RESEARCH ARTICLE
Body Mass Index and Risk of Parkinson’s Disease: A Dose-Response Meta-Analysis of Prospective Studies Yun-Liang Wang1*, Yu-Tong Wang2, Jin-Feng Li1, Yu-Zheng Zhang1, Hong-Lei Yin1, Bing Han1 1 Department of Neurology, the 148 Central Hospital of PLA, Zibo, 255000, China, 2 School of Medicine, Henan University, Kaifeng, 475000, China * [email protected]
Abstract Background A number of epidemiologic studies examining the relationship between body mass index (BMI) and the future occurrence of Parkinson’s disease (PD) reported largely inconsistent findings. We conducted a dose-response meta-analysis of prospective studies to clarify this association. OPEN ACCESS Citation: Wang Y-L, Wang Y-T, Li J-F, Zhang Y-Z, Yin H-L, Han B (2015) Body Mass Index and Risk of Parkinson’s Disease: A Dose-Response MetaAnalysis of Prospective Studies. PLoS ONE 10(6): e0131778. doi:10.1371/journal.pone.0131778 Editor: Shahrad Taheri, Weill Cornell Medical College in Qatar, QATAR
Methods Eligible prospective studies were identified by a search of PubMed and by checking the references of related publications. The generalized least squares trend estimation was employed to compute study-specific relative risks (RR) and 95% confidence intervals (CI) for an increase in BMI of 5 kg/m2, and the random-effects model was used to compute summary RR and 95% CI.
Received: February 14, 2015 Accepted: June 6, 2015 Published: June 29, 2015 Copyright: © 2015 Wang et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Data Availability Statement: All relevant data are within the paper and its Supporting Information files.
Results A total of 10 prospective studies were included in the final analysis. An increase in BMI of 5 kg/m2 was not associated with PD risk, with a summary RR of 1.00 (95% CI = 0.89-1.12). Results of subgroup analysis found similar results except for a week positive association in studies that adjusted for alcohol consumption (RR = 1.13, 95% CI = 0.99-1.29), and a week inverse association in studies that did not (RR = 0.90, 95% CI = 0.78-1.04). In a separate meta-analysis, no significant association between overweight (25 kg/m2 BMI 29.9 kg/m2), obesity (BMI30 kg/m2) or excess weight (BMI25 kg/m2) and PD risk was observed.
Funding: The authors have no support or funding to report.
Conclusion
Competing Interests: The authors have declared that no competing interests exist.
This meta-analysis does not support the notion that higher BMI materially increases PD risk. However, a week positive BMI-PD association that may be masked by confounders
PLOS ONE | DOI:10.1371/journal.pone.0131778 June 29, 2015
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Body Mass Index and Parkinson's Disease
still cannot be excluded, and future prospective studies with a good control for potential confounding factors are needed.
Introduction Obesity is a well-established risk factor for several metabolic and vascular disorders such as type 2 diabetes, coronary heart disease and stroke, some of which may be a contributor to Parkinson’s disease (PD)[1, 2]. However, the relationship between obesity and the occurrence of PD is unknown. A recent meta-analysis[3] of 12 case-control studies showed that PD patients had a significant lower BMI than controls. Nonetheless, patients with PD may have started to lose weight prior to the clinical diagnosis [4, 5], and a lower BMI in PD patients does not represent an inverse BMI-PD relationship. A very recent meta-analysis[6] including 3 case-control studies and 4 prospective studies reported that overweight (defined as 25 kg/m2BMI
Body Mass Index and Risk of Parkinson’s Disease: A Dose-Response Meta-Analysis of Prospective Studies Yun-Liang Wang1*, Yu-Tong Wang2, Jin-Feng Li1, Yu-Zheng Zhang1, Hong-Lei Yin1, Bing Han1 1 Department of Neurology, the 148 Central Hospital of PLA, Zibo, 255000, China, 2 School of Medicine, Henan University, Kaifeng, 475000, China * [email protected]
Abstract Background A number of epidemiologic studies examining the relationship between body mass index (BMI) and the future occurrence of Parkinson’s disease (PD) reported largely inconsistent findings. We conducted a dose-response meta-analysis of prospective studies to clarify this association. OPEN ACCESS Citation: Wang Y-L, Wang Y-T, Li J-F, Zhang Y-Z, Yin H-L, Han B (2015) Body Mass Index and Risk of Parkinson’s Disease: A Dose-Response MetaAnalysis of Prospective Studies. PLoS ONE 10(6): e0131778. doi:10.1371/journal.pone.0131778 Editor: Shahrad Taheri, Weill Cornell Medical College in Qatar, QATAR
Methods Eligible prospective studies were identified by a search of PubMed and by checking the references of related publications. The generalized least squares trend estimation was employed to compute study-specific relative risks (RR) and 95% confidence intervals (CI) for an increase in BMI of 5 kg/m2, and the random-effects model was used to compute summary RR and 95% CI.
Received: February 14, 2015 Accepted: June 6, 2015 Published: June 29, 2015 Copyright: © 2015 Wang et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Data Availability Statement: All relevant data are within the paper and its Supporting Information files.
Results A total of 10 prospective studies were included in the final analysis. An increase in BMI of 5 kg/m2 was not associated with PD risk, with a summary RR of 1.00 (95% CI = 0.89-1.12). Results of subgroup analysis found similar results except for a week positive association in studies that adjusted for alcohol consumption (RR = 1.13, 95% CI = 0.99-1.29), and a week inverse association in studies that did not (RR = 0.90, 95% CI = 0.78-1.04). In a separate meta-analysis, no significant association between overweight (25 kg/m2 BMI 29.9 kg/m2), obesity (BMI30 kg/m2) or excess weight (BMI25 kg/m2) and PD risk was observed.
Funding: The authors have no support or funding to report.
Conclusion
Competing Interests: The authors have declared that no competing interests exist.
This meta-analysis does not support the notion that higher BMI materially increases PD risk. However, a week positive BMI-PD association that may be masked by confounders
PLOS ONE | DOI:10.1371/journal.pone.0131778 June 29, 2015
1 / 12
Body Mass Index and Parkinson's Disease
still cannot be excluded, and future prospective studies with a good control for potential confounding factors are needed.
Introduction Obesity is a well-established risk factor for several metabolic and vascular disorders such as type 2 diabetes, coronary heart disease and stroke, some of which may be a contributor to Parkinson’s disease (PD)[1, 2]. However, the relationship between obesity and the occurrence of PD is unknown. A recent meta-analysis[3] of 12 case-control studies showed that PD patients had a significant lower BMI than controls. Nonetheless, patients with PD may have started to lose weight prior to the clinical diagnosis [4, 5], and a lower BMI in PD patients does not represent an inverse BMI-PD relationship. A very recent meta-analysis[6] including 3 case-control studies and 4 prospective studies reported that overweight (defined as 25 kg/m2BMI
