There is an association between body fat percentage and metabolic abnormality in normal weight subjects: Iranian large population

Abstract Background Normal weight obesity (NWO) is defined by a normal body mass index (BMI) but a high percentage body fat (%BF) composition. We aimed to examine the hypothesis that subjects having NWO are at higher risk for cardio metabolic abnormalities compared to normal body weight subjects with low body fat content. Method In this cross sectional study 2439 adults' normal body Mass Index were recruited as part of the Mashhad Stroke and Heart Atherosclerotic Disorders (MASHAD) cohort study. We measured 6 cardio-metabolic risk factors: Low-density lipoprotein cholesterol (LDL-C), triglycerides (TGs), and high-density lipoprotein cholesterol (HDL-C), fasting blood glucose (FBG), systolic and diastolic blood pressure, and serum C-reactive protein (hs-CRP). Two models were evaluated: in model A, the categorization of individuals utilized cut off values of BMI: 18.5-25 and %BF: > 25 in men and > 30 in women; in model B, the cut off values used were BMI: 18.5-25 and BF% with cut-offs depending on age: 20–39 years, >19% and >32%; 40–59 years, >21% and 33% and 60–79 years, > 24% and 35% for men and women were used, respectively. Cardiovascular risk estimates were made using QRISK2. SPSS version 18(SPSS Inc. Chicago, IL, USA) was used for all statistical analyses. GraphPad Prism 6 for figures was used. Result Of the 2439 individuals with a normal BMI, 38.5% were found to be in high group and 61.5% were placed in normal weight groups for %BF in model A. In model B, 53.8% and 46.2% were found to be in the normal and high groups for %BF. The odds ratio for the presence of a metabolic abnormality for the high %BF group was 1.82 (95% CI, 1.42- 2.34) and for high QRISK was 5.79 (95%CI, 4.17-8.02) after adjusted for age, in model A. In model B, the odds ratio for the presence of a metabolic abnormality for the high %BF group was 2.02 (95% CI, 1.68- 2.42) and for high QRISK was 6.03 (95%CI, 4.45-8.08) after adjusted for sex. Conclusion It can be stated that if body fat analysis among normal weight individuals can have an important contribution to the prevention of cardiovascular disease and other obesity-related conditions.