Energy metabolism and the metabolic syndrome: Does a lower basal metabolic rate signal recovery following weight loss?

SummaryAimTo determine whether basal metabolic rate (BMR) was causally related to MetS, and to study the role of gender in this relationship.MethodsSeventy-two Caucasian subjects (43 women, 29 men) had changes in basal metabolic rate (BMR), carbohydrate oxidation rate (COR), fat oxidation rate (FOR) and prevalence of the metabolic syndrome (MetS) assessed in response to weight loss.ResultsThere was a significant gender × MetS interaction in BMR at the start. Women with MetS had higher adjusted BMR, whilst men with MetS had lower adjusted BMR than their respective counterparts. Weight loss resulted in a significant decrease in fat mass (−5.2 ± 0.31 kg, p = 0.001), fat free mass (−2.3 ± 0.27 kg, p = 0.001), BMR (−549 ± 58 kJ/d, p = 0.001) and a decreased proportion of MetS (22/72, χ2 = 0.005). Subjects who recovered from MetS after weight loss (RMS) had ∼250 kJ/d significantly lower adjusted BMR compared to those who were never MetS (NMS, p = 0.046) and those who still had MetS (MetS+, p = 0.047). Regression analysis showed that change (Δ) in BMR was best determined by Δglucose × gender interaction (r2 = 23%), ΔFOR (r2 = 20.3%), ΔCOR (r2 = 19.4%) and Δtriglycerides (r2 = 7.8%).ConclusionsThere is a sexual dimorphism of BMR in MetS. Overall, the data support the notion that alterations in BMR may be central to the etiopathogenesis of MetS.

► There is a sexual dimorphism of basal metabolic rates in the metabolic syndrome.
► Women with metabolic syndrome and men without metabolic syndrome had higher adjusted basal metabolic rates than their counterparts.
► Recovery from metabolic syndrome following 12 weeks of weight loss was associated with a low adjusted basal metabolic rate.
► Gender specific decreases in fasting glucose, and lower triglycerides contributed significantly to this decline in basal metabolic rate.
► The study provides direct evidence for a role of energy metabolism in the metabolic syndrome.