Angeliki Lambrou

Background: Arsenic exposure has been linked to epigenetic modifications such as DNA methylation in in-vitro and animal studies. This association has also been explored in highly exposed human populations, but studies among populations environmentally exposed to low arsenic levels are lacking. Methods: We evaluated the association between exposure to arsenic, measured in toenails, and blood DNA methylation in Alu and Long Interspersed Nucleotide Element-1 (LINE-1) repetitive elements in elderly men environmentally exposed to low levels of arsenic. We also explored potential effect modification by plasma folate, cobalamin (vitamin B₁₂), and pyridoxine (vitamin B₆). The study population was 581 participants from the Normative Aging Study in Boston, of whom 434, 140, and 7 had 1, 2, and 3 visits, respectively, between 1999–2002 and 2006–2007. We used mixed-effects models and included interaction terms to assess potential effect modification by nutritional factors. Results: There was a trend of increasing Alu and decreasing LINE-1 DNA methylation as arsenic exposure increased. In subjects with plasma folate below the median (<14.1 ng/mL), arsenic was positively associated with Alu DNA methylation (β = 0.08 [95% confidence interval = 0.03 to 0.13] for one interquartile range [0.06 μg/g] increase in arsenic), whereas a negative association was observed in subjects with plasma folate above the median (β = −0.08 [−0.17 to 0.01]). Conclusions: We found an association between arsenic exposure and DNA methylation in Alu repetitive elements that varied by folate level. This suggests a potential role for nutritional factors in arsenic toxicity.

Introduction: Some persons with Charles Bonnet syndrome (CBS) suffer significant anxiety because of their visual hallucinations, while others do not. The aim of the study presented here was to compare levels of anxiety in persons with low vision with and without CBS. Methods: This retrospective study compared the level of anxiety in 31 persons with CBS and 26 persons without CBS. These participants were recruited voluntarily from senior centers, a low vision support group, and an ophthalmology practice in October and November 2010. All were administered surveys to measure cognitive function (TICS: Telephone Interview for Cognitive Status), anxiety (STAI: State and Trait Anxiety Inventory), and general health (GHQ: General Health Questionnaire). The responses of the two groups were compared. Results: The participants with CBS exhibited higher levels of anxiety than did those without CBS on both the STAI and GHQ surveys, but this difference did not reach statistical significance. The proportion of participants who were pharmacologically treated for anxiety was four times higher in the CBS cohort than in the cohort without CBS: CBS: 36% (11 of 31), those without CBS: 9% (2 of 22), p value = .03. The participants with CBS who took medication for anxiety scored higher on the STAI and GHQ than did those without CBS, but these differences did not reach statistical significance. Discussion: The findings indicate that persons with CBS have higher levels of anxiety than do those without CBS. The highest levels of anxiety occurred in the participants with CBS who were being treated for anxiety with medications. Although the findings did not reach statistical significance, they suggest that anxiety is an important consideration when treating individuals with CBS. Implications for practitioners: Persons with CBS who have difficulty tolerating visual hallucinations may benefit from interventions that are directed at managing anxiety, such as counseling, visual rehabilitation, and pharmacological treatment.