Background and objectives The coexistence of obesity and decreased muscle strength, defined as sarcopenic obesity, is often observed in older adults. The present study investigated whether sarcopenic obesity, defined as reduced grip strength and increased body mass index (BMI), is associated with cognitive impairment. Methods Study participants included 1,615 older adults aged 65 to 84 years who lived in an urban area of Tokyo, Japan, and participated in the Bunkyo Health Study. Mild cognitive impairment (MCI) and dementia were defined based on ≤22 points on the Montreal Cognitive Assessment and ≤23 points on the Mine Mental State Examination, respectively. Handgrip strength was measured using a dynamometer in the standing position. We divided the participants into four groups according to their (probable) sarcopenia (grip strength <28 kg in men and <18 kg in women) and obesity status (BMI ≥25 kg/m2) as control, obesity, sarcopenia and sarcopenic obesity. , and investigated the association between cognitive function, sarcopenia, and obesity status. Results The mean age was 73.1 ± 5.4 years and 57.6% of study participants were women. The prevalence of control, obesity, sarcopenia, and sarcopenic obesity was 59.4%, 21.2%, 14.6%, and 4.7%, respectively. The prevalence of MCI and dementia, respectively, was highest in participants with sarcopenic obesity, followed by those with sarcopenia, obesity, and controls. After multivariable adjustment, sarcopenic obesity was independently associated with increased odds of MCI and dementia compared with control (MCI: 2.11 [95% confidence interval, 1.12–3.62]; dementia: 6.17 [2.50–15.27]).
Conclusions Sarcopenic obesity was independently associated with BMI and dementia among Japanese older adults. Future studies are necessary to clarify the causal relationship. |
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Obesity, an increasingly prevalent lifestyle disease, often occurs alongside poor muscle mass. This condition, called sarcopenic obesity , is evaluated based on patients’ body mass index (BMI) and grip strength. Interestingly, sarcopenic obesity is known to increase the risk of cognitive decline. Dementia , a cognitive condition in which memory, thinking and social skills progressively decline, is known to significantly affect the quality of life of older people.
Is this condition associated with sarcopenic obesity?
In a new study published in Clinical Nutrition , a group of researchers led by Dr. Yoshifumi Tamura of Juntendo University, Japan, explored this very question. “If the association between sarcopenic obesity and dementia is established, appropriate preventive measures can be taken to reduce the occurrence of this condition and the risk of dementia in elderly patients,” says Dr. Tamura, who highlights the importance of his studio.
In the study, researchers recruited 1,615 Japanese older adults ages 65 to 84 who were participating in the Bunkyo Health Study. The researchers divided the subjects into four groups based on their sarcopenia and obesity status: those who had obesity, those who had sarcopenia, those who had sarcopenic obesity, and those who did not have obesity or sarcopenia (control).
They studied the link between various mental processes, sarcopenia and the state of obesity. Sarcopenia or low muscle strength was determined based on a grip strength of less than 28 kg in men and 18 kg in women, while obesity status was given to patients with a BMI greater than 25 kg/m2.
Two assessment methods were performed to establish the presence of mild cognitive impairment (MCI) and dementia. A score of less than 22 points on the Montreal Cognitive Assessment and less than 23 points on the Mine-Mental State Examination was used to confirm MCI and dementia, respectively.
They found that 59.4% of the population had neither obesity nor sarcopenia, 21.2% had obesity, 14.6% had sarcopenia, and 4.7% of the population had sarcopenic obesity. Participants with sarcopenic obesity had the highest rate of MCI and dementia, followed by those with sarcopenia, obesity and finally the control group.
When the team performed multivariate analyzes to check for statistically relevant associations, they found that sarcopenic obesity was independently associated with a higher prevalence of mild cognitive impairment and dementia compared to the absence of sarcopenia and obesity. The study also showed that sarcopenia is significantly associated with dementia in women, but not in men.
“This study clearly demonstrates that sarcopenic obesity, defined by the combination of BMI and handgrip strength, is associated with MCI and dementia among older people in Japan,” says Dr. Tamura.
But what are the long-term implications of this study?
Dr. Tamura’s answer to this question is encouraging. "Since we now know that there is a strong correlation between sarcopenic obesity and dementia, we can develop new treatment methods to control the condition, even reducing the prevalence of dementia."
