Published online: September 7, 2019
Overweight is a known risk factor for asthma within the individual, but it is not known whether overweight may also increase asthma risk in the next generation. A mother’s environment shortly before and during pregnancy influences the child’s health. However, emerging evidence suggests that fathers’ health and behaviours before conception could also be of importance. Intrauterine life and early puberty might possibly constitute periods with particular vulnerability for developing germ cells. It is challenging to study preconception exposures in humans whose reproductive life spans decades. The limited research in this field suggest that father’s smoking in puberty increases asthma risk in his future offspring. With the global epidemic of obesity, it is urgent to assess potential health effects on future offspring.
In an Original article published in The Journal of Allergy & Clinical Immunology (JACI), Johannessen and colleagues examined if parents’ overweight in childhood, adolescence or adulthood, was associated with asthma in their adult offspring. The analysis included 6347 adult offspring (age 18-52 yrs) participating in the RHINESSA multi-generation study, of 2044 fathers and 2549 mothers who were investigated in the RHINE/ECRHS studies.
The researchers analysed associations of parental overweight onset at age eight, puberty and age 30 with offspring asthma with or without nasal allergies. Parental overweight in each time window was defined using a validated figural drawing scale of nine body silhouettes, specific for men and women.
The authors found that fathers’ overweight onset in puberty appeared to cause increased asthma risk in his offspring. This was found for non-allergic asthma in adult offspring. This effect was not mediated through the offspring’s own overweight. No effects on offspring were found for father’s overweight onset in other time-windows or of mothers’ overweight. With regard to overweight in offspring, however, both fathers’ and mothers’ overweight increased the risk. The data were analysed with advanced statistical models developed to measure causal associations, and taking into account potential confounding factors in three generations.
Overweight in boys starting in puberty appeared to increase asthma risk in their future offspring. The findings suggest that factors long before conception may impact on asthma, and that male puberty is a time window of particular importance. Considering the global increase in obesity, also among the young, the results are alarming.
The Journal of Allergy and Clinical Immunology (JACI) is an official scientific journal of the AAAAI, and is the most-cited journal in the field of allergy and clinical immunology.