Cigarette smoking in renal transplant recipients

Cigarette smoking increases the risk for cancer and cardiovascular disease in the general population, but the effects of smoking in renal transplant r ecipients are unknown. The effects of smoking were investigated among patie nts transplanted at Hennepin County Medical Center between 1963 and 1997. I nformation on smoking was available in 1334 patients. The 24.7% prevalence of smoking at the time of transplantation was similar to that in the genera l population. After adjusting for multiple predictors of graft failure, smo king more than 25 pack-years at transplantation (compared to smoking less t han 25 pack-years or never having smoked) was associated with a 30% higher risk of graft failure (relative risk 1.30; 95% confidence interval [CI], 1. 04 to 1.63; P = 0.021). Having quit smoking more than 5 yr before transplan tation reduced the relative risk of graft failure by 34% (relative risk 0.6 6; 95% CI, 0.52 to 0.85; P < 0.001). The increase in graft failure was due to an increase in deaths (adjusted relative risk 1.42; 95% CI, 1.08 to 1.87 ; P = 0.012). The relative risk for major cardiovascular disease events wit h smoking 11 to 25 pack-years at transplant was 1.56 (95% CI, 1.06 to 2.31; P = 0.024), whereas that of smoking more than 25 pack-years was 2.14 (95% CI, 1.49 to 3.08; P < 0.001). The relative risk of invasive malignancies wa s 1.91 (95% CI, 1.05 to 3.48; P = 0.032). Smoking had no discernible effect on the rate of return to dialysis or on serum creatinine during the first year after transplantation. Thus, cigarette smoking is associated with an i ncreased risk of death after renal transplantation. The effects of smoking appear to dissipate 5 yr after quitting. These results indirectly suggest t hat greater efforts to encourage patients to quit smoking before transplant ation may decrease morbidity and mortality.