@article {1222, title = {Interactions of dietary whole-grain intake with fasting glucose- and insulin-related genetic loci in individuals of European descent: a meta-analysis of 14 cohort studies.}, journal = {Diabetes Care}, volume = {33}, year = {2010}, month = {2010 Dec}, pages = {2684-91}, abstract = {

OBJECTIVE: Whole-grain foods are touted for multiple health benefits, including enhancing insulin sensitivity and reducing type 2 diabetes risk. Recent genome-wide association studies (GWAS) have identified several single nucleotide polymorphisms (SNPs) associated with fasting glucose and insulin concentrations in individuals free of diabetes. We tested the hypothesis that whole-grain food intake and genetic variation interact to influence concentrations of fasting glucose and insulin.

RESEARCH DESIGN AND METHODS: Via meta-analysis of data from 14 cohorts comprising \~{} 48,000 participants of European descent, we studied interactions of whole-grain intake with loci previously associated in GWAS with fasting glucose (16 loci) and/or insulin (2 loci) concentrations. For tests of interaction, we considered a P value <0.0028 (0.05 of 18 tests) as statistically significant.

RESULTS: Greater whole-grain food intake was associated with lower fasting glucose and insulin concentrations independent of demographics, other dietary and lifestyle factors, and BMI (β [95\% CI] per 1-serving-greater whole-grain intake: -0.009 mmol/l glucose [-0.013 to -0.005], P < 0.0001 and -0.011 pmol/l [ln] insulin [-0.015 to -0.007], P = 0.0003). No interactions met our multiple testing-adjusted statistical significance threshold. The strongest SNP interaction with whole-grain intake was rs780094 (GCKR) for fasting insulin (P = 0.006), where greater whole-grain intake was associated with a smaller reduction in fasting insulin concentrations in those with the insulin-raising allele.

CONCLUSIONS: Our results support the favorable association of whole-grain intake with fasting glucose and insulin and suggest a potential interaction between variation in GCKR and whole-grain intake in influencing fasting insulin concentrations.

}, keywords = {Adult, Aged, Blood Glucose, Edible Grain, European Continental Ancestry Group, Fasting, Female, Genetic Loci, Genome-Wide Association Study, Genotype, Humans, Insulin, Male, Middle Aged, Polymorphism, Single Nucleotide}, issn = {1935-5548}, doi = {10.2337/dc10-1150}, author = {Nettleton, Jennifer A and McKeown, Nicola M and Kanoni, Stavroula and Lemaitre, Rozenn N and Hivert, Marie-France and Ngwa, Julius and van Rooij, Frank J A and Sonestedt, Emily and Wojczynski, Mary K and Ye, Zheng and Tanaka, Tosh and Garcia, Melissa and Anderson, Jennifer S and Follis, Jack L and Djouss{\'e}, Luc and Mukamal, Kenneth and Papoutsakis, Constantina and Mozaffarian, Dariush and Zillikens, M Carola and Bandinelli, Stefania and Bennett, Amanda J and Borecki, Ingrid B and Feitosa, Mary F and Ferrucci, Luigi and Forouhi, Nita G and Groves, Christopher J and Hallmans, G{\"o}ran and Harris, Tamara and Hofman, Albert and Houston, Denise K and Hu, Frank B and Johansson, Ingegerd and Kritchevsky, Stephen B and Langenberg, Claudia and Launer, Lenore and Liu, Yongmei and Loos, Ruth J and Nalls, Michael and Orho-Melander, Marju and Renstrom, Frida and Rice, Kenneth and Riserus, Ulf and Rolandsson, Olov and Rotter, Jerome I and Saylor, Georgia and Sijbrands, Eric J G and Sjogren, Per and Smith, Albert and Steingr{\'\i}msd{\'o}ttir, Laufey and Uitterlinden, Andr{\'e} G and Wareham, Nicholas J and Prokopenko, Inga and Pankow, James S and van Duijn, Cornelia M and Florez, Jose C and Witteman, Jacqueline C M and Dupuis, Jos{\'e}e and Dedoussis, George V and Ordovas, Jose M and Ingelsson, Erik and Cupples, L Adrienne and Siscovick, David S and Franks, Paul W and Meigs, James B} } @article {1308, title = {Total zinc intake may modify the glucose-raising effect of a zinc transporter (SLC30A8) variant: a 14-cohort meta-analysis.}, journal = {Diabetes}, volume = {60}, year = {2011}, month = {2011 Sep}, pages = {2407-16}, abstract = {

