The effects of the phenomenon known as the “stroke belt” may stretch beyond its geographic borders. People born in the Southeast not only have a higher risk of dying from stroke as adults, but they carry the increased risk of stroke with them when they relocate to another region as adults, according to a new study.
For the study, published in the December 1 issue of Neurology, researchers examined data from the 1980, 1990, and 2000 national death records for people age 30 to 80 who were born and lived in 49 states. Stroke death rates were calculated by linking this information to US census information. The stroke belt was defined as seven Southern states: North Carolina, South Carolina, Georgia, Tennessee, Arkansas, Mississippi, and Alabama.
Researchers then broke down the subjects into four groups: those who were born and lived in the stroke belt as adults, people born in the stroke belt but who did not live there as adults, those born outside the stroke belt but who lived there as adults,and those who were not born or lived in the stroke belt.
Those who were born in the stroke belt and then moved away had a higher risk of death caused by stroke than individuals who were born outside the area and remained outside the region as adults. This was the case with those who were born elsewhere but later moved to the stroke belt, as well. At the highest risk were those who were both born in the stroke belt and lived there as adults.
As an example, the authors note that both Caucasians and African-Americans who were born and lived in the stroke belt as adults had a 34 percent higher risk of dying from stroke in 2000 compared to people of the same gender, age, and race who were born and lived outside of the stroke belt in the same year. The death rate related to stroke was 74 per 100,000 for people who were born in the stroke belt and lived there in the year 2000, but just 47 per 100,000 for those who were not born in the stroke belt and did not live there in the year 2000, although this inequality partially reflects differences in age and race.
The authors conclude: “Elevated stroke mortality was associated with both SB birth and, independently, SB adult residence, with the highest risk among those who lived in the SB at birth and adulthood.” Compared to those living outside the region at birth and adulthood, odds ratios for SB residence at birth and adulthood for black subjects were 1.55 (95 percent confidence interval 1.28, 1.88) in 1980, 1.47 (1.31, 1.65) in 1990, and 1.34 (1.22, 1.48) in 2000. Comparable odds ratios for white subjects were 1.45 (95 percent confidence interval 1.33, 1.58), 1.29 (1.21, 1.37), and 1.34 (1.25, 1.44). Patterns were similar for every race, sex, and age subgroup examined.
"Our results cannot pinpoint a specific explanation, but they are consistent with other research suggesting that the roots of stroke risk begin in childhood or even infancy,” said study author M. Maria Glymour ScD, of Harvard School of Public Health, in a release. “Efforts to reduce the incidence of fatal stroke may need to consider how underlying physiologic changes accumulate from early life.” She added that it is possible that where a person lives affects stroke risk through socioeconomic conditions, social stressors, environmental factors, or access to preventive medical care.
"Many important behaviors such as diet, physical activity, and smoking are shaped by childhood social conditions,” Glymour says. “Future long-term national studies with detailed information on when people moved are needed to help show whether those who move may have different patterns of risk factors and also identify more precisely at what point in life stroke risk begins to build. This will help us understand how to reduce stroke for people living in every region of the country."
First Gene Therapy for AD to Begin
The first Phase II clinical trial to test gene therapy treatment for AD is set to begin. The experimental treatment utilizes a viral-based gene transfer system, CERE-110, that makes Nerve Growth Factor (NGF). CERE-110 was previously studied in animals, where it reversed brain degeneration in aged monkeys and rats. For this study, CERE-110, will be injected by a neurosurgeon directly into the nucleus basalis of Meynert (NBM) of the brain, an area where neuronal death occurs in Alzheimer's patients.
A Phase I study in Alzheimer's patients found increases in brain metabolism in several cortical regions of the brain at six- and 12-month follow-up in some of the participants. With follow-up ranging from six months to more than four years post-treatment, there have been no side effects thought to be caused by CERE-110.
Participants in the two-year Phase II study will be randomly placed into one of two groups, with half receiving CERE-110 via neurosurgery and half receiving placebo surgery without any cranial injections.
Phase III Trial Favorable for Post-Stroke Drug
Results published in October's Clinical Neuropharmacology reveal that Merz Pharmaceuticals' NT 201 (botulinum toxin type A free from complexing proteins), also known by the brand name Xeomin in Europe and Canada, was statistically significantly more efficacious than placebo for the treatment of patients with post-stroke upper limb spasticity.
For the study, 148 patients with an Ashworth Scale score of 2 or higher for wrist and finger flexors and at least moderate disability in their principal therapeutic target of the Disability Assessment Scale were treated either with NT 201 (median, 320U) or placebo and followed up for up to 20 weeks. Researchers found that a significantly higher percentage of patients treated with NT 201 were responders (improvement of ≥ 1 point in the Ashworth Scale score), compared to placebo four weeks after treatment in wrist flexors (odds ratio, 3.97; 95 percent confidence interval, 1.9- 8.3; P< 0.001, intent to treat). For all treated flexor muscle groups, statistically significant odds ratios in favor of NT 201 were observed at week four (P ≤ 0.009). Statistically significant results in favor of NT 201 were observed at all post-injection visits until week 12 in the principal therapeutic target (P ≤ 0.005), in the global assessment of efficacy (P < 0.001), and in some tasks of the Carer Burden Scale (P < 0.05).