%0 Journal Article %J PLoS Genet %D 2012 %T Novel loci for adiponectin levels and their influence on type 2 diabetes and metabolic traits: a multi-ethnic meta-analysis of 45,891 individuals. %A Dastani, Zari %A Hivert, Marie-France %A Timpson, Nicholas %A Perry, John R B %A Yuan, Xin %A Scott, Robert A %A Henneman, Peter %A Heid, Iris M %A Kizer, Jorge R %A Lyytikäinen, Leo-Pekka %A Fuchsberger, Christian %A Tanaka, Toshiko %A Morris, Andrew P %A Small, Kerrin %A Isaacs, Aaron %A Beekman, Marian %A Coassin, Stefan %A Lohman, Kurt %A Qi, Lu %A Kanoni, Stavroula %A Pankow, James S %A Uh, Hae-Won %A Wu, Ying %A Bidulescu, Aurelian %A Rasmussen-Torvik, Laura J %A Greenwood, Celia M T %A Ladouceur, Martin %A Grimsby, Jonna %A Manning, Alisa K %A Liu, Ching-Ti %A Kooner, Jaspal %A Mooser, Vincent E %A Vollenweider, Peter %A Kapur, Karen A %A Chambers, John %A Wareham, Nicholas J %A Langenberg, Claudia %A Frants, Rune %A Willems-Vandijk, Ko %A Oostra, Ben A %A Willems, Sara M %A Lamina, Claudia %A Winkler, Thomas W %A Psaty, Bruce M %A Tracy, Russell P %A Brody, Jennifer %A Chen, Ida %A Viikari, Jorma %A Kähönen, Mika %A Pramstaller, Peter P %A Evans, David M %A St Pourcain, Beate %A Sattar, Naveed %A Wood, Andrew R %A Bandinelli, Stefania %A Carlson, Olga D %A Egan, Josephine M %A Böhringer, Stefan %A van Heemst, Diana %A Kedenko, Lyudmyla %A Kristiansson, Kati %A Nuotio, Marja-Liisa %A Loo, Britt-Marie %A Harris, Tamara %A Garcia, Melissa %A Kanaya, Alka %A Haun, Margot %A Klopp, Norman %A Wichmann, H-Erich %A Deloukas, Panos %A Katsareli, Efi %A Couper, David J %A Duncan, Bruce B %A Kloppenburg, Margreet %A Adair, Linda S %A Borja, Judith B %A Wilson, James G %A Musani, Solomon %A Guo, Xiuqing %A Johnson, Toby %A Semple, Robert %A Teslovich, Tanya M %A Allison, Matthew A %A Redline, Susan %A Buxbaum, Sarah G %A Mohlke, Karen L %A Meulenbelt, Ingrid %A Ballantyne, Christie M %A Dedoussis, George V %A Hu, Frank B %A Liu, Yongmei %A Paulweber, Bernhard %A Spector, Timothy D %A Slagboom, P Eline %A Ferrucci, Luigi %A Jula, Antti %A Perola, Markus %A Raitakari, Olli %A Florez, Jose C %A Salomaa, Veikko %A Eriksson, Johan G %A Frayling, Timothy M %A Hicks, Andrew A %A Lehtimäki, Terho %A Smith, George Davey %A Siscovick, David S %A Kronenberg, Florian %A van Duijn, Cornelia %A Loos, Ruth J F %A Waterworth, Dawn M %A Meigs, James B %A Dupuis, Josée %A Richards, J Brent %A Voight, Benjamin F %A Scott, Laura J %A Steinthorsdottir, Valgerdur %A Dina, Christian %A Welch, Ryan P %A Zeggini, Eleftheria %A Huth, Cornelia %A Aulchenko, Yurii S %A Thorleifsson, Gudmar %A McCulloch, Laura J %A Ferreira, Teresa %A Grallert, Harald %A Amin, Najaf %A Wu, Guanming %A Willer, Cristen J %A Raychaudhuri, Soumya %A McCarroll, Steve A %A Hofmann, Oliver M %A Segrè, Ayellet V %A van Hoek, Mandy %A Navarro, Pau %A Ardlie, Kristin %A Balkau, Beverley %A Benediktsson, Rafn %A Bennett, Amanda J %A Blagieva, Roza %A Boerwinkle, Eric %A Bonnycastle, Lori L %A Boström, Kristina Bengtsson %A Bravenboer, Bert %A Bumpstead, Suzannah %A Burtt, Noel P %A Charpentier, Guillaume %A Chines, Peter S %A Cornelis, Marilyn %A Crawford, Gabe %A Doney, Alex S F %A Elliott, Katherine S %A Elliott, Amanda L %A Erdos, Michael R %A Fox, Caroline S %A Franklin, Christopher S %A Ganser, Martha %A Gieger, Christian %A Grarup, Niels %A Green, Todd %A Griffin, Simon %A Groves, Christopher J %A Guiducci, Candace %A Hadjadj, Samy %A Hassanali, Neelam %A Herder, Christian %A Isomaa, Bo %A Jackson, Anne U %A Johnson, Paul R V %A Jørgensen, Torben %A Kao, Wen H L %A Kong, Augustine %A Kraft, Peter %A Kuusisto, Johanna %A Lauritzen, Torsten %A Li, Man %A Lieverse, Aloysius %A Lindgren, Cecilia M %A Lyssenko, Valeriya %A Marre, Michel %A Meitinger, Thomas %A Midthjell, Kristian %A Morken, Mario A %A Narisu, Narisu %A Nilsson, Peter %A Owen, Katharine R %A Payne, Felicity %A Petersen, Ann-Kristin %A Platou, Carl %A Proença, Christine %A Prokopenko, Inga %A Rathmann, Wolfgang %A Rayner, N William %A Robertson, Neil R %A Rocheleau, Ghislain %A Roden, Michael %A Sampson, Michael J %A Saxena, Richa %A Shields, Beverley M %A Shrader, Peter %A Sigurdsson, Gunnar %A Sparsø, Thomas %A Strassburger, Klaus %A Stringham, Heather M %A Sun, Qi %A Swift, Amy J %A Thorand, Barbara %A Tichet, Jean %A Tuomi, Tiinamaija %A van Dam, Rob M %A van Haeften, Timon W %A van Herpt, Thijs %A van Vliet-Ostaptchouk, Jana V %A Walters, G Bragi %A Weedon, Michael N %A Wijmenga, Cisca %A Witteman, Jacqueline %A Bergman, Richard N %A Cauchi, Stephane %A Collins, Francis S %A Gloyn, Anna L %A Gyllensten, Ulf %A Hansen, Torben %A Hide, Winston A %A Hitman, Graham A %A Hofman, Albert %A Hunter, David J %A Hveem, Kristian %A Laakso, Markku %A Morris, Andrew D %A Palmer, Colin N A %A Rudan, Igor %A Sijbrands, Eric %A Stein, Lincoln D %A Tuomilehto, Jaakko %A Uitterlinden, Andre %A Walker, Mark %A Watanabe, Richard M %A Abecasis, Goncalo R %A Boehm, Bernhard O %A Campbell, Harry %A Daly, Mark J %A Hattersley, Andrew T %A Pedersen, Oluf %A Barroso, Inês %A Groop, Leif %A Sladek, Rob %A Thorsteinsdottir, Unnur %A Wilson, James F %A Illig, Thomas %A Froguel, Philippe %A van Duijn, Cornelia M %A Stefansson, Kari %A Altshuler, David %A Boehnke, Michael %A McCarthy, Mark I %A Soranzo, Nicole %A Wheeler, Eleanor %A Glazer, Nicole L %A Bouatia-Naji, Nabila %A Mägi, Reedik %A Randall, Joshua %A Elliott, Paul %A Rybin, Denis %A Dehghan, Abbas %A Hottenga, Jouke Jan %A Song, Kijoung %A Goel, Anuj %A Lajunen, Taina %A Doney, Alex %A Cavalcanti-Proença, Christine %A Kumari, Meena %A Timpson, Nicholas J %A Zabena, Carina %A Ingelsson, Erik %A An, Ping %A O'Connell, Jeffrey %A Luan, Jian'an %A Elliott, Amanda %A McCarroll, Steven A %A Roccasecca, Rosa Maria %A Pattou, François %A Sethupathy, Praveen %A Ariyurek, Yavuz %A Barter, Philip %A Beilby, John P %A Ben-Shlomo, Yoav %A Bergmann, Sven %A Bochud, Murielle %A Bonnefond, Amélie %A Borch-Johnsen, Knut %A Böttcher, Yvonne %A Brunner, Eric %A Bumpstead, Suzannah J %A Chen, Yii-Der Ida %A Chines, Peter %A Clarke, Robert %A Coin, Lachlan J M %A