Association of FTO genotype with obesity and bone health among communitydwelling adults ; Goto Island study on bone health

Bone mass is tuned by various factors, including aging, menopause, low body weight, and genetic variations. Here, we showed an independent association between a genotype on the fat mass- and obesity-associated FTO gene (#610966 on OMIM) and bone loss after adjusting for age and body mass index (BMI). A cross-sectional study was nested in a prospective observational study of 1,828 participants (median age: 69 [62-76] years in men and 68 [61-75] years in women) residing in a rural city in western Japan (Goto Island study). Participants were recruited during medical checkups in 2014 and 2016 from the community-dwelling population. The bone mass of the calcaneus was evaluated using quantitative ultrasound. The single nucleotide polymorphism (SNP) rs1421085 was genotyped using a hydrolysis probe. The chi-squared test was used to determine whether the variants were in equilibrium in this population. There were differences in medians of BMI among the genotypes (24.3 in CC, 23.0 in CT, and 22.6 in TT, P = 0.01), but not in those of bone mass. There was a significant association between the minor allele (C) and being overweight in a gene dosage-dependent manner (BMI > 25, OR per allele =1.52, 95% CI = 1.07-2.14, P = 0.02 in men, OR = 1.48, 95% CI = 1.16-1.95, P = 0.01 in women). Logistic regression analysis showed a significant protective association in male carriers of the minor allele against low bone mass (QUS T-score less than -2.0) after adjusting for age and BMI in men aged 65-75 years (OR = 0.50, 95% CI = 0.27-0.96, P = 0.036), with no significant association in women.Our study indicated an association between the genetic polymorphism of FTO and bone mass among community-dwelling men aged 65-75 years. The polymorphism may play a role in bone health with higher BMI and other beneficial functions.
Acta medica Nagasakiensia, 65(3), pp.77-87; 2022