Subclinical Risk Markers for Cardiovascular Disease (CVD) in Metabolically Healthy Obese (MHO) Subjects

Introduction: Metabolically Healthy Obesity/Metabolic Healthy Obesity (MHO) is an enigma in scientific medical literature. Debate is still on regarding the safety status of MHO phenotype. The general consensus states that it is a condition with obesity but lacking metabolic abnormalities such as dyslipidemia, impaired glucose tolerance, or Metabolic Syndrome (MS). MHO population has less visceral adipose tissue, and a decreased inflammatory profile as compared to MS. Aim: To assess subclinical cardiovascular risk markers like Carotid Intima-Media Thickness (CIMT), Non Alcoholic Fatty Liver Disease (NAFLD) and high sensitivity C-reactive Protein (hs-CRP) level in MHO subjects. Materials and Methods: This cross-sectional study was done in a tertiary care hospital conducted for a period of three years from January 2016 to January 2019. After obtaining institutional ethical clearance, this cross-sectional study was conducted on 222 MHO subjects, 65 MS and 81 Metabolic Healthy Non Obese (MHNO) subjects. Anthropometric data was obtained. Metabolic parameters like hs-CRP, CIMT and NAFLD status were estimated and compared with MS and MHNO group. The data was analysed using appropriate statistical significance tests. Results: In one way Analysis of Variance (ANOVA), anthropometric determinants and metabolic variables differed significantly across the groups p<0.0001). The mean hs-CRP in MHO was; 4.01 +/- 1.68 versus control group; 2.16 +/- 0.56 (p<0.0001). Using Pearson's correlation coefficient, significant positive correlation was found between the sub clinical CVD risk markers with other anthropometric and metabolic parameters. In multiple regression analysis body mass index Waist Circumference (WC), NAFLD and abnormal CIMT were significantly associated with elevated hs-CRP. The mean CI MT in MHO was; 0.74 +/- 0.17 versus control group; 0.65 +/- 0.14 (p<0.0001). In multiple regression analysis NAFLD and hs-CRP were significantly associated with CIMT values. Prevalence of NAFLD in MHO was 59.01%. In multiple regression analysis WC, CIMT and hsCRP were significantly associated with NAFLD. Adjusted Odd's Ratio (AOR) for high hs-CRP, NAFLD, and abnormal CIMT in MHO as compared to MHNO was 1.98, 1.81, 1.61 respectively. Conclusion: MHO phenotype is associated with higher prevalence of fatty liver, increased hs-CRP levels and abnormal CIMT as compared to MHNO phenotype. This indicates that obesity even if associated with a healthy metabolic profile, still harbour subclinical inflammation. So subjects with MHO should be targeted for appropriate preventive strategies in form of health education, life style modifications to avoid future cardiovascular morbidities. MHO phenotype with evidence of subclinical vascular inflammation should not be considered a benign condition.