African Caribbean women had worse levels of two blood biomarkers linked to Alzheimer’s disease than men from the same region, according to a pilot study conducted by researchers at Pitt’s School of Public Health. Led by Iva Miljkovic, MD, PhD, associate professor of epidemiology, the study was published in the April 12 issue of Alzheimer's & Dementia: Translational Research & Clinical Interventions, a journal of the Alzheimer’s Association.
Study researchers, who also included Caterina Rosano, MD, MPH, professor of epidemiology, and colleagues from the Department of Psychiatry at Pitt’s School of Medicine, measured blood biomarkers linked to brain health in men and women enrolled in the Tobago Health Study, a longitudinal project launched by the School of Public Health in 1997.
“We are seeing very high rates of hypertension, diabetes and obesity across all of the Caribbean islands, particularly among women,” says Miljkovic. “There is also a high prevalence and burden of dementia that is even greater than in the U.S., which is really concerning.”
The study included 309 Tobagonian women and men and found significant differences in serum levels of two blood biomarkers – phosphorylated tau-181, a highly specific marker for Alzheimer’s disease, and amyloid-beta 42/40, linked to the disease’s pathology – among the women participants.
Although previous studies noted a link between cardiometabolic diseases, such as hypertension and diabetes, to the prevalence of Alzheimer’s disease, the study researchers couldn’t find any risk factors among the women participants to explain their higher blood biomarker levels.
“We were absolutely certain that higher cardiometabolic burden among the women in the study would be associated with the observed higher burden of Alzheimer’s disease pathology measured by blood biomarkers, but we couldn't find any significant links,” says Miljkovic. “We realized we need more data on cardiometabolic disorders and when they are occurring. It may be possible that they are starting in women at a much younger age.”
Moving forward, the study team plans to lower the age of the study participants – the average age of participants in the current study was 70 years – and to focus on measuring blood biomarkers in younger women. They also plan to look at sleep duration and quality and its association with cardiometabolic disorders and cognitive functioning, as well as diet, physical activity and sedentary behavior.
There is very little information on Alzheimer’s disease among Caribbean populations with African ancestry, continues Miljkovic. “Even though Caribbean women appear to be at very high risk for Alzheimer’s and dementia, they are an underrepresented and understudied group.”
The research is also particularly relevant to U.S. populations given the large burden of cardiometabolic disorders among Caribbeans who have immigrated, she adds.
The study was funded by a grant from the U.S. National Institutes of Health.
-Clare Collins