A family member with Parkinson’s disease confers the strongest risk for developing the disease, according to findings from the largest and most comprehensive systematic review and meta-analysis of Parkinson’s disease risk factors suitable for screening. People with a first degree relative with PD had a more than threefold higher odds for developing PD themselves, compared with those without an affected first-degree relative, based on a meta-analysis of data from 2 case-control studies, and people with any relative with PD had a 4.5-fold greater odds, according to data collected in 19 case-control studies, a researcher in the institute of neurology, University College London, and his colleagues identified 202 articles published during 1966-March 2011, of which 173 made it into the meta-analysis. Following family history of PD, other strong associations identified in the meta-analysis included:
• Family history of tremor, which boosted the odds for development of PD 2.7-fold
• Constipation, considered an early symptom, which was associated with a 2.3-fold greater odds for PD.
• Mood disorder, another early symptom, which was linked to an 86% higher odds of PD.
• Pesticide exposure, a risk factor that was linked to a 78% higher odds
• Head injury, a risk factor associated with a 58% greater odds of PD.