Tracking the obesity epidemic: a comprehensive population-based epidemiological assessment of obesity prevalence and its cardiovascular-kidney-metabolic complications

Excess adiposity is increasingly prevalent worldwide and is associated with substantial cardiovascular-kidney–metabolic (CKM) morbidity. This study aimed to quantify the prevalence of general and abdominal obesity in an urban population and to compare estimates obtained using different anthropometric criteria. We further characterised cardiovascular (CV), metabolic, and renal multimorbidity across adiposity phenotypes and assessed how these associations varied according to the criteria applied. Białystok PLUS enrolled 3,524 adults aged 20–79 years from the general population of Białystok, Poland. Standardised anthropometry included body mass index (BMI), waist circumference (WC), and waist-to-height ratio (WtHR), while dual-energy X-ray absorptiometry (DEXA) was used to assess body composition. Fasting biochemistry, oral glucose tolerance testing, blood pressure measurement, carotid ultrasound, and kidney function assessment were performed. Adiposity phenotypes were defined using BMI, sex-specific WC thresholds, and their combination; high-risk fat accumulation was defined as BMI 25.0–29.9 kg/m2 with WtHR ≥0.5. Weighted analyses were used to generate population estimates, while inferential comparisons were adjusted for age and sex where appropriate. Based on BMI, 63.5% of participants were classified as having overweight or obesity, including 25.4% with obesity. Abdominal overweight or obesity based on WC criteria was present in 53.2%. After adjustment for age and sex, the combined BMI+WC obesity phenotype showed the most adverse CKM profile and the greatest multimorbidity burden, whereas WC-only and BMI-only obesity were broadly comparable with respect to glycaemic indices, triglycerides, and multimorbidity. Dysglycaemia increased across BMI and WC strata, and nearly all participants with class III obesity had prediabetes or diabetes. Triglycerides and blood pressure increased with adiposity, whereas the crude decline in eGFR was explained by age after adjustment. High-risk fat accumulation was present in 28.2% of participants and in 74.1% of those with overweight. In this population-based cohort, excess adiposity was highly prevalent and associated with a greater burden of CKM multimorbidity. Among individuals with overweight, WtHR ≥0.5 identified a subgroup with a higher CKM disease burden; however, its incremental discrimination beyond age, sex, and BMI was modest.