Performance in the Six-Minute Walking Test Does Not Discriminate Excessive Erythrocytosis Patients in a Severe Hypoxic Environment.

BACKGROUND: Chronic exposure to severe hypoxia causes an increase in hematocrit (Hct) and hemoglobin concentration ([Hb]), which can lead to excessive erythrocytosis (EE) and impact physical performance. This work aims to determine the differences in the six-minute walking test (6MWT) between EE and healthy subjects residing at more than 5000 m. METHODS: A prospective, cross-sectional study was performed on 71 men (36 healthy and 25 suffering from EE) living in La Rinconada, Peru (5100 m). Basal levels of [Hb] and Hct were obtained. All the subjects performed the 6MWT, and distance reached, vital signs, dyspnea, and fatigue (Borg scale) at the end of the test were recorded. RESULTS: The average [Hb] and Hct levels in the control group were 18.7 ± 1.2 g/dL and 60.4 ± 7.1%, respectively, contrasting with EE subjects, who showed 23.4 ± 1.6 g/dL and 73.6 ± 5.9% (p < 0.001). However, no statistically significant differences were observed in BMI or other anthropometric parameters. At the end of the 6MWT, the distance traveled and vital constants were similar between both groups, except for arterial oxygen saturation, which was consistently lower in subjects with EE throughout the test. CONCLUSION: EE does not significantly affect 6MWT performance at high altitudes, nor the hemodynamic control during moderate aerobic exercise of subjects who live permanently in a severely hypoxic environment.

Alteraciones cardiovasculares en pacientes con eritrocitosis excesiva en residentes a 5 200 metros sobre el nivel del mar / Cardiovascular alterations in patients with excessive erythrocytosis in residents at 5,200 meters above the sea level

RESUMEN Objetivo: describir la función cardiovascular y determinar las alteraciones cardiacas en pacientes con y sin eritrocitosis excesiva (EE). Materiales y métodos: estudio de tipo prospectivo, transversal y analítico. La muestra fue de 61 pacientes residentes del Centro Poblado La Rinconada, localizado en Puno - Perú, ubicado a 5 200 m.s.n.m. Se utilizó una ficha de recolección de datos, se aplicó el score de mal de montaña crónico de Qinghai y un cardiólogo experimentado realizo las ecocardiografías. Resultados: el promedio de edad fue de 44 ± 7 años y el tiempo de residencia fue de 16 ± 9,8 años. Del total de pacientes, el 80,3% presentó mal de montaña crónico; de estos, el 68,9% fue de grado leve, 6,6% de grado moderado y el 4,9% de grado severo. Dentro de los hallazgos ecocardiográficos se encontraron: dilatación de cavidades cardiacas (16,4%), leve alteración del llenado del ventrículo derecho (3,27%), válvula aórtica bicúspide (3,27%), dificultad del llenado del ventrículo izquierdo (8,2%), leve alteración en la relajación y llenado del ventrículo izquierdo (1,6%), insuficiencia aórtica leve (1,6%) e hipertensión pulmonar (1,6%). El 83,6% presentaba hemoglobina ≥ 21 mg/dl. Conclusiones: el grupo con EE presentó más alteraciones cardiacas, la alteración cardiaca más frecuente fue la dilatación de cavidades cardiacas derechas.

ABSTRACT Objective: to describe cardiovascular function and determine cardiac disturbances in patients with and without excessive erythrocyteosis (EE). Materials and methods: a prospective, transversal and analytical type study. The sample was of 61 resident patients of the Centro Poblado La Rinconada, located in Puno - Peru, located at 5,200 meters above the sea level. A data collection sheet was used, Qinghai's chronic mountain sickness score was applied, and an experienced cardiologist performed echocardiographies. Results: the average age was 44 ± 7 years and the residence time was 16 ± 9.8 years. Of the total number of patients, 80.3% had chronic mountain sickness; of these, 68.9% were mild grade, 6.6% moderate grade and 4.9% severe grade. Among the echocardiographic findings were found: dilation of cardiac cavities (16.4%), slight alteration of the filling of the right ventricle (3.27%), bicuspid aortic valve (3.27%), difficulty filling the left ventricle (8.2%), slight alteration in relaxation and filling of the left ventricle (1.6%), mild aortic insufficiency (1.6%) pulmonary hypertension (1.6%). 83.6% had hemoglobin ≥ 21 mg/dL. Conclusions: the group with EE had more cardiac disturbances, the most common cardiac disturbance was the dilation of right heart chambers.

Eritrocitosis excesiva y mal de montaña crónico en mujeres residentes a extrema altura (la Rinconada 5200 msnm, Perú) / Excessive erythrocytosis and acute mountain sickness in women living at extreme altitude (La Rinconada, 5200 msnm, Perú)

El objetivo del trabajo fue determinar la prevalencia y el impacto de la eritrocitosis excesiva (EE) y mal de montaña crónico (MMC) en mujeres, y factores asociados en el desarrollo de estas alteraciones, principalmente la edad e índice de masa corporal (IMC). Los resultados mostraron una prevalencia de EE y MMC, de 19,72% y 25,35%, respectivamente. La edad promedio es de 39,79 ± 10,87; el hematocrito promedio fue 51,95 ± 6,85; la saturación de oxígeno fue 79,88 ± 5,24 y el IMC promedio de la participantes es 28,08 ± 3,87. La prevalencia de EE en el sexo femenino es mayor en las mujeres posmenopáusicas, en comparación a las premenopáusicas. Por otro lado, se determinó que un mayor índice de masa corporal se asocia fuertemente a menores valores de saturación de oxígeno. Entonces, así el incremento de la edad y del índice de masa corporal, favorecen el presencia de eritrocitosis excesiva más marcada condicionando un desarrollo de mal de montaña crónico de mayor severidad.

The aim of the work was to determine the prevalence and impact of excessive erytrochytes (EE) and chronic mountain sickness (MMC) in women, and related factors of the development of these alterations, mainly age and body max index (IMC). Results displayed incidence of EE and MMC, by 19.72% and 25.35%, respectively. The average age was 39.79 ± 10.87; the average hematocrit was 51.95 ± 6.85; the oxygen saturation was 79.88 ± 5.24 and the average IMC of the participants was 28.08 ± 3.87. The prevalence of EE on females is greater in postmenopausal women, in comparison to pre menopausals. On the other hand, it was determined that a greater body mass index is strongly associated to lesser oxygen saturation values. Hence, the increase of age and body max index, favor the most marked excesive erytrochytes presence conditioning the most serious acute mountain sickness.