Tri-Ponderal Mass Index versus Body Mass Index: Correlation to Body Fat and Metabolic Profile

Abstract

Abstract Background Obesity is a worldwide health problem. Obese individuals are at a high risk of developing dyslipidemia, hypertension, impaired glucose tolerance and insulin resistance. Recently, tri-ponderal mass index (TMI) has been reported as an alternative to body mass index (BMI) because it may estimate body fat levels more accurately than BMI, especially in adolescents. TMI is nearly stable throughout adolescence . Aim of the Study To compare (BMI) and (TMI) as predictors of fat mass percentage (FM %) as detected by DXA scan and to compare the efficacy of TMI and BMI in predicting insulin resistance (IR), hyperlipidaemia. Methods This study was conducted on sixty Egyptian healthy male and female with simple obesity with age range between 5-18 years. Patients were interviewed for data including, socio- economic status, dietetic history, physical activity, family history of obesity, cardiovascular disease, diabetes and hypertension. Clinical examination included complete physical examination, Tanner stage, anthropometric measurements, their standard deviation scores (SDSs ). Lab investigations included fasting lipid profile, insulin, glucose and Insulin resistance by (HOMA-IR) index. Assessment of body composition including fat mass percentage (FM %) and bone density was done by (DXA) scanner . Results We found that BMI and TMI were significantly positively correlated with blood pressure. They were also positively correlated with the presence of acanthosis nigricans indicating IR. They were both negatively correlated with cholesterol levels, while fat percentage was positively correlated with insulin levels and HbA1c. BMI was significantly correlated with glucose levels. We found a lower prevalence of obesity was obtained when we used TMI classifications rather than BMI. There was a positive correlation between BMI and each of TMI and fat percentage. Furthermore, only BMI correlated with percentage of body fat (BF%) measured by DXA. Conclusion BMI seems to predict adiposity better than TMI in children and adolescents. In addition, TMI seemed to perform similarly as BMI for identifying metabolic syndrome.