Prevalence of hypertension at high altitude: cross-sectional survey in Ladakh, Northern India 2007-2011

Objective: Prevalence of hypertension was examined in a widely dispersed (45 110 km2) representative group of Ladakhi in Northern India. The influence of hypoxic environment of wide-ranged altitude (2600–4900 m) and lifestyle change on hypertension was studied. Methods: 2800 participants (age 20–94 years) were enrolled. Systolic blood pressure ≥140 mm Hg and/or diastolic blood pressure of ≥90 mm Hg and/or taking current anti-hypertensive medicine was defined as hypertension. Height and weight for body mass index and SpO2 were examined. The rural population comprised six subdivisions with a distinct altitude, dietary and occupational pattern. Participants in the urban area of Leh consist of two groups, that is, migrants settled in Leh from the Changthang nomadic area, and dwellers born in Leh. The prevalence of hypertension in the two groups was compared with that in the farmers and nomads in rural areas. The effects of ageing, hypoxia, dwelling at high altitude, obesity, modernised occupation, dwelling in an urban area, and rural-to-urban migration to hypertension were analysed by multiple logistic regression. Results: The prevalence of hypertension was 37.0% in all participants and highest in migrants settled in Leh (48.3%), followed by dwellers born in Leh town (41.1%) compared with those in rural areas (33.5). The prevalence of hypertension in nomads (all: 27.7%, Tibetan/Ladakhi: 19.7/31.9%)) living at higher altitude (4000–4900 m) was relatively low. The associated factors with hypertension were ageing, overweight, dwelling at higher altitude, engagement in modernised sedentary occupations, dwelling in urban areas, and rural-to-urban migration. The effects of lifestyle change and dwelling at high altitude were independently associated with hypertension by multivariate analysis adjusted with confounding factors. Conclusions: Socioeconomic and cultural factors play a big role with the effect of high altitude itself on high prevalence of hypertension in highlanders in Ladakh

Adaptation and Mal-Adaptation to Ambient Hypoxia; Andean, Ethiopian and Himalayan Patterns

The study of the biology of evolution has been confined to laboratories and model organisms. However, controlled laboratory conditions are unlikely to model variations in environments that influence selection in wild populations. Thus, the study of “fitness” for survival and the genetics that influence this are best carried out in the field and in matching environments

Adaptation, Aging and Disease Epidemiology in High Altitude Population of Ladakh

While altitude acclimatization refers to the physiological responses that takes place on ascending to hypobaric hypoxic high altitude environment; adaptation is both genetic and non-genetic, consisting of physiological, biochemical or behavioral adjustments. Average hemoglobin of 17.46 (±2.18) g/dl and SpO2 84 % (±9.5 %) found in natives of korzok (4550 m) is a well known response to low oxygen saturation. However a substantially higher value of FEVI/FVC and MMEF in these highlanders was a surprise finding. About 2% of korzok men develop chronic mountain sickness at about 48 years, a condition of accelerated ageing due to decreasing hypoventilatory drive following prolonged stay at altitude. CAVI shows extreme increase with age in some high altitude natives. Changing disease ecology comparing contemporary scenario with historical perspective indicates a marked rural- urban distinction. Nutritional factor, poor food and water hygiene, poor health care facilities, high risk diet, environmental dust and domestic fire pollution are responsible for high prevalence of upper GI and hepatobiliary cancers and poor respiratory health in rural population. Obesity, diabetes, coronary heart disease and vehicular accidents are the main disease burden in the urban population. High prevalence of HBV carriers (8%) in rural population and H. pylori acquisition in (95% of population) resulting in high prevalence of chronic liver disease, liver cancers and cancer of the stomach are cause of concern in the contemporary disease epidemiology

<Award Paper of 4th Congress of Asian Pacific Society of Mountain Medicine (APSMM)>Glucose Intolerance by Interaction between Hypoxia Adaptation and Lifestyle Change in Highlanders in Tibet Plateau

