Relationship between soluble Semaphorin4D and cognitive impairment in patients with obstructive sleep apnea–hypopnea syndrome

To investigate the relationship between plasma soluble semaphorin4D (sSema4D) and obstructive sleep apnea–hypopnea syndrome (OSAHS), and to ascertain the effect of sSema4D on cognitive dysfunction in patients with OSAHS. We prospectively recruited 30 men with moderate–severe OSAHS diagnosed by polysomnography, and 30 healthy controls with matched gender, age and education level. Montreal Cognitive Assessment (MoCA) was administered to determine cognitive impairment. Plasma sSema4D levels were measured. Among the total of 60 study patients, the overall plasma sSema4D level was 7.81 ± 1.91 ng/ml. Plasma sSema4D level in OSAHS group was significantly higher than that in controls (8.92 ± 1.79 vs 6.70 ± 1.28 ng/ml, p < 0.001). In OSAHS subgroup, patients with cognition impairment (CI) had higher plasma sSema4D level (10.50 ± 1.16 vs 8.00 ± 1.41 ng/ml, p < 0.001) and apnea–hypopnea index (AHI) (48.1 ± 14.0 vs 30.3 ± 9.2, p < 0.001) than those in non-CI group. Multiple logistic regression revealed that plasma sSema4D level (AOR 2.824, 95 % CI 1.562–5.103; p = 0.001) and BMI (AOR 2.237, 95 % CI 1.345–3.722; p = 0.002) were significantly associated with OSAHS, and plasma sSema4D was a significant predictor of CI after adjustment for other confounders (AOR 4.956, 95 % CI 1.581–15.538; p = 0.006). OSAHS patients, especially those with cognition impairment, are featured by elevated plasma sSema4D level, and sSema4D is significantly associated with cognition impairment induced by OSAHS.