Variants in MTNR1B influence fasting glucose levels.
Prokopenko I., Langenberg C., Florez JC., Saxena R., Soranzo N., Thorleifsson G., Loos RJF., Manning AK., Jackson AU., Aulchenko Y., Potter SC., Erdos MR., Sanna S., Hottenga J-J., Wheeler E., Kaakinen M., Lyssenko V., Chen W-M., Ahmadi K., Beckmann JS., Bergman RN., Bochud M., Bonnycastle LL., Buchanan TA., Cao A., Cervino A., Coin L., Collins FS., Crisponi L., de Geus EJC., Dehghan A., Deloukas P., Doney ASF., Elliott P., Freimer N., Gateva V., Herder C., Hofman A., Hughes TE., Hunt S., Illig T., Inouye M., Isomaa B., Johnson T., Kong A., Krestyaninova M., Kuusisto J., Laakso M., Lim N., Lindblad U., Lindgren CM., McCann OT., Mohlke KL., Morris AD., Naitza S., Orrù M., Palmer CNA., Pouta A., Randall J., Rathmann W., Saramies J., Scheet P., Scott LJ., Scuteri A., Sharp S., Sijbrands E., Smit JH., Song K., Steinthorsdottir V., Stringham HM., Tuomi T., Tuomilehto J., Uitterlinden AG., Voight BF., Waterworth D., Wichmann H-E., Willemsen G., Witteman JCM., Yuan X., Zhao JH., Zeggini E., Schlessinger D., Sandhu M., Boomsma DI., Uda M., Spector TD., Penninx BW., Altshuler D., Vollenweider P., Jarvelin MR., Lakatta E., Waeber G., Fox CS., Peltonen L., Groop LC., Mooser V., Cupples LA., Thorsteinsdottir U., Boehnke M., Barroso I., Van Duijn C., Dupuis J., Watanabe RM., Stefansson K., McCarthy MI., Wareham NJ., Meigs JB., Abecasis GR.
To identify previously unknown genetic loci associated with fasting glucose concentrations, we examined the leading association signals in ten genome-wide association scans involving a total of 36,610 individuals of European descent. Variants in the gene encoding melatonin receptor 1B (MTNR1B) were consistently associated with fasting glucose across all ten studies. The strongest signal was observed at rs10830963, where each G allele (frequency 0.30 in HapMap CEU) was associated with an increase of 0.07 (95% CI = 0.06-0.08) mmol/l in fasting glucose levels (P = 3.2 x 10(-50)) and reduced beta-cell function as measured by homeostasis model assessment (HOMA-B, P = 1.1 x 10(-15)). The same allele was associated with an increased risk of type 2 diabetes (odds ratio = 1.09 (1.05-1.12), per G allele P = 3.3 x 10(-7)) in a meta-analysis of 13 case-control studies totaling 18,236 cases and 64,453 controls. Our analyses also confirm previous associations of fasting glucose with variants at the G6PC2 (rs560887, P = 1.1 x 10(-57)) and GCK (rs4607517, P = 1.0 x 10(-25)) loci.