Metabolic profiles associated with fat loss in Parkinson's disease.

Patients with PD had significantly lower body weight, BMI, and body fat mass compared with healthy controls.

• Study enrolled 91 patients with PD and 47 healthy controls between July 2021 and October 2023.
• Body weight was lower in PD patients (p=0.003).
• BMI was lower in PD patients (p=0.001).
• Body fat mass was lower in PD patients (p<0.001).
• Body composition was evaluated using bioelectrical impedance analysis.

Glycolysis and Krebs cycle markers were reduced in patients with PD compared with controls.

• Lactic acid (a glycolysis marker) was reduced in PD patients.
• Succinic acid (a Krebs cycle intermediate) was reduced in PD patients.
• Plasma metabolite profiling was conducted via mass spectrometry.
• These reductions suggest lower glycolytic activity in PD.

Ketone bodies were elevated in patients with PD compared with controls.

• Acetoacetic acid was elevated in PD patients.
• 3-hydroxybutyric acid was elevated in PD patients.
• Acetoacetic acid negatively correlated with BMI in patients with PD.
• 3-hydroxybutyric acid also negatively correlated with BMI in patients with PD.

Amino acid catabolism-related markers and acetic acid were elevated in patients with PD.

• 2-hydroxybutyric acid was elevated in PD patients.
• 2-oxobutyric acid was elevated in PD patients.
• Acetic acid was elevated in PD patients.
• These metabolites are described as amino acid catabolism-related markers.

Phosphatidylcholine (40:2) was elevated in PD and showed higher levels at more advanced Hoehn and Yahr stages.

• Phosphatidylcholine (40:2) levels were higher in PD patients compared with controls.
• Higher levels were observed in individuals at more advanced Hoehn and Yahr stages.
• Phospholipids were among the metabolite classes profiled via mass spectrometry.

The metabolic profile in PD fat loss is consistent with a potential shift in energy utilisation away from glycolysis toward lipid and amino acid metabolism.

• The combination of lower glycolytic activity markers and higher ketone body and amino acid catabolism markers suggests an energy substrate shift.
• The authors describe this as 'consistent with a potential shift in energy utilisation.'
• These findings highlight metabolic pathways as potential targets for interventions to mitigate weight loss in PD.