Longitudinal relationships between family routines and biological profiles among youth with asthma.

OBJECTIVE: To investigate whether longitudinal trajectories of inflammatory markers of asthma can be predicted by levels of family routines in youth with asthma. DESIGN: Family routines were assessed through parent questionnaires and peripheral blood samples obtained from youth every 6 months throughout the 18-month study period. Longitudinal relationships were evaluated using hierarchical linear modeling. MAIN OUTCOME MEASURES: Mitogen-stimulated production of cytokines implicated in asthma, specifically IL-4, IL-5, and IL-13. RESULTS: Youth with more family routines in their home environment showed decreases in IL-13 (but not IL-4 or IL-5) over the course of the study period. In turn, within-person analyses indicated that at times when stimulated production of IL-13 was high, asthma symptoms were also high, pointing to the clinical relevance of changes in IL-13 over time. A variety of child and parent psychosocial as well as child behavioral characteristics could not explain these effects. However, medication use eliminated the relationship between family routines and stimulated production of IL-13. CONCLUSION: Our study suggests that family routines predict asthma outcomes at the biological level, possibly through influencing medication use. Considering daily family behaviors when treating asthma may help improve both biological and clinical profiles in youth with asthma.