Impact of Pulmonary Hypertension on Renal Functions in Obstructive Sleep Apnea Syndrome

Pulmonary hypertension (PH) is common in obstructive sleep apnea syndrome (OSAS). This study aimed to evaluate the effect of PH on kidney functions in patients with OSAS.

The data of patients who were diagnosed as having OSAS after referral to the sleep center in the Gaziantep University Medical Faculty between January 2005 and June 2017 were evaluated. The estimated glomerular filtration rate was calculated with the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equation. Renal functions of the subjects who had data after 5 years were included for long-term analysis.

A total of 2152 patients with OSAS (n = 1540), PH (n = 49), OSAS and PH coexistence (n = 359), and the control group (n = 204) were included in the study. Pulmonary arterial pressure (PAP) was 44.51 ± 23.73 in the PH group; it was 37.1 ± 13.14 in the group with OSAS + PH (P = 0.001) Urea and uric acid were found to be higher in the association of OSAS + PH. CKD-EPI was lower in the presence of PH or OSAS + PH than in the presence of OSAS. PH was present in 16.06% of males and 25.10% of females (P = 0.000), and PAP was detected as 35.80 ± 13.23 and 40.96 ± 16.65, respectively (P = 0.001). PH was present in 15.99% of males and 25.84% of females with OSAS (P = 0.000). The PAP of males with OSAS was 36.03 ± 13.46, and the PAP of females was 38.68 ± 12.55 (P = 0062). Urea, creatinine, and uric acid were higher and CKD-EPI was lower in male subjects in the presence of OSAS and PH, whereas the same scenario also was present in the presence of PH alone in female subjects. Long-term comparisons (n = 343) revealed significant decreases in the CKD-EPI in those with OSAS and OSAS + PH and these decrease were more pronounced in the presence of OSAS and PH. The regression analysis revealed that female patients had lower CKD-EPI in the presence of PH, although the presence of PH had no effect on CKD-EPI in males.

PH is a risk factor for the deterioration of renal function in OSAS and more prominent in the long term.