Prevalence of Chronic Mountain Sickness in high altitude districts of Himachal Pradesh

Abstract

Introduction:Chronic Mountain Sickness (CMS) is a maladaptation condition that can affect people who reside permanently at high altitude (HA). It is characterized by polycythemia, hypoxemia and dyspnea and can be fatal. Over 140 million people live permanently at HA around the world. Unfortunately, research into CMS is lacking and accurate data on the prevalence of this condition do not exist for many regions around the world. In this study, we sought to examine prevalence rates of CMS in the Indian Himalayas, focusing on the Northern State of Himachal Pradesh.Materials and Methods:We surveyed 83 individuals (69 males) in eight towns across the HA districts of Sirmaur, Kinnaur and Lahaul and Spiti in Himachal Pradesh, India. Altitudes ranged from 2350 to 4150 m. We used an adapted Qinghai CMS scoring system to diagnose CMS. Information related to subject demographics, medical history, socioeconomic status, and geography were collected to identify risk factors for CMS. Physiologic recordings of oxygen saturation (SpO2) and pulse rate were made through pulse oximetry.Results:Overall CMS prevalence was 6.17% and mean altitude was 3281 m. At altitudes above 3000 m CMS prevalence rose to 13.73%. All cases of CMS were mild and there was a significant positive correlation between CMS scores and altitude (R = 0.784, P = 0.0213). Mean SpO2 was 90.7 ± 0.4% and mean pulse rate was 80.3 ± 1.3 bpm. SpO2 significantly correlated with altitude (R = −0.929, P < 0.001). In our study, age, gender, and tobacco use were not independent risk factors for CMS. Individuals with CMS lived at higher altitudes than their non-CMS counterparts (3736.00 ± 113.30 m vs. 3279.80 ± 69.50 m, respectively; P = 0.017).Conclusion:CMS prevalence in HA towns of the Indian Himalayas of Himachal Pradesh is 6.17% and 13.73% for towns above 3000 m. Further research is required to determine the prevalence of CMS in other regions of the world and to determine risk factors associated with CMS.

Noninvasive Assessment of Excessive Erythrocytosis as a Screening Method for Chronic Mountain Sickness at High Altitude

“…At high altitude, it is well recognized that oxyhemoglobin saturation values are associated with hemoglobin concentrations (Hurtado, 1942. León-Velarde et al, 1994, Peñaloza et al, 2007, Sahota et al, 2013.…”

“…Specifically, we calculated sensitivity and specificity of having excessive erythrocytosis (defined as measured hemoglobin concentrations ‡ 21.0 g/dL in males and ‡ 19.0 g/dL in females) for lower threshold value for a range of oxyhemoglobin saturation values. threshold of oxyhemoglobin saturation will likely vary with altitude, body mass index, pregnancy, and behavioral factors such as chronic alcohol drinking and tobacco smoking (Sahota et al, 2013, Peng et al, 2013.…”

Spatiotemporal Changes of Hazard Intensity-Adjusted Population Exposure to Multiple Hazards in Tibet During 1982–2015

“…Studies show that Tibetans have a higher risk of hypertension caused by CMS than people in other high-altitude areas (Wu and Kayser 2006). The CMS risk of the Han population moving into Tibet increased linearly with altitude (Li et al 2012) and its average prevalence was 5.6%, much higher than the 0.91-1.2% for Tibetans (Sahota and Panwar 2013). According to the 2010 Census, 1 the average life expectancy of Tibetans is 68.17 years, 6.66 years lower than the Chinese average, and this is associated with hypoxia.…”

Chronic Mountain Sickness (Cms) Misdiagnosed As High Altitude Cerebral Edema (Hace) At Extreme Altitude (6400 M/21000 Ft)

“…11 Furthermore, while CMS has been found in 4%-28% of native mountain residents on the South American Andean Altiplano, Central Asia, and Indian Himalayas, the prevalence of CMS is extremely low or absent in Tibetans and East Africans who are better adapted to hypoxia. 12,13 A prevalence of 36.5% has been reported in the military. 14 Moreover, certain polycythemic mountain residents may not be prone to thrombotic events.…”