Abstract
Objective:
Obstructive sleep apnea (OSA), with daytime drowsiness, nocturnal hypoxia, could result in systemic inflammation and oxidative damage. We hypothesize that parental OSA, with chronic systemic inflammation and oxidative stress, might contribute to children’s neurodevelopmental disorders, such as ADHD.
Method:
By linking National Birth Registry with the National Health Insurance Research Database, Taiwan, we identified 2006–2015 birth cohort, which comprised 1,723,873 singleton live births, and conducted a nested case-control study. We included children with ADHD and compared them with non-ADHD controls matched with ADHD case on index date. Conditional logistic regression was utilized to calculate adjusted odds ratio (aOR) when investigating the association between parental diseases with risk of ADHD in their offspring.
Results:
The aOR (95% CI) of offspring’s ADHD was 1.758 (1.458–2.119) with paternal OSA and 2.159 (1.442–3.233) with maternal OSA. The subgroup analysis revealed different effects of parental diseases among children’s gender.
Conclusion:
Our study demonstrates an association in parental OSA and offspring ADHD, which could inspire further research to clarify the mechanisms.
Introduction
ADHD is the most common neurodevelopmental behavioral disorder in childhood, characterized by inattention, hyperactivity, and impulsivity according to DSM 5 diagnostic criteria (American Psychiatric Association, 2013), which could extend into adolescence and adulthood. It affects many aspects, including physical health, academic, social, or occupational performance (Posner et al., 2020). According to previous worldwide studies, the prevalence of ADHD was estimated as 5.29% (95% CI 5.01–5.56; Polanczyk et al., 2007).
It has raised more concerns due to increasing research about the disease and its pathophysiology over the past several decades. The etiology is multifactorial, including hereditary, environmental exposures, and gene-environment interactions. Previous reports have shown that prenatal and postnatal risk factors, including prematurity, low birth body weight (Nigg & Breslau, 2007), maternal mental disorders, especially depression, anxiety (Vizzini et al., 2019; Wolford et al., 2017), various inflammation status, maternal autoimmune diseases, family history of autoimmune diseases (thyrotoxicosis, type 1 diabetes, gestational diabetes, autoimmune hepatitis, psoriasis, and ankylosing spondylitis), atopic diseases, or asthma are associated with ADHD or ADHD symptoms (Dalsgaard, 2021; Han et al., 2021; P. R. Nielsen et al., 2017; T. C. Nielsen et al., 2021).
The association between maternal diseases and offspring ADHD could be explained through the proposed concept of shared genetic and environmental risk factors or direct effects of maternal autoantibodies/cytokines crossing the placenta and altering the fetal immune response, which in turns leads to changes in the fetus central nervous system (Dalsgaard, 2021). Maternal inflammatory states, which could result from autoimmune diseases or other diseases, might also play a role in immune activation during pregnancy through the placenta and immature blood-brain barrier, rendering the immature fetal brain to be more susceptible to evolve into various neurodevelopmental disorders through microglia activation and epigenetic alterations (Han et al., 2021).
Obstructive sleep apnea (OSA) syndrome is characterized by snoring and/or increased respiratory effort secondary to increased upper airway resistance and pharyngeal collapsibility, with disruption of normal oxygenation, ventilation, and sleep pattern (Kaditis et al., 2016). OSA affects 24% of men and 9% of women of the middle-aged population in the US (Hiestand et al., 2006). It was not until 2019, Vizzini birth cohort study (Vizzini et al., 2019) showed the relative increase in ADHD scores are associated with maternal sleep disorders, which was the first study reporting an association between maternal sleep disorders and offspring ADHD symptoms. OSA, with daytime drowsiness, nocturnal hypoxia, could result in systemic inflammation and oxidative damage (Dehlink & Tan, 2016). We hypothesized the systemic maternal inflammation status and oxidative stress caused by OSA symptoms, might contribute to children’s neurodevelopmental disorders, such as ADHD.
