Insight into the longitudinal relationship between chronic subclinical inflammation and obesity from adolescence to early adulthood: a dual trajectory analysis

Objectives and design: This study aimed to understand the longitudinal relationship between C-reactive protein (CRP) and body mass index (BMI) from adolescence to early adulthood. Methods: CRP and BMI were collected from participants of the Raine Study Gen2 at 14-, 17-, 20- and 22-year follow-ups (n = 1312). A dual trajectory analysis was conducted to assess the association between CRP and BMI trajectories, providing conditional probabilities of membership of CRP trajectory membership given BMI trajectory membership. Best model fit was assessed by systematically fitting two to eight trajectory groups with linear and quadratic terms and comparing models according to the Bayesian Information Criterion statistic. Results: The three CRP trajectories were; “stable-low” (71.0%), “low-to-high” (13.8%) and “stable-high” (15.2%). Participants in a “high-increasing” BMI trajectory had a higher probability of being in the “stable-high” CRP trajectory (60.4% of participants). In contrast, individuals in the “medium-increasing” BMI trajectory did not have a significantly increased probability of being in the “stable-high” CRP trajectory. Conclusions: These findings support that chronic sub-clinical inflammation is present through adolescence into early adulthood in some individuals. Targeting chronic sub-clinical inflammation though obesity prevention strategies may be important for improving future health outcomes.