**5. Conclusions**

In our study, we conducted a GWAS and discovered five SNPs (rs2074356 in *HECTD4*, rs11066015 in *ACAD10*, rs12229654 in *MYL2*, rs11065828 and rs79105258 in *CUX2*) associated with habitual coffee consumption in a Korean population. We observed that moderate black coffee and sugared coffee consumption reduced the risk of prediabetes and type 2 diabetes combined. We found that an inverse association was stronger among black-coffee consumers with minor alleles of five SNPs related to coffee consumption compared to those with major alleles. Further Asian GWASs and epidemiological studies are needed to elucidate the effects of coffee-related genetic variation and high coffee consumption on chronic disease risk.

**Supplementary Materials:** The following are available online at http://www.mdpi.com/2072-6643/12/8/2228/s1. Table S1: Baseline characteristics of the participants included in the GWAS on coffee consumption; Table S2: The significant SNPs discovered from the GWAS on coffee consumption; Table S3: The significant SNPs discovered from the GWAS on coffee consumption after additionally adjusted for BMI.

**Author Contributions:** Conceptualization, T.J. and J.E.L.; data curation, T.J., J.Y., K.K., J.S. and J.E.L.; formal analysis, T.J., J.Y. and J.E.L.; investigation, T.J., J.Y., A.N.K., M.K., K.K., J.S. and J.E.L.; methodology, T.J., J.Y., M.K., K.K., J.S. and J.E.L.; project administration, J.S. and J.E.L.; supervision, J.E.L.; writing—original draft, T.J. and J.E.L.; writing—review & editing, T.J., J.Y., A.N.K., M.K., K.K., J.S. and J.E.L. All authors have read and agreed to the published version of the manuscript.

**Funding:** This research received no external funding.

**Acknowledgments:** This study was conducted with bioresources from National Biobank of Korea, the Center for Disease Control and Prevention, Republic of Korea (KBN-2018-044).

**Conflicts of Interest:** The authors declare no conflict of interest.

#### **References**


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