Since numerous observational studies showed various prenatal, perinatal factors, and maternal status that might be associated with offspring ADHD, few studies focused on paternal impacts which might also contribute to children’s outcomes by genetic-environmental interplay. Moreover, previous conclusions regarding associations between offspring ADHD and maternal autoimmune diseases, systemic diseases during pregnancy or through the lifetime were still not consistent. Maternal sleep disorders, to our knowledge, have not yet been studied before in association with children diagnosed as ADHD by physicians and paternal sleep disorders have not been done for association between offspring ADHD.
Understanding the familial risk of OSA, parental autoimmune or systemic diseases and offspring ADHD will help clinicians to identify children at risk and offer opportunities for early intervention and treatment. The present study represents a different perspective, that is, investigating the relationship between parental OSA and offspring ADHD, and also provides more evidence between specific autoimmune diseases and offspring ADHD. Additionally, we assessed whether these risk factors differed by patient’s gender.
Methods
Ethical Statements
This study was approved by the Institutional Review Board of The Institutional Review Board of Chung Shan Medical University Hospital in Taiwan. IRB, CS 19009. Need for informed consent was waived because the data we used consisted of a de-identified secondary data set which had been released for research purposes and only de-identified data. The protocol for the research project is conformed to the provisions of the Declaration of Helsinki.
Data Source
This study is based on record linkage of the datasets between the National Birth Registry with National Health Insurance Research Database (Hsieh et al., 2019) and we selected the birth cohort that involved children were born from 2006 to 2015 for analysis. National Birth Registry was initiated in 2003 under the auspices of the Health Promotion Administration in Taiwan and has routinely collected perinatal data in Taiwan. These data include demographic characteristics, infants’ gender, birth weight, gestational week, mode of delivery, and parental age (at delivery). Taiwan’s National Health Insurance (NHI) program was established in 1995 and covers up to 99.99% of Taiwan’s population. The National Health Insurance Research Database (NHIRD) was released for research purposes and thoroughly provided population-based evidence to support clinical decisions. The NHIRD comprised comprehensive demographic characteristics, and the insurance claim records including diagnosis, procedures, expenses, as well as prescription in outpatient, inpatient, and emergency service.
Selection of ADHD Cases and Non-ADHD Controls
Initially, there were 1,939,449 infants (the birth cohort) were born from 2006 and 2015. The exclusion criteria include missing birth data from National Birth Registry (n = 42,396), stillbirth (n = 610), infants from multiple birth (n = 57,976), and mothers with foreign nationality (n = 114,594). A total of 1,723,873 singleton live births were selected after exclusion.
We obtain independently paired mother–child data (mother–child dyads) and associated medical information regarding relevant variables of parents and children. The nested case-control study was conducted. The ADHD children were identified by International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM) code 314.x from birthdate to the 31th, December 2017. In each ADHD case, the first date of ADHD diagnosis was defined as index date, then the 1:4 ratio of non-ADHD controls were individually matched by the birth year and sex on the index date.
In order to ensure the accuracy, diagnosis of ADHD would need to be documented at least three times by board-certified psychiatrists during the follow-up period. We finally identified 60,367 mother-child dyads when the children were diagnosed with ADHD and compared them with 241,468 control mother-child dyads (Figure 1). Supplemental Figure 1 showed the age distribution of newly diagnosed ADHD, which identified from birthdate until the end of 2017, in the 2006 to 2015 birth cohort.

Flowchart of enrolment of study subjects.
Exposure of Parental Diseases Before Birth
The records of parental diseases were obtained from the NHIRD and the diagnosis was identified within 3 years before the child birth. The various kinds of parental autoimmune diseases that have ever been reported in previous comprehensive studies (Nielsen et al., 2017, 2021; Vizzini et al., 2019), including rheumatoid arthritis (ICD-9-CM code 714.0), systemic lupus erythematosus (SLE, ICD-9-CM code 710.0), Sjogren’s syndrome (ICD-9-CM code 710.2), ankylosing spondylitis (AS, ICD-9-CM code 720.0), psoriasis (ICD-9-CM code 696.0, 696.1), hyperthyroidism (ICD-9-CM code 240.9) were selected to clarify if the link to offspring ADHD is universal.
