Study Finds Bidirectional Association Between Asthma and Type 2 Diabetes

According to research presented at the European Association for the Study of Diabetes Annual Meeting, which was held in Madrid, Spain from September 9 to 13, patients with type 2 diabetes (T2D) are more likely to develop asthma. Additionally, those who have asthma are also more likely to develop T2D. These results, the investigators noted, emphasize the significance of screening for asthma when patients are diagnosed with T2D or T2D when diagnosed with asthma.¹

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The association between asthma and type 1 diabetes (T1D) has previously been well-established with a 2022 study published in Nature demonstrating children with asthma have an increased risk of developing immune diseases such as T1D,² and a 2024 study published in Allergy, Asthma, & Clinical Immunology presenting a prevalence of asthma that ranged from 1.7% to 23.1% in patients with T1D.³ However, the association between asthma and T2D has been relatively understudied with emerging evidence suggesting that the relationship may be more complex than previously thought.^1,4

For this systematic review and meta-analysis, the investigators aimed to evaluate the interconnection between asthma and T2D, as well as explore any potential underlying mechanisms and factors. The investigators searched 4 databases up to October 31, 2013, focusing on specific studies that explain the relationship or causation between asthma and T2D. Additionally, studies that lacked a clear specification of diabetes type were excluded. Data from about 17 million people aged 50 to 70 years across a total of 14 studies conducted over a range of countries (eg, US, UK, Finland, Korea) were included.^1,2

“The global rates of asthma and T2D, both of which are common health issues, are on the rise,” Nam Nguyen, PhD candidate, research assistant at the College of Medicine in Taipei Medical University, Taipei, Taiwan, said in the news release. “These conditions negatively impact an individual's quality of life and are expected to create an increasing medical and economic burden. However, the evidence linking the 2 and the mechanisms behind this connection remain unclear, highlighting the need for comprehensive research into their association.”¹

According to the findings, a bidirectional association between asthma and T2D was discovered (OR 1.50, 95% CI 1.15-1.96, I2 = 99%, P < .01), which can indicate potentially shared pathomechanisms. Individuals with asthma were approximately 28% more likely to develop T2D compared with those who do not have asthma. In addition, those with T2D were about 83% more likely to develop asthma compared with those who did not have T2D. Asthma severity was also associated with a higher T2D risk, with the risk increasing in line with severity (P = .01); however, asthma duration was not associated with a risk of T2D. Further, the authors noted that hypertension and dyslipidemia—which is unhealthy levels of blood fats, such as cholesterol—may also contribute to this association.^1,4

“Our findings have important implications for clinical practice. Firstly, this relationship emphasizes the need for greater awareness among patients with T2D or asthma and their health care providers. Secondly, preventive strategies should be considered to lower the risk of T2D in individuals with asthma. For instance, screening for and addressing prediabetes in asthma patients promptly before it develops into T2D, or carefully managing the use of systemic corticosteroids, which can not only cause temporary hyperglycemia but are also linked to an increased risk of T2D,” said Nguyen in the news release. “In addition, the potential shared mechanistic pathways between asthma and T2D proposed by our study offer a new framework for research.”¹

REFERENCES

1. Diabetologia. Individuals with type 2 diabetes are at higher risk of asthma – and vice versa. News release. September 9, 2024. Accessed September 24, 2024. https://www.eurekalert.org/news-releases/1057021

2. Liljendahl, MS, Sevelsted, A, Chawes, BL, et al. Childhood asthma is associated with development of type 1 diabetes and inflammatory bowel diseases: a Danish nationwide registry study. Sci Rep 12, 21728 (2022) doi:10.1038/s41598-022-26067-4

3. Kamei, JM, Maués, RD, de Oliveira Silva, G, et al. Prevalence of asthma in people with type 1 diabetes mellitus: a scoping review. Allergy Asthma Clin Immunol 20, 12 (2024) doi:10.1186/s13223-024-00869-9

4. Nguyen, N. Abstract #359—The association between asthma and type 2 diabetes: a systematic review and meta-analysis including 17 million individuals. Presented at: European Association for the Study of Diabetes; Madrid, Spain. September 9-13, 2024.