A recent genome-wide association study (GWAS) in Samoans (a Polynesian population) identified strong associations of CREBRF variants with BMI. The G allele at rs12513649 (frequency=25.8%) was associated with ∼1.3 kg/m2 higher BMI per copy, as was the Gln allele at rs373863828 (which codes for an ArgGln substitution). The Gln allele at rs373863828 has frequency of 25.9% in Samoans and is rare in most global populations, although it has been observed at low frequency in some other Oceanic populations. The alleles associated with higher BMI were suggestively associated with lower risk of type 2 diabetes [T2D, odds ratio (OR)=0.69 per copy, P=4.7×10-7]. We investigated the associations of rs12513649 and rs373863828 with BMI and T2D in 2029 Pacific Islanders from Guam and Saipan, who participated in a GWAS. Frequencies of the G allele at rs12513649 and the Gln allele at rs373863828 were 8.1 and 5.4% respectively in full-heritage Chamorros (N=928), 4.1 and 0.2% in Filipinos (N=249), 6.1 and 3.7% in Chuukis (N=153), 2.2 and 1.1% in Carolinians (N=43), and 20.7 and 2.2% in Palauans (n=45). Using a genomic control procedure with adjustment for age, sex, end-stage renal disease and the first four genetic principal components, the G allele at rs12513649 and the Gln allele at rs373863828 were associated with higher BMI (β=1.60 kg/m2, P=0.002 and β=1.36 kg/m2, P=0.058 respectively). They were also modestly associated with taller height (β=0.8 cm, P=0.11, and β=1.5 cm, P=0.019). The alleles conferring higher BMI were associated with lower prevalence of T2D (OR=0.62, P=0.0and OR=0.45, P=0.001). When combined with previously published results for Samoans via meta-analysis, the association of rs373863828 with T2D achieved genome-wide statistical significance (OR=0.67, P=2.9×10-8). These results suggest that CREBRF variants may be important contributors to obesity in Oceanic populations, and they confirm the associations of the allele conferring higher BMI with lower risk of T2D.

Disclosure

R.L. Hanson: None. S. Safabakhsh: None. J. Curtis: None. D.K. Mahkee: None. L. Baier: None. W.C. Knowler: None. R. Nelson: None. W. Hsueh: None.

© 2018 by the American Diabetes Association.
2018
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