In addition, the parental systemic diseases include anemia (ICD-9-CM code 285.9), chronic obstructive pulmonary disease (COPD, ICD-9-CM code 490–492, 493–496), and sleep apnea (ICD-9-CM code 327.2), and the parental allergic disease of asthma (ICD-9-CM code 493) and atopic dermatitis (ICD-9-CM code 691) were identified to verify our hypothesis.
Other Infants and Parental Characteristics During Perinatal Period
Baseline data including birth weight, gestational weeks, infant’s sex, gestational age, mode of delivery, insurance characteristics (which was assumed to be related to socioeconomic status), parental age during delivery, maternal preeclampsia, or gestational diabetes were collected and adjusted.
Statistical Analysis
This study had nationwide and large-scale sample size, it is likely to reveal a statistically significant difference of p < .05, even if the effect size is negligible or small (Sullivan & Feinn, 2012). The absolute standardized difference (ASD) was used to compare the statistical values, including the means and proportion, of baseline covariates between groups in this large-sample observational study. When the ASD less than 0.1, the characteristic was small or no difference between ADHD and non-ADHD groups. We applied inverse probability of treatment weighting (IPTW) to minimize the potential confounding effect due to the difference on the baseline characteristics between two groups. The average treatment effect (ATE) of ADHD was estimated by using the logistic regression that contains the variables including infant’s sex, birth weight, gestational age, mode of delivery, maternal age, maternal preeclampsia, gestational diabetes, and paternal age during pregnancy. The primary results, odds ratios, were inverse weighted by the treatment weighting.
In this study, the birth year and sex matched ADHD cases and non-ADHD controls were selected for analysis, therefore, a conditional logistic regression model was conducted to estimate the adjusted odds ratio (aOR) and 95% confidence interval (CI) of children’s ADHD after adjustment for infant’s sex, birth weight, gestational age, mode of delivery, maternal age, maternal preeclampsia, gestational diabetes, and paternal age during pregnancy. Sensitivity analysis was further conducted to evaluate whether the influences of parental diseases on offspring ADHD differed between genders.
All statistical analysis was conducted using Statistical Analysis Software (SAS) version 9.4 (Cary, NC: SAS Institute Inc.). A p-value less than .05 was considered statistically significant.
Results
Demographic Characteristics and Prevalence of Comorbidities
Table 1 shows the baseline characteristics of the ADHD group and control group. According to the absolute standardized difference (ASD) of baseline characteristics between ADHD and control group, the ADHD group had a higher prevalence of small gestational week (defined as <36 weeks) than the control group. After IPTW, there were small or no difference in the infant’s sex, birth weight, gestational age, mode of delivery, maternal age, preeclampsia, gestational diabetes, employment status, and paternal age at delivery between ADHD cases and non-ADHD controls.
Baseline Characteristics Between ADHD and Control Groups From 2006 to 2015 Birth Cohort in Taiwan.
Note. ASD = absolute standardized difference, the small difference of characteristic appeared between study groups when ASD < 0.1; IPTW = inverse probability of treatment weighting.
Comparison of Adjusted Odds Ratios of Parental Diseases Between ADHD Group and Control Group
Table 2 (the exposure as maternal diseases) and Table 3 (the exposure as paternal diseases) show the odds ratios of ADHD estimated by conditional logistic regression analysis and adjusted for infant’s sex, birth weight, gestational age, mode of delivery, maternal age, preeclampsia, gestational diabetes, employment status, and paternal age during pregnancy. The following factors were associated with a higher risk of ADHD, including parental OSA, COPD, hyperthyroidism, maternal rheumatoid arthritis, psoriasis, atopic dermatitis, and asthma. The odds ratio (95% CI) of developing ADHD was 1.413 (1.285–1.553) for paternal OSA and 1.654 (1.347–2.031) for maternal OSA.
