Longitudinal association between dopamine agonists and weight in Parkinson's disease.

Objective: To examine the longitudinal relation of dopamine agonists (DA) use with body mass index (BMI) change and weight gain in Parkinson's disease (PD).

Methods: In a cohort of 356 patients with PD annually followed up to 6 years, BMI, antiparkinsonian drugs use, and impulse control disorders (ICDs) were assessed at each visit. DA dose trajectories were estimated using latent class mixed models. The association of DA use with BMI change and weight gain was examined using latent-process mixed models and time-dependent Cox models respectively, while adjusting for disease severity and levodopa (LD) use.

Results: In the mixed model, BMI (kg/m) increased over the follow-up in DA users (beta = 0.13, 95% CI = 0.02, 0.24) compared to non-users, while it decreased in LD users (beta = -0.26, 95% CI = -0.38, -0.13). We identified three trajectories of average daily DA dose over the follow-up. Patients in the high trajectory gained more weight than patients who never used DA (P = .001) and in the low (P = .02) or moderate (P = .04) trajectories. The incidence of weight gain of ≥6 kg was 2.10-fold (95% CI = 1.03, 4.28) higher in DA users compared to non-users, while LD users were less likely to gain weight (HR = 0.60, 95% CI = 0.33, 1.11). Associations decreased in analyses adjusted for compulsive eating or ICDs.

Conclusion: Weight increased in DA users over 6 years, and DA use was associated with increased incidence of weight gain. These associations were partially explained by compulsive eating. Alternatively, weight decreased in LD users. These findings warrant careful monitoring of compulsive eating and weight in PD patients.