Adolescents and young adults with attention-deficit/hyperactivity disorder (ADHD) have an increased risk for type 2 diabetes, according to a longitudinal study published in the Journal of Clinical Psychiatry.
Previous studies have suggested an association between ADHD and type 2 diabetes-related risk factors such as obesity, hypertension, and dyslipidemia, but few have investigated the association between ADHD and type 2 diabetes.
The study was conducted using the Taiwan National Health Insurance Research Database. From 2002 to 2009, researchers enrolled 35,949 adolescents age 10 to 17 years and young adults age 18 to 29 years who had been diagnosed with ADHD by a board-certified psychiatrist and who had no history of diabetes and 71,898 age- and sex-matched controls.
Follow-up was conducted through 2011, and participants who were diagnosed with type 2 diabetes were identified. Additionally, medical comorbidities, including hypertension, dyslipidemia, and obesity, as well as ADHD medications (methylphenidate and atomoxetine) and atypical antipsychotic medications taken, were monitored and assessed. Level of urbanization was also considered. The longitudinal follow-up study design used a Cox regression analysis with adjustments for demographic data, taking ADHD medications and atypical antipsychotic medications, and comorbidities.
Researchers found an elevated incidence of type 2 diabetes (0.83 vs 0.21 per 1000 person-years, P <.001) and a shorter duration from enrollment to onset in participants with ADHD. They also found a higher prevalence of related comorbidities: hypertension (0.3% vs 0.2%), dyslipidemia (0.6% vs 0.3%), and obesity (2.3% vs 1.0%; all P <.001). Participants with comorbidities and long-term use of atypical antipsychotic medications had the highest risk. The crude hazard ratio of ADHD for type 2 diabetes risk was 4.01 (95% CI, 3.06-5.25). Those with ADHD resided in more urbanized regions and had a lower income-related insured amount. Researchers found that short- or long-term use of ADHD medications was not related to the risk for type 2 diabetes. The temporal association between ADHD and subsequent type 2 diabetes may be explained by immunologic dysregulation and proinflammatory cytokine oversecretion, and the researchers advocate further research.
There were several limitations in this study. Only patients who sought medical help and consultation were included in the study, which could have resulted in an underestimation of the incidence of type 2 diabetes. However, the diagnostic validity within the study is high because diagnoses were conducted by board-certified doctors based on laboratory examinations. Other pertinent information, including disease severity of ADHD, lifestyle, body mass index, and family history are unavailable in the Taiwan National Health Insurance Research Database and thus could not be included for examination within the study.
Researchers concluded that “these findings can inform clinical practice in that type 2 [diabetes] should be considered in ADHD even in the absence of other known risk factors.” They added that the use of atypical antipsychotic medications in patients with ADHD should be carefully evaluated for the risks and benefits.
The researchers also noted that the significant association in this study indicates that further study on the relationship between ADHD and type 2 diabetes is warranted.
Chen M-H, Pan T-L, Hsu J-W, et al. Risk of type 2 diabetes in adolescents and young adults with attention-deficit/hyperactivity disorder: a nationwide longitudinal study. J Clin Psychiatry. 2018;79(3):17m11607.