The impact of parental history on children’s risk of asthma: a study based on the National Health and Nutrition Examination Survey-III

Abstract

Purpose

This study aimed to examine the separate effects of maternal and paternal history on the onset of asthma in children and evaluate the relationship between age of asthma onset in parents and risk of asthma in their children.

Methods

We used data from the third National Health and Nutrition Examination Survey. We developed new continuous standardized scores for survey data to quantify parental history that incorporated both the occurrence of asthma and the age at onset, and associated these scores with asthma risk in the children. The association analysis was adjusted for sex and obesity status.

Results

Children with maternal history have elevated asthma risk (hazard ratio of 3.71, 95% CI: 1.19–11.60) than those without, and those whose mothers had earlier age of onset have increased risk of asthma compared to those whose mothers had later age of onset. On the contrary, paternal history had a relatively smaller effect that may be only detectable in larger samples (hazard ratio of 2.17, 95% CI: 0.69–6.79).

Conclusion

Maternal asthma history was strongly associated with the onset of asthma in the second generation, and children whose mother had an earlier age of onset had an increased risk of 3.71. For an approximately 10-year decrease in mother’s age at onset of asthma, the risk of asthma for the offspring increased by 1.37-fold. Using our new risk scores led to smaller standard errors and thus more precise estimates than using a binary indicator.

Keywords:

• parental history
• asthma risk
• maternal history
• survey
• family data

Supplementary material

Figure S1 Log-log(survival) versus log(age) for checking the proportional hazards assumption.

Abbreviations: HH, household; PIR, poverty-income ratio.

Figure S2 Relationship of proposed risk scores and age at onset of asthma.

Note: A one-unit increase in the log-rank risk score corresponds to about a 10-year decrease in the parent’s age at onset of asthma.

Acknowledgments

The study was supported by the National Institutes of Health grant R01GM088566.

Disclosure

The authors report no conflicts of interest in this work.