New Genetic Risk Factors for Stroke Determined
New genetic risk factors for stroke have been identified, thereby tripling the number of gene regions known to affect stroke risk, according to a study published online ahead of print March 12 in Nature Genetics. Researchers conducted a multiancestry genome-wide-association meta-analysis in 521,612 individuals (67,162 with stroke) and discovered 22 new stroke risk loci, bringing the total to 32. In addition, the investigators found shared genetic variation with related vascular traits (eg, blood pressure, cardiac traits, and venous thromboembolism) at individual loci and using genetic risk scores and linkage-disequilibrium-score regression. Several loci had distinct association and pleiotropy patterns for etiological stroke subtypes. Eleven new susceptibility loci indicate mechanisms not previously implicated in stroke pathophysiology. The researchers prioritized risk variants and genes through bioinformatics analyses using functional datasets.
Malik R, Chauhan G, Traylor M, et al. Multiancestry genome-wide association study of 520,000 subjects identifies 32 loci associated with stroke and stroke subtypes. Nat Genet. 2018 Mar 12 [Epub ahead of print].
MS Medication Withdrawn Because of Safety Concerns
Citing concerns about safety, Biogen and AbbVie announced March 2 that they will be withdrawing daclizumab (Zinbryta) from worldwide markets. Daclizumab has known risks, so it was usually prescribed only for people with relapsing multiple sclerosis who had tried two or more other medications that had not worked well enough. Reports of inflammatory encephalitis and meningoencephalitis led the European Medicines Agency to initiate an Article 20 referral procedure. In such referrals, a medicine or class of medicines are scientifically assessed because of concerns over safety or quality. However, Biogen and AbbVie concluded that, because of the complex nature of these reports and how few patients were taking daclizumab, it would be difficult to characterize the nature of the medication’s harms and benefits, so the companies instead have decided to withdraw the medication from the market.
Many Elderly Patients With Epilepsy Receive Interacting Treatments
Many elderly patients with epilepsy receive combinations of nonepilepsy drugs (NEDs) and antiepileptic drugs (AEDs) that could interact, according to a study published February 7 in Epilepsia. Researchers retrospectively analyzed 2008–2010 Medicare claims for a random sample of beneficiaries age 67 and older. Prevalent cases had a diagnosis of epilepsy and took one or more AEDs. Incident cases had no seizure or epilepsy claim codes or AEDs in the preceding 365 days. Interacting pairs of AEDs and NEDs were identified by literature review. Logistic regression models were used to examine factors affecting the likelihood of interaction risk. Interacting drug pairs affected NED efficacy in 24.5% of incident cases and 39% of prevalent cases. Combinations affected AED efficacy in 20.4% of incident cases and 29.3% of prevalent cases.
Faught E, Szaflarski JP, Richman J, et al. Risk of pharmacokinetic interactions between antiepileptic and other drugs in older persons and factors associated with risk. Epilepsia. 2018;59(3):715-723.
Are Physically Fit Women at Reduced Risk for Dementia?
High cardiovascular fitness in midlife is associated with decreased risk of subsequent dementia, according to a study published online ahead of print March 14 in Neurology. Physicians examined a population-based sample of 1,462 women ages 38 to 60 in 1968. A subsample of 191 women with an average age of 50 took a maximal ergometer cycling test to measure their peak cardiovascular capacity. Over the following 44 years, participants were tested for dementia six times. By 2012, 44 of the women developed dementia. Approximately 5% of the highly fit women developed dementia, compared with 25% of moderately fit women, and 32% of the women with low fitness. The highly fit women were 88% less likely to develop dementia than the moderately fit women.
Hörder H, Johansson L, Guo X, et al. Midlife cardiovascular fitness and dementia: A 44-year longitudinal population study in women. Neurology. 2018 Mar 14 [Epub ahead of print].
Data on Geriatric TBI May Be Inadequate
Many older adults with traumatic brain injury (TBI) respond well to aggressive management and rehabilitation, which suggests that age and TBI severity alone are inadequate prognostic markers, according to a study published online ahead of print February 15 in the Journal of Neurotrauma. Researchers reviewed the literature on incident TBI sustained in older adulthood. They found few geriatric-specific TBI guidelines to assist with complex management decisions and concluded that TBI prognostic models do not perform optimally in this population. Major barriers in management of geriatric TBI include underrepresentation of older adults in TBI research, lack of systematic measurement of preinjury health that may predict outcome and response to treatment, and lack of geriatric-specific TBI common data elements. Investigators need to develop more age-inclusive TBI research protocols, said the authors.