“The more severe the metabolic syndrome is, the higher the risk of dementia rises.”

That was the conclusion of a joint research team that analyzed the correlations between metabolic syndrome and the risk of dementia incidence, according to a news release issued by Seoul St. Mary’s Hospital on Monday.

The research was led by Professors Lee Seung-Hwan of the Department of Internal Medicine at Seoul St. Mary’s Hospital, Cho Yun-jung of the Department of Internal Medicine at Incheon St. Mary’s Hospital, and Han Kyung-do of Department of Statistics and Actuarial Science at Soongsil University.

Using the National Health Insurance Service data, the team analyzed the correlations in nearly 1.5 million people aged 45 years or more who received health checks for four consecutive years. It discovered that the group with metabolic syndrome had a 1.35 times higher risk of dementia of all causes than the group without metabolic syndrome.

In the case of vascular dementia, the difference of risk was 1.50 times between the two groups. Alzheimer’s disease was the most common cause of dementia by accounting for more than half of the total, followed by vascular dementia resulting from cerebrovascular disease.

Metabolic symptoms include high blood pressure, high blood glucose (sugar) level, high blood triglycerides level, low HDL (“good”) cholesterol level in the blood, and large waist circumference, which can increase the risks of diabetes, heart and brain diseases. A person is diagnosed with metabolic syndrome when he or she has more than three of those conditions mentioned.

More specifically, a person has metabolic syndrome if he or she meets three or more of the following five criteria – waist size of 90 centimeters or more for men (85ch for women), blood pressure of 130/85 mmHg, triglyceride of 150 mg/dL or more, HDL cholesterol of 40 mg/dL or less, fasting blood sugar of 100 mg/dL or more.

To find a correlation between the number of conditions to which a person is exposed and the time of exposure to dementia, the five conditions were each given a score of 1. If a person was diagnosed with none of the five risk factors for four consecutive years, he or she was given a score of 0. If a person was diagnosed with all five conditions for four straight years, he or she was given a score of 20.

It was concluded that the group with a score of 20 had 2.6 times higher chances of dementia than the group with a score of 0 from all factors. In addition, the risk caused by Alzheimer’s was 2.33 times, and that by vascular dementia was 2.30 times. Also, the risk of dementia was 40 percent higher than the group that scored 1 by having one of the five factors than the group that scored 0, which was meaningful, according to the team.

The researchers reaffirmed that not only the diagnosis itself with metabolic syndrome but the duration and the level of exposure to the five conditions increases the chance of dementia of all causes, including those resulting from vascular dementia and Alzheimer’s.

“It is important for a person with elements that compose metabolic syndrome to strive to prevent dementia by reducing exposure to metabolic syndrome by, for instance, through regular exercises and dietary changes,” Professor Lee said.

The study result was published in the April edition of Endocrinology and Metabolism, the official journal of the Korean Endocrine Society.