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- Nowak, Christoph, et al.
(författare)
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Metabolite profiles during an oral glucose tolerance test reveal new associations with clamp-measured insulin sensitivity
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- Impaired insulin sensitivity (IS) is a major risk factor for cardiovascular disease and type 2 diabetes. Metabolomic profiling during an oral glucose tolerance test (OGTT) can reveal early pathogenic alterations in healthy individuals. Our aim was to identify IS biomarkers and gain new pathophysiologic insights by applying untargeted metabolomics to repeated OGTT plasma samples in association with a hyperinsulinemic-euglycemic clamp assessment. We studied 192 metabolites identified by non-targeted liquid chromatography/mass spectrometry in plasma samples taken at 0, 30, and 120 min during an OGTT in 470 non-diabetic 71-yr-old men. Insulin sensitivity was associated with 35 metabolites at one or more time points in multivariable-adjusted linear regression. The trajectories of nine metabolites during the OGTT were related to IS, six of which (oleic and palmitoleic acid, decanoyl- and dodecanoylcarnitine, deoxycholate-glycine and hexose) showed no associations with IS in the baseline fasting state. The strongest effects were detected for medium-chain acylcarnitines, which increased between 30-120 min in insulin-resistant individuals compared to those with normal IS. In this large community sample, we identified novel associations between clamp-measured IS and metabolite profiles that became apparent only after an oral glucose challenge. Associations of differential medium-chain acylcarnitine and monounsaturated fatty acid trajectories with IS provide new insights into the pathogenesis of insulin resistance.
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| 3. |
- Nowak, Christoph, et al.
(författare)
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Type 2 diabetes, glycaemic traits and cardiovascular disease : a Mendelian Randomization study
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- Type 2 diabetes (T2D) and its hallmarks insulin resistance, impaired insulin secretion, and hyperglycaemia affect over 400 million persons worldwide and are associated with raised cardiovascular risk, but their causal role has been difficult to dissect due to overlap between risk factors. We used Mendelian randomization analysis, which utilises genetic polymorphisms associated with a risk factor, to assess causal effects of T2D, insulin resistance, insulin secretion, and fasting glucose on mortality, ischaemic stroke, and coronary artery disease (CAD) risk in 120,091 adults in the UK Biobank and in the CARDIoGRAMplusC4D consortium (63,746 cases of CAD and 130,681 controls). We found evidence for a causal effect of T2D on raised CAD risk (odds ratio (OR) per doubling in the odds of T2D, 1.07, 95% confidence interval (CI) 1.05 – 1.09, P = 1.2 x 10-9) and for a causal effect of impaired insulin secretion on the risk of CAD (OR per SD-unit decrease, 1.14, 95% CI 1.06 – 1.22, P = 0.002). The genetic score for insulin resistance was associated with increased coronary artery disease risk; however, sensitivity analysis indicated that the instrument might not be appropriate to use for robust causal inference testing. Our results support previous reports of a causal role of T2D and impaired insulin secretion in coronary artery disease and point to a complex relationship between variants affecting insulin resistance and cardiovascular outcomes.
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