Oslo University Hospital, Rikshospitalet, Sognsvannsvn 20, Oslo N-0027, Norway. E-mail: hallvard.holdaas@rikshospitalet.no Received 19 April 2013; revised 26 August 2013; accepted 29 August 2013; published online 27 November 2013 162 Kidney International (2014) 86, 162–167 The aim of the present study was to estimate long-term all-cause mortality, cardiovascular mortality, and risk for ESRD in kidney donors compared with a selected control group screened for eligibility for live-kidney donation. RESULTS During 1963–2007, 2269 live-kidney donations were performed at Oslo University Hospital. After excluding marginal donors, 1901 donors were included (Figure 1). Among these, 1519 were first-degree relatives, 89 were other relatives, and 293 were unrelated. Median follow-up time was 15.1 (1.5–43.9) years. Mean estimated glomerular filtration rate (eGFR) at donation was 104.7 ml/min per 1.73 m2 (n ¼ 1766, s.d. 13.7). All donors were Caucasians. Controls were included from the Health Study of NordTrndelag (HUNT) population study. Out of the 74,991 individuals participating in this population-based survey, a control group of 32,621 was constructed to fit criteria for kidney donation (Table 1). Median follow-up time for the control group was 24.9 (0.1–26.0) years. For donors, outcome data on all-cause mortality and renal replacement therapy were ascertained as of January 2010 and cardiovascular mortality as of January 2008. For controls, all outcome data were ascertained as of January 2010. During the observation period, there were 224 deaths among 1901 kidney donors from the initial inclusion group, 68 (30.4%) of which were due to cardiovascular disease. There were 2425 deaths among the 32,621 controls, 688 (28.4%) of which were due to cardiovascular disease. No donors died during or immediately after the surgical procedure. Figure 2 shows the survival data for donors and controls. The survival curves were significantly different (Po0.001). Table 2a shows the hazard ratio (HR) for death by any cause in kidney donors compared with controls. The unadjusted risk associated with kidney donation was 2.49 (95% confidence interval (CI), 2.13–2.91, Po0.001). In adjusted complete case analysis, the HR for kidney donors was 1.48 (95% CI, 1.17–1.88, P ¼ 0.001). After multiple imputation, HR was 1.30 (95% CI, 1.11–1.52, P ¼ 0.001). There was a corresponding increase in cardiovascular mortality (HR 1.40, 95% CI 1.03–1.91, P ¼ 0.03) (Table 2b). A total of nine donors (0.47%) developed ESRD. All were family members. Median time from donation was 18.7 (10.3–24.3) years. Renal failure in donors was mainly caused by immunological diseases: glomerulonephritis (n ¼ 3), systemic lupus erythematosus (n ¼ 1), Wegener’s granulomatosis (n ¼ 1), ANCA (anti-neutrophil cytoplasmic antibodies)-positive vasculitis (n ¼ 1), sarcoidosis (n ¼ 1), and diabetes/nephrosclerosis (n ¼ 2). In the control group, 22 individuals developed ESRD. Reported causes were glomerulonephritis (n ¼ 5), pyelonephritis (n ¼ 4), polycystic kidney disease (n ¼ 4), hypertension (n ¼ 3), diabetes (n ¼ 1), amyloidosis (n ¼ 1), systemic lupus erythematosus (n ¼ 1), Kidney donors in Norway 1963–2007, n =2269 General adult population in Norway HUNT 1 survey, 1985–1987, n =74,991 Age>70 years (n =89) Age30 kg/m2 (n =125) BMI140/90 mm Hg (n =98) BP medication (n =8) eGFR < 70 ml/min per 1.73 m2 (n =41) Age>70 years (n =12,745) Age30 kg/m2 (n =1998) BMI140/90 mm Hg (n =8964) BP medication (n =4991) Diabetes (n =1348) CVD (n =2765) Reduced general health (n =9512) Exclusion: Exclusion: 1901 Donors and 32,621 controls fulfilling standard donation criteria Figure 1 | Flow chart showing inclusion and exclusion of kidney donors and controls. BMI, body mass index; BP, blood pressure; CVD, cardiovascular disease; eGFR, estimated glomerular filtration rate; HUNT 1, Health Study of Nord-Trndelag. Tabl1 Abbreviations: BMI, body mass index; BP, blood pressure. 0.20 Kidney donors Controls 0.15 Cumulative all-cause mortality 0.10 0.05 0.00 0 5 10 15 20 25 Time (years) Figure 2 | Cumulative mortality risk in kidney donors and controls, adjusted for year of donation. Controls are matched to donors for age, sex, systolic blood pressure, body mass index, and smoking status. G Mjen et al.: Risks for kidney donors clinical investigation Kidney International (2014) 86, 162–167 163 drug induced nephropathy (n ¼ 1), medullary cystic disease (n ¼ 1), and unknown (n ¼ 1). The crude incidence of ESRD in donors was 302 per million person-years. The overall incidence rate for development of ESRD in Norway is about 100 per million per person-year. After multiple imputation of missing values, the estimated HR for ESRD in kidney donors was 11.38 (4.37–29.63, Po0.001) (Table 2c). Assessing competing risks for the outcomes of cardiovascular death and ESRD did not change our findings. Neither did