New Study Challenges Prediabetes as a Robust Risk Factor for Dementia, Sheds Light on the Startling Impact of Early-Onset Diabetes

“Diabetes and dementia: A perplexing relationship revealed in a groundbreaking study,” states a report published in the prestigious journal Diabetologia. The study delved into the intricate connection between prediabetes, diabetes, and the risk of developing dementia later in life.

Contrary to previous beliefs, the report challenges the notion that prediabetes poses a substantial risk for dementia. Instead, the association primarily stems from the fact that a staggering 70% of prediabetes cases progress to full-blown diabetes, a condition strongly linked to dementia.

Moreover, the research uncovered a striking pattern: the younger individuals are diagnosed with diabetes, the higher their likelihood of experiencing memory loss and cognitive deficits in their later years. This observation points to the potential impact of long-term exposure to hyperglycemia, characterized by persistently elevated blood sugar levels.

Elucidating this matter, Dr. Jonathan J. Rasouli, Director of Complex and Adult Spinal Deformity Surgery at Staten Island University Hospital, explained, “Basically, the younger you are if you are diagnosed with diabetes, the higher the chances you may develop memory loss and other cognitive deficits later in life. This study provides more evidence that diabetes and insulin resistance can lead to neurodegeneration,” he conveyed passionately in an interview with Healthline.

To unravel the intricacies of this phenomenon, the researchers meticulously analyzed the health data of 11,656 individuals enrolled in the Atherosclerosis Risk in Communities study. These participants, aged 45 to 64 during the years 1987 to 1989, underwent comprehensive assessments on glycated hemoglobin levels (HbA1c) and cognitive function.

The baseline assessment revealed that 2,330 participants had prediabetes, with the highest incidence among Black individuals and those with limited education. Subsequent cognitive function evaluations took place during the fourth visit (1996-1998), the more comprehensive fifth visit (2011-2013), and the subsequent follow-up visits.

Among the study cohort, 3,143 individuals developed diabetes, while 2,274 individuals developed dementia. Scrutinizing the relationship between prediabetes and dementia, the research team found that prediabetes alone did not appear to be a robust risk factor for dementia. Instead, it was the progression from prediabetes to overt type 2 diabetes that drove this association with dementia risk, as stated by Dr. Marilyn Tan, a distinguished endocrinologist and chief of the Stanford Endocrine Clinic.

Furthermore, the age at which diabetes was diagnosed emerged as a crucial determinant of future dementia risk. The study revealed that individuals diagnosed with diabetes before the age of 60 faced nearly triple the risk of developing dementia. Those diagnosed between the ages of 60 and 69 experienced a 73% higher risk, while those diagnosed between 70 and 79 exhibited a 23% increased risk. Surprisingly, being diagnosed with diabetes after the age of 80 did not correlate with a heightened risk of dementia.

Scientists theorize that sustained exposure to hyperglycemia contributes to the increased risk of dementia. “The younger one is when diagnosed with diabetes, the longer the body is exposed to hyperglycemia,” elucidated Dr. Tan. The detrimental effects of hyperglycemia on insulin function in the brain, impairment of amyloid-beta clearance, and accumulation of tau protein are all known contributors to dementia.

Additionally, elevated glucose levels can lead to inflammation, oxidative stress, cellular dysfunction, and damage, along with the accumulation of glycation end-products. Dr. Benjamin Nwosu, Chief of Endocrinology at the Cohen Children’s Medical Center and researcher at the Feinstein Institutes for Medical Research, emphasized the consequences, stating, “Additionally, the cellular and vascular damage could lead to impaired blood-brain barrier and the accumulation of deleterious products in brain cells,” shared Dr. Benjamin Nwosu, an esteemed researcher.

It is worth noting that lifestyle factors associated with diabetes, such as an unhealthy diet and a sedentary lifestyle, can also contribute to cognitive decline. Dr. Tan emphasized the importance of recognizing this correlation, stating that these factors can further exacerbate the risk of developing dementia.

In light of these findings, the researchers stress the significance of delaying or preventing the progression of prediabetes to diabetes in order to safeguard cognitive function. Two specific groups warrant focused attention: individuals diagnosed with prediabetes before the age of 65 and Black individuals, who face a higher risk of prediabetes diagnosis.

Dr. Rasouli emphasizes the need for proactive measures, asserting, “These findings suggest we need to be more aggressive with primary prevention and address modifiable risk factors of diabetes as early as possible. This would involve earlier screening of at-risk patients and education.”