Loss of a Child and the Risk of Amyotrophic Lateral Sclerosis
 

Loss of a Child and the Risk of Amyotrophic Lateral Sclerosis


Fang Fang1, Weimin Ye1, Katja Fall1, Mats Lekander2, Hans Wigzell3, Pär Sparén1, Hans-Olov Adami1,4 and Unnur Valdimarsdóttir1,5
1 Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden
2 Department of Clinical Neuroscience and Osher Center for Integrative Medicine, Karolinska Institutet, Stockholm, Sweden
3 Microbiology and Tumor Biology Center, Karolinska Institutet, Stockholm, Sweden
4 Department of Epidemiology, Harvard School of Public Health, Boston, MA
5 Centre for Public Health Sciences, Faculty of Medicine, University of Iceland, Reykjavík, Iceland

Correspondence to Dr. Fang Fang, Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Box 281, 171 77 Stockholm, Sweden (e-mail: fang.fang@ki.se).

Received for publication June 19, 2007. Accepted for publication September 11, 2007.

Between 1987 and 2005, the authors conducted a case-control study nested within the entire Swedish population to investigate whether loss of a child due to death is associated with the risk of amyotrophic lateral sclerosis (ALS). The study comprised 2,694 incident ALS cases and five controls per case individually matched by year of birth, gender, and parity. Odds ratios and their corresponding 95% confidence intervals for ALS were estimated by using conditional logistic regression models. Compared with that for parents who never lost a child, the overall odds ratio of ALS for bereaved parents was 0.7 (95% confidence interval (CI): 0.6, 0.8) and decreased to 0.4 (95% CI: 0.2, 0.8) 11–15 years after the loss. The risk reduction was also modified by parental age at the time of loss, with the lowest odds ratio of 0.4 (95% CI: 0.2, 0.9) for parents older than age 75 years. Loss of a child due to malignancy appeared to confer a lower risk of ALS (odds ratio = 0.5, 95% CI: 0.3, 0.8) than loss due to other causes. These data indicate that the risk of developing ALS decreases following the severe stress of parental bereavement. Further studies are needed to explore potential underlying mechanisms.


amyotrophic lateral sclerosis; etiology; stress



http://aje.oxfordjournals.org/cgi/co...hort/167/2/203
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Abbreviations: ALS, amyotrophic lateral sclerosis; ICD, International Classification of Diseases