Subsequent risks of Parkinson disease in patients with autoimmune and related disorders: a nationwide epidemiological study from Sweden.
OBJECTIVE
To investigate associations between autoimmune disorders and Parkinson disease (PD), and to study whether the risk is associated with follow-up time and age.


METHODS
Standardized incidence ratios (SIRs) were calculated for PD in patients with autoimmune disorders by comparing them to subjects without autoimmune disorders.


RESULTS
Among 310,522 patients with a total of 33 conditions of autoimmune disorders, 932 patients developed subsequent PD, giving an overall SIR of 1.33 and 1.19 for PD diagnosed later than 1 year after follow-up. Six types of autoimmune disorders showed an increased risk. These conditions included: amyotrophic lateral sclerosis, Graves's disease/hyperthyroidism, Hashimoto's disease/hypothyroidism, multiple sclerosis, pernicious anemia, and polymyalgia rheumatica. The risks depended on the age at hospitalization for PD.


CONCLUSIONS
A 33% overall excess risk of PD was noted among patients with an autoimmune disorder; the risk was increased during the first 10 years of follow-up after hospitalization of autoimmune disorders.
Center for Primary Health Care Research, Lund University, Malmö, Sweden. xinjun.li@med.lu.se
Xinjun
X
Li
Jan
J
Sundquist
Kristina
K
Sundquist
D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D001327:Autoimmune Diseases / Q000145:classification / Q000175:diagnosis / Q000453:epidemiology*; D016021:Epidemiologic Studies; D005260:Female; D006801:Humans; D015994:Incidence; D038801:International Classification of Diseases; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D010300:Parkinson Disease / Q000453:epidemiology*; D011237:Predictive Value of Tests; D012189:Retrospective Studies; D013548:Sweden / Q000453:epidemiology