Obesity Abstracts

The study determines the prevalence and lifestyle predictors of metabolic health (MH) among normal weight and obese individuals within a Maltese cohort using two main approaches a) the Metabolic Syndrome (Met-S) framework as per NCEP-ATPIII and b) Insulin Resistance (IR) as defined by HOMA-IR; and to determine which cut-off valueof HOMA-IR best predicts metabolic health. This was a cross sectional study. Subjects with a BMI <25 kg/m² were considered normal weight. Subjects with BMI ≥ 25 kg/m² were considered overweight/obese. Participants having ≤1 features of the Met-S (as per NCEP ATPIII) or a HOMA-IR of <2.5 were deemed metabolically healthy. Subjects were then classified into one of the following body composition phenotypes: Metabolically healthy normal weight (MHNW); metabolically unhealthy normal weight (MUHNW); metabolically healthy obese (MHO) and metabolically unhealthy obese (MUHO). Out of 521 individuals recruited, 63% were female, 69% were overweight/obese and the median age was 41 years. There were 28.9% MHNW; 1.4% MUHNW; 16.7% MHO and 53% MUHO subjects as per the IR criterion and 27.8% MHNW; 2.1% MUHNW, 39.3% MHO and 30.7% MUHO individuals as per Met -S criteria. A higher proportion of individuals were MHO and MUHNW when assessed by the Met-S criteria. A higher percentage of females were MHO and significant differences in anthropometric and biochemical parameters were noted between the MHO and MUHO cohorts by both criteria. In the normal weight cohort, two-thirds of the MUHNW individuals were females by Met-S criteria and there were no MUHNW male subjects by IR criteria. There were no significant differences in anthropometric and biochemical parameters between the MHNW and MUHNW individuals by both criteria. Physical activity and non-smoking status were predictors of the MHO phenotype by both criteria but no significant association between lifestyle parameters and the MUHNW phenotype was found. Finally, a receiver operational characteristic analysis showed that a HOMA-IR value of >2 gave 69% sensitivity for defining metabolic health by NCEP ATPIII.

Conclusion: More than two thirds of the study population was overweight or obese. Prevalence of MHO and MUHNW phenotypes varied according to the definition used. Physical activity and no-smoking status were independent predictors of the MHO phenotype.