Preliminary findings of a longitudinal study aimed at better understanding geographic and ethnic differences in stroke incidence, which began enrolling patients 20 years ago, has identified a metabolite biomarker called gluconic acid. The biomarker is associated with high blood pressure, increased risk of ischemic stroke, eating a Southern diet, lower level of education, and lack of exercise among Black adults.
“We have identified a biomarker called gluconic acid that we believe is a lifestyle-related biomarker, providing a direct link to diet and exercise,” said Naruchorn Kijpaisalratana, MD, PhD, lead study author and a research fellow in neurology at Massachusetts General Hospital. “Gluconic acid may be considered as a dietary-related oxidative stress marker due to its availability in food, potentially produced by the gut microbiome, and related to diseases with oxidative stress. We think that this biomarker may provide a pathway to improve diet and exercise habits to help prevent a future stroke.”
The study analyzed health data of more than 2,000 people participating in the Reasons for Geographic and Racial Difference in Stroke (REGARDS) study. The ongoing REGARDS study has enrolled more than 30,000 Black and White adults since 2003 from the Southeastern U.S., known as the “stroke belt,” and other states across the country. The aim of REGARDS is to investigate the reasons for the high rate of stroke among African Americans.
The latest analysis from the study included 1,075 ischemic stroke survivors with a mean follow-up period of 7 years. Of those, 439 were Black adults and 636 were White adults with a median age of 70 years and roughly equally split among men and women. A random comparison group drawn from study participants consisted of nearly 1,000 Black adults and White adults who had not had a stroke (mean age of 65 years; 55% female).
Using the samples collected between 2003 and 2007 the researchers extracted and measured levels of 162 metabolites in the blood of the participants. Important findings of the analysis found:
- Of the 162 metabolites measured, elevated levels of the metabolite gluconic acid were found in Black adults who had high blood pressure but not their white peers with high blood pressure.
- Black adults with the highest gluconic acid levels were 86% more likely to have high blood pressure.
- Black adults with the highest gluconic acid levels had a 53% increased risk of ischemic stroke. No such association was found for white participants.
- Gluconic acid accounted for 25% of the association between high blood pressure and stroke among Black adults.
- In Black adults, after adjusting for multiple factors, a higher level of gluconic acid was associated with a Southern diet (foods high in added fats, fried foods, processed meats and sugary drinks), a lower level of education, and a lack of exercise.
Since gluconic acid is a lifestyle biomarker, the researchers envision that it could be use in the future to help measure the effects for patients of adding exercise, or altering their diet to reduce stroke risk.
“In the future, we envision that a metabolite like gluconic acid may be used as a biomarker to inform health care professionals whether the patient is eating healthy enough or exercising enough,” Kijpaisalratana said. “A biomarker like gluconic acid may point individuals toward more targeted guidance for stroke prevention.”
The investigators noted that a limitation of their research was that participants had high blood pressure high blood pressure at the beginning of the study, which prevent them from researchers tracking the risk as it developed.