A1 Refereed original research article in a scientific journal
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: Hruby A, Ngwa JS, Renstrom F, Wojczynski MK, Ganna A, Hallmans G, Houston DK, Jacques PF, Kanoni S, Lehtimaki T, Lemaitre RN, Manichaikul A, North KE, Ntalla I, Sonestedt E, Tanaka T, van Rooij FJA, Bandinelli S, Djousse L, Grigoriou E, Johansson I, Lohman KK, Pankow JS, Raitakari OT, Riserus U, Yannakoulia M, Zillikens MC, Hassanali N, Liu YM, Mozaffarian D, Papoutsakis C, Syvanen AC, Uitterlinden AG, Viikari J, Groves CJ, Hofman A, Lind L, McCarthy MI, Mikkila V, Mukamal K, Franco OH, Borecki IB, Cupples LA, Dedoussis GV, Ferrucci L, Hu FB, Ingelsson E, Kahonen M, Kao WHL, Kritchevsky SB, Orho-Melander M, Prokopenko I, Rotter JI, Siscovick DS, Witteman JCM, Franks PW, Meigs JB, McKeown NM, Nettleton JA
Publisher: AMER SOC NUTRITION-ASN
Publication year: 2013
Journal: Journal of Nutrition
Journal name in source: JOURNAL OF NUTRITION
Journal acronym: J NUTR
Number in series: 3
Volume: 143
Issue: 3
First page : 345
Last page: 353
Number of pages: 9
ISSN: 0022-3166
DOI: https://doi.org/10.3945/jn.112.172049
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 (In-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 [beta = -0.009 mmol/L (95% CI: -0.013, -0.005), P< 0.0001] and insulin (-0.020 In-pmo/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 SLC30A8and rs3740393 near CNNM2showed 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. J. Nutr. 143: 345-353, 2013.
