Impact of Moderate Altitude on Lung Diseases and Risk of High Altitude Illnesses

ABSTRACT A large world population resides at moderate altitudes. In the Valley of Mexico (2240 m above sea level) and for patients with respiratory diseases implies more hypoxemia and clinical deterioration, unless supplementary oxygen is prescribed or patients move to sea level. A group of individuals residing at 2500 or more meters above sea level may develop acute or chronic mountain disease but those conditions may develop at moderate altitudes although less frequently and in predisposed individuals. In the valley of México, at 2200 m above sea level, re-entry pulmonary edema has been reported. The frequency of other altitude-related diseases at moderate altitude, described in skiing resorts, remains to be known in visitors to Mexico City and other cities at similar or higher altitudes. Residents of moderate altitudes inhale deeply the city's air with all pollutants and require more often supplementary oxygen.

Capacidad cardio-respiratoria de niños escolares que viven a moderada altitud / Cardiorespiratory capacity in children living at moderate altitude

Objetivo: Determinar la capacidad cardio-respiratoria de niños escolares que viven a moderada altitud. Pacientes y Método: Fueron seleccionados 795 niños (394 niños y 401 niñas) de escuelas públicas del área urbana de moderada altitud (2.320 msnm) de Arequipa, Perú. Se evaluaron variables antropométricas (masa corporal, estatura, porcentaje de grasa) y capacidad cardio-respiratoria a través del test indirecto de Course Navette, considerando las siguientes categorías: deficiente, malo, aceptable, bueno, muy bueno y excelente. Resultados: Los resultados muestran diferencias significativas en todas las categorías (p < 0,05). Se verificó que los valores medios de las categorías malo y deficiente en ambos sexos son inferiores a los de la categoría aceptable (p < 0,05). Se determinó que el 19 por ciento de niños y 21 por ciento de niñas mostraron bajo nivel de capacidad cardio-respiratoria, además se verificó correlación negativa baja con la categoría sobrepeso (r = -0,20 a -0,22) y moderada con la obesidad (r = -0,39 a -0,42) en ambos sexos. Conclusiones: Existen bajos niveles de capacidad cardio-respiratoria en niños de ambos sexos niños escolares que viven a moderada altitud, que se correlaciona negativamente con el exceso de peso corporal. Los resultados sugieren que uno de cada 5 niños se encuentra con posibilidades de padecer algún evento de índole cardiovascular.

Objective: To determine the cardiorespiratory capacity of school children living at moderate altitude. Patients and Method: 795 children (394 children and 401 girls) were selected from urban public schools in Arequipa, Peru at moderate altitude (2,320 m). Anthropometric variables (body mass, height, body fat percentage) and cardiorespiratory capacity were assessed using the Course Navette test, considering the following categories: deficient, poor, fair, good, very good and excellent. Results: The results showed significant differences in all categories (p < 0.05). It was described that the median values of the poor and deficient categories in both gender were lower than what is considered acceptable (p < 0.05). It was concluded that 19 percent of boys and 21 percentof girls showed low level of cardiorespiratory capacity and a low negative correlation with overweight (r = -0.20 to -0.22) and a moderate negative correlation with obesity (r = -0.39 to -0.42) were described for both genders. Conclusions: Low levels of cardiorespiratory capacity in boys and girls living at moderate altitude are observed, which is negatively correlated with excess body weight. The results suggest that 1 in 5 children are likely to suffer some type of cardiovascular event.

Clinical Chemistry Reference Intervals in a Rwandan Population.

Aim: To establish clinical chemistry reference intervals for the Rwandan population. Study Design: A population-based cross-sectional study. Place and Duration of Study: The study was carried out in three blood transfusion centres: Buhanda, Ruhango and Nyaruteja, between August and December 2011. Methods: Serum clinical chemistry tests were performed on a Cobas C311 automated chemistry analyzer. Results: Results of 187 subjects (age range: 17-54 years) presented as median, with 2.5th-97.5th percentiles (95% reference interval) in brackets are as follows: For males: alanine aminotransferase: 25 (12-43) U/L; aspartate aminotransferase: 29 (16-47) U/L; gamma-glutamyl transferase: 22 (9-77) U/L; total bilirubin: 0.6 (0.2-1.7) mg/dL; direct bilirubin: 0.2 (0.1-0.4) mg/dL; creatinine: 0.8 (0.5-1.1) mg/dL; uric acid: 5 (3-7) mg/dL. For males and females: alkaline phosphatase: 71 (27-122) U/L; amylase: 144 (50-235) U/L; lactate dehydrogenase: 176 (114-237) U/L; triglycerides: 82 (32-172) mg/dL; highdensity lipoprotein: 48 (29-86) mg/dL; glucose: 87 (70-114) mg/dL; total protein: 7.6 (6.5- 8.5) g/dL; albumin: 4.4 (3.4-5.4) g/dL; sodium: 142 (137-147) mmol/L; potassium: 4.1 (3.3-5.0) mmol/L; chloride: 106 (100-112) mmol/L; phosphate: 1.16 (0.87-1.49) mmol/L. Conclusion: The clinical chemistry reference values are in agreement with those reported in other African studies, with variations.

Haematological Values at Moderate Altitude in a Low-Income Population.

Aim: To illustrate haematological adaptation to moderate altitude in Rwanda. Study Design: A population-based cross-sectional study. Place and Duration of Study: The study was carried out at moderate altitude (1,649-1,768 m) among students of the National University of Rwanda and blood donors from Buhanda, Ruhango and Nyaruteja centres, from August to December 2011. Methods: Healthy volunteers (238 males and 106 females, age range: 18-40 years) were recruited in the study. Complete blood count was performed on a Coulter AcT 5diff and for some samples on a Sysmex KX-21N automated haematology analyzer. Results: Results (mean ± SD) were: erythrocyte count: males: 5.28 ± 0.53 X 1012/L, females: 4.72 ± 0.63 X 1012/L; haemoglobin concentration: males: 160 ± 16 g/L, females: 140 ± 18 g/L; haematocrit: males: 45 ± 4 %, females: 40 ± 5 %. The differential leukocyte count showed eosinophilia (4%) and increased lymphocytes (44%). Conclusion: The values for erythrocyte count, haemoglobin concentration, haematocrit, erythrocyte indices and leukocyte count are comparable to sea level values. The fact that haemoglobin concentration is not low as is the case in low-income populations living at sea level can be attributed to adaptation to moderate altitude.