By Brenda L. Mooney
SILVER SPRING, MD — Military research is raising a new question about an old issue: Why do African-Americans have higher incidence rates of hypertension compared with servicemembers of other races and ethnicities despite equitable access to healthcare within the armed forces?
According to a report in Medical Surveillance Monthly Report, black, non-Hispanic servicemembers had a rate of 24.4 new diagnoses of hypertension per 1,000 person-years (p-yrs), almost 50% higher than all other racial and ethnic groups studied. The analysis was conducted by the Armed Forces Health Surveillance Center (AFHSC).1
“We would expect to see less disparity in hypertension rates across racial groups due to equal access to healthcare and equitable social and economic status; however, black, non-Hispanic servicemembers remained disproportionately affected,” said Army Col. William Corr, deputy director of AFHSC’s division of Epidemiology and Analysis. “Continued research examining this disparity is warranted and may favorably impact all servicemembers’ long-term health.”
The study, entitled “Incidence and Prevalence of Select Cardiovascular Risk Factors and Conditions, Active Component, U.S. Armed Forces, 2003-2012,” looked at all members of the U.S. Army, Navy, Air Force, Marine Corps and Coast Guard who served in the active component at any time during the surveillance period.
During that time, 230,564 incident diagnoses of essential hypertension were made in active component servicemembers, with an overall incidence rate of 16.1 per 1,000 p-yrs.
Rates were highest in 2005 (17.4 per 1,000 p-yrs.) but dropped in the last four years of the surveillance period compared with the first four years.
Across all age groups, incidence rates among African-American servicemembers were higher than rates in other racial and ethnic group. The incidence of hypertension in that cohort decreased over the time period in servicemembers 35 years old or older but increased in those younger.
“Ongoing research to examine the factors that may influence this continued disparity is warranted,” the AFHSC researchers wrote.
They noted that black, non-Hispanic civilians also have higher prevalence rates of hypertension than any other group and also develop the condition earlier but suggested that theories on the reasons for the differences might not be as applicable in a military population.
The AFHSC authors pointed out that the results of their analysis are in line with a 2012 Air Force report examining some of the same conditions. That report noted that hypothesized factors for the disparity, such as social and economic disadvantage or less access to healthcare, did not hold up in a “prescreened USAF population with equitable heath care and living conditions.”
“Because servicemembers undergo frequent and routine periodic health assessments, there are multiple opportunities to assess, diagnose and treat CVD risk factors during the course of their service. In fact, the increasing incidence rates of several conditions among younger servicemembers (e.g., hypertension) may reflect increased awareness and earlier diagnosis,” the AFHSC authors pointed out.
They added that, while cardiovascular disease issues might not be as obvious during active military service, “increased surveillance and control of these risk factors have the potential to favorably impact service members’ long term health, thereby improving their quality of life and potentially reducing future medical costs for the care of chronic health conditions.”
Other key findings of the AFHSC report included:
- Hyperlipidemia was diagnosed in 300,340 servicemembers during the 10-year surveillance period, with about 90% of them occurring in males. As with hypertension, the strongest demographic correlate of increasing incidence of hyperlipidemia was increasing age. Incidence rates of hyperlipidemia were similar among all race-ethnicity groups with the exception of American Indian/Alaskan Native servicemembers who had much lower incidence rates.
- Overall incidence rates of obesity were highest in the final year of the surveillance period (2012: 21.5 cases per 1,000 p-yrs), although incidence rates fluctuated over the 10-year period, and no steady increasing trend was seen. A total of 235,407 servicemembers received an obesity diagnosis over the time period.
- Annual incidence rates of diagnoses of abnormal glucose metabolism increased dramatically over the 10-year period, with 17 cases per 1,000 p-yrs in 2003, rising to 5.3 per 1,000 p-yrs in 2012. Relative to hypertension and hyperlipidemia, however, fewer servicemembers were diagnosed — about 47,000.
- Of the five risk factors examined, diabetes had the lowest effect on servicemembers, with only 13,901 diagnosed over the 10-year period. The incidence rates remained stable during the study period.
1Armed Forces Health Surveillance Center (AFHSC). Incidence and prevalence of select cardiovascular risk factors and conditions, active component, U.S. Armed Forces, 2003-2012. MSMR. 2013 Dec;20(12):16-9. PubMed PMID: 24428539.