U) were significantly associated with dependence of basic ADL after adjustment for age, sex and ethnicity (odds ratio = 2.51, P = 0.028). CONCLUSION: The findings of this study imply the possibility that ROS is higher among Tibetan elderly highlanders than that of Han, which related to the geriatric items. Further studies are needed to show the impact of oxidative stress on the aging of highlanders.

Comprehensive geriatric assessment of elderly highlanders in Qinghai, China IV: comparison of food diversity and its relation to health of Han and Tibetan elderly.

AIM: To examine the association between food diversity and health status of Han and Tibetan elderly highlanders in Qinghai Plateau, China. METHODS: The study population consisted of 240 community-dwelling elderly subjects aged 60 years or more (176 Han elderly subjects, 64 Tibetan ones). Food diversity was determined using an 11-item Food Diversity Score Kyoto (FDSK-11). Subjects were interviewed on health status including activities of daily living (ADL), screening-based depression and quality of life (QOL). Blood chemical investigation was carried out in association with food diversity. RESULTS: ADL was significantly lower in both Han and Tibetan elderly with lower food diversity than those with higher diversity. In Han elderly with lower food diversity, QOL was significantly lower in the items of subjective sense of health, relationship with family and subjective happiness, but not significant in Tibetan elderly. A close association was found between lower food diversity and lower financial satisfaction in both Han and Tibetan subjects. No association was found between food diversity and age or body mass index. Higher food diversity was associated with lower blood glucose level in Han elderly subjects, but the opposite association was found in Tibetan ones. CONCLUSION: Food diversity was associated with ADL and QOL in highlanders in Qinghai, China. Food assessment is very important as a useful indicator to establish the actual condition of diet and its relation to health status of community-dwelling elderly as well as the change of economic background in the Qinghai highlands.

El tiempo de reserva voluntaria respiratoria (VBHT) es reducido en la altura. ¿Cómo y porqué? / Voluntary Breath holding time (VBHT) is shortened at high altitude. How and why?

OBJETIVOS: Revisar 5 artículos propios del autor sobre la reducción del tiempo de reserva voluntaria respiratoria (VBHT) en la altura, desde el año 1970, cuando viajó en la expedición japonesa al monte Everest. Después repitió la misma observación en sí mismo y también en escaladores del Himalaya. MÉTODOS: El tiempo de reserva respiratoria significa el espacio de tiempo entre el inicio y el punto de interrupción de la reserva respiratoria, lo que fue observado en posición sentada y luego de una inspiración completa (TLC), usando un reloj de muñeca. Estos datos fueron analizados en su relación entre VBHT por ciento y la altura (presión atmosférica), VBHT por ciento = VBHT en altura / VBHT a nivel del mar x 100. RESULTADOS: La tendencia común observada entre losescaladores del Himalaya fue que el VBHT disminuyó directamente con el incremento de la altura. La relación entreVBHT por ciento y la altura mostró una línea discontinua. Las líneas fueron interrumpidas abruptamente en alguna elevación y luego desviadas hacia la derecha y continuaron como nuevas líneas rectas. CONCLUSIONES: Hipotéticamente, este fenómeno podría ser explicado como que la alcalosis respiratoria inducida por la hiperventilación podría ser corregida por la excreción intermitente de la reserva alcalina por el riñón.

OBJECTIVES: To review five papers of author's own works on shortness of Voluntary Breath Holding Time (VBHT) at high altitude, since 1970, when he joined Japanese Mt. Everest Expedition. After that, he repeated the same observation on himself and some other Himalayan climbers to whom he asked to re-examine it. METHODS: The breath holding time means the time span between the start and the breaking point, and it was observed at sitting and full inspiratory (TLC) position using the subject's wristwatch. The data obtained were analyzed on the view point of relationship between VBHT per cent and altitude (atmospheric pressure), here, VBHT per cent = VBHT at altitude / VBHT at sea level ×x100. RESULTS: The common tendency observed among Himalayan climbers was that VBHT decreased straightly with increasing of altitude, and the relationship between VBHT per cent and altitude was revealed as a not continuous but discontinuous line. All of these lines were interrupted abruptly at some altitude, then, shifted rightward on the graph drawing new straight lines. CONCLUSIONS: This phenomenon could be hypothesized that respiratory alkalosis induced by hyperventilation could be corrected byintermittent excretion of alkali reserve through kidneys.