Total Mortality by Elevated Transferrin Saturation in PatientsWith Diabetes

OBJECTIVEdIt is not known to what extent iron overload predicts prognosis in patients with diabetes after diagnosis or whether iron overload is a risk factor independent of the HFE geno-type. We investigated total and cause-specific mortality according to increased transferrin satu-ration ($50 vs.,50%), whether mortality is driven by the HFE genotype, and whether early measurement of transferrin saturation helps to predict mortality outcome. RESEARCH DESIGN AND METHODSdCohort 1 included patients with late-onset type 1 diabetes (n = 716) with a cross-sectional measurement of transferrin saturation and HFE genotype. Cohort 2 included consecutively recruited patients with any diabetes (n = 6,120), transferrin saturation measurement at referral, andHFE genotype if transferrin saturation was above 50%. RESULTSdIn cohort 1, the hazard ratio for total mortality was 2.3 (95 % CI 1.3–3.9; P = 0.002) and for cause-specific mortality by neoplasms was 5.8 (2.4–14; P = 0.00007) in patients with transferrin saturation $50 vs.,50%. Excluding genotypes C282Y/C282Y and C282Y/ H63D gave similar results. The hazard ratio for total mortality was 4.0 (1.2–13; P = 0.01) and for cause-specific mortality by neoplasms was 13 (3.6–49; P = 0.0001) in patients with C282Y