A recent study has shown that dementia patients who experience significant weight loss face a substantially higher risk of death. Conversely, those who maintain a relatively stable weight or experience moderate weight gain within an appropriate range tend to have a lower mortality risk.
Professor Nam Ga-eun from Korea University’s Guro Hospital, in collaboration with Professor Heo Yeon from Seoul St. Mary’s Hospital and Professor Han Kyung-do from Soongsil University’s Department of Information Statistics and Actuarial Science, conducted a large-scale analysis on the correlation between body mass index (BMI) and mortality risk before and after dementia diagnosis. The findings, based on the Korean population, were announced on Tuesday.
Dementia is a progressive condition associated with increased mortality and various health risks. While weight changes in older adults are known to correlate with health deterioration, there has been limited research on how weight status and changes before and after a dementia diagnosis affect mortality rates.
The research team analyzed data from the National Health Insurance Service, tracking over 37,000 dementia patients for an average of 4.1 years. Their findings revealed that patients diagnosed with dementia who were underweight had about a 1.6 times higher risk of death compared to those with a normal weight.
The highest mortality risk was observed in patients who transitioned from obesity to being underweight (approximately a twofold increase). Those who moved from normal or overweight to underweight also showed increased risk. In contrast, patients who maintained obesity or gained weight from normal or overweight to obesity exhibited relatively lower mortality risk.
Professor Nam emphasized that weight loss itself can be a crucial indicator of disease progression or nutritional decline. She stressed the importance of nutritional management and continuous monitoring to prevent weight loss after a dementia diagnosis.
The research team noted that weight loss in dementia patients may be linked to reduced food intake due to swallowing difficulties, cognitive decline, and overall health deterioration, potentially leading to increased mortality risk.
Professor Heo pointed out that subgroup analysis revealed the association between BMI changes and mortality risk was more pronounced in middle-aged individuals than in the elderly. This relationship was particularly strong in women with Alzheimer’s disease, which could be attributed to differences in body composition, hormonal variations, and vascular risk factors.
The study’s findings have been published in the international journal Alzheimer’s Research & Therapy.
Meanwhile, as South Korea enters a super-aged society, the number of dementia patients is expected to continue increasing. According to statistics from the Health Insurance Review and Assessment Service, the number of patients increased by about 25% from 567,433 in 2020 to 709,620 in 2024. The Ministry of Health and Welfare projects that the number of elderly dementia patients in Korea will reach 2 million by 2044.