Hidden cardiometabolic risk: normal weight central obesity in a nationally representative study from Türkiye

This study aimed to assess the prevalence of normal-weight central obesity (NWCO) in Türkiye and its associations with cardiometabolic diseases. The analyses utilized data from the Türkiye Household Health Survey (STEPS 2023), which was conducted in accordance with the World Health Organization’s STEPwise approach. A total of 6,017 individuals participated in the survey; 4,991 with complete anthropometric data were included in the primary analytic sample. Weighted prevalence estimates, multivariable logistic regression, and population attributable fraction (PAF) analyses were performed, accounting for the complex sampling design. The prevalence of central obesity in Türkiye was 62.0%. Among individuals with a normal BMI, 25.2% had central obesity, and the prevalence of normal weight central obesity (NWCO) in the overall population was 8.8%. The prevalence of NWCO was higher in women than in men (11.9% vs. 5.7%; p < 0.001). In the NWCO group, the prevalence of hypertension (21.3%), diabetes (10.4%), and hypercholesterolemia (28.1%) was significantly higher compared to individuals with a normal BMI and no central obesity (p < 0.001). In multivariable analyses, NWCO was associated with hypertension (OR 2.20, 95% CI 1.27–3.80) and hypercholesterolemia (OR 2.43, 95% CI 1.06–5.59) in women and with diabetes in men (OR 4.19, 95% CI 1.13–15.54), although some subgroup-specific estimates were imprecise and should be interpreted cautiously. PAF estimates suggested that NWCO may have meaningful population-level relevance; however, the wide confidence intervals surrounding several estimates indicate substantial uncertainty. These findings indicate that abdominal fat accumulation is associated with adverse cardiometabolic profiles even among individuals with a normal BMI. In Türkiye, incorporating waist circumference alongside BMI into routine clinical assessment, particularly within primary care, may enhance identification of individuals with potentially elevated cardiometabolic risk not captured by BMI alone.