Serum growth differentiation factor 15, but not lactate, is elevated in patients with Parkinson's disease

Parkinson's disease (PD) is among the most frequently-occurring neurodegenerative diseases in humans. Although mitochondrial dysfunction is suggested to play a central role in PD pathogenesis, few studies have clinically evaluated mitochondrial function in PD patients. We therefore aimed to determine whether mitochondrial function is altered in PD patients by applying two approaches that are normally used for the diagnosis of mitochondrial disorder (MD).

We measured serum growth differentiation factor 15 (GDF15) levels in 36 PD patients, 30 age-matched healthy controls, and 5 MD patients. Among these, 20 PD patients and 18 healthy controls underwent the lactate stress test. Serum GDF15 levels were evaluated with respect to clinical characteristics.

Mean GDF15 levels were significantly higher in the PD (1472 pg/mL, p = .034) and MD (3363 pg/mL, p < .001) groups than in the control group (1093 pg/mL). The lactate stress test exhibited no significant differences between PD patients and controls. Age was identified as an independent factor that correlated with serum GDF15 levels in both groups. In PD patients, there was no significant difference between serum GDF15 levels and other clinical parameters including sex, cognitive function, and lifestyle.

Serum GDF15 levels, but not lactate levels, were elevated in Japanese patients with PD, thus highlighting the potential association between PD and GDF15.