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 variants (Thr₃₄₇→Ser; Gln₃₆₀→His), and body mass index (BMI) and percentage 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 percentage 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/m². Individuals homozygous for the Ser₃₄₇ allele had higher BMI (32.3 ± 6.6 vs 28.6 ± 5.3 kg/m²; P < 0.01) and percentage body fat (36.9 ± 7.8 vs 31.0 ± 9.6%; P < 0.05) compared with individuals homozygous for Thr₃₄₇. In contrast, the presence of at least one copy of the His₃₆₀ allele was associated with lower BMI (27.2 ± 5.0 vs 28.4 ± 5.6 kg/m²; 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 grouped by BMI percentile, the frequency of the Ser₃₄₇/Ser₃₄₇ genotype increased while the frequency of the His₃₆₀ allele decreased with increasing BMI. CONCLUSIONS: These data suggest a role for apoA-IV in fat storage or mobilization and that genetic variations in the apoA-IV gene may play a role in the development of obesity.