Background: Resting metabolic rate (RMR) composes the largest portion of daily energy expenditure. After adjusting for height and weight, less progression towards obesity was noted among the higher RMR group than those of lower groups. Based on the theory that obesity increases the risk of cardiovascular disease, this study was conducted to investigate whether obesity is associated with lower RMR after adjusting for weight and height. The relationship between RMR and cardiovascular risk. factors was also investigated.
Methods: The study population consisted of 39 women aged from 40 to 67 years old who had visited a health promotion center in a university hospital since January, 2005 until May, 2007. Self-reported answers on daily activity, smoking, drinking, medication and past medical history were assessed. Height, weight, waist circumference and blood pressure were measured. Baseline blood samples were evaluated and RMR was measured by indirect calorimetry.
Results: As body mass index (BMI) increased, hs-CRP increased (P = 0.004) however, RMR per kilogram (P < 0.000) decreased as BMI increased. RMR had a significant correlation with height (P = 0.041), weight (P < 0.000), fat free mass (P = 0.001), BMI (P = 0.003) and fat mass (P = 0.004). Both before and after adjusting for age, height and weight, there were positive relationship only with fat free mass (P = 0.001) and fat mass (P = 0.004).
Conclusion: Cardiovascular risk factor and RMR showed no significant correlation before and after adjusting for height, weight and age. Only fat free mass and fat mass showed significant positive relationship with RMR in both cases.