Almost 50% increase seen in US sarcoidosis mortality rates

Between 1999 and 2016 in the United States, deaths from sarcoidosis increased by an overall 42.9%, with the largest increases seen in the Western states (216.7%) and the smallest in the Northeast (40.7%), according to a recent study conducted at East Carolina University, Greenville, NC. Results are currently in press in Respiratory Medicine.

Researchers led by Gregory D. Kearney, DrPH, MPH, assistant professor, Department of Public Health, Brody School of Medicine, East Carolina University, used mortality data on sarcoidosis compiled by the National Vital Statistics Systems from 1999-2016 in all 50 states and the District of Columbia.

Such a study, it seems, has been long overdue.

“While numerous published studies exist on the pathophysiology and clinical disease presentation of sarcoidosis, few studies have examined the trends of sarcoidosis mortality. To our knowledge, there has not been a published mortality study of sarcoidosis in the US in the past decade,” noted Dr. Kearney and colleagues.

In all, 16,665 deaths from sarcoidosis were reported in the United States during this 18-year period. Since 1999, the overall age-adjusted mortality rate from sarcoidosis increased, from 2.1 deaths per 1,000,000 persons to 3.1 in 2002. After this time, however, the rates remained relatively the same through 2016. Over the entire study period, the overall, age-adjusted mortality rate attributed to sarcoidosis was 2.9 deaths per 1,000,000.

In both men and women, unadjusted sarcoidosis death rates were higher among all individuals aged 35 years and older. The highest rates were observed among those aged 65-74 years (8.5 deaths per 1,000,000) and 75-84 years (9.0 per 1,000,000). In younger age groups (25-34 years and 35-44 years), mortality rates from sarcoidosis actually declined (-50.0% and -37.9%, respectively).

Black men and women had the highest overall number of deaths and average age-adjusted mortality rate (15.0 deaths per 1,000,000). This was nearly 14 times the rate in white men and women. Among Hispanic individuals, the overall death rate was 0.8 deaths per 1,000,000, and Hispanic women had a higher death rate compared with Hispanic men (0.9 vs 0.7 per 1,000,000, respectively).

Southern states had the highest overall mean age-adjusted mortality rate at 3.7 deaths per 1,000,000 compared with 3.1 deaths per 1,000,000 in the Northeast, 2.8 deaths per 1,000,000 in the Midwest, and 1.6 deaths per 1,000,000 in the West.

Upon stratifying these data for race, sex, and region, the highest age-adjusted death rates were seen among black women in the Midwest (18.7 deaths per 1,000,000) and black men in the Northeast (13.2 deaths per 1,000,000); the lowest rates were seen among white females in the South (1.1 deaths per 1,000,000) and in white men in the West (1.0 deaths per 1,000,000).

The District of Columbia (13.8 per 1,000,000), South Carolina (6.6. deaths per 1,000,000), Maryland (5.7 deaths per 1,000,000), and North Carolina (5.4 deaths per 1,000,000) had the highest mortality rates among states in the South. The greatest change in the number of deaths from sarcoidosis during this time occurred in non-core, non-metro areas (116.7%).

Dr. Kearney and fellow researchers also found the following with respect to sex:

• Deaths in women increased by 32.0% (from 2.5 to 3.3 per 1,000,000).
• Deaths in white males increased by a full 73.3% (from 1.5 to 2.6 deaths per 1,000,000).
• Black women and men had the highest age-adjusted mortality rate (17.0 and 12.4 deaths per 1,000,000, respectively), nearly 16 times higher than in white women (1.5 per 1,000,000) and higher than in white men, as well (1.2 per 1,000,000).
• Women had the highest age-adjusted death rates, but white men had the largest percentage increase compared with females (73.3% vs 32.01%, respectively).

“The steady increase of sarcoidosis deaths from 1999 to 2002 is difficult to explain as incidence rates across this time period are not readily available,” noted the authors.

Furthermore, they added, the increase in death rates among black women is troubling. Its causes are, as yet, unknown.

“…while mortality across both genders increased during that period, deaths were more pronounced in black females. It is plausible to consider whether the increase was driven by other underlying co-morbidities. One suggestion may be that an increased focus and higher awareness of the disease in black females is now yielding more reported deaths on the death certificate,” they wrote.

Dr. Kearney and colleagues hope that their results detailing the increases in the sarcoidosis-caused mortality and specific racial, regional, and sex differences will garner a renewed interest among clinicians and epidemiologists.

“It is anticipated that this paper will spark new interest among others, particularly national funding agencies, to recognize the need for more advanced epidemiological research to examine this multifactorial, chronic health condition. More in-depth epidemiological studies that combine clinical findings with population-based studies to explore the interplay between socio-demographic factors (eg, income, poverty, and occupation) or modifiable risk factors (eg, obesity, fewer years of education) may provide vital clues for better understanding and evaluating causal relationships of this serious condition that can lead to death,” they concluded.