Referenced in: none

Automatically associated channels: TRP , TRPM , TRPM6

Title: Higher magnesium intake is associated with lower fasting glucose and insulin, with no evidence of interaction with select genetic loci, in a meta-analysis of 15 CHARGE Consortium Studies.

Authors: Adela Hruby, Julius S Ngwa, Frida Renström, Mary K Wojczynski, Andrea Ganna, Göran Hallmans, Denise K Houston, Paul F Jacques, Stavroula Kanoni, Terho Lehtimäki, Rozenn N Lemaitre, Ani Manichaikul, Kari E North, Ioanna Ntalla, Emily Sonestedt, Toshiko Tanaka, Frank J A van Rooij, Stefania Bandinelli, Luc Djoussé, Efi Grigoriou, Ingegerd Johansson, Kurt K Lohman, James S Pankow, Olli T Raitakari, Ulf Riserus, Mary Yannakoulia, M Carola Zillikens, Neelam Hassanali, Yongmei Liu, Dariush Mozaffarian, Constantina Papoutsakis, Ann-Christine Syvänen, André G Uitterlinden, Jorma Viikari, Christopher J Groves, Albert Hofman, Lars Lind, Mark I McCarthy, Vera Mikkilä, Kenneth Mukamal, Oscar H Franco, Ingrid B Borecki, L Adrienne Cupples, George V Dedoussis, Luigi Ferrucci, Frank B Hu, Erik Ingelsson, Mika Kähönen, W H Linda Kao, Stephen B Kritchevsky, Marju Orho-Melander, Inga Prokopenko, Jerome I Rotter, David S Siscovick, Jacqueline C M Witteman, Paul W Franks, James B Meigs, Nicola M McKeown, Jennifer A Nettleton

Journal, date & volume: J. Nutr., 2013 Mar , 143, 345-53

PubMed link: http://www.ncbi.nlm.nih.gov/pubmed/23343670

Abstract
Favorable associations between magnesium intake and glycemic traits, such as fasting glucose and insulin, are observed in observational and clinical studies, but whether genetic variation affects these associations is largely unknown. We hypothesized that single nucleotide polymorphisms (SNPs) associated with either glycemic traits or magnesium metabolism affect the association between magnesium intake and fasting glucose and insulin. Fifteen studies from the CHARGE (Cohorts for Heart and Aging Research in Genomic Epidemiology) Consortium provided data from up to 52,684 participants of European descent without known diabetes. In fixed-effects meta-analyses, we quantified 1) cross-sectional associations of dietary magnesium intake with fasting glucose (mmol/L) and insulin (ln-pmol/L) and 2) interactions between magnesium intake and SNPs related to fasting glucose (16 SNPs), insulin (2 SNPs), or magnesium (8 SNPs) on fasting glucose and insulin. After adjustment for age, sex, energy intake, BMI, and behavioral risk factors, magnesium (per 50-mg/d increment) was inversely associated with fasting glucose [β = -0.009 mmol/L (95% CI: -0.013, -0.005), P < 0.0001] and insulin [-0.020 ln-pmol/L (95% CI: -0.024, -0.017), P < 0.0001]. No magnesium-related SNP or interaction between any SNP and magnesium reached significance after correction for multiple testing. However, rs2274924 in magnesium transporter-encoding TRPM6 showed a nominal association (uncorrected P = 0.03) with glucose, and rs11558471 in SLC30A8 and rs3740393 near CNNM2 showed a nominal interaction (uncorrected, both P = 0.02) with magnesium on glucose. Consistent with other studies, a higher magnesium intake was associated with lower fasting glucose and insulin. Nominal evidence of TRPM6 influence and magnesium interaction with select loci suggests that further investigation is warranted.