Abstrak: A recent meta-analysis of 7 genome-wide association studies on early balding (alopecia) revealed single nucleotide polymorphism variants in the region of the amyotrophic lateral sclerosis (ALS) gene TAR DNA-binding protein 43 (TARDBP/TDP-43). We therefore explored the association of early-onset alopecia and ALS in the Health Professionals Follow-up Study, a large cohort of 51,529 US men. In 1992, the participants (then aged 46-81 years) were asked to report their hair line pattern at age 45 years. During the follow-up period (1992-2008), 42 men were diagnosed with ALS. Of those, 13 had reported no alopecia, 18 had reported moderate alopecia, and 11 had reported extensive alopecia at age 45 years. Those who reported extensive alopecia had an almost 3-fold increased risk of ALS compared with those who reported no alopecia (relative risk = 2.74, 95% confidence interval: 1.23, 6.13). Furthermore, we observed a linear trend of increased risk of ALS with increasing level of balding at age 45 years (Ptrend = 0.02). In conclusion, men with early-onset alopecia seem to have a higher risk of ALS. The mechanisms underlying this association deserve further investigation.

Abstrak: In this study, we examined the relationship between exposure to siblings and 1) the risk of age-related macular degeneration (AMD) and 2) C-reactive protein levels. We retrospectively analyzed pooled cross-sectional data from 2 studies: the Cardiovascular Health and Age-Related Maculopathy Study (2001-2002) and the Age-Related Maculopathy Statin Study (2004-2006). Associations between number of siblings and AMD were assessed by using multinomial logistic regression. Associations between number of siblings and C-reactive protein levels were examined by using a generalized linear model for γ distribution. A higher number of younger siblings was associated with significantly lower odds of early AMD in those with a family history of AMD (odds ratio = 0.2, 95% confidence interval: 0.1, 0.8) (P = 0.022) but was unrelated to AMD for those who had no family history of the disease (odds ratio = 1.0, 95% confidence interval: 0.9, 1.2) (P = 0.874). A higher number of younger siblings correlated with lower C-reactive protein levels (β = -0.19, 95% confidence interval: -0.38, -0.01) (P = 0.036). This supports the theory that immune modulation contributes to AMD pathogenesis and suggests that exposure to younger siblings might be protective when there is a family history of AMD.

Abstrak: In a national cohort comprising 1.5 million Danes born from 1966 to 1992, we studied the association between childhood socioeconomic status (SES) and the risk of multiple sclerosis (MS) from 1981 to 2007 using information about household income and parental educational levels at the person's 15th birthday. The association between childhood SES and MS was evaluated using MS incidence rate ratios with 95% confidence intervals obtained in log-linear Poisson regression analyses. We found no strong association between childhood SES and MS but did observe a tendency toward a reduced risk of MS among children from households with more highly educated parents, particularly mothers. Children whose mothers had a secondary (rate ratio = 0.95, 95% confidence interval: 0.86, 1.04) or higher (rate ratio = 0.86, 95% confidence interval: 0.76, 0.97) education had reduced risks of MS (5% and 14%, respectively) compared with children of mothers with a basic education (P for trend = 0.02). Results were practically unchanged in an analysis restricted to persons aged 15-29 years, among whom the possible effect of own SES on MS risk is considered limited. Overall, SES in childhood seems of no major importance for the subsequent risk of MS; however, offspring of well-educated mothers may be at a slightly reduced risk of MS.