Department of Chemical, Biological and Macro-Molecular Sciences, S. N. Bose National Centre for Basic Sciences, Salt Lake, JD Block, Sector III, Kolkata-700106, India.
J Breath Res. 2017 Jun 1;11(2):026005. doi: 10.1088/1752-7163/aa6bcf.
A new method to replace commercially prepared C-labelled glucose with naturally available C-enriched substrates could result in promotion of the clinical applicability of the isotopic breath test for detection of type 2 diabetes (T2D). Variation of the carbon-13 isotope in human breath depends on the C enrichment in the diet taken by subjects. Here, we formulated a new test meal comprising naturally available C-enriched foods and subsequently administered it to non-diabetic control (NDC) subjects and those with T2D. We found that the new test meal-derived C enrichment of breath CO was significantly lower in T2D compared with NDC. Furthermore, from our observations T2D exhibited higher isotopic enrichment of oxygen-18 (O) in breath CO compared with NDC following ingestion of the new meal. We determined the optimal diagnostic cut-off values of C (i.e. δ C‰ = 7.5‰) and O (i.e. δ O‰ = 3.5‰) isotopes in breath CO for precise classification of T2D and NDC. Our new method involving the administration of naturally C-abundant nutrients showed a typical diagnostic sensitivity and specificity of about 95%, suggesting a valid and potentially robust global method devoid of any synthetically manufactured commercial C-enriched glucose which thus may serve as an alternative diagnostic tool for routine clinical applications.
一种用天然富集碳底物替代市售 C 标记葡萄糖的新方法，可能会促进同位素呼气试验用于检测 2 型糖尿病（T2D）的临床适用性。人体呼气中碳-13 的变化取决于受试者所摄入的饮食中的 C 富集程度。在这里，我们设计了一种新的测试餐，包含天然富集的食物，然后将其给予非糖尿病对照（NDC）受试者和 T2D 患者。我们发现，与 NDC 相比，新测试餐衍生的呼气 CO 中的 C 富集在 T2D 中显著降低。此外，我们的观察结果表明，在摄入新餐后，T2D 患者呼气 CO 中的氧-18（O）的同位素富集明显高于 NDC。我们确定了呼气 CO 中 C（即 δ C‰=7.5‰）和 O（即 δ O‰=3.5‰）同位素的最佳诊断截止值，以精确分类 T2D 和 NDC。我们新的方法涉及给予天然丰富的营养物质，显示出约 95%的典型诊断灵敏度和特异性，表明这是一种有效且具有潜在稳健性的全球方法，没有任何合成制造的商业 C 富集葡萄糖，因此可能成为常规临床应用的替代诊断工具。
