Comparing anthropometric measures and Lancet Commission definitions in relation to hypertension: Population-level evidence from a small island with high metabolic burden.

Objectives: Obesity is a major public health challenge, yet its classification remains debated. This study applies the newly proposed Lancet Diabetes & Endocrinology Commission definitions of pre-clinical and clinical obesity within a population with high obesity prevalence. These are compared with traditional anthropometric measures body mass index (BMI), waist circumference (WC), and waist-to-height ratio (WHtR) to evaluate how different classification approaches identify individuals at elevated risk of obesity-related complications and their association with hypertension (HTN). Study design: This cross-sectional study utilized data from a nationally representative health examination survey conducted in Malta between 2014 and 16, weighted N = 3947. Methods: Anthropometric, biochemical, and sociodemographic information was gathered, with hypertension (HTN) explored as an obesity-related complication. Logistic regression models examined the associations between obesity classifications and HTN adjusting for sex, age, education, and locality. Results: Obesity prevalence differed by classification, with BMI-defined obesity at 34.08%, high WC at 34.81%, high WHtR at 39.17%, clinical obesity at 22.40%, and pre-clinical obesity at 18.19%, based on the modified Lancet Commission definitions. All adiposity measures were significantly associated with hypertension (HTN). BMI-defined obesity was associated with a 6-fold increase in HTN, and overweight with a 3-fold increase. Clinical obesity was associated with a 5-fold increase in HTN, while high-risk WC and high WHtR were associated with 3-fold and 2-fold increases, respectively; all associations remained significant after adjustment. Conclusion: Anthropometric measures classify obesity inconsistently within the Maltese population, with BMI showing the strongest adjusted association with hypertension. However, interpretation of findings related to clinical obesity should consider the overlap between hypertension as both an outcome and a defining criterion. The Lancet Commission framework identified a smaller high-risk subgroup illustrating the need for clearer guidance and population-specific adaptation to population context, supporting the need for country-specific, sex- and age-sensitive obesity diagnostic criteria.