Plasma high-sensitivity troponin T predicts end-stage renal disease and cardiovascular and all-cause mortality in patients with type 1 diabetes and diabetic nephropathy

High-sensitivity troponin T (hsTnT) is a marker of cardiovascular disease (CVD) and in type 2 diabetes also a marker of renal events, but has not been evaluated in type 1 diabetics. We therefore reviewed a type 1 diabetes cohort of 442 without and 458 with diabetic nephropathy. Baseline samples were analyzed for hsTnT levels. Cox regression analyses assessed predictive value in relation to the development of end-stage renal disease (ESRD) in 99 patients, all-cause mortality in 178, and CVD events in 134 after up to 12 years of follow-up. To assess if hsTnT improved risk prediction beyond traditional clinical risk markers, we calculated c statistics and relative integrated discrimination improvement. HsTnT was significantly higher in patients with diabetic nephropathy compared to normoalbuminuria (median 8.9 vs 3.1 ng/L). For a doubling in hsTnT levels, and after adjustment for well-known risk factors, including NT-proBNP and hsCRP, the hazard ratio for ESRD at 1.26 was not significant in the diabetic nephropathy group, but there was a significant association with GFR decline after adjustment during follow-up (2.9 ml/min/1.73 m(2) annual decline per doubling in hsTnT). The unadjusted and adjusted hazard ratios for mortality (1.64 and 1.32, respectively) were significant in patients with, but not for patients without, nephropathy. Adjusted hazard ratios for fatal and non-fatal CVD events were significant for the whole cohort (1.13), and those with nephropathy (1.14), but not significant for normoalbuminuria (1.06). Addition of hsTNT to traditional risk factors significantly increased the area under the curve by 0.01 in a receiver-operating characteristic curve for mortality. The relative integrated discrimination improvement was increased 15.7% for mortality, 6.3% for CVD, and 1.9% for ESRD (all significant). Thus, higher hsTnT is an independent predictor of renal decline and cardiovascular events in patients with type 1 diabetes and diabetic nephropathy.