Uncontrolled Hypertension More Likely in Black Americans With MS
Black Americans with multiple sclerosis (MS) have a higher chance of having uncontrolled high blood pressure (hypertension), despite being more likely to receive anti-hypertensive medication than white patients, a large study found.
Further studies are needed to confirm these findings and identify the underlying causes of these racial discrepancies, the researchers noted.
The study, “Racial disparities in hypertension management among multiple sclerosis patients,” was published in Multiple Sclerosis and Related Disorders.
Hypertension is common among MS patients and may affect how the disease progresses over time. It’s been linked to a more rapid onset of movement problems and an increase in symptoms of depression.
Previous research in the U.S. suggests Black Americans with MS more commonly have hypertension than white Americans. Black Americans in general also are more likely to have uncontrolled and treatment-resistant hypertension compared with whites.
Treatment-resistant hypertension occurs when blood pressure remains high despite treatment with anti-hypertensive medications.
“Disparities in care due to structural racism may lead to suboptimal hypertension detection and control in Black American MS patients,” the researchers wrote. But “the extent of uncontrolled hypertension in MS patients and the impact of racial disparities on hypertension management in this population are unknown.”
A team of researchers in the U.S. analyzed data from American adults with MS who were participating in MS PATHS, a Biogen-sponsored registry that collects clinical and demographic data from MS patients over time.
Across the seven participating U.S. centers, there were 10,673 MS patients with hypertension — classified as two or more blood pressure readings of at least 140/90 millimeters of mercury (mmHg) between May 2015 and November 2020.
A total of 8,679 (81.3%) patients were white, 1,442 (13.5%) were Black, and the remaining 552 (5.2%) were of other races. They were followed for an average of 2.4 years and had a mean of 6.4 blood pressure measurements.
Results showed that despite being a mean of 3.5 years younger (45.7 vs. 49.2 years), Black Americans had a 31% higher chance of having uncontrolled hypertension compared with white Americans. This figure was adjusted for potential influencing factors, including age, sex, disease duration, MS type, insurance, smoking status, and education level.
Black American patients were also 19% more likely to have a milder form of hypertension, classified as two or more blood pressure readings of at least 130/80 mmHg.
The mean systolic blood pressure was 1.84 mmHg higher in Black American patients than white Americans and the mean diastolic blood pressure was 1.28 mmHg higher. Systolic blood pressure refers to pressure pushing against artery walls when the heart contracts to pump blood, while diastolic blood pressure is the force exerted on artery walls as the heart relaxes between heartbeats.
Black Americans with uncontrolled hypertension were 68% more likely to be on anti-hypertensive treatment and took an average of 0.61 more of such medications than white Americans.
“While one hypothesis is that Black Americans with MS are more prone to treatment-resistant hypertension, another hypothesis is that anti-hypertensive dosages are not being adjusted properly for Black Americans or that there are discrepancies in the frequency of follow-up with primary care physicians,” the researchers wrote.
Among all patients, older age, having diabetes, and hyperlipidemia (abnormally high levels of fatty molecules in the blood) were predictors of using anti-hypertensive medications in all patients with uncontrolled hypertension. These links were more pronounced among Black Americans.
This suggests that “patients who have more routine visits are more likely to have underlying hypertension detected and treated,” the team wrote, adding that “Black Americans have higher rates of [diabetes] than White Americans, which is probably caused more by socioeconomic factors than genetics.”
These findings highlight that “uncontrolled hypertension is a significant problem in MS patients and that there are also prominent racial disparities in its prevalence,” the research team wrote.
“MS patients should be encouraged to see their primary care physician for more than a yearly physical, even in the absence of other underlying health conditions.” the researchers said. “This is especially true for Black Americans, in whom hypertension may be less well controlled, which could contribute to a more severe course of MS.”
“Whether uncontrolled hypertension more significantly impacts MS prognosis in Black versus White Americans is an important research question that warrants further investigation,” they wrote.
They also noted that further research is “needed to uncover the drivers and mediators of the observed racial disparities and to determine if Black MS patients with hypertension are more likely to be inadequately treated, and if so, what approaches to patient and physician behaviors can rectify this problem.”