|Authors||Nettleton, Jennifer A., McKeown Nicola M., Kanoni Stavroula, Lemaitre Rozenn N., Hivert Marie-France, Ngwa Julius, van Rooij Frank J. A., Sonestedt Emily, Wojczynski Mary K., Ye Zheng, Tanaka Tosh, Garcia Melissa, Anderson Jennifer S., Follis Jack L., Djousse Luc, Mukamal Kenneth, Papoutsakis Constantina, Mozaffarian Dariush, Zillikens Carola M., Bandinelli Stefania, Bennett Amanda J., Borecki Ingrid B., Feitosa Mary F., Ferrucci Luigi, Forouhi Nita G., Groves Christopher J., Hallmans Goran, Harris Tamara, Hofman Albert, Houston Denise K., Hu Frank B., Johansson Ingegerd, Kritchevsky Stephen B., Langenberg Claudia, Launer Lenore, Liu Yongmei, Loos Ruth J., Nalls Michael, Orho-Melander Marju, Renstrom Frida, Rice Kenneth, Riserus Ulf, Rolandsson Olov, Rotter Jerome I., Saylor Georgia, Sijbrands Eric J. G., Sjogren Per, Smith Albert, Steingrímsdóttir Laufey, Uitterlinden André G., Wareham Nicholas J., Prokopenko Inga, Pankow James S., van Duijn Cornelia M., Florez Jose C., Witteman Jacqueline C. M., Dupuis Josée, Dedoussis George V., Ordovas Jose M., Ingelsson Erik, Cupples Adrienne L., Siscovick David S., Franks Paul W., and Meigs James B. |
|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. |