Usefulness of impedanciometry for the assessment of obesity in a high risk dyslipidemia screening unit

Abstract

Abstract Funding Acknowledgements Type of funding sources: None. Introduction Residual risk is related to future events in already treated patients. In addition, obesity increases cardiovascular risk. Body mass index (BMI) is the OMS-defined measure for the diagnosis of obesity, but not the only one, as body fat percentage (%BF) allows a more accurate estimation of visceral fat. Objective To identify the clinical utility of adding body fat percentage (%BF) measured by impedanciometry to the assessment of obesity, and to compare the residual lipid profile of obese versus non-obese patients according to the measurement methods. Methods Prospective observational study, which analysed 213 patients included in a High Risk Dyslipidemia Screening Unit. Three groups were classified: group A (BMI <30 and %BF <25%-35% according to gender; group B (BMI <30 but %BF ≥25% -35%) and group C (BMI ≥30 and %BF ≥25-35%). Clinical characteristics, screening unit inclusion variables and residual lipid profile were analysed, as well as the association with early coronary heart disease and with the development of cardiovascular disease among the three groups. Results Of the 213 patients included, 91 belonged to Group A (non-obese patients), 80 belonged to Group C (obese according to BMI and %BF) and 42 patients belonged to Group B (classified as obese according to %BF but with BMI <30). When comparing the three groups, it was observed that the patients in group B had a residual lipid profile more similar to that of group C patients. They had higher levels of TG, remnant cholesterol and VLDL; with lower levels of HDL (p<0.05), with no statistically significant differences in the levels of Lp(a), ApoB, LDL and non-HDL in relation to those in group A. Fifty percent of group B patients developed coronary heart disease, compared to 56% of group C and 36% of group A patients (p= 0.029). There were no differences in the development of early coronary heart disease. There were 31.6% of patients with BMI<30 who were reclassified as obese according to %BF. If we classified the obese according to BMI, 45.5% developed cardiovascular disease and 45.2% developed early coronary heart disease. If we reclassify the obese according to %BF, the percentage rises to 65.7% and 65.6% respectively. All data are shown in table 1. Conclusion Adding the % of BF by impedanciometry for the diagnosis of obesity in a high risk dyslipidemia screening unit allows the identification of an important percentage of patients with a higher cardiovascular risk and a worse residual lipid profile. BMI is insufficient as a single parameter for the assessment of obesity and for stratifying cardiovascular risk.