Basal metabolic rate predicts dementia in community-dwelling older adults: a 5-year longitudinal study

Although basal metabolic rate (BMR) is reportedly associated with physiological function decline, there is no consensus regarding its relationship with cognitive function. Therefore, we investigated the relationship between BMR and dementia risk over a 5-year period in 2550 of the 2975 older adults who were available for analysis (age 73.2 ± 6.0 years, 59.8% women).

BMR was calculated using the TANITA, Mifflin-St Jeor, Harris-Benedict, and Cunningham equations. Furthermore, the BMR assessment method developed by the National Institute of Health and Nutrition (NIBIOHN) was used. Participants were classified into quartiles for BMR obtained using each method. Cox proportional hazards regression analysis was performed using the highest quartile (Q4) of each BMR to evaluate the association between BMR and dementia risk. Additionally, differences in the performance of each formula in predicting dementia risk were examined using the time-dependent receiver operating characteristic curve.

Participants in the lowest BMR quartile (Q1) had a higher risk of dementia than those in Q4 [TANITA BMR: hazard ratio (HR) = 2.49, p < 0.001; Harris-Benedict BMR: HR = 1.70, p < 0.05; Mifflin-St. Jeor BMR: HR: 3.83, p < 0.001; Cunningham BMR: HR = 2.78, p < 0.001; NIBIOHN BMR: HR = 2.98, p < 0.001]. The time-dependent ROC of Harris-Benedict BMR demonstrated the highest predictive accuracy among all BMRs calculated (area under the curve = 0.71, p < 0.05).

Our results reveal the association of low BMR with increased dementia risk, suggesting its potential as an early predictive biomarker, and demonstrate the usefulness of the Harris-Benedict equation for predicting dementia risk.