Adjusted Odds Ratios of Offspring’s ADHD When Maternal Diseases Exposed Within 3 years Before Birth by Using Multiple Variable Logistic Regression Analysis and IPTW Model.
Note. AD = atopic dermatitis; AS = ankylosing spondylitis; COPD = chronic obstructive pulmonary disease; IPTW = inverse probability of treatment weighting; OSA = obstructive sleep apnea; RA = rheumatoid arthritis; SLE = systemic lupus erythematosus; SS = Sjogren’s syndrome.
This analysis excluded the missing data in paternal information.
Both Adjusted OR and IPTW OR were adjusted for the co-variates including infant’s sex, birth weight, gestational age, mode of delivery, maternal age, maternal preeclampsia, gestational diabetes, and paternal age during pregnancy.
Adjusted Odds Ratios of Offspring’s ADHD When Paternal Diseases Exposed Within 3 years Before Birth by Using Multiple Variable Logistic Regression Analysis and IPTW Model.
Note. AD = atopic dermatitis; AS = ankylosing spondylitis; COPD = chronic obstructive pulmonary disease; IPTW = inverse probability of treatment weighting; OSA = obstructive sleep apnea; RA = rheumatoid arthritis; SLE = systemic lupus erythematosus; SS = Sjogren’s syndrome.
This analysis excluded the missing data in paternal information.
Both Adjusted OR and IPTW OR were adjusted for the co-variates including infant’s sex, birth weight, gestational age, mode of delivery, maternal age, maternal preeclampsia, gestational diabetes, and paternal age during pregnancy.
In the IPTW models, the results show parental AS significant increased the risk of offspring ADHD. The aOR (95% CI) of developing ADHD was 1.195 (1.082–1.320) in children exposed to paternal AS and 1.758 (1.458–2.119) in children exposed to maternal AS. Moreover, the odds ratio (95% CI) were 1.758 (1.458–2.119) for paternal OSA and 2.159 (1.442–3.233) for maternal OSA.
Subgroup analysis of ADHD patients stratified by gender
Figure 2a (for maternal diseases) and Figure 2b (for paternal diseases) demonstrated the odds ratio of children ADHD in parental autoimmune, systemic, and allergic diseases between gender subgroups. The subgroup analysis revealed the different effects of parental diseases on the risk of ADHD between children’s gender. Table 4 provides more detail results of subgroup analysis.

(a) Children’s gender-stratified analysis for odds ratio of ADHD in maternal autoimmune, systemic, and allergic disease during pregnancy and (b) Children’s gender-stratified analysis for odds ratio of ADHD in paternal autoimmune, systemic, and allergic disease during pregnancy.
Children’s Gender-Stratified Analysis for Odds Ratio of ADHD in Parental Autoimmune, Systemic, and Allergic Disease During Pregnancy.
Note. AD = atopic dermatitis; AS = ankylosing spondylitis; COPD = chronic obstructive pulmonary disease; OSA = obstructive sleep apnea; RA = rheumatoid arthritis; SLE = systemic lupus erythematosus; SS = Sjogren’s syndrome.
Odds ratios were adjusted for the co-variates including infant’s sex, birth weight, gestational age, mode of delivery, maternal age, maternal preeclampsia, gestational diabetes, and paternal age during pregnancy.
Figure 2a (for maternal diseases) shows the sex stratified analysis showed aORs (95% CI) of ADHD were 1.512 (1.190–1.921) in boys and 2.159 (1.442–3.233) in girls when exposure to maternal OSA before birth. Maternal Sjogren’s syndrome showed aOR (95% CI) 1.248 (1.118–1.393) in boys, while maternal Sjogren’s syndrome showed 1.190 (0.962–1.474) in girls with ADHD. However, there was no significant interaction (maternal disease × infant’s sex) observed in this study.
Figure 2b (for paternal diseases) shows the paternal OSA contribute the different effect on the boys ADHD (aOR = 1.316, 95% CI = 1.179–1.470) and girl ADHD (aOR = 1.758, 95% CI = 1.458–2.119), the significant interaction effect (paternal OSA × infant’s sex) on children ADHD was observed.
