The TCF7L2 rs7903146 polymorphism, dietary intakes and type 2 diabetes risk in an Algerian population.

Hadjira Ouhaibi-Djellouli,Aline Meirhaeghe,Djabaria Naima Meroufel,Leila Houti,Philippe Amouyel,Xavier Hermant,Sounnia Mediene-Benchekor,Sarah Aïcha Lardjam-Hetraf,Nadhira Saidi-Mehtar,Louisa Goumidi,Imane Hamani-Medjaoui,Houssam Boulenouar

doi:10.1186/s12863-014-0134-3

Abstract

BackgroundThe transcription factor 7-like 2 (TCF7L2) gene is the most significant genetic risk factor for type 2 diabetes (T2D). Association analyses were performed on participants (n = 751, aged between 30 and 64) in the ISOR population-based study in the city of Oran. Dietary intakes were estimated using a weekly food frequency questionnaire.ResultsThe T allele of the rs7903146 single nucleotide polymorphism (SNP) was associated with lower body weight (p = 0.02), lower BMI (p = 0.009), lower waist circumference (p = 0.01) and a lower waist-to-hip ratio (p = 0.02). The T allele was associated with a significantly higher risk of T2D (odds ratio (OR) (95% confidence interval) = 1.55 (1.09–2.20), p = 0.01) and this association was independent of BMI. When considering the T2D risk, there were nominal interactions between the rs7903146 SNP and dessert (p = 0.05) and milk intakes (p = 0.01). The T2D risk was greater in T allele carriers with high dessert and milk intakes (OR = 2.61 (1.51-4.52), p = 0.0006, and 2.46 (1.47-4.12), p = 0.0006, respectively). In subjects with a high dessert intake, the T allele was also associated with higher fasting plasma glucose concentrations (4.89 ± 0.46 mmol/L in TT subjects, 4.72 ± 0.48 mmol/L in CT subjects and 4.78 ± 0.51 mmol/L in CC subjects; p = 0.03).ConclusionsThe T allele of the rs7903146 SNP is associated with a significantly higher risk of T2D in an Algerian population. This association was further strengthened by a high dessert intake, suggesting that gene-diet interactions increase the T2D risk.

Highlights

The transcription factor 7-like 2 (TCF7L2) gene is the most significant genetic risk factor for type 2 diabetes (T2D)
Genome-wide association studies in populations of European descent have shown that TCF7L2 is the T2Dpredisposing gene with the largest effect reported to date [5,7]
Algerian populations are generally more genetically diverse than European, Asian or indigenous American populations, our results extend the list of populations in which the rs7903146 single nucleotide polymorphism (SNP) is associated with T2D risk

Summary

Introduction

The transcription factor 7-like 2 (TCF7L2) gene is the most significant genetic risk factor for type 2 diabetes (T2D). The prevalence of diabetes is increasing in Algeria. An association between rs7903146 of the transcription factor 7like 2 (TCF7L2) gene and the T2D risk was identified for the first time in a study of Icelandic, American and Danish subjects [4], and has since been consistently replicated in various European and non-European populations (including Indian and Japanese populations) [5,6,7,8,9]. In Arab populations, strong associations have been observed in Tunisian [10,11], Moroccan, Palestinian [12], Iranian [13] and Lebanese [14] studies

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