Objective:

To establish longitudinal normative weight data for Parkinson’s disease (PD) patients, enabling early identification of patients at risk for significant weight loss who may benefit from clinical intervention.

Background:

PD patients tend to lose weight faster than age-matched controls. Low weight in PD is consistently linked to frailty, malnutrition, and increased morbidity and mortality. Despite its clinical relevance, there is a lack of normative longitudinal data for weight trajectories in PD. Comparative benchmarks using healthy aging controls are also lacking, impeding the ability to identify patients requiring intervention for weight decline.

Design/Methods:

We analyzed a retrospective, longitudinal cohort of PD patients from the University of Pennsylvania, comparing their weight to National Center for Health Statistics (NCHS) National Health and Nutrition Examination Survey (NHANES) data representative of aging in the United States. A mixed model was used to control for patient age, disease duration, and sex. Population-level weight and percent-change in weight was analyzed as a function of disease duration and age- and sex-matched NHANES projections served as a control reference.

Results:

PD patients consistently weigh less than NHANES controls across age bins and exhibit a significantly greater reduction in body weight both early and throughout disease progression. These patterns are robust after adjustment for baseline age and sex. We have applied these data to develop tools that calculate weight percentiles and weight trajectory percentiles for individual PD patients, enabling risk stratification and clinical decision support.

Conclusions:

These results require validation in additional cohorts but provide a foundation for future standardized care pathways and targeted intervention for weight loss in PD.