Increased breath biomarkers of oxidative stress in diabetes mellitus

Background: Oxidative stress has been implicated in the major complications of diabetes mellitus, including retinopathy, nephropathy, neuropathy and accelerated coronary artery disease. There is a clinical need for a marker of oxidative stress which could potentially identify diabetic patients at increased risk for these complications. We measured oxidative age, a new breath marker of oxidative stress, in diabetic patients. Methods: Three groups were studied: type 1 diabetes mellitus (n = 9), type 2 diabetes mellitus (n = 53) and non-diabetic normals (n = 39). Volatile organic compounds (VOCs) in breath were assayed by gas chromatography and mass spectroscopy to construct the breath methylated alkane contour (BMAC), a three-dimensional display of oxidative stress markers, C4-C20 alkanes and monomethylated alkanes. The collective abundance of these VOCs was reduced to a single value, the oxidative age, comprising the volume under the curve of the BMAC corrected for chronological age. Results: Oxidative age was significantly increased in type 1 diabetes (mean=0.103, S.E.M.=0.119, p < 0.0 1) and type 2 diabetes (mean = 0.103, S.E.M. = 0.047, p < 0.05) compared to age-matched normals (mean = - 0.248, S.E.M. = 0.079). No significant correlation between oxidative age and blood glucose or hemoglobin A(I)C was observed in either group. Conclusions: Oxidative age, a marker of oxidative stress, was significantly increased in both type 1 and type 2 diabetes mellitus. Oxidative age merits further study as a candidate marker of risk for the complications of diabetes mellitus. (C) 2004 Elsevier B.V. All rights reserved.