Genetic variation in GIPR influences the glucose and insulin responses to an oral glucose challenge.
Saxena R., Hivert M-F., Langenberg C., Tanaka T., Pankow JS., Vollenweider P., Lyssenko V., Bouatia-Naji N., Dupuis J., Jackson AU., Kao WHL., Li M., Glazer NL., Manning AK., Luan J., Stringham HM., Prokopenko I., Johnson T., Grarup N., Boesgaard TW., Lecoeur C., Shrader P., O'Connell J., Ingelsson E., Couper DJ., Rice K., Song K., Andreasen CH., Dina C., Köttgen A., Le Bacquer O., Pattou F., Taneera J., Steinthorsdottir V., Rybin D., Ardlie K., Sampson M., Qi L., van Hoek M., Weedon MN., Aulchenko YS., Voight BF., Grallert H., Balkau B., Bergman RN., Bielinski SJ., Bonnefond A., Bonnycastle LL., Borch-Johnsen K., Böttcher Y., Brunner E., Buchanan TA., Bumpstead SJ., Cavalcanti-Proença C., Charpentier G., Chen Y-DI., Chines PS., Collins FS., Cornelis M., J Crawford G., Delplanque J., Doney A., Egan JM., Erdos MR., Firmann M., Forouhi NG., Fox CS., Goodarzi MO., Graessler J., Hingorani A., Isomaa B., Jørgensen T., Kivimaki M., Kovacs P., Krohn K., Kumari M., Lauritzen T., Lévy-Marchal C., Mayor V., McAteer JB., Meyre D., Mitchell BD., Mohlke KL., Morken MA., Narisu N., Palmer CNA., Pakyz R., Pascoe L., Payne F., Pearson D., Rathmann W., Sandbaek A., Sayer AA., Scott LJ., Sharp SJ., Sijbrands E., Singleton A., Siscovick DS., Smith NL., Sparsø T., Swift AJ., Syddall H., Thorleifsson G., Tönjes A., Tuomi T., Tuomilehto J., Valle TT., Waeber G., Walley A., Waterworth DM., Zeggini E., Zhao JH., GIANT consortium None., MAGIC investigators None., Illig T., Wichmann HE., Wilson JF., van Duijn C., Hu FB., Morris AD., Frayling TM., Hattersley AT., Thorsteinsdottir U., Stefansson K., Nilsson P., Syvänen A-C., Shuldiner AR., Walker M., Bornstein SR., Schwarz P., Williams GH., Nathan DM., Kuusisto J., Laakso M., Cooper C., Marmot M., Ferrucci L., Mooser V., Stumvoll M., Loos RJF., Altshuler D., Psaty BM., Rotter JI., Boerwinkle E., Hansen T., Pedersen O., Florez JC., McCarthy MI., Boehnke M., Barroso I., Sladek R., Froguel P., Meigs JB., Groop L., Wareham NJ., Watanabe RM.
Glucose levels 2 h after an oral glucose challenge are a clinical measure of glucose tolerance used in the diagnosis of type 2 diabetes. We report a meta-analysis of nine genome-wide association studies (n = 15,234 nondiabetic individuals) and a follow-up of 29 independent loci (n = 6,958-30,620). We identify variants at the GIPR locus associated with 2-h glucose level (rs10423928, beta (s.e.m.) = 0.09 (0.01) mmol/l per A allele, P = 2.0 x 10(-15)). The GIPR A-allele carriers also showed decreased insulin secretion (n = 22,492; insulinogenic index, P = 1.0 x 10(-17); ratio of insulin to glucose area under the curve, P = 1.3 x 10(-16)) and diminished incretin effect (n = 804; P = 4.3 x 10(-4)). We also identified variants at ADCY5 (rs2877716, P = 4.2 x 10(-16)), VPS13C (rs17271305, P = 4.1 x 10(-8)), GCKR (rs1260326, P = 7.1 x 10(-11)) and TCF7L2 (rs7903146, P = 4.2 x 10(-10)) associated with 2-h glucose. Of the three newly implicated loci (GIPR, ADCY5 and VPS13C), only ADCY5 was found to be associated with type 2 diabetes in collaborating studies (n = 35,869 cases, 89,798 controls, OR = 1.12, 95% CI 1.09-1.15, P = 4.8 x 10(-18)).