[Click! Health] "Weight Loss in Non-Obese Elderly May Signal Dementia Risk"

Weight Loss in Non-Obese Elderly May Be a Precursor to Dementia Onset

A study has found that weight loss in elderly individuals who are not obese may be an early warning sign of dementia.

The photo is not related to the article content. [Photo provided by Pixabay]

Seoul Metropolitan Government Boramae Medical Center announced that a research team consisting of Professors Junyoung Lee and Geunyu Kim from the Department of Psychiatry and Behavioral Sciences, along with Professor Eosu Kim from the Department of Psychiatry at Severance Hospital, analyzed a national elderly cohort based on the hypothesis that the relationship between weight change and dementia may vary depending on obesity status, and reached this conclusion.

The research team defined obesity based on body mass index (BMI) and abdominal obesity by waist circumference, investigating weight changes over one year and subsequent dementia incidence over four years in more than 4,600 subjects aged 65 and older. Specifically, BMI was defined as 25 kg/m² or higher, and waist circumference as 90 cm or more for men and 85 cm or more for women.

Analysis showed that among non-obese subjects, a 1% decrease in BMI over one year was associated with a 3.3% increase in the risk of developing dementia. In particular, the risk of Alzheimer's disease increased by 4.8%, whereas there was no correlation between BMI decrease and dementia risk in obese subjects. Conversely, in obese individuals, a reduction in waist circumference was linked to a lower incidence of Alzheimer's disease.

Professor Geunyu Kim (first author) explained, "Weight loss may precede cognitive impairment symptoms due to degeneration of brain nerve cells responsible for smell and appetite," but also noted, "Since muscle mass, which has a neuroprotective role, is included in the BMI index alongside fat tissue mass, the degree of muscle mass may have influenced the study results."

He further added, "The decrease in waist circumference, which better reflects fat mass than BMI, actually reduced the risk of Alzheimer's dementia, supporting this hypothesis." This means that maintaining an appropriate weight and good nutritional status, including muscle mass, is more helpful in preventing dementia than simply losing weight, and that if weight is reduced, it should be abdominal fat rather than overall body weight. This also implies the critical importance of proper nutrition and muscle mass maintenance in old age.

Regarding the significance of the study, Professor Kim said, "This is the first study to clarify the association between decreases in BMI or waist circumference and dementia incidence according to obesity status in old age," and added, "Weight loss can be considered a prodromal symptom of dementia only in non-obese individuals." However, he noted that the study could not determine the causes of weight loss among participants, stating, "Future research should clarify how intentional weight loss through exercise or dietary control affects dementia onset."

This study was conducted with funding from the Ministry of Health and Welfare's research-oriented hospital development R&D project and the National Research Foundation of Korea. The research findings were recently published in the official journal of the Alzheimer's Association, Alzheimer's & Dementia.

This content was produced with the assistance of AI translation services.