Evaluating the long-term impact of glycemic control on dementia risk in older patients with Type 1 diabetes

This study investigated the impact of long-term glycemic (blood sugar) control on developing dementia in patients with Type 1 diabetes (T1D). This study concluded that higher HbA1c levels were associated with an increased risk of developing dementia.

The goal of T1D management is to reach and maintain normal glucose levels. Studies have found that glycemic control is an important predictor of cognition (memory, reasoning and thinking process) in individuals with T1D. Indeed, previous studies have also found that T1D may be a risk factor for dementia. 

As life expectancy for patients with T1D increases, the risk of developing aging-related diseases such as dementia also increases. However, the relationship between glycemic control and the risk of developing dementia in patients with T1D remains unclear.

This study involved the records of 3,433 patients with T1D. Patients were followed-up for an average of 6.3 years. Glycemic control was evaluated by repeated measurements of the HbA1c (an average of blood sugar levels of the last 3 months).

Overall, 4.5% of all patients were diagnosed with dementia. The risk of developing dementia was 2.13 to 2.51 times higher in patients with HbA1c levels of 8 – 9% and higher than 9% at most times (75% of times) compared to patients with similar HbA1c levels during 10% of times. In patients who had HbA1c levels higher than 8% at least half of the time, this risk was 1.65 to 1.79 times higher.

In patients with HbA1c levels of 6.0 – 7.9% at most times, the risk of developing dementia was 58 – 61% lower compared to patients with higher HbA1c levels. In patients who had 6.0 – 7.9% HbA1c at least half of the time, this risk was 45% lower.

This study concluded that in patients with T1DM, higher HbA1c levels were associated with a higher risk of developing dementia. The authors suggest that effective glycemic control could help reduce the risk of dementia in these patients.

This study was retrospective, meaning it looked back in time to analyze data. Some data such as time form diabetes onset and other risk factors for developing dementia might have been missing. This could change the results.