Parkinson disease male-to-female ratios increase with age: French nationwide study and meta-analysis

Abstract

BackgroundParkinson’s disease (PD) is 1.5 times more frequent in men than women. Whether age modifies this ratio is unclear. We examined whether male-to-female (M–F) ratios change with age through a French nationwide prevalence/incidence study (2010) and a meta-analysis of incidence studies.MethodsWe used French national drug claims databases to identify PD cases using a validated algorithm. We computed M–F prevalence/incidence ratios overall and by age using Poisson regression. Ratios were regressed on age to estimate their annual change. We identified all PD incidence studies with age/sex-specific data, and performed a meta-analysis of M–F ratios.ResultsOn the basis of 149 672 prevalent (50% women) and 25 438 incident (49% women) cases, age-standardised rates were higher in men (prevalence=2.865/1000; incidence=0.490/1000 person-years) than women (prevalence=1.934/1000; incidence=0.328/1000 person-years). The overall M–F ratio was 1.48 for prevalence and 1.49 for incidence. Prevalence and incidence M–F ratios increased by 0.05 and 0.14, respectively, per 10 years of age. Incidence was similar in men and women under 50 years (M–F ratio <1.2, p>0.20), and over 1.6 (p<0.001) times higher in men than women above 80 years (p trend <0.001). A meta-analysis of 22 incidence studies (14 126 cases, 46% women) confirmed that M– F ratios increased with age (0.26 per 10 years, p trend=0.005).ConclusionsAge-increasing M–F ratios suggest that PD aetiology changes with age. Sex-related risk/protective factors may play a different role across the continuum of age at onset. This finding may inform aetiological PD research.

Projections of prevalence, lifetime risk, and life expectancy of Parkinson's disease (2010‐2030) in France

“…However, this would considerably complicate the estimation process and would require additional input data that are not available at the present time. Another limitation is that we probably failed to identify some patients (eg, untreated or undiagnosed, in institutions with in‐house pharmacies), but we were able to correct our frequency estimates for the sensitivity and specificity of the method used to identify PD patients, and we previously showed that our frequency estimates are consistent with those from other studies . In addition, we took into account the underestimation in the oldest persons by correcting estimates for underdiagnosis after age 80.…”

“…First, PD patients were identified in the French National Health Insurance database (SNIIRAM) using a prediction model based on drug claims that allow one to estimate the probability that people who used antiparkinsonian drugs in a given year are being treated for PD . We have previously shown that this approach identifies treated patients with 92.5% sensitivity and 86.4% specificity and yields age‐ and gender‐specific incidences consistent with 22 previously published studies . We applied this prediction model for years 2009 to 2012.…”

“…Our model predicts that the lifetime risk of PD will increase between 2010 and 2030. One striking finding is that, although PD incidence is about 1.5 times higher in men when compared with women and the male‐to‐female ratio increases with age, the difference in lifetime risk between men and women was considerably less pronounced (ratio 2030 = 1.17). This is because the longer life expectancy in women counterbalanced the higher PD incidence in men.…”

“…PD is rare before the age of 50 years, and its incidence increases sharply after that age; more than 80% of patients are older than 65 years . In addition, PD is ∼1.5 times more frequent in men than women . According to the Global Burden of Disease, PD was the neurological disease with the largest increase in age‐standardized prevalence between 1990 and 2015 .…”

Parkinson’s Disease: From Pathogenesis to Pharmacogenomics

“…Prevalence and incidence male/female (M/F) ratios increase by 0.05 and 0.14, respectively, per 10 years of age. Incidence is similar in men and women under 50 years (M/F ratio < 1.2), and over 1.6 times higher in men than women above 80 years [8]. Furthermore, PD coexists with dementia in over 25% of the cases and with depression in over 30% of the cases in some countries [7].…”