Higher diastolic blood pressure (DBP) is cross-sectionally and independently associated with cognitive impairment, investigators reported in the August 25 Neurology. The association was found after adjusting for economic factors, depressive symptoms, and current use of any antihyperintensive medication in 30,228 black and white men and women (45 and older). “An increment of 10 mm Hg in DBP was associated with a 7% higher odds of cognitive impairment,” the researchers stated. “No independent association was identified between impaired cognitive status and systolic blood pressure (odds ratio [OR], 1.02) or pulse pressure (OR, 0.99).” No evidence of nonlinear relationships between any blood pressure components and impaired cognitive status was found.
Use of smokeless tobacco products is associated with risk of fatal myocardial infarction and stroke, according to the August 18 online BMJ. Investigators from Sweden and the United States conducted a meta-analysis of 11 observational studies (primarily including men). “Eight risk estimates were available for fatal myocardial infarction: the relative risk for ever use of smokeless tobacco products was 1.13 and the excess risk was restricted to current users,” the investigators stated. “The relative risk of fatal stroke, on the basis of five risk estimates, was 1.40.” Increased risk of fatal myocardial infarction was shown in studies from both geographic locations. “Data on dose-response were limited but did not suggest a strong relation between risk of dying from either disease and frequency or duration of use of smokeless tobacco products,” the researchers noted.
A mutation in transcriptional repressor hDEC2-P385R is associated with a human short sleep phenotype, according to a study in the August 14 issue of Science. Investigators found that within a small extended family, two members with the mutation had lifelong shorter daily sleep requirements than most persons. The researchers then genetically engineered mice and fruit flies to express the mutated human gene and studied its impact on behavior and sleep patterns. “Activity profiles and sleep recordings of transgenic mice carrying this mutation showed increased vigilance time and less sleep time than control mice in a zeitgeber time- and sleep deprivation-dependent manner,” the study authors stated. “These mice represent a model of human sleep homeostasis that provides an opportunity to probe the effect of sleep on human physical and mental health.”
The FDA has approved Extavia for reducing the frequency of clinical exacerbations in patients with relapsing forms of multiple sclerosis (MS). It is also indicated in patients who have had a first clinical episode of MS and have features consistent with the disease as shown by MRI. Extavia is a new branded version of interferon beta-1b and the same medicinal product as Betaseron. Interferon beta-1b has been shown to reduce annualized relapse rates by 34%, with patients nearly twice as likely to remain relapse-free for more than two years, compared with those receiving placebo. Injection site necrosis has been reported in 4% of patients in controlled trials, and anaphylaxis has been reported as a rare complication of interferon use. Extavia is marketed by the Pharmaceuticals Division of Novartis (East Hanover, NJ) and is expected to be available this fall.
White matter hyperintensity (WMH) is more strongly related to amnestic mild cognitive impairment (aMCI), and infarcts are more strongly related to nonamnestic MCI, according to a study in the August 11 issue of Neurology. Researchers investigated the relationship of WMH volume and infarcts in brain per MRI to MCI in 679 elderly persons without dementia. WMH was adjusted for total cranial volume, and MCI was defined using the Peterson criteria. WMH was more strongly related to aMCI (OR, 1.9) than nonamnestic MCI (OR, 1.6). However, infarcts were more strongly related to nonamnestic MCI (OR, 2.7) than aMCI (OR, 1.4). “In secondary analyses using continuous cognitive scores as outcomes, WMH, but not infarcts, were related to memory, while infarcts were more strongly related with nonamnestic domains,” the researchers noted. “The nature of WMH in aMCI requires further study,” they concluded.
Intellectually normal children with seizures had neuropsychologic deficits at seizure onset, per a study published in the August 18 issue of Neurology. Investigators compared 282 children between ages 6 and 14 who had an IQ of 70 or higher and with a first recognized seizure to 147 healthy siblings. “In this intellectually normal cohort, 27% with just one seizure and up to 40% of those with risk factors exhibited neuropsychologic deficits at or near onset,” the researchers stated. Risk factors included multiple seizures (ie, second unprovoked seizure, odds ratio [OR], 1.96), use of antiepileptic drugs (OR, 2.27), symptomatic/cryptogenic etiology (OR, 2.15), and epileptiform activity on the initial EEG (OR, 1.96). Increased odds for neuropsychologic impairment were associated with absence epilepsy (OR, 2.00).