A recent study published in Diabetologia, the journal of the European Association for the Study of Diabetes, has shed light on the connection between type 2 diabetes (T2D) and the increased risk of dementia as individuals grow older. The research indicates that individuals who develop T2D at a younger age face a higher risk of dementia later in life. The study, conducted by Ph.D. student Jiaqi Hu, Professor Elizabeth Selvin, and their team from the Johns Hopkins Bloomberg School of Public Health in Baltimore, MD, USA, aimed to explore the correlation between prediabetes and dementia.
Prediabetes is an initial stage characterized by elevated blood sugar levels that have not yet reached the threshold for a diagnosis of T2D. While prediabetes puts individuals at a heightened risk of progressing to full-blown diabetes, it is also independently associated with various other health outcomes. In fact, most people diagnosed with T2D experience this prediabetic phase beforehand.
The study found that the risk of transitioning from prediabetes to T2D is substantial. Among middle-aged adults with prediabetes, 5-10% per year develop T2D, with a total of 70% of those with prediabetes progressing to T2D in their lifetime. In the United States alone, up to 96 million adults have prediabetes, accounting for 38% of the adult population.
To assess the risks of dementia associated with prediabetes, the researchers analyzed data from participants in the Atherosclerosis Risk in Communities (ARIC) study. The participants, aged 45-64 years between 1987 and 1989, hailed from four counties in the United States: Forsyth County, North Carolina; Jackson, Mississippi; suburbs of Minneapolis, Minnesota; and Washington County, Maryland. The study’s baseline period for analysis was the second visit of the study conducted between 1990 and 1992, which marked the initial measurement of glycated hemoglobin (HbA1c), a measure of blood sugar control, and cognitive function.
The cognitive function assessments included data from a scoring system based on three cognitive tests administered during the second (1990-1992) and fourth (1996-1998) visits, as well as an expanded neuropsychological ten-test collection administered from the fifth visit (2011-2013) onwards. The Mini-Mental State Examination (MMSE) and informant interviews using the Clinical Dementia Rating (CDR) scale and Functional Activities Questionnaire (FAQ) were also conducted. Participants were followed up until 2019.
Prediabetes was defined as HbA1c levels between 39 and 46 mmol/mol (5.7-6.4%). The subsequent development of T2D during the follow-up period was also considered.
The researchers examined the association between prediabetes and dementia risk, both before and after accounting for the subsequent development of T2D among ARIC participants with prediabetes at baseline. This was done to determine how much of the association between prediabetes and dementia could be explained by the progression to diabetes. The study also explored whether the age of diabetes diagnosis influenced the risk of dementia.
Among the 11,656 participants without diabetes at baseline, 20% (2330 individuals) had prediabetes. After considering the diabetes cases that developed after the baseline period, the researchers found no statistically significant association between prediabetes and dementia. However, they did discover that an earlier age of progression to T2D was strongly associated with dementia. Those who developed T2D before the age of 60 had a threefold increased risk of dementia, which decreased to a 73% increased risk for those developing T2D between 60 and 69 years old, and a 23% increased risk for those developing T2D between 70 and 79 years old. Developing T2D at the age of 80 or older was not associated with an increased risk of dementia.
The authors of the study conclude that prediabetes is indeed linked to the risk of dementia, but this risk can be attributed to the development of diabetes. They emphasize that early-onset diabetes is particularly strongly connected to dementia. Therefore, preventing or delaying the progression from prediabetes to diabetes would significantly reduce the future burden of dementia.
Reference: “Prediabetes, intervening diabetes and subsequent risk of dementia: the Atherosclerosis Risk in Communities (ARIC) study” by Jiaqi Hu, Michael Fang, James R. Pike, Pamela L. Lutsey, A. Richey Sharrett, Lynne E. Wagenknecht, Timothy M. Hughes, Jesse C. Seegmiller, Rebecca F. Gottesman, Thomas H. Mosley, Josef Coresh and Elizabeth Selvin, 24 May 2023, Diabetologia. DOI: 10.1007/s00125-023-05930-7
Table of Contents
Frequently Asked Questions (FAQs) about dementia risk
What is the connection between early-onset type 2 diabetes and dementia risk?
A new study published in Diabetologia reveals that individuals who develop type 2 diabetes at a younger age face a higher risk of dementia later in life. The progression from prediabetes to type 2 diabetes, particularly at a younger age, significantly increases the chances of developing dementia. Preventing or delaying the onset of type 2 diabetes can help reduce future cases of dementia.
What is prediabetes?
Prediabetes is a preliminary stage characterized by elevated blood sugar levels that have not yet reached the threshold for a diagnosis of type 2 diabetes. It places individuals at a higher risk of developing full-blown diabetes. Prediabetes is also independently associated with various other clinical outcomes and is experienced by a majority of people diagnosed with type 2 diabetes.
How significant is the risk of developing type 2 diabetes from prediabetes?
The risk of progression from prediabetes to type 2 diabetes is substantial. Among middle-aged adults with prediabetes, approximately 5-10% per year go on to develop type 2 diabetes. In total, around 70% of individuals with prediabetes progress to type 2 diabetes during their lifetime. This highlights the importance of addressing prediabetes as an early intervention to prevent the development of diabetes.
What were the findings of the study regarding prediabetes and dementia risk?
The study found that prediabetes itself was not associated with a significant increase in dementia risk. However, the progression from prediabetes to type 2 diabetes, especially at a younger age, dramatically increased the chances of developing dementia. Individuals who developed type 2 diabetes before the age of 60 had a threefold increased risk of dementia compared to those who developed it at older ages.
How can preventing or delaying the onset of type 2 diabetes help reduce the future burden of dementia?
The study highlights the importance of preventing or delaying the progression from prediabetes to type 2 diabetes. By addressing risk factors and adopting healthy lifestyle choices, such as maintaining a balanced diet, engaging in regular physical activity, and managing weight, individuals can reduce their chances of developing type 2 diabetes. This, in turn, can significantly reduce the future burden of dementia associated with early-onset type 2 diabetes.
More about dementia risk
- Study: “Prediabetes, intervening diabetes and subsequent risk of dementia: the Atherosclerosis Risk in Communities (ARIC) study” (DOI: 10.1007/s00125-023-05930-7)
- Diabetologia Journal: Link
- European Association for the Study of Diabetes: Link
- Johns Hopkins Bloomberg School of Public Health: Link
6 comments
alright, so prediabetes itself not linked to dementia risk. got it. but once it turns into type 2 diabetes, the risk shoots up, especially if you’re younger. that’s scary. take care of your health, people!
thanks for the info! gonna check out that study and learn more. it’s fascinating how our health conditions can be connected like that. always something new to discover in the world of research!
hey, this study say early-onset type 2 diabetes increase risk of dementia. so important prevent or delay it to reduce future cases of dementia! but prediabetes not itself big risk. progression to type 2 diabetes, esp at younger age, bigger risk! got it?
whoa, the risk of going from prediabetes to type 2 diabetes is huge! 70% chance? that’s no joke. we gotta catch it early and take action to prevent diabetes. healthy eating and exercise, here I come!
so, preventing or delaying type 2 diabetes can help reduce the burden of dementia. that’s good news! let’s eat right, stay active, and take care of ourselves. we don’t want dementia knocking on our doors!
wait, what’s prediabetes? never heard of it. so it’s like a stage before type 2 diabetes? hmm, interesting. seems like most people with type 2 diabetes go through this prediabetic thing. gotta be careful!