Hemoglobin Levels in Peruvian Patients with Chronic Kidney Disease at Different Altitudes.

Hurtado-Aréstegui, Abdías, Karina Rosales-Mendoza, Yanissa Venegas-Justiniano, José Gonzales-Polar, Rina Barreto-Jara, and Alaciel Melissa Palacios-Guillén. Hemoglobin levels in Peruvian patients with chronic kidney disease at different altitudes. High Alt Med Biol. 24:209-213, 2023. Background: Decreased hemoglobin is a manifestation of chronic kidney disease (CKD), and people who reside at high altitude adapt to hypoxia by increasing their hemoglobin. The study's objective was to determine the influence of altitude and the associated factors on the hemoglobin levels of patients with CKD who were not on dialysis (ND). Methods: This exploratory and cross-sectional study was carried out in three Peruvian cities, located at different altitudes: (1) "sea level" (161 m), (2) "moderate altitude" (2,335 m), and "high altitude" (3,399 m). The study included female and male individuals between 20 and 90 years old, with CKD stage 3a, through stage 5. Results: Of the 256 volunteers evaluated, 92 lived at sea level, 82 at moderate altitude, and 82 at high altitude. The three groups were similar in age, number of volunteers in each CKD stage, systolic blood pressure, and diastolic blood pressure. Hemoglobin levels were statistically different according to gender (p = 0.024), CKD stage, and altitude (p < 0.001). High-altitude dwellers had higher hemoglobin by 2.5 g/dl (95% confidence interval: 1.8-3.1, p < 0.001) than those living at lower altitudes (adjusted for gender, age, nutritional status, and smoking habit). For all CKD stages, the high-altitude population had higher hemoglobin levels than population at moderate altitude and at sea level. Conclusion: Subjects living at high altitude with CKD stages 3 to 5 who are yet ND have higher hemoglobin levels than those who live at moderate altitude and at sea level.

Saturación de oxígeno en pacientes durante hemodiálisis a diferentes altitudes

Introducción : Los pacientes en hemodiálisis pueden presentar hipoxemia durante este procedimiento, la cual puede ser mayor si la hemodiálisis se realiza en ciudades de gran altitud. Objetivos : Evaluar las variaciones de la saturación de oxígeno en pacientes en hemodiálisis a diferentes altitudes. Material y métodos : Es una serie de casos prospectivos, donde se evaluaron pacientes de un programa de hemodiálisis crónica en tres ciudades, localizadas a diferentes altitudes:101, 2 335 y3 825 metros sobre el nivel del mar, en los que se evaluó la saturación de oxígeno en posición semisentada con pulsoxímetro: antes, durante y al finalizar el procedimiento de hemodiálisis. Resultados : Se incluyeron 65 pacientes en hemodiálisis, de 3 ciudades de diferente altitud, con características similares, la saturación de oxígeno disminuyó significativamente a medida que aumentaba la altitud (97,32 ± 1,10 vs 94,75 ± 2,17 vs 84,85 ± 5,86 p=0,00), la saturación de oxígeno mostró cambios antes, durante y al final del procedimiento de hemodiálisis en las diferentes altitudes. Los niveles de ferritina fueron menores en pacientes de gran altitud comparado con los de nivel del mar y altitud moderada (131,75 [106,04 - 157,45] vs 493,38 [273,19 - 713,56] vs 550,66 [329,75-771,57] p=0,01). Los valores de hemoglobina fueron menores en los pacientes de mediana altitud (10,8 [10,12- 11,47] vs 11,32 [10,79-11,85] vs 11,84 [11,54-12,14] p=0,03). Conclusiones : En pacientes en hemodiálisis crónica la saturación de oxígeno disminuye a medida que incrementa la altitud y se encontró variaciones significativas durante el procedimiento de hemodiálisis.

Introduction : Patients undergoing hemodialysis may develop hypoxemia during the procedure, and hypoxemia may become more intense if hemodialysis is performed in a high altitude environment. Objectives: To assess variations in oxygen saturation in patients undergoing hemodialysis at different altitude levels. Material and methods : This is a prospective case series, where patients from hemodialysis programs in three cities were assessed. These places were at 101-, 2335-, and 3825- meters above sea level. Patients had their oxygen saturation measured in a semi-sitting position with a pulse oxymeter device. Measurements were taken before, during, and at the end of hemodialysis sessions. Results : Sixty-five patients undergoing hemodialysis were included. They were from three cities at different altitude above sea level. Oxygen saturation significantly decreased as long as altitude increased (97,32 ± 1,10 vs. 94,75 ± 2,17 vs. 84,85 ± 5,86 p= 0,00). Oxygen saturation showed changes before, during, and at the end of hemodialysis procedures at different altitude. Ferritin levels were lower in high altitude patients compared with those at sea level and at moderate altitude (131,75 [106,04 - 157,45] vs. 493,38 [273,19 - 713,56] vs. 550,66 [329,75-771,57] p=0,01). Hemoglobin values were lower in patients from middle altitude levels (10,8 [10,12-11,47] vs 11,32 [10,79-11,85] vs 11,84 [11,54-12,14] p=0,03). Conclusions : In patients undergoing chronic hemodialysis oxygen saturation is reduced as long as altitude increases, and significant variations were found during hemodialysis procedures.