Socioeconomic factors and hypoxia play major roles in the prevalence of glucose intolerance in highlanders. Hypoxemia and polycythemia were closely associated with glucose intolerance after adjustment for the effects of lifestyle changes in our study. Tibetan people may be vulnerable to glucose intolerance, with polycythemia as a sign of poor hypoxic adaptation. Epigenetics is also play a role in its vulnerability with quick lifestyle change. Prevention of lifestyle-related diseases and health education should be advocated, especially in high altitude dwellers with rapidly prevailing socioeconomic globalization

Glocally Comprehensive Health Watch at High Altitude

Background: On 1 August 2010, an entire hemisphere of the sun erupted. Filaments of magnetism snapped and exploded, shock waves raced across the stellar surface, and billion-ton clouds of hot gas billowed into space. A coronal mass ejection (CME) headed directly for Earth. The huge solar storm triggered unusual northern and southern auroras appearing on the night of August 3. Geomagnetic turbulence in Japan was observed on 4 August. The CME could have driven disastrous flooding occurring in Ladakh on 5 and 6 August 2010 in association with an annual acrophase of environmental temperature recorded by us there and also reported in Pakistan and in Gansu, China. A heat wave and smog were presumably associated with the CME in Moscow on 2-9 August. Aim: A chronoecologic health watch in Ladakh, using "glocal comprehensive assessment (GCA)" to study the human circulation, autonomic nervous system activity and health quality as a physiological system at high altitude, complements a chronoecological study in Japanese towns. Ladakh is a very arid region of east Kashmir, adjacent to Tibet, at an altitude of 2500 to 4600 m between the Karakoram and the Himalaya ranges. Subjects: 3418 Ladakh residents, i.e., 549, 461, 447, 164, 788, 420 and 589 citizens, were checked out annually since 2004 to 2010, respectively. High-altitude environments have less oxygen, lower pressure, cold temperature and strong UV-radiation. From June 2009 to September 2011, we monitored, every 30-min, among other data, air temperature, relative humidity, air pressure, wind direction, wind speed, rainfall, upward/downward long/short wave radiation and UVradiation investigated in chronomic serial sections with a 24-hour and a separate 7-day cosine fit. Results: Disastrous floods on 5 August followed the CME on 1 August 2010, seen in serial sections of rainfall. Meteorological observation disclosed a disruption of 1/f fractal scaling of the environmental temperature before the floods in Ladakh, whereas serial sections showed the circannual acrophase. Annual Health Watch shows, as compared to Japanese subjects, that residents in Ladakh slept less (7.8 vs. 6.9 hours, p<0.001), a lower SpO2 (84.4 vs. 96.0%, p<0.00001), decreased parasympathetic activity (lower LF and HF; p<0.05), higher sympathetic activity (increased LF/HF ratio, p<0.05, higher diastolic blood pressure (BP) and heart rate (p<0.00001). Floods on 5 August affected the health of Ladakh citizens: Systolic and diastolic BPs increased from 130.1/81.7 to 135.2/85.7 mmHg (p<0.005), arterial stiffness CAVI increased from 7.72 to 8.22 m/sec (p<0.0001). The percentage of citizens suffering from depressive mood increased from 5.3 to 8.8 % (p<0.0001). Discussion & conclusion: Space weather affected the citizen' health, as demonstrated in this investigation, at least around a 11-year cycle. Thus, an astro-glocal assessment, in space and time, is recommended as background for diagnosis and treatment, especially at high altitude. We can ask whether one of the longer solar, or galactic geological, cycles can override the conditions of the citizen' health as well as the earth weather especially in Ladakh of the minimum in a Horrebow-Schwabe about 11-year sunspot cycle

Impaired Cognitive Function and Increased Aortic Stiffness, Estimated by Cardio-Ankle Vascular Index, in Ladakh, at an Altitude of 3250 to 4647m, Compared with Japanese Town

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