Women with Down syndrome who experienced early menopause were almost twice as likely to develop dementia at a younger age than those who entered menopause later, according to research in the January Journal of Alzheimer’s Disease. In a prospective longitudinal cohort study of dementia and mortality in women with Down syndrome, researchers followed 85 postmenopausal subjects for an average of 4.3 years and found a significant correlation between the age at menopause onset and age at diagnosis of dementia. Subjects with an earlier onset of menopause had a 1.8-fold increased risk of dementia. In addition, women who experienced menopause earlier had a twofold increased risk of dying younger.
White, elderly cancer survivors have a reduced risk of developing Alzheimer’s disease, as reported in the January 12 Neurology. Conversely, patients with Alzheimer’s disease have a reduced cancer risk, investigators found. In a prospective cohort study of 3,020 subjects ages 65 and older, the presence of Alzheimer’s disease was associated with a reduced risk of cancer hospitalizations, after adjustments for demographic and other factors. Prevalent cancer was also associated with a reduced risk of Alzheimer’s disease among white subjects after the researchers adjusted for demographics, number of apolipoprotein ε4 alleles, hypertension, diabetes, and coronary heart disease. The opposite was found in minorities, although the sample size was considered too small. No significant association was found between cancer and vascular dementia.
Ginkgo biloba did not preserve cognitive function any better than a placebo, per a study in the December 23, 2009, JAMA. In the randomized, double-blind, placebo-controlled Ginkgo Evaluation of Memory study, researchers at six academic medical centers in the US tracked 3,069 community-dwelling subjects ages 72 to 96 years for an average of 6.1 years. Subjects were given either a twice-daily dose of 120 mg extract of Ginkgo biloba or a placebo. Cognition was measured as rates of change over time in the Modified Mini-Mental State Examination, the cognitive subscale of the Alzheimer Disease Assessment Scale (ADAS-Cog), and neuropsychologic domains of memory, attention, visual-spatial construction, language, and executive functions. Investigators found no significant difference in cognitive decline between the herb and placebo.
A decreased ability to smell is common in patients with Alzheimer’s disease and may be a useful early diagnostic tool, researchers reported in the January 13 Journal of Neuroscience. The study linked olfactory dysfunction with an accumulation of amyloid-β protein in Alzheimer’s disease model mice. “The usefulness of olfactory screens to serve as informative indicators of Alzheimer’s is precluded by a lack of knowledge regarding why the disease impacts olfaction,” the study authors stated. The investigators assayed olfactory perception and amyloid-β deposition in the genetically engineered mice and found that amyloid-β pathology first occurred in an area of the brain responsible for smelling. Mice with higher concentrations of amyloid-β also displayed olfactory dysfunction. Researchers noted the “odor cross-habitation test [was] a powerful behavioral assay…[which] may serve to monitor the efficacy of therapies aimed at reducing amyloid-β.”
The Lancet has retracted the 1998 paper by Wakefield et al that suggested a link between autism and the childhood measles, mumps, and rubella (MMR) vaccine. The retraction, published in the February 2 online issue, follows a judgment by the UK General Medical Council’s Fitness to Practice Panel on January 28. “It has become clear that several elements of the 1998 paper by Wakefield et al are incorrect,” the editors wrote. “In particular, the claims in the original paper that children were ‘consecutively referred’ and that investigations were ‘approved’ by the local ethics committee have been proven to be false.” In 2004, 10 of the original authors retracted parts of the study, stating, “in this paper no causal link was established between MMR vaccine and autism as the data were insufficient.”
Advanced maternal age may be linked to an increased risk of autism, researchers reported in the February 8 online Autism Research. In a study of 12,159 cases of autism from a pool of almost 5 million births between 1990 and 1999, the investigators found a monotonic increased risk of autism related to advancing maternal age (40 and older) regardless of paternal age. However, the study authors noted fathers aged 40 and up who mated with women younger than 30 also had an increased risk of autistic offspring, compared with men in their mid- to late-20s. Yet when the mother was older than 30 and the father was 40 or older, the associated autism risk was similar to that of younger men. The investigators also noted that the “recent trend towards delaying childbearing contributed approximately a 4.6% increase in autism diagnoses in California over the decade.”