Common apolipoprotein A-IV variants are associated with differences in body mass index levels and percentage body fat

OBJECTIVE: To determine the relationship between two common apoA-IV variant s (Thr(347)-->Ser; Gln(360)-->His), and body mass index (BMI) and percentag e body fat. DESIGN: Cross-sectional study. SUBJECTS: Eight-hundred and forty-eight subjects screened for participation in ongoing clinical studies. MEASUREMENTS: ApoA-IV genotype, body mass index, waist-to-hip ratio and per centage body fat by bioelectric impedance. RESULTS: Participants had an average age of 41 +/- 12 y and an average BMI of 28.2 +/- 5.5 kg/m(2). Individuals homozygous for the Ser(347) allele had higher BMI (32.3 +/- 6.6 vs 28.6 +/- 5.3 kg/m(2); P < 0.01) and percentage body fat (36.9 +/- 7.8 vs 31.0 +/- 9.6%; P < 0.05) compared with individua ls homozygous for Thr(347) In contrast, the presence of at least one copy o f the His(360) allele was associated with lower BMI (27.2 +/- 5.0 vs 28.4 /- 5.6 kg/m(2); P < 0.05) and percentage body fat (28.6 +/- 8.2 vs 30.7 +/- 9.1%; P < 0.05). The genotype effects persisted after normalization of the data for the potential confounding effects of gender, age and race. When g rouped by BMI percentile, the frequency of the Ser(347)/Ser(347) genotype i ncreased while the frequency of the His(360) allele decreased with increasi ng BMI. CONCLUSIONS: These data suggest a role for apoA-IV in fat storage or mobili zation and that genetic variations in the apoA-IV gene may play a role in t he development of obesity.