Discussion
This large nationwide case-control study is the first study, to our knowledge, displayed positive associations of parental obstructive sleep apnea and ADHD diagnosis in children. Two of our novel findings deserve further investigation. First, both maternal and paternal OSA are associated with offspring with ADHD. Second, it seems that the association differed by child sex. The subgroup analysis revealed the different effects of parental diseases among children’s gender. Paternal OSA shows aOR (95% CI) 1.316 (1.179–1.470) in boys with ADHD, while maternal OSA showed 1.758 (1.458–2.119) in girls with ADHD. We also found out that maternal diagnosis of ankylosing spondylitis during pregnancy was associated with higher risk of children with ADHD.
Vizzini birth cohort study in 2019 showed the relative increase in ADHD scores are associated with maternal sleep disorders, which was the first study reporting an association between maternal sleep disorders and offspring ADHD. The outcome was ADHD scores (ADHD symptoms) assessed by children’s mothers through questionnaires (Vizzini et al., 2019). On the contrary, our study used ADHD diagnosis by physicians, which requires more detailed evaluation in at least two different settings. OSA symptoms, including daytime drowsiness, nocturnal hypoxia is postulated to result in systemic inflammation and oxidative damage, which could affect neurocognitive, cardiovascular, and metabolic systems from previous studies (Esposito et al., 2013). Developing large studies have been conducted to support the mechanism that maternal inflammatory states might play a role in immune activation during pregnancy through the placenta and immature blood-brain barrier, rendering the immature fetal brain to be more susceptible to evolve into various neurodevelopmental disorders through microglia activation and epigenetic alterations (Han et al., 2021). We speculate these mechanisms might explain why maternal OSA, which results in maternal inflammation status and oxidative change caused by chronic hypoxia, is associated with children’s ADHD. On the other hand, paternal OSA has not shown association with offspring ADHD before. The shared vulnerability between OSA and ADHD may suggest genetic mechanisms behind both diseases, superimposed with gene–environment interactions, causing epigenetic alterations including DNA methylation, histone modifications, and chromatin remodeling which are highly sensitive to environmental stimuli. Dysregulations of Wingless-INT (Wnt)-signaling pathway, which is known to orchestrate cellular proliferation, polarity, and differentiation; and mammalian target of rapamycin (mTOR)-signaling pathway, which is involved in several significant processes of neurodevelopment and synaptic plasticity, might have an important role in the pathophysiology of ADHD (Yde Ohki et al., 2020) . However, future investigation is needed to clarify the mechanism between paternal OSA and offspring ADHD.
Our findings also showed generally consistent results with those reported by previous studies that maternal autoimmune diseases, especially rheumatoid arthritis and ankylosing spondylitis especially during pregnancy, were associated with increased ADHD among children. Nielsen et al. (2017) conducted the first nationwide cohort study that investigated the association between parental history of autoimmune disease and risk of offspring ADHD. Instanes et al. (2017) performed a population-based nested case-control study which also searched for the relationship between maternal diseases with immune components and offspring ADHD. It defined individuals receiving ADHD medications as patients with ADHD, concerning the more severe disease requiring medications that would affect one’s daily life most (Instanes et al., 2017). T. C. Nielsen et al. (2021) conducted a hybrid study which combined a birth cohort study and systematic review, which was the most recent comprehensive study related to association of maternal autoimmune disease with ADHD children from our search. It included one or more maternal autoimmune diagnoses out of 35 conditions linking with hospital admission records. Besides the large-scale studies mentioned above, many observational studies regarding this aspect showed associations between maternal autoimmune diseases and ADHD in children, but the influence of individual diseases varied through different research designs. Further comprehensive research is required to clarify the associations and increase understanding of the mechanisms.
