Abstract
Previous studies have demonstrated the difference between the basal meta-bolic rate (BMR) and the sleeping metabolic rate (SMR); however, the difference in the Japa-nese population has not yet been explored. This study examined the relationship between the BMR and SMR in ninety-four healthy Japanese subjects (37 males and 57 females, 39±12y of age and 22, 0±7.4% body fat) in a respiratory chamber. The SMR was signifi-cantly lower than the BMR (1, 416±245 vs. 1, 492±256kcal/d); however, there was a highly significant correlation between the two (r=0.867; p<0.001). The ratio of SMR/BMR largely varied among individuals (0.95±0.08, 8.4% of the coefficient of variation). The ratio was significantly lower in males than in females (0.93±0.10 vs. 0.97±0.06, p<0.05). None of the anthropometric measures (age, weight, body mass index, body surface area or percent body fat) correlated with the ratio. These results showed that SMR was 95% of BMR on average in a healthy Japanese group. However, when applied over a longer time period (24h or more), the difference tends to become negligible for most analyses in a group. Although the difference between SMR and BMR will induce a 5% gap of physical activity level defined as the total energy expenditure divided by the BMR or SM, this factor seems to have little practical importance in epidemiological research.
