The missense variant, rs373863828, in CREBRF plays a role in longitudinal changes in body mass index in Samoans.

Objective: A missense variant, rs373863828, in CREBRF is associated with obesity in Polynesians. We investigate whether rs373863828 and other factors are associated with body mass index (BMI) rate-of-change between 2010 and 2017-19 in Samoans.

Methods: We used sex-stratified models to test whether BMI rate-of-change was associated with rs373863828, baseline BMI, age, residence, physical activity, and household asset score in a cohort study of 480 Samoan adults measured in both 2010 (mean age 43.8 years) and 2017-19.

Results: Mean BMI increased from 32.1 to 33.5 kg/m in males (n = 220, p = 1.3 ×10) and from 35.9 to 37.8 kg/m in females (n = 260, p = 1.2 ×10). In females, the A allele was associated with a higher rate-of-change (0.150 kg/m/year/allele, p = 1.7 ×10). Across 10-year age groups, mean BMI rate-of-change was lower in older participants. The BMI rate of change differed by genotype: it was, in females with AA genotype, approximately half that seen in GG and AG participants. In females lower baseline household asset scores were associated with a higher rate-of-change (p = 0.002).

Conclusions: In Samoans, the minor A allele of rs373863828 is associated with an increased rate-of-change in BMI in females. On average, BMI of females with the AA genotype increased 0.30 kg/m/year more than of those with the GG genotype.