Hypothesis models had been postulated that exaggerated cytokines, inflammatory responses, increase in oxidative stress, and neuroinflammation might contribute to the etiology of ADHD (Buske-Kirschbaum et al., 2013; Corona, 2020). There are also developing studies within this field regarding the association between maternal autoimmune diseases and neurodevelopmental disorders. It has been suggested maternal inflammatory conditions, such as infections, hypoxia, allergy, autoimmune disease, may cause an exaggerated fetal central nervous system inflammatory response (Strickland, 2014). These speculated mechanisms could be summarized as shared genetic and environmental risk factors or direct effects of maternal autoantibodies or cytokines crossing the placenta and altering the fetal immune response, which in turns leads to impairment in the central nervous system (Dalsgaard, 2021). Previous studies have been conducted to investigate the association between maternal autoimmune diseases and neurodevelopmental diseases, including autism spectrum disorder (Chen et al., 2016; Croen et al., 2005), obsessive-compulsive disorder, and Tourette’s/chronic tic disorders (Mataix-Cols et al., 2018). It was not until recent 10 years that large studies focused more on offspring ADHD.
Strengths and Limitations
Our findings provide further evidence that maternal autoimmune diseases (especially for AS) during perinatal period are positively associated with offspring ADHD diagnosis, and extend the existing evidence to maternal OSA and paternal OSA, which could also cause general inflammatory conditions through genetic or environmental factors. Meanwhile, our findings suggest the importance of the sleep disorders assessment in parents of reproductive age.
However, our study has some limitations that should be considered when interpreting the results. First, we assessed only doctor-diagnosed obstructive sleep apnea, therefore, the effect of less severe sleep disturbances, which have much higher prevalence in the general population and among pregnant women, requires future research. Second, our nationwide data bank did not include smoking, alcohol drinking conditions which could be important confounding factors to ADHD. Third, we lack information on parental ADHD diagnosis that potentially could act as a confounding factor. However, given the relatively low ADHD prevalence in the general population compared with sleep disorders, the relatively strong associations that we found, might be unlikely that confounding by maternal ADHD could entirely explain the findings of our study. Last, previous study has shown that children diagnosed with OSA could be associated with the development of ADHD (Wu et al, 2017). Considering the genetic predisposition of OSA, we did not further discuss about the children diagnosed with OSA, which could be a relevant factor of mediation between OSA in the parents and ADHD.
Conclusion
Our study suggested positive associations of parental obstructive sleep apnea and ADHD diagnosis in children. It could provide clinicians more considerations about sleep disorders in reproductive parents. Further research should be done to clarify the result and mechanism.
Supplemental Material
sj-tiff-1-jad-10.1177_10870547221120695 – Supplemental material for Epidemiological Study of Parental Obstructive Sleep Apnea and Subsequent Risk of ADHD in Their Children: A Nationwide Population-Based Study
Supplemental material, sj-tiff-1-jad-10.1177_10870547221120695 for Epidemiological Study of Parental Obstructive Sleep Apnea and Subsequent Risk of ADHD in Their Children: A Nationwide Population-Based Study by Iwen Chen, Jing-Yang Huang, Renin Chang, Yao-Min Hung and James Cheng-Chung Wei in Journal of Attention Disorders
Footnotes
Contributor Information
Study conception and design: Chen, Chang, Hung, and Wei JC; Acquisition of data: Huang; Analysis and interpretation of data: Chen, Hung, Chang, Huang, and Wei JC; Writing (original draft preparation): Chen, Huang, and Hung; Writing (review and editing): Hung and Wei.
Declaration of Conflicting Interests
The author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.
Funding
The author(s) disclosed receipt of the following financial support for the research, authorship, and/or publication of this article: The study was supported by Chung Shan Medical University Hospital (Grant Number CSH-2019-C-004).
Patient and Public Involvement
Patients and/or the public were not involved in the design, or conduct, or reporting, or dissemination plans of this research.
Patient Consent for Publication
Not required because the data we used was a de-identified secondary data set which had been released for research purposes and analyzed anonymously.
Data availability statement
All data relevant to the study are included in the article or uploaded as online supplementary information.
Author Biographies
References
Supplementary Material
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