Weight Gain Trajectory and Pain Interference in Young Adulthood: Evidence from a Longitudinal Birth Cohort Study

OBJECTIVE: Obesity is associated with chronic pain, but the contribution of body mass index (BMI) trajectories over the life course to the onset of pain problems remains unclear. We retrospectively analyzed how BMI trajectories during the transition to adulthood were associated with a measure of pain interference obtained at age 29 in a longitudinal birth cohort study. METHODS: Data from the National Longitudinal Survey of Youth, 1997 Cohort (follow-up from 1997 to 2015), were used to determine BMI trajectories from age 14 to 29 via group trajectory modeling. At age 29, respondents described whether pain interfered with their work inside and outside the home over the past four weeks (not at all, a little, or a lot). Multivariable ordinal logistic regression was used to evaluate pain interference according to BMI trajectory and study covariates. RESULTS: Among 7,875 respondents, 11% reported "a little" and 4% reported "a lot" of pain interference at age 29. Four BMI trajectory groups were identified, varying in starting BMI and rate of weight gain. The "obese" group (8% of respondents) had a starting BMI of 30 kg/m2 and gained an average of 0.7 kg/m2/y. On multivariable analysis, this group was the most likely to have greater pain interference, compared with "high normal weight" (odds ratio [OR] = 1.47, 95% confidence interval [CI] = 1.14-1.88), "low normal weight" (OR = 1.45, 95% CI = 1.13-1.87), and "overweight" trajectories (OR = 1.33, 95% CI = 1.02-1.73). CONCLUSIONS: Obesity and rapid weight gain during the transition to adulthood were associated with higher risk of pain interference among young adults.