Familial aggregation of airway responsiveness: a community-based study

We investigated the familial aggregation of airway hyper-responsiveness (AHR) to methacoline among randomly chosen families in a rural community in Anqing, China.

Airway responsiveness (AR) to methacoline and related risk factors were assessed in each subject. We first modeled the within family correlation in AR and demonstrated the familial aggregation of this trait. Furthermore, we examined the effect size (e.g., odds ratio, OR) of this correlation in a "subsequent offspring model."

The correlation coefficient is significantly positive for parent-offspring and offspring-offspring pairs, but not significant in father-mother pairs, suggesting a genetic component. The strength of the relationships is in the order of father-offspring < mother-offspring < offspring-offspring. The OR of a positive AHR test for subsequent offspring who had mothers and an eldest sibling with positive AHR is 4.12 (95% CI, 1.72-9.87), compared with subsequent offspring whose mother and eldest sibling were negative in the test.

Our study supports a familial clustering of AHR in a Chinese population, which points to a role for genetic factors.