Obstructive and Restrictive Lung Function Measures and CKD: National Health and Nutrition Examination Survey (NHANES) 2007-2012.

backgroundPrevalence and factors associated with obstructive and restrictive lung function in people with chronic kidney disease (CKD) are unknown. STUDY

designCross-sectional and longitudinal analyses. SETTING &

participantsParticipants aged 40 to 79 years from NHANES (National Health and Nutrition Examination Survey) 2007 to 2012 who underwent spirometry testing. PREDICTOR: CKD (estimated glomerular filtration rate [eGFR] >15-<60mL/min/1.73m(2) or urinary albumin-creatinine ratio ≥ 30mg/g). OUTCOMES: Restrictive lung function (defined as FEV1/FVC≥0.70 and baseline FVC<80% predicted), obstructive lung function (defined as FEV1/FVC<0.70 based on postbronchodilator spirometric results), and mortality data (available for 2007-2008 and 2009-2010 survey periods).

results7,610 participants (CKD=1,338; non-CKD=6,272) were included. Prevalences of obstructive lung function adjusted to the mean age of 55 years and 50% men in the CKD and non-CKD groups were 15.6% and 13.3%, respectively (P=0.2). Similarly, adjusted prevalences of restrictive lung function in the CKD and non-CKD groups were 9.8% and 6.7%, respectively (P=0.01). Presence of albumin-creatinine ratio ≥ 30mg/g was associated with obstructive (OR, 1.42; 95% CI, 1.07-1.88) and restrictive lung function (OR, 1.43; 95% CI, 1.01-2.03) in the entire study cohort. eGFR<60mL/min/1.73m(2) was associated with higher odds of obstructive lung function. In a multivariable Cox model, age (HR, 1.07; 95% CI, 1.04-1.11) and presence of obstructive lung function (HR, 2.68; 95% CI, 1.80-3.97), but not CKD measures, were associated with death. LIMITATIONS: Small proportion of participants with advanced kidney disease.

conclusionsIn a representative sample of US adults, impaired lung function is common in those with and without CKD. Albuminuria was independently associated with both obstructive and restrictive lung function, and eGFR<60mL/min/1.73m(2) was associated with higher odds of obstructive lung function. Older age and obstructive lung function were associated with higher likelihood of death. Further studies examining the burden of lung disease in advanced CKD are needed.