Body mass index, metabolic abnormality burden, and hypertension among young adults undergoing health examinations: a cross-sectional study

Abstract Background Hypertension in young adults frequently coexists with excess adiposity and metabolic abnormalities. However, the joint cross-sectional associations of body mass index (BMI) and concurrent metabolic abnormality burden with hypertension remain incompletely characterized. We examined these associations among young adults undergoing routine health examinations. Methods This retrospective cross-sectional study included adults aged 18–34 years with BMI ≥ 18.5 kg/m² who underwent routine health examinations at Northern Jiangsu People’s Hospital in 2024. Metabolic abnormality burden comprised elevated triglycerides, low high-density lipoprotein cholesterol, hyperuricemia, ultrasonography-detected fatty liver, and type 2 diabetes. Participants were classified as normal weight with lower burden (NW-LB), normal weight with higher burden (NW-HB), overweight/obesity with lower burden (OWO-LB), or overweight/obesity with higher burden (OWO-HB). Modified Poisson regression with robust variance estimation was used to estimate prevalence ratios (PRs) and 95% confidence intervals (CIs). Results Among 3,550 participants, 360 had hypertension. Compared with NW-LB, OWO-LB and OWO-HB were associated with higher hypertension prevalence after multivariable adjustment, with PRs of 2.15 (95% CI 1.59–2.92, P < 0.001) and 2.73 (95% CI 2.01–3.70, P < 0.001), respectively. The association for NW-HB was not statistically significant (PR 1.16, 95% CI 0.69–1.96, P = 0.572). Metabolic abnormality count was associated with hypertension before BMI was included in the model, but the association was attenuated after further adjustment for BMI category. Participants with four or more abnormalities nevertheless had a higher hypertension prevalence than those without abnormalities after BMI adjustment (PR 1.58, 95% CI 1.08–2.30). Conclusions Among young adults undergoing health examinations, overweight/obesity showed the most consistent association with hypertension, while concurrent metabolic abnormalities provided complementary information, particularly at the highest burden level. Considering BMI together with metabolic abnormality burden may provide a more complete description of the metabolic characteristics accompanying hypertension in young adults.