Risk assessment of obesity-related noncommunicable diseases through body mass index trajectories in adulthood: NHANES 2007-2018.

Aim: To assess the impact of adult body mass index (BMI) trajectories on the risk of obesity-related noncommunicable diseases (NCDs) in the U.S. adults after adjustment for sociodemographic and lifestyle factors.

Methods: Data were extracted from the National Health and Nutrition Examination Survey conducted from 2007 to 2018, including male and female participants aged 29-59 years. Rao-Scott adjusted chi-square was employed to detect associations between categorical variables in descriptive analyses. Cox proportional hazards models estimated hazard ratios (HR) and 95% confidence intervals (CI) for NCDs and BMI trajectories, adjusted for sociodemographic and lifestyle factors. Kaplan-Meier curves illustrated the cumulative incidence over time.

Results: Analyses were carried out on 15 721 participants and revealing significant differences among BMI trajectories in terms of demographic, lifestyle, and health characteristics. The overall prevalence of NCDs was 28.0% (95%CI:26.6-28.9). The cumulative incidence over time was higher in the high increase, moderate increase, and mixed trajectory groups, with a correspondingly higher cumulative risk (p < 0.001). Non-overweight trajectory was considered reference category in Cox models. The BMI trajectories were independently associated with an increased risk of NCDs, even after adjusting for potential confounders (HR: 1.7; 95%CI: 1.4-1.9 for moderate increase; HR: 3.6; 95%CI: 3.2-4.1 for high increase; and HR: 2.4; 95%CI: 2.1-2.7, for mixed). Furthermore, differences between males and females were also observed.

Conclusion: The transition to and persistence of obesity into adulthood increases the risk of NCDs. The implementation of targeted interventions with long-term monitoring of BMI may be beneficial in the prevention of future obesity-related NCDs.