Abstract: Objective To explore the changes of respiratory function in patients with chronic renal failure and the effect of hemodialysis and microinflammatory on the impairments. Methods Fourty-two patients with chronic renal failure (CRF) who were on maintenance hemodialysis (MHD) received pulmonary function test (PFT) before and shortly after a hemodialysis (HD) session. At the same time, high-sensitivity C-reactive protein (hs-CRP) was measured to evaluate the microinflammatory state in CRF patients. CRF patients were divided into two groups Group A (hs-CRP＞10mg/L) and group B (hs-CRP＜10mg/L). The PFT parameters of the two groups were compared. Results The mean values of PFT parameters including FVC, FEV1.0, PEF, V25, V50, DLco, MIP, MEP in CRF patients were significantly lower than normal subjects (P＜0.01). The PFT parameters in group A including FVC, FEV1.0, PEF, MIP, MEP were significantly lower than those in group B (P ＜0.01, P ＜0.05).Whereas, there were no significant differences V25, V50 and DLco (P ＞0.05).There was significant correlation between hs-CRP and FVC, FEV1.0, PEF, MIP, age, serum albumin, serum creatinine，serum transferrin (P＜0.01), MEP, Hemoglobin, PA (P ＜0.05). Correlation analysis revealed no relationship between hs-CRP and Sex, Duration of HD, V25, V50, Dlco (P ＞0.05). After the HD session, repeat PFT revealed significant increase in FVC,FEV1.0, PEF, V25, V50, DLco, (P ＜0.01，P ＜0.05). But there were no significant difference of MIP,MEP. Conclusion Patients with CRF showed significant reductions in lung ventilation, pulmonary diffusing capacity and small airway function.The parameters about respiratory muscle strength decreased significantly. The function of ventilation and respiratory muscle are possibly associated with microinflammatory state. Hemodialysis can partly improve the impairment of respiratory function.

Key words: Hemodialysis, Microinflammatory state, Pulmonary function