Objective       To invest

igate the characteristics of sleep-related breathing and blood oxygen saturation (SaO

2

) of high altitude polycythemia (HAPC) in migrant Han in order to provide evidence for therapy.       Methods       Polysomnography (PSG) were performed on 40 HAPC and 20 healthy volunteers (control group) of migrant Han ethnic in a quiet and comfortable room. The apnea-hypopnea index (AHI)

apnea index (AI)

hypopnea index (HI)

awake SaO

2

(ASaO

2

)

mean SaO

2

(MSaO

2

)

lowest SaO

2

(L SaO

2

)

percentage of reduced SaO

2

(A-MSaO

2

%)

oxygen desaturation index (ODI

4

) and percentage of time for ODI

4

(T

ODI4

%) were calculated. Pittsburgh Sleep Quality Index (PSQI) was employed to evaluate the sleep quality measured after PSG. Red blood cells (RBC)

hemoglobin (HGB)

and haematocrit (HCT) were compared between 2 groups.       Results      RBC

HGB

and HCT were significantly higher in HAPC group (P0.01)

while there was no significant difference in total score and every score of PSQI between 2 groups (P0.05). Although there was no difference in AHI and AI (P0.05)

HI was significantly higher in HAPC than in control group (P0.05). ASaO

2

MSaO

2

and LSaO

2

were obviously lower

but A-MSaO

2

%

ODI4 and T

ODI4

% were remarkably higher in HAPC than in control group (P0.05).       Conclusion       HAPC in migrant Han high altitude dwellers are characterized as hypoventilation and hyoxemia during sleeping.