Final answer:
African Americans are at an increased risk for hypertension due to a combination of genetic predispositions, socioeconomic factors, and lifestyle choices.
Step-by-step explanation:
The ethnic background at increased risk for hypertension is African American. Studies, including one by Sims et al. (2012) published in the American Journal of Public Health, have shown that African Americans have a higher propensity for hypertension compared to other ethnic groups. This increased risk is often associated with both genetic predispositions and socioeconomic factors, including perceived discrimination which can elevate stress levels, thereby affecting blood pressure. In addition to genetic factors, lifestyle factors such as obesity, poor nutrition, lack of physical activity, and tobacco use contribute to hypertension risk in general.