[Analysis of related factors in secondary erythrocytosis of obstructive sleep apnea hypopnea syndrome in Gansu province].

To analyze the related factors of secondary erythrocytosis of obstructive sleep apnea（OSA） in Gansu province. Polysomnography recording and analysis from January 2013 to January 2021, A total of 448 OSA patients of long-resident Han nationality in Gansu province. Hemoglobin（Hb） values were divided into group A（Hb 120-160 g/L） 41 cases, B（Hb 161-179 g/L） 142 cases, C（Hb 180-199 g/L） 152 cases, D（Hb 200-219 g/L） 79 cases, and E（Hb ≥220 g/L） 30 cases. General clinical data, altitude of residence, disease course, apnea hypopnea index （AHI）, and Lowest oxyhemoglobin（LSpO₂） were compared among these groups. Multivariate regression and ROC curves were used to analyze the influencing factors of OSA secondary erythrocytosis. There were no significant differences in age, sex, and course of disease among groups A, B, C, D, and E （>0.05）.The altitude of group E was higher than that of groups A, B, C, and D （<0.05）, but there was no significant difference between groups A, B, C and D （>0.05）.AHI was significantly different among groups A, B, C, D, and E （<0.05）, groups C, D, and E were significantly higher than A; group D was significantly higher than B, C.LSpO₂ was significantly different among groups A, B, C, D, and E （P <0.05）, groups B, C, D, and E was significantly lower than A; group D, E was significantly lower than B, C.MSpO₂ was significantly different among groups A, B, C, D, and E （<0.05）, groups B, C, D, and E was significantly lower A; groups D, E was significantly lower than B , C.Multivariate regression showed that the higher the altitude, the lower the MSpO₂, the more serious the secondary hyperhemoglobinemia.Age, course of the disease, AHI, and LSpO₂ were not the influencing factors of OSA secondary hemoglobin increase.The areas under the ROC curve for MSpO₂ and altitude to predict Hb≥180 g/L were 0.694（<0.001） and 0.570（=0.009）, with statistically significant differences（Z=3.205, =0.001）. Altitude and MSpO₂ were independent risk factors for OSA secondary erythrocytosis; MSpO₂ predicted that Hb≥180 g/L in OSA patients was better than altitude.