Relationship between sleep disorders and serum vitamin D in Parkinson's disease

Objective To analyze the relationship between sleep disorders and serum vitamin D level in Parkinson's disease(PD)patients. Methods A total of 85 PD patients were divided into deficiency group(vitamin D<50 nmol/L, n=60)and normal group(vitamin D≥50 nmol/L, n=25). Motor symptoms evaluated by Parkinson's Disease Unified Scoring Scale(UPDRS)score and Hoehn-Yahr(H-Y)staging, non-motor symptoms including sleep disorders, cognitive function, hypoosmia, constipation and rapid sleep eye movement behavior disorder［Sleep disorder was assessed using the Pittsburgh Sleep Quality Index(PSQI)］and other clinical indicators were assessed in all PD patients. Results The proportion of vitamin D deficiency in PD patients was as high as 70.59%(60/85). For the motor symptoms indicators, UPDRS Ⅱ score and UPDRS Ⅲ score were significantly higher in the deficiency group than those in the normal group(P<0.05), and no significant difference was found in H-Y staging(P>0.05). In terms of the non-motor symptoms indicators, the total score of PSQI and sleep quality score in the deficiency group were higher than those in the normal group(P<0.05). After adjustment of age, disease duration and UPDRS Ⅱ and Ⅲ scores, vitamin D level was negatively correlated with PSQI total score, sleep quality score, sleeping time score, sleep disorder score(P<0.05 or P<0.01). Conclusion Vitamin D deficiency is common in PD patients, and vitamin D level is correlated with motor symptoms and sleep disorders in PD.