Comparison of Metabolic Syndrome Components, Inflammation and Oxidative Stress Indices in Normal Weight Obese and Normal Weight Women: A Case- Control Study

Background: Normal Body Mass Index (BMI)=18.5-24.9 kg/m2 and high Body Fat (BF), have been defined as Normal Weigh Obesity (NWO), which can increase the risk of Metabolic Syndrome (MetS) and cardiovascular diseases. The present study aimed to determine the association between NWO and MetS indicators, Insulin Resistance (IR), and inflammatory and oxidative stress indices in NW obese compared to normal weight women referring to Imam Reza medical center, Shiraz, Iran. Methods: In this case-control study, 41 healthy NW obese Iranian women were recruited and compared to 45 healthy non-obese control subjects. Anthropometric features, body composition, blood pressure, inflammation and oxidative stress indices, fasting insulin, lipid profile, and blood sugar were measured. IR was also assessed by means of special formulas. Results: The results showed a significant difference between the NWO and the control group regarding anthropometric measurements and body composition, including waist (P=0.008) and hip (P<0.001) circumferences, BF (P<0.001), skeletal muscle (P=0.03), protein (P=0.04), body cell mass (P=0.02), bone mass content (P=0.04), and arm circumference (P<0.001). All subjects had normal systolic and diastolic blood pressures. However, the NWO group showed significantly higher serum concentrations of triglycerides (P=0.02), total cholesterol (P=0.02), and C-reactive protein (P<0.001). On the other hand, the results of McAuley test indicated significantly lower insulin sensitivity in the NWO group (P=0.03). Besides, serum MDA concentration did not have a marked differences in both study groups. Conclusion: Comparison of body composition and anthropometric indices between NWO and normal weight women demonstrated that counting just on BMI to distinguish the individuals who are at risk of metabolic disorders might fail to identify a large number of individuals who, despite having a normal BMI, present excess BF and are at a high risk of metabolic imbalances.