@article{5bcff4818f834d9a8269d05ada9e0f95,
title = "Association of the SLC30A8 missense polymorphism R325W with proinsulin levels at baseline and after lifestyle, metformin or troglitazone intervention in the diabetes prevention program",
abstract = "Aims/hypothesis: Individuals with impaired glucose tolerance have increased proinsulin levels, despite normal glucose or C-peptide levels. In the Diabetes Prevention Program (DPP), increased proinsulin levels predicted type 2 diabetes and proinsulin levels were significantly reduced following treatment with metformin, lifestyle modification or troglitazone compared with placebo. Genetic and physiological studies suggest a role for the zinc transporter gene SLC30A8 in diabetes risk, possibly through effects on insulin-processing in beta cells. We hypothesised that the risk allele at the type 2 diabetes-associated missense polymorphism rs13266634 (R325W) in SLC30A8 would predict proinsulin levels in individuals at risk of type 2 diabetes and may modulate response to preventive interventions. Methods: We genotyped rs13266634 in 3,007 DPP participants and examined its association with fasting proinsulin and fasting insulin at baseline and at 1 year post-intervention. Results: We found that increasing dosage of the C risk allele at SLC30A8 rs13266634 was significantly associated with higher proinsulin levels at baseline (p = 0.002) after adjustment for baseline insulin. This supports the hypothesis that risk alleles at SLC30A8 mark individuals with insulin-processing defects. At the 1 year analysis, proinsulin levels decreased significantly in all groups receiving active intervention and were no longer associated with SLC30A8 genotype (p = 0.86) after adjustment for insulin at baseline and 1 year. We found no genotype × treatment interactions at 1 year. Conclusions/interpretation: In prediabetic individuals, genotype at SLC30A8 predicts baseline proinsulin levels independently of insulin levels, but does not predict proinsulin levels after amelioration of insulin sensitivity at 1 year.",
keywords = "Diabetes Prevention Program, Genetic association, Proinsulin, Single nucleotide polymorphisms, SLC30A8, Zinc transporter",
author = "Majithia, {A. R.} and Jablonski, {K. A.} and McAteer, {J. B.} and Mather, {K. J.} and Goldberg, {R. B.} and Kahn, {S. E.} and Florez, {J. C.}",
note = "Funding Information: Acknowledgements The investigators gratefully acknowledge the commitment and dedication of the participants of the DPP. The National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) of the National Institutes of Health provided funding to the clinical centres and the Coordinating Center for the design and conduct of the study, and for collection, management, analysis and interpretation of the data. The Southwestern American Indian Centers were supported directly by the NIDDK and the Indian Health Service. The General Clinical Research Center Program, National Center for Research Resources and the Department of Veterans Affairs supported data collection at many of the clinical centres. Funding for data collection and participant support was also provided by the Office of Research on Minority Health, the National Institute of Child Health and Human Development, the National Institute on Aging, the Office of Research on Women{\textquoteright}s Health, the Centers for Disease Control and Prevention and the American Diabetes Association. Bristol-Myers Squibb and Parke-Davis provided medication. This research was also supported, in part, by the intramural research programme of the NIDDK. LifeScan, Health O Meter, Hoechst Marion Roussel, Merck-Medco Managed Care, Merck, Nike Sports Marketing, Slim Fast Foods and Quaker Oats donated materials, equipment or medicines for concomitant conditions. McKesson BioServices, Matthews Media Group and the Henry M. Jackson Foundation provided support services under subcontract with the Coordinating Center. The opinions expressed are those of the investigators and do not necessarily reflect the views of the Indian Health Service or other funding agencies. A complete list of centres, investigators and staff can be found in the ESM. This work was supported in part by R01 DK072041 to J. C. Florez and K. A. Jablonski. S. E. Kahn is supported in part by the Department of Veterans Affairs. J. C. Florez is supported by a Physician Scientist Development Award by the Massachusetts General Hospital and a Clinical Scientist Development Award from the Doris Duke Charitable Foundation. We also thank the late A. F. Moore for his intellectual contribution to the genesis of this project. Copyright: Copyright 2013 Elsevier B.V., All rights reserved.",
year = "2011",
month = oct,
doi = "10.1007/s00125-011-2234-1",
language = "English (US)",
volume = "54",
pages = "2570--2574",
journal = "Diabetologia",
issn = "0012-186X",
publisher = "Springer Verlag",
number = "10",
}