Cooper, Matthew N %A Crisponi, Laura %A Day, Ian N M %A de Geus, Eco J C %A Delplanque, Jerome %A Fedson, Annette C %A Fischer-Rosinsky, Antje %A Forouhi, Nita G %A Franzosi, Maria Grazia %A Galan, Pilar %A Goodarzi, Mark O %A Graessler, Jürgen %A Grundy, Scott %A Gwilliam, Rhian %A Hallmans, Göran %A Hammond, Naomi %A Han, Xijing %A Hartikainen, Anna-Liisa %A Hayward, Caroline %A Heath, Simon C %A Hercberg, Serge %A Hillman, David R %A Hingorani, Aroon D %A Hui, Jennie %A Hung, Joe %A Kaakinen, Marika %A Kaprio, Jaakko %A Kesaniemi, Y Antero %A Kivimaki, Mika %A Knight, Beatrice %A Koskinen, Seppo %A Kovacs, Peter %A Kyvik, Kirsten Ohm %A Lathrop, G Mark %A Lawlor, Debbie A %A Le Bacquer, Olivier %A Lecoeur, Cécile %A Li, Yun %A Mahley, Robert %A Mangino, Massimo %A Martínez-Larrad, María Teresa %A McAteer, Jarred B %A McPherson, Ruth %A Meisinger, Christa %A Melzer, David %A Meyre, David %A Mitchell, Braxton D %A Mukherjee, Sutapa %A Naitza, Silvia %A Neville, Matthew J %A Orrù, Marco %A Pakyz, Ruth %A Paolisso, Giuseppe %A Pattaro, Cristian %A Pearson, Daniel %A Peden, John F %A Pedersen, Nancy L %A Pfeiffer, Andreas F H %A Pichler, Irene %A Polasek, Ozren %A Posthuma, Danielle %A Potter, Simon C %A Pouta, Anneli %A Province, Michael A %A Rayner, Nigel W %A Rice, Kenneth %A Ripatti, Samuli %A Rivadeneira, Fernando %A Rolandsson, Olov %A Sandbaek, Annelli %A Sandhu, Manjinder %A Sanna, Serena %A Sayer, Avan Aihie %A Scheet, Paul %A Seedorf, Udo %A Sharp, Stephen J %A Shields, Beverley %A Sigurðsson, Gunnar %A Sijbrands, Eric J G %A Silveira, Angela %A Simpson, Laila %A Singleton, Andrew %A Smith, Nicholas L %A Sovio, Ulla %A Swift, Amy %A Syddall, Holly %A Syvänen, Ann-Christine %A Tönjes, Anke %A Uitterlinden, André G %A van Dijk, Ko Willems %A Varma, Dhiraj %A Visvikis-Siest, Sophie %A Vitart, Veronique %A Vogelzangs, Nicole %A Waeber, Gérard %A Wagner, Peter J %A Walley, Andrew %A Ward, Kim L %A Watkins, Hugh %A Wild, Sarah H %A Willemsen, Gonneke %A Witteman, Jaqueline C M %A Yarnell, John W G %A Zelenika, Diana %A Zethelius, Björn %A Zhai, Guangju %A Zhao, Jing Hua %A Zillikens, M Carola %A Borecki, Ingrid B %A Meneton, Pierre %A Magnusson, Patrik K E %A Nathan, David M %A Williams, Gordon H %A Silander, Kaisa %A Bornstein, Stefan R %A Schwarz, Peter %A Spranger, Joachim %A Karpe, Fredrik %A Shuldiner, Alan R %A Cooper, Cyrus %A Serrano-Ríos, Manuel %A Lind, Lars %A Palmer, Lyle J %A Hu, Frank B %A Franks, Paul W %A Ebrahim, Shah %A Marmot, Michael %A Kao, W H Linda %A Pramstaller, Peter Paul %A Wright, Alan F %A Stumvoll, Michael %A Hamsten, Anders %A Buchanan, Thomas A %A Valle, Timo T %A Rotter, Jerome I %A Penninx, Brenda W J H %A Boomsma, Dorret I %A Cao, Antonio %A Scuteri, Angelo %A Schlessinger, David %A Uda, Manuela %A Ruokonen, Aimo %A Jarvelin, Marjo-Riitta %A Peltonen, Leena %A Mooser, Vincent %A Sladek, Robert %A Musunuru, Kiran %A Smith, Albert V %A Edmondson, Andrew C %A Stylianou, Ioannis M %A Koseki, Masahiro %A Pirruccello, James P %A Chasman, Daniel I %A Johansen, Christopher