According to new research, individuals diagnosed with type 2 diabetes at a younger age face a significantly higher risk of developing dementia compared to those who receive a later diagnosis. This heightened risk is notably greater in adults who are also experiencing obesity.
New research reveals that individuals diagnosed with type 2 diabetes at a younger age are more likely to develop dementia than those diagnosed later in life. This study, conducted by researchers at NYU Rory Meyers College of Nursing, highlights a particularly significant risk for adults with obesity. The findings are published in PLOS ONE.
“Our study indicates that early onset type 2 diabetes may lead to cognitive issues, underscoring the need for preventive measures against dementia that address both diabetes and obesity,” explained Xiang Qi, an assistant professor at NYU Meyers and the lead author of the study.
Type 2 diabetes is recognized as a risk factor for dementia. While the exact mechanisms are still not entirely clear, researchers believe that certain diabetes-related factors—like elevated blood sugar levels, insulin resistance, and inflammation—could contribute to the development of dementia in the brain.
Previously considered a condition primarily affecting older adults, type 2 diabetes is now increasingly found among younger people: globally, one in five individuals with type 2 diabetes is under the age of 40.
To investigate how the age at which one is diagnosed with type 2 diabetes impacts dementia risk, the research team analyzed data from the Health and Retirement Study, a long-term project run by the University of Michigan Institute for Social Research, covering the years 2002 to 2016. The study incorporated 1,213 U.S. adults aged 50 and above, all confirmed to have type 2 diabetes through blood tests and without dementia at the start of the study. Over the course of up to 14 years, 216 participants (or 17.8%) were diagnosed with dementia during follow-up telephone interviews.
The analysis found that those diagnosed with type 2 diabetes at a younger age were at a greater risk for developing dementia compared to individuals diagnosed at age 70 or older. Specifically, individuals diagnosed before age 50 were 1.9 times more likely to develop dementia compared to those diagnosed at 70 or above, while those diagnosed in their 50s had a 1.72 times higher risk, and those diagnosed in their 60s had a 1.7 times higher risk.
Moreover, statistical testing indicated a consistent relationship between the age of diagnosis and dementia risk; each year younger at diagnosis raised the risk of developing dementia by 1.9%.
“While the precise reasons behind the increased dementia risk linked to an earlier diabetes diagnosis remain unclear, earlier research indicates that individuals diagnosed with type 2 diabetes during mid-life often face more vascular issues, poorer blood sugar regulation, and higher insulin resistance—all of which are known contributors to cognitive decline,” stated Bei Wu, the Dean’s Professor in Global Health and vice dean for research at NYU Meyers and the study’s senior author.
Additionally, obesity seems to play a significant role in the connection between type 2 diabetes and dementia. Individuals with obesity who were diagnosed with type 2 diabetes before age 50 showed the highest dementia risk in the study.
The researchers emphasize that a better understanding of the link between the onset of diabetes, obesity, and dementia could guide the development of targeted strategies to prevent dementia.
“This study highlights the critical influence of age at diabetes diagnosis and suggests that focusing on obesity—through lifestyle changes or possibly medication—could be key in preventing dementia in younger adults with diabetes,” Wu concluded.
Along with Qi and Wu, the study’s authors include Zheng Zhu from NYU Meyers, Huabin Luo from East Carolina University, and Mark D. Schwartz from NYU Grossman School of Medicine. The research received partial funding from the National Institute of Aging (P30AG083257, R56AG067619) and the National Institute of Minority Health and Health Disparities (P50MD017356).
