Speech Impediment a Risk for Type 2 Diabetes

A new study shows that teenage boys who stutter may have a higher likelihood of developing early-onset type 2 diabetes.

This study was conducted using 4,000 young men who had a stutter, between the ages of 16- and 20-years old, living in Israel. These men had a 30% chance of being diagnosed with diabetes and a more than 60% chance of being diagnosed with type 2 diabetes before 40. This risk factor was studied independently of any other factors or comorbidities that may increase the risk of type 2 diabetes; therefore, there could have been other contributors affecting this study’s results. 

One theory as to why stuttering may cause an increased risk of type 2 diabetes in young men is the potential anxiety from their speech impediment. It is believed that the anxiousness they experience due to their inability to speak without stuttering causes an increase in the stress hormone cortisol. An increase in cortisol can then eventually lead to an increase in weight, causing the patient to potentially be overweight. Obesity, as we all know, is one of the risk factors of type 2 diabetes.  

Another theory as to why stuttering may cause a disproportionate type 2 diabetes rate in young men is irregular dopamine levels and unbalanced blood flow in the brain. Inconsistent dopamine levels can be seen in both patients with type 2 diabetes and patients with stuttering issues. With this category of patients being at an abnormally high risk of developing type 2 diabetes, whether it is early-onset or not, it is pertinent for them to keep the risk factors that they can control in check. These modifiable risk factors include obesity, diet, blood pressure, smoking, and physical inactivity.  

This study was conducted among a group of approximately 2.1 million individuals. Of the about 2.1 million individuals in this study, there were roughly 1.2 million males and around 900,000 females; approximately 4,500 males and 500 females experienced stuttering issues in their speech. For the young men in the group, there was a 3.6% incidence of developing type 2 diabetes those with stuttering problems, vs. a 2.1% incidence in those with no issues with their speech.  

Having additional comorbidities and diabetes risk factors only increased their odds of developing type 2 diabetes. This fact was proven by the 1.23 odds ratio observed in young men with a BMI < 85th percentile versus the 1.48 odds ratio of the young men whose BMI fell in the 85th percentile or more. This study also showed that developing type 2 diabetes was a more significant risk among the men born more recently (since 1980) than in those born earlier, with an odds ratio of 2.37 for 1980 and beyond versus the odds ratio of 1.21 from the men born in the 1960s.  

It is still unclear whether stuttering alone can contribute to the development of type 2 diabetes in men. Men who stutter and have other risk factors for potentially developing type 2 diabetes may require more observation as they may be at a higher risk than men that have risk factors without stuttering in their speech.  

Practice Pearls: 

• Stuttering has been linked to an increased incidence of developing type 2 diabetes and early-onset type 2 diabetes in men. 
• It is believed that the anxiety caused by stuttering increases cortisol levels, and this may be responsible for the increased risk of developing type 2 diabetes in men who stutter. 
• More studies are needed to show that stuttering could be a risk factor for developing T2D. 

Avishai M Tsur, et.al. Stuttering and Incident Type 2 Diabetes: A Population-Based Study of 2.2 Million Adolescents. The Journal of Clinical Endocrinology & Metabolism, Volume 106, Issue 4, April 2021, Pages 978–987, https://doi.org/10.1210/clinem/dgaa988 

Tucker, Miriam E. “Youth Stuttering Tied to Early Onset Type 2 Diabetes in Males.”  Medscape, Jan. 26, 2021. 

Oluwatayo Ishola, PharmD. Candidate, South College, School of Pharmacy