T %A Fouchier, Sigrid W %A Peloso, Gina M %A Barbalic, Maja %A Ricketts, Sally L %A Bis, Joshua C %A Feitosa, Mary F %A Orho-Melander, Marju %A Melander, Olle %A Li, Xiaohui %A Li, Mingyao %A Cho, Yoon Shin %A Go, Min Jin %A Kim, Young Jin %A Lee, Jong-Young %A Park, Taesung %A Kim, Kyunga %A Sim, Xueling %A Ong, Rick Twee-Hee %A Croteau-Chonka, Damien C %A Lange, Leslie A %A Smith, Joshua D %A Ziegler, Andreas %A Zhang, Weihua %A Zee, Robert Y L %A Whitfield, John B %A Thompson, John R %A Surakka, Ida %A Spector, Tim D %A Smit, Johannes H %A Sinisalo, Juha %A Scott, James %A Saharinen, Juha %A Sabatti, Chiara %A Rose, Lynda M %A Roberts, Robert %A Rieder, Mark %A Parker, Alex N %A Paré, Guillaume %A O'Donnell, Christopher J %A Nieminen, Markku S %A Nickerson, Deborah A %A Montgomery, Grant W %A McArdle, Wendy %A Masson, David %A Martin, Nicholas G %A Marroni, Fabio %A Lucas, Gavin %A Luben, Robert %A Lokki, Marja-Liisa %A Lettre, Guillaume %A Launer, Lenore J %A Lakatta, Edward G %A Laaksonen, Reijo %A Kyvik, Kirsten O %A König, Inke R %A Khaw, Kay-Tee %A Kaplan, Lee M %A Johansson, Asa %A Janssens, A Cecile J W %A Igl, Wilmar %A Hovingh, G Kees %A Hengstenberg, Christian %A Havulinna, Aki S %A Hastie, Nicholas D %A Harris, Tamara B %A Haritunians, Talin %A Hall, Alistair S %A Groop, Leif C %A Gonzalez, Elena %A Freimer, Nelson B %A Erdmann, Jeanette %A Ejebe, Kenechi G %A Döring, Angela %A Dominiczak, Anna F %A Demissie, Serkalem %A Deloukas, Panagiotis %A de Faire, Ulf %A Crawford, Gabriel %A Chen, Yii-der I %A Caulfield, Mark J %A Boekholdt, S Matthijs %A Assimes, Themistocles L %A Quertermous, Thomas %A Seielstad, Mark %A Wong, Tien Y %A Tai, E-Shyong %A Feranil, Alan B %A Kuzawa, Christopher W %A Taylor, Herman A %A Gabriel, Stacey B %A Holm, Hilma %A Gudnason, Vilmundur %A Krauss, Ronald M %A Ordovas, Jose M %A Munroe, Patricia B %A Kooner, Jaspal S %A Tall, Alan R %A Hegele, Robert A %A Kastelein, John J P %A Schadt, Eric E %A Strachan, David P %A Reilly, Muredach P %A Samani, Nilesh J %A Schunkert, Heribert %A Cupples, L Adrienne %A Sandhu, Manjinder S %A Ridker, Paul M %A Rader, Daniel J %A Kathiresan, Sekar %K Adiponectin %K African Americans %K Asian Continental Ancestry Group %K Cholesterol, HDL %K Diabetes Mellitus, Type 2 %K European Continental Ancestry Group %K Female %K Gene Expression %K Genetic Predisposition to Disease %K Genome-Wide Association Study %K Glucose Tolerance Test %K Humans %K Insulin Resistance %K Male %K Metabolic Networks and Pathways %K Polymorphism, Single Nucleotide %K Waist-Hip Ratio %X

Circulating levels of adiponectin, a hormone produced predominantly by adipocytes, are highly heritable and are inversely associated with type 2 diabetes mellitus (T2D) and other metabolic traits. We conducted a meta-analysis of genome-wide association studies in 39,883 individuals of European ancestry to identify genes associated with metabolic disease. We identified 8 novel loci associated with adiponectin levels and confirmed 2 previously reported loci (P = 4.5×10(-8)-1.2×10(-43)). Using a novel method to combine data across ethnicities (N = 4,232 African Americans, N = 1,776 Asians, and N = 29,347 Europeans), we identified two additional novel loci. Expression analyses of 436 human adipocyte samples revealed that mRNA levels of 18 genes at candidate regions were associated with adiponectin concentrations after accounting for multiple testing (p<3×10(-4)). We next developed a multi-SNP genotypic risk score to test the association of adiponectin decreasing risk alleles on metabolic traits and diseases using consortia-level meta-analytic data. This risk score was associated with increased risk of T2D (p = 4.3×10(-3), n = 22,044), increased triglycerides (p = 2.6×10(-14), n = 93,440), increased waist-to-hip ratio (p = 1.8×10(-5), n = 77,167), increased glucose two hours post oral glucose tolerance testing (p = 4.4×10(-3), n = 15,234), increased fasting insulin (p = 0.015, n = 48,238), but with lower in HDL-cholesterol concentrations (p = 4.5×10(-13), n = 96,748) and decreased BMI (p = 1.4×10(-4), n = 121,335). These findings identify novel genetic determinants of adiponectin levels, which, taken together, influence risk of T2D and markers of insulin resistance.

%B PLoS Genet %V 8 %P e1002607 %8 2012 %G eng %N 3 %1 http://www.ncbi.nlm.nih.gov/pubmed/22479202?dopt=Abstract %R 10.1371/journal.pgen.1002607 %0 Journal Article %J PLoS Med %D 2017 %T Impact of common genetic determinants of Hemoglobin A1c on type 2 diabetes risk and diagnosis in ancestrally diverse populations: A transethnic genome-wide meta-analysis. %A Wheeler, Eleanor %A Leong, Aaron %A Liu, Ching-Ti %A Hivert, Marie-France %A Strawbridge, Rona J %A Podmore, Clara %A Li, Man %A Yao, Jie %A Sim, Xueling %A Hong, Jaeyoung %A Chu, Audrey Y %A Zhang, Weihua %A Wang, Xu %A Chen, Peng %A Maruthur, Nisa M %A Porneala, Bianca C %A Sharp, Stephen J %A Jia, Yucheng %A Kabagambe, Edmond K %A Chang, Li-Ching %A Chen, Wei-Min %A Elks, Cathy E %A Evans, Daniel S %A Fan, Qiao %A Giulianini, Franco %A Go, Min Jin %A Hottenga, Jouke-Jan %A Hu, Yao %A Jackson, Anne U %A Kanoni, Stavroula %A Kim, Young Jin %A Kleber, Marcus E %A Ladenvall, Claes %A Lecoeur, Cécile %A Lim, Sing-Hui %A Lu, Yingchang %A Mahajan, Anubha %A Marzi, Carola %A Nalls, Mike A %A Navarro, Pau %A Nolte, Ilja M %A Rose, Lynda M %A Rybin, Denis V %A Sanna, Serena %A Shi, Yuan %A Stram, Daniel O %A Takeuchi, Fumihiko %A Tan, Shu Pei %A van der Most, Peter J %A van Vliet-Ostaptchouk, Jana V %A Wong, Andrew %A Yengo, Loic %A Zhao, Wanting %A Goel, Anuj %A Martinez Larrad, Maria Teresa %A Radke, Dörte %A Salo, Perttu %A Tanaka, Toshiko %A van Iperen, Erik P A %A Abecasis, Goncalo %A Afaq, Saima %A Alizadeh, Behrooz Z %A Bertoni, Alain G %A Bonnefond, Amélie %A Böttcher, Yvonne %A Bottinger, Erwin P %A Campbell, Harry %A Carlson, Olga D %A Chen, Chien-Hsiun %A Cho, Yoon Shin %A Garvey, W Timothy %A Gieger, Christian %A Goodarzi, Mark O %A Grallert, Harald %A Hamsten, Anders %A Hartman, Catharina A %A Herder, Christian %A Hsiung, Chao