Early weight loss in parkinsonism predicts poor outcomes: evidence from an incident cohort study

Objective: We aimed to compare weight change over time in Parkinson’s disease (PD), atypical parkinsonism, and matched controls; identify baseline factors that influence weight loss in parkinsonism; and examine whether it predicts poor outcome. Methods: We analysed data from the PINE study, an incident, population-based prospective cohort of parkinsonian patients and age-sex matched controls with annual follow-up. Mixed model analysis described weight change in PD, atypical parkinsonism and controls. Baseline determinants of sustained clinically-significant weight loss (>5% loss from baseline) and associations between early sustained weight loss and death, dementia and dependency in parkinsonism were studied with Cox-regression. Results: A total of 515 participants (240 controls, 187 PD, 88 atypical parkinsonism), were followed for median of 5 years. At diagnosis atypical parkinsonian patients had lower body weights than PD who were lighter than controls. Patients with PD lost weight more rapidly than controls and weight loss was most rapid in atypical parkinsonism. After multivariable adjustment for potential confounders, only age was independently associated with sustained clinically significant weight loss (HR, ten-year age increase, 1.83, 95% CI 1.44-2.32). Weight loss occurring within one year of diagnosis was independently associated with increased risk of dependency (HR 2.11, 95% CI 1.00-4.42), dementia (HR 3.23, 95% CI 1.40-7.44) and death (HR 2.23, 95% CI 1.46-3.41). Conclusion: Weight loss occurs in early parkinsonism and is greater in atypical parkinsonism than in PD. Early weight loss in parkinsonism has prognostic significance and targeted dietary interventions to prevent it may improve long-term outcomes.