Persistent infection of Helicobacter pylori affects weight loss in obese population compared with persistent negative: A case‐control study based on healthy Chinese

Background The relationship between Helicobacter pylori ( H pylori ) and body mass index (BMI) is still inconclusive. Not only the high rate of H pylori infection but also the increasing higher BMI levels are endangering Chinese today. Methods The aim of this research was to evaluate the association between different situations of H pylori infection and BMI values or levels in Chinese healthy population. A total of 39 091 individuals aged from 18 years to 80 years, performed healthy examination including a 13 C/ 14 C urease breath test ( 13 C/ 14 C‐UBT), were included. Among them, 30 224 individuals only had one time of health examination, and 8867 had two or more times. A case‐cohort data of 8752 with an interval time more than 6 months, collected by the first and the last time, were established from the latter. BMI groups are classified according to the China recommendation: low weight (<18.5 kg/m 2 ), normal weight (18.5 ~ 23.9 kg/m 2 ), overweight (24.0 ~ 27.9 kg/m 2 ), and obesity (≥28.0 kg/m 2 ). Results The rate of H pylori infection among low weight, normal weight, overweight, and obesity was 43.2%, 44.7%, 46.4%, and 48.0%, respectively ( P  = .000). H pylori infection increased the risk of higher level of BMI (OR = 1.077, 95% confidence interval = 1.036‐1.119, χ 2  = 14.048, P  = .000) with adjustments for sex and age. In the case‐control study, the rate of persistent negative, persistent infection, new infection, and eradicated infection was 39.5%, 25.8%, 15.8%, and 18.9%, respectively, with a median interval time of 13 months. The mean obesity BMI descend values in the persistent negative subgroup were lower than those in the persistent infection subgroup (−0.21 ± 1.19 kg/m 2 vs −0.003 ± 1.01 kg/m 2 , P  = .021). But the change of BMI classifications had no difference between the subgroups of H pylori infection in different BMI levels. Conclusions H pylori infection was positively correlated with higher BMI levels. And H pylori persistent infection had a negative effect on the fall of BMI values in Chinese obese population.