Identification of current smokers among renal transplant recipients

In renal transplant recipients, smoking is associated with a high burden of cardiovascular disease and a higher risk of graft loss. Surprisingly, the results of measurement of cotinine serum level, the gold standard for the detection of active smoking, have not been confronted with self-reported smoking history in this group. The aim of our study was to identify and characterize the smoking group of renal transplant recipients.

Cotinine serum level was measured and all patients were asked to fill out an anonymous questionnaire on smoking history.

Out of 233 renal transplant recipients, 106 (45%) reported to be lifetime and current non-smokers: cotinine serum level was below detection limit in all; among the 127 renal transplant recipients (55%) with a lifetime history of smoking, cotinine level was diagnostic of current smoking in 32 (25%). Only 21 of the current smokers (66%) declared to the nephrologist that they had continued smoking whereas 11 (34%) claimed to be non-smokers. Current smokers were younger (P=0.01) than former smokers.

The identification of current smokers among renal transplant recipients should start with questioning about lifetime history of smoking and if positive, measurement of cotinine serum level. Indeed up to 34% of current smokers do not acknowledge they are active smokers and would otherwise not offer to participate in programmes to stop smoking.