Dr Esther Hui on how Ozempic may protect against dementia in people with type-2 diabetes
Diabetes is a key risk factor for dementia. Can certain diabetes medicines, like Ozempic reduce that risk? We spoke to Dr Esther Hui about her research on the topic.
The number of people living with type-2 diabetes is at an all-time high. Our ageing population and increasing rates of obesity and inactivity mean that there are now an estimated 5.8 million people living with diabetes in the UK.
Likewise, dementia is posing its own health epidemic, affecting 50 million people worldwide, with projections indicating an increase to 152 million by 2050.
This means that across the UK, millions of people will be affected by dementia or type-2 diabetes in their lifetime. Because diabetes is a key risk factor for dementia, many of us will be affected by both conditions. But are there any existing medications that could reduce the risk of dementia for diabetes patients? Dr Esther Hui (UCL Division of Psychiatry) shares her insights about what the latest research tells us.
The exact reasons why diabetes is a significant risk factor for dementia remain unclear.
Dr Hui explains: “We don’t fully understand why diabetes increases the risk of dementia. However, it could be related to blood vessel damage, insulin resistance, inflammation, and alterations in brain metabolism. For example, people with diabetes are known to have long-term complications that affect both small and large blood vessels. We do know that insulin resistance is a mechanism associated with diabetes and Alzheimer’s disease.”
According to the latest Lancet Commission report on dementia, evidence is now stronger than ever that tackling the risk factors for dementia (i.e. less education, hearing loss, hypertension, smoking, obesity, depression, physical inactivity, diabetes, excessive alcohol consumption, traumatic brain injury, air pollution, high LDL cholesterol, visual loss and social isolation) reduces the risk of developing dementia. The report indicates that if everyone took measures to prevent or manage diabetes, there would be a reduction of two dementia cases for every 100 current cases.
“It is really helpful for us to understand what interventions can be taken to reduce the risk of developing dementia among people with known risk factors. We already know that wearing hearing aids can reduce the risk of dementia among people with hearing loss, so in planning our research, we wanted to see what could be done to reduce the risk among people with diabetes,” Dr Hui says.
To explore whether there is a link between taking diabetes medication and the chance of developing dementia, Dr Hui and her team completed a systematic review of all the existing studies on diabetes medication and dementia risk.
“We wanted to see if there is a link between taking diabetes medication and the chance of getting dementia or memory and thinking problems in people with type 2 diabetes. If so, what are the individual drugs that affect the dementia risk? How much can they reduce the risk by?” Dr Hui explains.
One of the diabetes medicines the team looked at was GLP-1RA, also known by the brand name Ozempic. GLP-1RA is a treatment for type 2 diabetes, which can help patients to manage blood sugar levels.
The researchers found that GLP-1RA reduced dementia risk by 53% in clinical trials and 27% in observational studies.
Thiazolidinediones (glitazones) was another type of medication that also consistently showed neuroprotective effects. Other diabetes medications like metformin, sulfonylureas, insulin, DDP-1V had inconsistent findings and didn’t seem to make a difference to dementia risk.
Dr Hui said: “It was surprising that metformin, which a lot of people think could reduce dementia, actually didn't. Our findings were inconsistent for metformin.”
“From the review, GLP-1RA (Ozempic) had the most evidence in reducing dementia risk, but we do not exactly know why. The potential mechanisms could be lowering blood sugar levels, helping people lose weight, reducing blood pressure and reducing the risk of heart diseases.”
One limitation of the research was that the dosage of medicine, severity and duration of the diabetes were not included in all the studies. The researchers recommend that these be included in future studies to build a better understanding of the effectiveness of diabetes medication of reducing the risk of dementia.
As dementia takes many years to develop, we may need to wait to truly understand the long-term data and the effectiveness of these medications.
Dr Hui says: “Some of the things we can do to help reduce our risk of dementia include being mentally and physically active, maintaining a healthy weight, and treating diabetes if we have it. If you are concerned about dementia, it is always best to speak to your GP for diagnosis, guidance and support.”