Former smoking is a risk factor for chronic kidney disease after lung transplantation

Chronic kidney disease (CKD) is a common complication after lung transplantation (LTx). Smoking is a risk factor for many diseases, including CKD. Smoking cessation for >6 months is required for LTx enlistment. However, the impact of smoking history on CKD development after LTx remains unclear. We investigated the effect of former smoking on CKD and mortality after LTx. CKD was based on glomerular filtration rate (GFR) ((125) I-iothalamate measurements). GFR was measured before and repeatedly after LTx. One hundred thirty-four patients never smoked and 192 patients previously smoked for a median of 17.5 pack years. At 5 years after LTx, overall cumulative incidences of CKD-III, CKD-IV and death were 68.5%, 16.3% and 34.6%, respectively. Compared to never smokers, former smokers had a higher risk for CKD-III (hazard ratio [HR] 95% confidence interval [95%CI]= 1.69 [1.27-2.24]) and IV (HR = 1.90 [1.11-3.27]), but not for mortality (HR = 0.99 [0.71-1.38]). Adjustment for potential confounders did not change results. Thus, despite cessation, smoking history remained a risk factor for CKD in LTx recipients. Considering the increasing acceptance for LTx of older recipients with lower baseline renal function and an extensive smoking history, our data suggest that the problem of post-LTx CKD may increase in the future.