title: Prevalence of high altitude pulmonary hypertension among the natives of Spiti Valley--a high altitude region in Himachal Pradesh, India.
abstract: The study aimed to determine the prevalence of high altitude pulmonary hypertension (HAPH) and its predisposing factors among natives of Spiti Valley. A cross-sectional survey study was done on the permanent natives of Spiti Valley residing at an altitude of 3000 m to 4200 m. Demographic characteristics, health behavior, anthropometrics, and blood pressure were recorded. Investigations included recording of 12 lead electrocardiogram (ECG), SaO2 with pulse oximeter, spirometry and echocardiography study, and measurement of Hb levels using the cynmethhemoglobin method. HAPH was diagnosed using criteria; tricuspid regurgitation (TR) gradient of ≥46 mmHg. ECG evidence of RV overload on 12 lead ECG was documented based on presence of 2 out of 3 criteria; R>S in V1, right axis deviation or RV strain, T wave inversion in V1 and V2. Data of 1087 subjects were analyzed who were free of cardiorespiratory diseases to determine the prevalence of HAPH and its predisposing factors. HAPH was recorded in 3.23% (95% C.I. of 0.9-8.1%) and ECG evidence of right ventricular (RV) overload was 1.5% in the study population. Prevalence of HAPH was not different in men and women 2.63% vs. 3.54% p<0.2. Age (Z statistics of 3.4 p<0.0006), hypoxemia (Z statistics of 2.9 p<0.002), and erythrocythemia (Z statistics of 4.7 p<0.003) were independently associated with HAPH. Altitude of residence was not found to be significantly associated with HAPH, although there was a trend of increasing prevalence with increasing altitude. It can be concluded that HAPH is prevalent in 3.23% of natives of Spiti Valley. Increasing age, erythrocythemia and hypoxemia are independent predisposing factors.
authors.affiliation: Department of Cardiology, Indira Gandhi Medical College , Shimla, Himachal Pradesh, India .
authors.forename: Prakash Chand
authors.initials: PC
authors.lastname: Negi
authors.forename: Rajeev
authors.initials: R
authors.lastname: Marwaha
authors.forename: Sanjeev
authors.initials: S
authors.lastname: Asotra
authors.forename: Arvind
authors.initials: A
authors.lastname: Kandoria
authors.forename: Neeraj
authors.initials: N
authors.lastname: Ganju
authors.forename: Rajesh
authors.initials: R
authors.lastname: Sharma
authors.forename: Ravi V
authors.initials: RV
authors.lastname: Kumar
authors.forename: Rajeev
authors.initials: R
authors.lastname: Bhardwaj
mesh_terms: D000328:Adult; D000531:Altitude; D000532:Altitude Sickness / Q000453:epidemiology* / Q000209:etiology*; D000886:Anthropometry / Q000379:methods; D001794:Blood Pressure; D015984:Causality; D003430:Cross-Sectional Studies; D005260:Female; D015438:Health Behavior; D006801:Humans; D006976:Hypertension, Pulmonary / Q000453:epidemiology* / Q000209:etiology*; D000860:Hypoxia / Q000209:etiology; D007194:India / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D044382:Population Groups; D015995:Prevalence
keywords: Himalayas India; high altitude; pulmonary hypertension