This study was designed to see if there was a correlation between verbal intelligence, Type 2 diabetes, and walking speed. They had each participant take the Groningen Intelligence Test which tested their vocabulary and then were assigned a score. This score was then compared to indicators if Type 2 diabetes like A1C and glucose levels. This vocabulary score was also compared to other diabetic health complications like chronic kidney disease, cardiovascular disease, and neuropathic pain. Lastly, they assessed this vocabulary score with the speed at which the individual walked. They tried to minimize confounding variables like age or gender.
In total, only 228 patients were fully assessed on all three tests. When the verbal score was compared to the indicators of Type 2 diabetes (A1C, LDL, glucose, etc.) there was no association between the two. The verbal score was also not associated with kidney disease. Lower verbal scores did show an association with increased cardiovascular disease and neuropathic pain and decreased walking speed.
They noted that the lower verbal intelligence might be correlated with some diabetic functions because they aren’t as educated and have a lesser understanding of their disease state. But I’d like to pose the question that if they don’t understand their disease state, then why isn’t there a correlation between low intelligence and out-of-range A1C, LDL, etc. I also wonder why low intelligence was associated with slower walking. It would be very interesting to see why exactly they chose to compare these three very different assessments and compared them to each other. The walking speed especially seems unrelated.
Tang JYM, Wong GHY, Ng CKM, et al. Lower verbal intelligence is associated with diabetic complications and slower walking speed in people with Type 2 diabetes: the Maastricht Study. J Am Geriatr Soc. 10.1111/jgs.13938 (1 March 2016).