Familial and environmental risk factors in Parkinson's disease: a case-control study in north-east Italy

Abstract

We conclude that both familial and environmental factors may contribute to PD aetiology.

Epidemiology and etiology of Parkinson’s disease: a review of the evidence

“…A similar Danish study also reported a weak association (standardized hospitalization ratio, SHR, 1.30, 95% CI 1.03-1.63) [354]. Among 29 case-control studies that studied rural living as an exposure, 11 reported an increased risk of PD [136,141,142,147,153,289,293,303,305,309,314] with ORs ranging between 1.5 and 4.9. One study reported an inverse association [350], whereas the others found no association [131, 143-146, 154, 291, 307, 311, 312, 315, 316, 321, 325, 356-358].…”

“…Although familial aggregation has been investigated in a large number of studies, most of them were hospital-based . The relative risk (RR) of PD when having a firstdegree relative with PD compared to having no first-degree relative with PD in these studies ranged between 1.6 and 10.4, although one study reported an odds ratio (OR) of 41.7 [147]. In general, population-based studies [155][156][157][158][159][160][161][162][163] reported lower RRs, with a range between 1.5 and 7.5.…”

“…In most studies of pesticides in relation to PD exposure was assessed retrospectively as a broad category, rather than examining specific substances. Of 38 case-control studies, 19 reported increased risk of PD [147,154,156,[289][290][291][292][293][294][295][296][297][298][299][300][301][302][303][304] with ORs ranging between 1.3 and 3.7 for most studies. One study reported an OR of 7.0 (p value <0.05) [289] and another an OR of 10.9 (95% CI 2.5-48.0) [301].…”

“…On the other hand, smoking may be associated with higher exposure to pesticides (for example, one study showed that smoking was associated with higher levels of polychlorinated biphenyls and organochlorine pesticides in breast milk samples [318]), which would confound an association between pesticides and PD towards the null. Adjustment for smoking, however, gave lower risk estimates for pesticides than unadjusted analyses in several of the studies [144,147,293,319]. A substantial proportion of the studies that observed no association between pesticides and PD did not adjust for smoking in the analyses [131, 136, 141, 142, 145, 305-309, 311, 314, 315].…”

“…reported an increased risk [140,142,147,305,309,312,316,346,355]. Most of these studies reported ORs ranging between 1.7 and 2.8.…”