Impact of kidney function and urinary protein excretion on pulmonary function in Japanese patients with chronic kidney disease

• DOI: 10.1007/s10157-013-0920-7
• Publication Date: 2013-12-14T12:50:44Z
• Authors: Yusuke Nakade; Tadashi Toyama; Kengo Furuichi; Shinji Kitajima; Noriyuki Ohkura; Akihiro Sagara; Yasuyuki Shinozaki; Akinori Hara; Kiyoki Kitagawa; Miho Shimizu; Yasunori Iwata; Hiroyasu Oe; Mikio Nagahara; Hiroshi Horita; Yoshio Sakai; Shuichi Kaneko; Takashi Wada
• Keywords: Adult; Male; Middle Aged; 16. Peace & justice; Respiratory Function Tests; 3. Good health; Proteinuria; 03 medical and health sciences; 0302 clinical medicine; Japan; Humans; Female; Renal Insufficiency, Chronic; Lung; Aged; Glomerular Filtration Rate

Although the cardiorenal relationship in chronic kidney disease has been investigated, information about the lung-kidney relationship is limited. Here, we investigated the impact of kidney function and urinary protein excretion on pulmonary dysfunction.The data from pulmonary function tests and kidney function (estimated glomerular filtration rate [eGFR] and urinary protein) between 1 April 2005 and 30 June 2010 were selected from our laboratory database. Data were classified into 4 categories according to eGFR and proteinuria. Category 1, eGFR ≥60 ml/min/1.73 m(2) and urinary protein <0.3 g/gCr; category 2, eGFR <60 ml/min/1.73 m(2) and urinary protein <0.3 g/gCr; category 3, eGFR ≥60 ml/min/1.73 m(2) and urinary protein ≥0.3 g/gCr; and category 4, eGFR <60 ml/min/1.73 m(2) and urinary protein ≥0.3 g/gCr. Pulmonary function data were evaluated according to these 4 categories.A total of 133 participants without major respiratory disease, abnormal computed tomography and smoking history were enrolled. Hemoglobin (Hb)-adjusted percentage carbon monoxide diffusing capacity (%DLCO) in category 4 (46.2 ± 7.5) and category 2 (63.6 ± 17.8) were significantly lower than in category 1 (75.8 ± 18.9) (P < 0.05). In addition, Hb-adjusted %DLCO was weakly correlated with eGFR in participants with urinary protein <0.3 g/gCr (R = 0.30, P = 0.001). Hb-adjusted %DLCO was strongly correlated with eGFR in participants with urinary protein ≥0.3 g/gCr (R = 0.81, P < 0.001). Other pulmonary function test markers (percentage (%) vital capacity, % forced expiratory volume in one second (FEV1), FEV1/forced vital capacity, % total lung capacity, and % residual volume) were not significantly different between categories.This study suggests that decreased eGFR is associated with decreased %DLCO in proteinuric patients.