Effect of metformin therapy on circulating amino acids in a randomized trial: the CAMERA study: Metabolism

<strong>Aims</strong> To investigate whether metformin therapy alters amino acid concentrations, increased levels of which have been found to predict Type 2 diabetes. <strong>Methods</strong> In the Carotid Atherosclerosis: Metformin for Insulin Resistance (CAMERA) study (NC...

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Main Authors: Preiss, D, Rankin, N, Welsh, P, Holman, R, Kangas, A, Soininen, P, Würtz, P, Ala-Korpela, M, Sattar, N
Format: Journal article
Published: Wiley 2016
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author Preiss, D
Rankin, N
Welsh, P
Holman, R
Kangas, A
Soininen, P
Würtz, P
Ala-Korpela, M
Sattar, N
author_facet Preiss, D
Rankin, N
Welsh, P
Holman, R
Kangas, A
Soininen, P
Würtz, P
Ala-Korpela, M
Sattar, N
author_sort Preiss, D
collection OXFORD
description <strong>Aims</strong> To investigate whether metformin therapy alters amino acid concentrations, increased levels of which have been found to predict Type 2 diabetes. <strong>Methods</strong> In the Carotid Atherosclerosis: Metformin for Insulin Resistance (CAMERA) study (NCT00723307), 173 individuals without Type 2 diabetes, but with coronary disease, were randomized to metformin (n=86) or placebo (n=87) for 18 months. Plasma samples, taken every 6 months, were analysed using quantitative nuclear magnetic resonance spectroscopy. Ten metabolites consisting of eight amino acids [three branched-chain (isoleucine, leucine, valine), three aromatic (tyrosine, phenylalanine, histidine) and two other amino acids (alanine, glutamine)], lactate and pyruvate were quantified and analysed using repeated-measures models. On-treatment analyses were conducted to investigate whether amino acid changes were dependent on changes in weight, fat mass or insulin resistance measured using homeostasis model assessment. <strong>Results</strong> Tyrosine decreased [-6.1 μmol/l (95% CI -8.5, -3.7); P&lt;0.0001], while alanine [42 umol/l (95% CI 25, 59); P&lt;0.0001] increased in the metformin-treated group compared with the placebo-treated group. Decreases in phenylalanine [-2.0 μmol/l (95% CI -3.6, -0.3); P=0.018] and increases in histidine [2.3 μmol/l (95% CI 0.1, 4.6); P=0.045] were also observed in the metformin group, although these changes were less statistically robust. No changes in these four amino acids were accounted for by changes in weight, fat mass or homeostasis model assessment of insulin resistance values. Levels of branched-chain amino acids, glutamine, pyruvate and lactate were not altered by metformin therapy. <strong>Conclusions</strong> Metformin therapy results in a sustained and specific pattern of changes in aromatic amino acid and alanine concentrations. These changes are independent of any effects on weight and insulin sensitivity. Any causal link to metformin's unexplained cardiometabolic benefit requires further study.
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spelling oxford-uuid:c44bd9f2-12d5-4868-8a8c-b6ed7bfc45382022-03-27T06:22:27ZEffect of metformin therapy on circulating amino acids in a randomized trial: the CAMERA study: MetabolismJournal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:c44bd9f2-12d5-4868-8a8c-b6ed7bfc4538Symplectic Elements at OxfordWiley2016Preiss, DRankin, NWelsh, PHolman, RKangas, ASoininen, PWürtz, PAla-Korpela, MSattar, N<strong>Aims</strong> To investigate whether metformin therapy alters amino acid concentrations, increased levels of which have been found to predict Type 2 diabetes. <strong>Methods</strong> In the Carotid Atherosclerosis: Metformin for Insulin Resistance (CAMERA) study (NCT00723307), 173 individuals without Type 2 diabetes, but with coronary disease, were randomized to metformin (n=86) or placebo (n=87) for 18 months. Plasma samples, taken every 6 months, were analysed using quantitative nuclear magnetic resonance spectroscopy. Ten metabolites consisting of eight amino acids [three branched-chain (isoleucine, leucine, valine), three aromatic (tyrosine, phenylalanine, histidine) and two other amino acids (alanine, glutamine)], lactate and pyruvate were quantified and analysed using repeated-measures models. On-treatment analyses were conducted to investigate whether amino acid changes were dependent on changes in weight, fat mass or insulin resistance measured using homeostasis model assessment. <strong>Results</strong> Tyrosine decreased [-6.1 μmol/l (95% CI -8.5, -3.7); P&lt;0.0001], while alanine [42 umol/l (95% CI 25, 59); P&lt;0.0001] increased in the metformin-treated group compared with the placebo-treated group. Decreases in phenylalanine [-2.0 μmol/l (95% CI -3.6, -0.3); P=0.018] and increases in histidine [2.3 μmol/l (95% CI 0.1, 4.6); P=0.045] were also observed in the metformin group, although these changes were less statistically robust. No changes in these four amino acids were accounted for by changes in weight, fat mass or homeostasis model assessment of insulin resistance values. Levels of branched-chain amino acids, glutamine, pyruvate and lactate were not altered by metformin therapy. <strong>Conclusions</strong> Metformin therapy results in a sustained and specific pattern of changes in aromatic amino acid and alanine concentrations. These changes are independent of any effects on weight and insulin sensitivity. Any causal link to metformin's unexplained cardiometabolic benefit requires further study.
spellingShingle Preiss, D
Rankin, N
Welsh, P
Holman, R
Kangas, A
Soininen, P
Würtz, P
Ala-Korpela, M
Sattar, N
Effect of metformin therapy on circulating amino acids in a randomized trial: the CAMERA study: Metabolism
title Effect of metformin therapy on circulating amino acids in a randomized trial: the CAMERA study: Metabolism
title_full Effect of metformin therapy on circulating amino acids in a randomized trial: the CAMERA study: Metabolism
title_fullStr Effect of metformin therapy on circulating amino acids in a randomized trial: the CAMERA study: Metabolism
title_full_unstemmed Effect of metformin therapy on circulating amino acids in a randomized trial: the CAMERA study: Metabolism
title_short Effect of metformin therapy on circulating amino acids in a randomized trial: the CAMERA study: Metabolism
title_sort effect of metformin therapy on circulating amino acids in a randomized trial the camera study metabolism
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