Serum Uric Acid Levels and Non-Motor Symptoms in Parkinson’s Disease

The Influence of Serum Uric Acid Level on Non-Motor Symptoms Occurrence and Severity in Patients with Idiopathic Parkinson’s Disease and Atypical Parkinsonisms—A Systematic Review

“…Seven articles [ 15 , 16 , 17 , 18 , 19 , 20 , 21 ] were included in the analysis out of which two [ 15 , 19 ] were prospective studies and five [ 16 , 17 , 18 , 20 , 21 ] were cross-sectional studies ( Table S1—Supplementary Material ). Huang et al [ 15 ] had a 5-year follow up and Moccia et al [ 19 ] had a 2-year follow-up.…”

“…The mean age of patients from all the publications was 65.32 years. The age range was presented in five studies and varied from 17 to 92 years [ 16 , 17 , 18 , 19 , 21 ]. The average disease span was shown in all studies but two [ 19 , 20 ] and equated to 5.93 years.…”

“…In six of the studies, the main inclusion criterion was a definitive PD diagnosis based on the United Kingdom Parkinson’s Disease Society Brain Bank Diagnostic Criteria (UKPDSBBDC) [ 16 , 17 , 18 , 19 , 20 , 21 ]. In the study by Huang et al [ 15 ], the inclusion criterion fulfilled the benchmark for PD diagnosis according to the National Institute of Neurological Disorders and Stroke (NINDS).…”

“…Three authors excluded all patients with the diagnosis of atypical Parkinsonism, vascular, familial, or secondary Parkinsonism [ 16 , 18 , 19 ]. Pan et al [ 17 ] and Chen et al [ 20 ] disqualified patients with disabilities caused by neurological disorders other than PD and with any somatic disorder that could influence NMS (e.g., pain syndromes, advanced diabetes mellitus, severe anemia).…”

“…Three authors [ 15 , 17 , 21 ] excluded patients with acute and chronic conditions that could be life-threatening (e.g., symptomatic and clinically diagnosed stroke, cancer, failure of any internal organs). Pan et al [ 17 ] and van Wamelen et al [ 18 ] eliminated patients with moderate and severe cognitive disorders according to Mini-Mental State Examination (MMSE; score < 26 points) adjusted to patients’ age and education.…”