The study conducted by researchers at the NYU Rory Meyers College of Nursing, recently published in PLOS ONE, reveals that an earlier diagnosis of type 2 diabetes is associated with an increased risk of developing dementia, particularly among adults who are obese. This research underscores the potential cognitive repercussions of being diagnosed with type 2 diabetes at a younger age, and it highlights the necessity for preventive strategies against dementia that address both diabetes and obesity, according to Xiang Qi, assistant professor at NYU Meyers and the study’s lead author.
Type 2 diabetes has long been recognised as a risk factor for dementia, although the exact mechanisms linking the two conditions remain unclear. Researchers speculate that characteristics typical of diabetes, such as elevated blood sugar levels, insulin resistance, and chronic inflammation, might facilitate the development of dementia-related changes within the brain. The condition, traditionally seen in older adults, is now increasingly diagnosed in younger individuals, with statistics showing that one in five people with type 2 diabetes globally is under 40.
The research team delved into the relationship between the age at which diabetes is diagnosed and the subsequent risk of dementia by analysing data from 2002 to 2016 from the Health and Retirement Study conducted by the University of Michigan Institute for Social Research. The study comprised 1,213 U.S. adults over the age of 50 who had confirmed type 2 diabetes via blood tests and were free of dementia at the onset of the study. Over a follow-up period of up to 14 years, 216 participants (17.8%) developed dementia, as determined through follow-up telephone interviews.
Findings indicated that those diagnosed with type 2 diabetes at younger ages faced a significantly higher risk of developing dementia compared to those diagnosed after the age of 70. Specifically, adults diagnosed before 50 were 1.9 times more likely to develop dementia than those diagnosed at 70 or older. Similarly, those diagnosed between 50-59 and 60-69 had 1.72 and 1.7 times the risk, respectively. Moreover, linear trend tests conducted by the researchers revealed a graded relationship between the age at diabetes diagnosis and the risk of dementia, with each younger year of diagnosis correlating with a 1.9% increase in dementia risk.
Bei Wu, the Dean’s Professor in Global Health and vice dean for research at NYU Meyers and the study’s senior author, speculated that earlier diagnosis of diabetes might increase dementia risk due to more prevalent vascular complications, poorer blood sugar control, and increased insulin resistance, all known contributors to cognitive decline. Additionally, obesity seemed to exacerbate the relationship between diabetes and dementia, with those diagnosed before 50 who were also obese showing the highest dementia risk in the study.
This research offers new insights into the interconnectedness of diabetes onset, obesity, and dementia, which could help shape targeted interventions aimed at preventing dementia. It emphasises the importance of age in diabetes diagnosis and suggests that addressing obesity—through dietary changes, physical activity, or possibly medication—could play a critical role in preventing dementia in younger adults with diabetes. Wu’s closing remarks highlighted the study’s call to action for focusing on obesity as a modifiable factor in reducing dementia risk among younger populations with diabetes.
More information: Xiang Qi et al, Age at diagnosis of diabetes, obesity, and the risk of dementia among adult patients with type 2 diabetes, PLOS ONE. DOI: 10.1371/journal.pone.0310964
Journal information: PLOS ONE Provided by New York University
