[A cross-sectional survey of crab intolerance positive rate and its determinants in healthy medical examination population in Beijing].

Objective: To explore the positive rate of crab intolerance and its related factors in a healthy physical examination population in Beijing, China.

Methods: A cross-sectional survey was carried out from August 1, 2008 to July 30, 2009. It recruited a total of 12 765 adults with crab intolerance at Health Sciences Center, Chinese PLA General Hospital. The epidemiological data were entered into computer by two persons and organized by Epidata3.0. Non-conditional Logistic regression model was used to calculate the values of odd ratio (OR) and 95%CI. Statistic analysis was performed by SPSS 13.0.

Results: The incidence rate of crab intolerance was 24.5% (3128/12 765) and increased with age. Grades of crab intolerance were associated with age and gender and there was a linear correlation tendency (P < 0.05). Incidence rate of crab intolerance in females (27.5%, 1077/3912) was higher than that of males (23.2%, 2051/8853). Multiple regression analysis showed that crab intolerance was correlated with age, gender, body mass index and helicobacter infections(all P < 0.05). In comparison with age group < 40 years old, the values of OR (95%CI) of age groups 41 - 50, 51 - 60 and > 60 years old were 1.224 (1.095 - 1.368), 1.616 (1.431 - 1.827) and 2.177 (1.799 - 2.634) respectively. In comparison with males, the OR (95%CI) of females was 1.286 (1.174 - 1.408). The OR (95%CI) of Helicobacter pylori infections was 1.303(1.201 - 1.413). In comparison with normal weighters, the OR (95%CI) of obese subjects was 1.154 (1.026 - 1.298).

Conclusions: Crab intolerance may be correlated with age, gender, Helicobacter pylori infections and body mass index. Health education should be targeted at its characteristics.