Study: Controlling Blood Sugar May Prevent Dementia

Controlling blood-sugar levels may help prevent dementia, a study released on Tuesday showed, offering hope to patients with diabetes that keeping glucose levels in check might reduce the risk of developing Alzheimer’s disease and other types of cognitive impairments.

Studying 350,000 patients with Type 2 diabetes, researchers at the University of Gothenburg in Sweden found that those with poor blood-sugar control had a 50% higher risk of being admitted to hospital than those with good control.

Scientists have previously suggested a link between elevated blood-sugar levels and Alzheimer’s disease, but the researchers said this was the first large-scale study looking at how controlling the presence of glucose in the blood affected the risk of being diagnosed with dementia in the future.

The study, presented at the European Association for the Study of Diabetes conference in Stockholm, shows an association between the two conditions but doesn’t prove cause and effect.

Still, scientists say the results underline the need for people with diabetes to monitor their blood-sugar levels closely and for physicians to actively treat diabetes patients even as cognitive functions decline.

“As a preventative measure, this research could be incredibly important,” said Krister Westerlund, chairman of the association Alzheimer Sweden. “We tend not to notice difficult cognitive brain diseases until one needs care, so if we can discover potential problem sources earlier, it’s very valuable.”

Diabetes occurs when the body is unable to transform sugar, or glucose, into energy, leading to high concentrations of sugar in the blood. According to the International Diabetes Federation, some 387 million people world-wide suffer from the disease, which if left untreated can cause heart disease, kidney failure, blindness and death. Dementia affects nearly 47 million people around the world, with most people suffering from Alzheimer’s disease, which develops over time and causes progressively worse memory loss, according to Alzheimer’s Disease International.

In the Gothenburg study, data were taken from the Swedish National Diabetes Registry between January 2003 and December 2012. Patients with Type 2 diabetes—the most common form—were followed up until the study ended, they were hospitalized for dementia or they died. To determine the level of blood-sugar control, clinicians used a diabetic test called glycated hemoglobin or HbA1c, which measures average blood-sugar levels over a period of weeks or months.

After adjusting for various factors such as age, gender and weight, the researchers found that patients who had blood-sugar levels of 10.5% or higher were 50% more likely to be diagnosed with dementia than those with blood-sugar levels of 6.5% or lower. In all patients, those who had suffered a stroke were 40% more likely to develop dementia than those who hadn’t.

To keep their blood-sugar levels in a healthy range, people with Type 2 diabetes should exercise daily and maintain a diet low in saturated fats and sugars, said Aidin Rawshani, a doctor at Sahlgrenska University Hospital, and the National Diabetes Register and Institute of Medicine at the University of Gothenburg, who presided over the study.

Physicians who treat diabetes patients should actively control blood-sugar levels—even as their patients show signs of Alzheimer’s or other forms of dementia, he said. Dr. Rawshani said his research suggests physicians tend to decrease potent therapies used to control blood-glucose levels, such as insulin, when they notice a cognitive impairment in patients.

This is partly because the patients’ ability to self-regulate their blood-sugar levels declines as their brain function gradually decreases.

“But we think that since there is a pattern between blood glucose and risk of dementia, physicians should try to control blood-glucose levels as the cognitive functions impairs in patients,” he said.

Of the 350,000 people in the study, 3.5%, or 11,035, were admitted to hospital and diagnosed with some form of dementia. The research included people aged 50 and older with a mean age of 67 at the start of the study.

Read more: Wall Street Journal