(Reuters Health) – Living with moderate or high stress levels year after year may increase the risk of high blood pressure, suggests U.S. research focused on African Americans. Among more than 1,800 participants in a large, long-term health study in Jackson, Mississippi, researchers found that nearly half developed high blood pressure, or hypertension, over an average seven-year follow-up. About 30% of new diagnoses happened after a period of low stress, about 35% after years of moderate stress and almost 40% after a period of chronic high stress. “African Americans who reported high levels of perceived stress over time were more likely to develop hypertension compared to those who consistently reported low stress,” said Tanya Spruill of the departments of population health and medicine at the NYU School of Medicine in New York City, who led the study. And this was independent of traditional risk factors, including age, obesity and smoking, Spruill said in an email. The African American community already faces a high burden of hypertension, and also of chronic stressors like discrimination and low socioeconomic status, Spruill’s team notes in the Journal of the American Heart Association. When the 1,829 participants in the current analysis attended the first of three assessments, all had normal blood pressure. At that first visit, between 2000 and 2004, participants had physical exams and answered interview questions about their lives. Follow-up phone interviews happened every year, and return visits for exams and in-person interviews took place in 2005-2008 and in 2009-2012. Between 2005 and 2012, 48.5% of participants were newly diagnosed with high blood pressure. After accounting for other hypertension risk factors like obesity or smoking, Spruill’s team calculated that prolonged moderate stress between exam visits raised the risk of a new high blood pressure diagnosis at the next exam by 15% compared to low or no stress. Chronic high stress raised that risk by 22%. “Few prior studies have included significant numbers of African Americans,” said Spruill, adding the large community-based sample and yearly reviews of stress were important because stress levels fluctuate. The onset of hypertension was somewhat stronger in women, but the difference was small and might have been due to chance, the researchers note. “Still, there is evidence that women experience different types of stressors than men and respond differently,” Spruill said. This could be because women have pivotal roles as caregivers and heads of households in African-American society, said Dr. George E. Matthews, the SUNY assistant professor of medicine at Jacobs School of Medicine and Biomedical Sciences at the University at Buffalo in New York. “Further research is needed to identify which psychosocial stressor may be contributing to the risk among women,” Matthews, who was not involved in the study, told Reuters Health by email. The study did not examine why people felt stressed. “It could be the environment, diet, exposure to issues in their life experience,” noted Dr. Clyde Yancy, national spokesperson for the American Heart Association and chief of cardiology at Northwestern University in Chicago. It could also be “something they were exposed to, like violence and trauma,” he noted in a phone interview. The study was not designed to determine how stress might raise hypertension risk and cannot say whether reducing stress would lower that risk, Spruill said. Even so, the results highlight the need for culturally-sensitive stress management interventions for African Americans, the study authors write. With hypertension becoming a worldwide burden, this data may apply wherever stress is a component of life and work experiences, Yancy said. SOURCE: bit.ly/2PBSuNi Journal of the American Heart Association, online October 16, 2019.