Prevalence and factors related to orthostatic syndromes in recently diagnosed, drug-naïve patients with Parkinson disease.

The aim of this study was to explore the prevalence of and factors related to orthostatic syndromes in recently diagnosed drug-naïve patients with Parkinson disease (PD).This was a cross-sectional study that included 217 drug-naïve patients with PD and 108 sex- and age-matched non-parkinsonian controls from the Parkinson's Progression Markers Initiative (PPMI) prospective cohort study who were devoid of diabetes, alcoholism, polyneuropathy, amyloidosis, and hypotension-inducing drugs. Orthostatic symptoms were evaluated using the Scales for Outcomes in PD-Autonomic Dysfunction (SCOPA-AUT). Ioflupane-I single-photon emission computerized tomography was used to evaluate striatal dopamine active transporter (DaT) levels. Blood pressure was assessed both in the supine position and 1-3 min after the switch to a standing position. Orthostatic hypotension (OH) was defined by international consensus, and orthostatic intolerance (OI) was defined as the presence of orthostatic symptoms in the absence of OH.Compared with non-parkinsonian controls, patients with PD experienced a mild fall in systolic blood pressure upon standing (p = 0.082). The prevalence of OH was 11.1% in PD patients and 5.6% in controls (p = 0.109). The prevalence of OI was higher in patients with PD than in controls (31.3 vs. 13.3%; p = 0.003). Logistic regression revealed that OH and OI were related to a lower striatal DaT level and higher SCOPA-AUT gastrointestinal score.Orthostatic syndromes were common in the recently diagnosed drug-naïve patients with PD enrolled in the study, but only the prevalence of OI was higher in PD patients than in the non-parkinsonian controls. Unlike motor or functional disability indicators, markers of dopaminergic striatal deficit and gastrointestinal dysfunction were associated with OH and OI.