PT  - JOURNAL ARTICLE
AU  - Moisan, Frédéric
AU  - Kab, Sofiane
AU  - Mohamed, Fatima
AU  - Canonico, Marianne
AU  - Le Guern, Morgane
AU  - Quintin, Cécile
AU  - Carcaillon, Laure
AU  - Nicolau, Javier
AU  - Duport, Nicolas
AU  - Singh-Manoux, Archana
AU  - Boussac-Zarebska, Marjorie
AU  - Elbaz, Alexis
TI  - Parkinson disease male-to-female ratios increase with age: French nationwide study and meta-analysis
AID  - 10.1136/jnnp-2015-312283
DP  - 2016 Sep 01
TA  - Journal of Neurology, Neurosurgery & Psychiatry
PG  - 952--957
VI  - 87
IP  - 9
4099  - http://jnnp.bmj.com/content/87/9/952.short
4100  - http://jnnp.bmj.com/content/87/9/952.full
SO  - J Neurol Neurosurg Psychiatry2016 Sep 01; 87
AB  - Background Parkinson’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.Methods We 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.Results On 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).Conclusions Age-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.