Metabolic syndrome in midlife linked to higher dementia risk

Having a larger waist, high blood pressure and other risk factors that form metabolic syndrome are associated with an increased risk of dementia for young people, according to a study published on April 23, 2025, online in Neurology^®The Medical Journal of the American Academy of Neurology. Young-Start Dementia is diagnosed before the age of 65. The study does not prove that metabolic syndrome causes dementia for young people, it only shows an association.

The metabolic syndrome is defined as excess belly fat plus two or more of the following risk factors: high blood pressure, high blood sugar, higher than normal triglycerides, a kind of fat found in the blood, and low lipoprotein (HDL) cholesterol, or “good”.

Although most dementia is diagnosed in old age, dementia occurs on young people while a person still works and perhaps raises a family. Our research showed that middle -aged metabolic syndrome is a risk factor for dementia with young people. “

Minwoo Lee, MD, PhD, Study author from Hallym University Sacred Heart Hospital in Anyang, Zuid -Korea

For the study, researchers have assessed national health insurance data in South Korea to identify nearly two million people between 40 and 60 years who had a health control. The control included measurements of waist circumference, blood pressure, blood sugar, triglyceride and cholesterol levels. Of all participants, 25% had metabolic syndrome.

During an average follow-up period of eight years, 8,921 people, or 0.45% of all participants, developed dementia. For people with metabolic syndrome, the incidence rate was 0.86 cases per 1,000 person years, compared to 0.49 cases for people without metabolic syndrome. Personal years represent both the number of people in the study and the amount of time that each person spends on the study.

After correction for age, education and health factors such as the level of physical activity, depression and stroke, researchers found metabolic syndrome associated with a 24% higher risk of dementia. When viewing specific types of dementia, it was associated with a 12% increased risk of Alzheimer’s disease and a 21% increased risk of vascular dementia.

Researchers discovered that female participants with metabolic syndrome had an increased risk of dementia of 34% compared to male participants who had an increased risk of 15%. People from in forty had a greater risk than people in fifty.

Researchers discovered that every component of metabolic syndrome was associated with an increased risk of dementia, which was cumulative. People with all five components had an increased risk of dementia of 70%.

“Our findings suggest that lifestyle is changing to reduce the risk of metabolic syndrome, such as eating a healthy diet, regular exercise, maintaining a healthy weight, quitting smoking and reducing stress, can help reduce the risk of dementia for young people,” Lee said. “Future research that people are following for a longer period of time and uses brain scans to look for biomarkers of dementia is needed to confirm and expand our findings.”

A limitation of the study was that researchers did not view a genetic risk factors for Alzheimer’s disease.

The study was supported by the Korean National Research Foundation.