Abstract
BACKGROUND: There is a controversy about the relation between anti-hepatitis B (anti-HBs) antibody level and obesity. We designed this study to compare the vaccine efficacy in obese/overweight and non-obese cases. METHODS: In this cross-sectional study, 242 obese/overweight and 85 non-obese individuals were participated. Cases were selected from a referral clinic for obesity and a referral hepatology clinic, both in Tehran, Iran. RESULTS: Obese cases had lower percentage of liver diseases (66.9% vs. 100%, P<0.001) but higher hepatitis B vaccination history (74.9% vs. 51.2%, P<0.001). Median±inter-quartile range of anti-HBs titer in obese cases was significantly lower than controls (48.5±194.5 vs. 100±557.6, P=0.012). CONCLUSION: The level of anti-HBs surface antigen antibody's titer in obese cases without liver disease is lower than control group. Therefore, a suitable strategy is needed to overcome this problem, which can be the use of longer needles for vaccination.