OBJECTIVE: Many genetic variants have been associated with glucose homeostasis and type 2 diabetes in genome-wide association studies. Zinc is an essential micronutrient that is important for β-cell function and glucose homeostasis. We tested the hypothesis that zinc intake could influence the glucose-raising effect of specific variants.

RESEARCH DESIGN AND METHODS: We conducted a 14-cohort meta-analysis to assess the interaction of 20 genetic variants known to be related to glycemic traits and zinc metabolism with dietary zinc intake (food sources) and a 5-cohort meta-analysis to assess the interaction with total zinc intake (food sources and supplements) on fasting glucose levels among individuals of European ancestry without diabetes.

RESULTS: We observed a significant association of total zinc intake with lower fasting glucose levels (β-coefficient {\textpm} SE per 1 mg/day of zinc intake: -0.0012 {\textpm} 0.0003 mmol/L, summary P value = 0.0003), while the association of dietary zinc intake was not significant. We identified a nominally significant interaction between total zinc intake and the SLC30A8 rs11558471 variant on fasting glucose levels (β-coefficient {\textpm} SE per A allele for 1 mg/day of greater total zinc intake: -0.0017 {\textpm} 0.0006 mmol/L, summary interaction P value = 0.005); this result suggests a stronger inverse association between total zinc intake and fasting glucose in individuals carrying the glucose-raising A allele compared with individuals who do not carry it. None of the other interaction tests were statistically significant.

CONCLUSIONS: Our results suggest that higher total zinc intake may attenuate the glucose-raising effect of the rs11558471 SLC30A8 (zinc transporter) variant. Our findings also support evidence for the association of higher total zinc intake with lower fasting glucose levels.

}, keywords = {Blood Glucose, Cation Transport Proteins, Cohort Studies, Humans, Polymorphism, Single Nucleotide, Zinc, Zinc Transporter 8}, issn = {1939-327X}, doi = {10.2337/db11-0176}, author = {Kanoni, Stavroula and Nettleton, Jennifer A and Hivert, Marie-France and Ye, Zheng and van Rooij, Frank J A and Shungin, Dmitry and Sonestedt, Emily and Ngwa, Julius S and Wojczynski, Mary K and Lemaitre, Rozenn N and Gustafsson, Stefan and Anderson, Jennifer S and Tanaka, Toshiko and Hindy, George and Saylor, Georgia and Renstrom, Frida and Bennett, Amanda J and van Duijn, Cornelia M and Florez, Jose C and Fox, Caroline S and Hofman, Albert and Hoogeveen, Ron C and Houston, Denise K and Hu, Frank B and Jacques, Paul F and Johansson, Ingegerd and Lind, Lars and Liu, Yongmei and McKeown, Nicola and Ordovas, Jose and Pankow, James S and Sijbrands, Eric J G and Syv{\"a}nen, Ann-Christine and Uitterlinden, Andr{\'e} G and Yannakoulia, Mary and Zillikens, M Carola and Wareham, Nick J and Prokopenko, Inga and Bandinelli, Stefania and Forouhi, Nita G and Cupples, L Adrienne and Loos, Ruth J and Hallmans, G{\"o}ran and Dupuis, Jos{\'e}e and Langenberg, Claudia and Ferrucci, Luigi and Kritchevsky, Stephen B and McCarthy, Mark I and Ingelsson, Erik and Borecki, Ingrid B and Witteman, Jacqueline C M and Orho-Melander, Marju and Siscovick, David S and Meigs, James B and Franks, Paul W and Dedoussis, George V} }