Agnes %A Huang, Jie %A Igase, Michiya %A Isono, Masato %A Katsuya, Tomohiro %A Khor, Chiea-Chuen %A Kiess, Wieland %A Kohara, Katsuhiko %A Kovacs, Peter %A Lee, Juyoung %A Lee, Wen-Jane %A Lehne, Benjamin %A Li, Huaixing %A Liu, Jianjun %A Lobbens, Stephane %A Luan, Jian'an %A Lyssenko, Valeriya %A Meitinger, Thomas %A Miki, Tetsuro %A Miljkovic, Iva %A Moon, Sanghoon %A Mulas, Antonella %A Müller, Gabriele %A Müller-Nurasyid, Martina %A Nagaraja, Ramaiah %A Nauck, Matthias %A Pankow, James S %A Polasek, Ozren %A Prokopenko, Inga %A Ramos, Paula S %A Rasmussen-Torvik, Laura %A Rathmann, Wolfgang %A Rich, Stephen S %A Robertson, Neil R %A Roden, Michael %A Roussel, Ronan %A Rudan, Igor %A Scott, Robert A %A Scott, William R %A Sennblad, Bengt %A Siscovick, David S %A Strauch, Konstantin %A Sun, Liang %A Swertz, Morris %A Tajuddin, Salman M %A Taylor, Kent D %A Teo, Yik-Ying %A Tham, Yih Chung %A Tönjes, Anke %A Wareham, Nicholas J %A Willemsen, Gonneke %A Wilsgaard, Tom %A Hingorani, Aroon D %A Egan, Josephine %A Ferrucci, Luigi %A Hovingh, G Kees %A Jula, Antti %A Kivimaki, Mika %A Kumari, Meena %A Njølstad, Inger %A Palmer, Colin N A %A Serrano Ríos, Manuel %A Stumvoll, Michael %A Watkins, Hugh %A Aung, Tin %A Blüher, Matthias %A Boehnke, Michael %A Boomsma, Dorret I %A Bornstein, Stefan R %A Chambers, John C %A Chasman, Daniel I %A Chen, Yii-Der Ida %A Chen, Yduan-Tsong %A Cheng, Ching-Yu %A Cucca, Francesco %A de Geus, Eco J C %A Deloukas, Panos %A Evans, Michele K %A Fornage, Myriam %A Friedlander, Yechiel %A Froguel, Philippe %A Groop, Leif %A Gross, Myron D %A Harris, Tamara B %A Hayward, Caroline %A Heng, Chew-Kiat %A Ingelsson, Erik %A Kato, Norihiro %A Kim, Bong-Jo %A Koh, Woon-Puay %A Kooner, Jaspal S %A Körner, Antje %A Kuh, Diana %A Kuusisto, Johanna %A Laakso, Markku %A Lin, Xu %A Liu, Yongmei %A Loos, Ruth J F %A Magnusson, Patrik K E %A März, Winfried %A McCarthy, Mark I %A Oldehinkel, Albertine J %A Ong, Ken K %A Pedersen, Nancy L %A Pereira, Mark A %A Peters, Annette %A Ridker, Paul M %A Sabanayagam, Charumathi %A Sale, Michele %A Saleheen, Danish %A Saltevo, Juha %A Schwarz, Peter Eh %A Sheu, Wayne H H %A Snieder, Harold %A Spector, Timothy D %A Tabara, Yasuharu %A Tuomilehto, Jaakko %A van Dam, Rob M %A Wilson, James G %A Wilson, James F %A Wolffenbuttel, Bruce H R %A Wong, Tien Yin %A Wu, Jer-Yuarn %A Yuan, Jian-Min %A Zonderman, Alan B %A Soranzo, Nicole %A Guo, Xiuqing %A Roberts, David J %A Florez, Jose C %A Sladek, Robert %A Dupuis, Josée %A Morris, Andrew P %A Tai, E-Shyong %A Selvin, Elizabeth %A Rotter, Jerome I %A Langenberg, Claudia %A Barroso, Inês %A Meigs, James B %K Diabetes Mellitus, Type 2 %K Genetic Variation %K Genome-Wide Association Study %K Glycated Hemoglobin A %K Humans %K Phenotype %K Risk %X

