Diabetes disproportionately impacts underrepresented minorities, who have a higher prevalence of diagnosis and complication rates of diabetes compared to white individuals. Despite this, the prevalence of metabolic syndrome – the proportion of a population that at any given time has a group of five conditions that can lead to health problems like heart disease and diabetes – is similar across races.
Why?
“Traditional health markers for metabolic syndrome – high blood glucose, low levels of HDL which is known as the “good” cholesterol, a high body mass index, high levels of LDL which is known as the “bad” cholesterol, and elevated triglycerides – were developed from studies including only men of Western European descent,” says biochemistry assistant professor Judith “Judi” Simcox. “But what works for them doesn’t work for others.”
For example, a woman’s body mass index (BMI) isn’t indicative of whether she is likely to develop metabolic disease, and correlations between HDL, blood pressure and metabolic syndrome don’t hold for African Americans. Scientists need to identify and develop more equitable biomarkers for metabolic syndrome, Simcox says. Then, new interventions to prevent and treat diabetes that work for more people can be developed.
Simcox’s research will identify and classify previously unstudied lipids to determine whether these could be possible biomarkers for metabolic disease in women and underrepresented minorities. Lipids are a class of biomolecules with a diverse array of functions essential for life, and scientists have yet to characterize thousands of lipids that appear in biological samples obtained from humans.
In their most recent study, Simcox and students in her lab took plasma samples from individuals participating in two longitudinal studies based at UW-Madison and processed the samples using mass spectrometry, a technique that measures the mass-to-charge ratio of ions to identify and quantify molecules in samples. The scientists identified 529 lipids in Caucasians and 137 in African Americans that might inform diagnoses of metabolic syndrome, and over 100 lipids that overlapped between the two groups of people. Further analysis identified 76 lipids that predict metabolic syndrome and that could help diagnose metabolic syndrome in Black women.
These findings have opened new lines of investigation for Simcox and her team. Their next steps will be to learn more about the lipids they identified: can they be clinically measured? What cells or tissues are producing the lipids, and how are they circulating throughout the body? Are these lipids precursors to inflammation, and could an inflammatory panel be used as a biomarker for metabolic syndrome?
“One of the great things about UW-Madison is that it is the head of giant longitudinal population studies like the Midlife in the United States study and the Survey of the Health of Wisconsin, so we can perform studies like this one,” Simcox said.
Simcox and her collaborators may soon be able to explore their questions on an even larger scale and with more collaborators. Last year, Simcox and Dudley Lamming, a professor in the Department of Medicine, received a UW2020: WARF Discovery Initiative Award. Since then, they have established and staffed research facilities and funded twelve pilot projects like Simcox’s to bolster innovative research in diabetes, obesity and metabolism. These projects will help advance diabetes research and support a new Comprehensive Diabetes Center at UW–Madison.
Written by Catherine Steffel, Ph.D. Direct questions and media inquiries to communications@biochem.wisc.edu.