BACKGROUND: Glycated hemoglobin (HbA1c) is used to diagnose type 2 diabetes (T2D) and assess glycemic control in patients with diabetes. Previous genome-wide association studies (GWAS) have identified 18 HbA1c-associated genetic variants. These variants proved to be classifiable by their likely biological action as erythrocytic (also associated with erythrocyte traits) or glycemic (associated with other glucose-related traits). In this study, we tested the hypotheses that, in a very large scale GWAS, we would identify more genetic variants associated with HbA1c and that HbA1c variants implicated in erythrocytic biology would affect the diagnostic accuracy of HbA1c. We therefore expanded the number of HbA1c-associated loci and tested the effect of genetic risk-scores comprised of erythrocytic or glycemic variants on incident diabetes prediction and on prevalent diabetes screening performance. Throughout this multiancestry study, we kept a focus on interancestry differences in HbA1c genetics performance that might influence race-ancestry differences in health outcomes.

METHODS & FINDINGS: Using genome-wide association meta-analyses in up to 159,940 individuals from 82 cohorts of European, African, East Asian, and South Asian ancestry, we identified 60 common genetic variants associated with HbA1c. We classified variants as implicated in glycemic, erythrocytic, or unclassified biology and tested whether additive genetic scores of erythrocytic variants (GS-E) or glycemic variants (GS-G) were associated with higher T2D incidence in multiethnic longitudinal cohorts (N = 33,241). Nineteen glycemic and 22 erythrocytic variants were associated with HbA1c at genome-wide significance. GS-G was associated with higher T2D risk (incidence OR = 1.05, 95% CI 1.04-1.06, per HbA1c-raising allele, p = 3 × 10-29); whereas GS-E was not (OR = 1.00, 95% CI 0.99-1.01, p = 0.60). In Europeans and Asians, erythrocytic variants in aggregate had only modest effects on the diagnostic accuracy of HbA1c. Yet, in African Americans, the X-linked G6PD G202A variant (T-allele frequency 11%) was associated with an absolute decrease in HbA1c of 0.81%-units (95% CI 0.66-0.96) per allele in hemizygous men, and 0.68%-units (95% CI 0.38-0.97) in homozygous women. The G6PD variant may cause approximately 2% (N = 0.65 million, 95% CI 0.55-0.74) of African American adults with T2D to remain undiagnosed when screened with HbA1c. Limitations include the smaller sample sizes for non-European ancestries and the inability to classify approximately one-third of the variants. Further studies in large multiethnic cohorts with HbA1c, glycemic, and erythrocytic traits are required to better determine the biological action of the unclassified variants.

CONCLUSIONS: As G6PD deficiency can be clinically silent until illness strikes, we recommend investigation of the possible benefits of screening for the G6PD genotype along with using HbA1c to diagnose T2D in populations of African ancestry or groups where G6PD deficiency is common. Screening with direct glucose measurements, or genetically-informed HbA1c diagnostic thresholds in people with G6PD deficiency, may be required to avoid missed or delayed diagnoses.

%B PLoS Med %V 14 %P e1002383 %8 2017 Sep %G eng %N 9 %R 10.1371/journal.pmed.1002383