Stroke rates increase for younger adults from 1999 to 2014

After adjusting for age, researchers found that adults born in New Jersey from 1945 to 1954 had a significantly lower risk of stroke compared with those born in earlier or later time periods. The risk of ST-segment elevation MI (STEMI) was similar among the age groups.

During the study, there were significant increases in the rate of stroke from the first period (1995 to 1999) to the last two periods (2005 to 2009 and 2010 to 2014) for adults from 35 to 39 years old, 40 to 44 years old and 45 to 49 years old. Meanwhile, the rates of stroke among adults from 55 to 84 years declined in recent years.

Lead researcher Joel N. Swerdel, MS, MPH, of the Rutgers University School of Public Health in Piscataway, New Jersey, and colleagues published their results online Nov. 23 in the Journal of the American Heart Association.

“People, especially those under 50, need to realize that stroke does not just occur in the old, and the outcome can be much more debilitating than a heart attack—leaving you living for another 30 to 50 years with a physical disability,” Swerdel said in a news release.

Previous research from the Centers for Disease Control and Prevention found that deaths from MI decreased by 56 percent and deaths from stroke declined by 70 percent from 1950 to 1999. Another study estimated the incidence of stroke decreased nearly 50 percent from 1988 to 2008.

For this study, the researchers obtained information on strokes and STEMI from 1995 to 2014 from the Myocardial Infarction Data Acquisition System, an administrative database containing hospital records of all patients discharged from nonfederal hospitals in New Jersey with a diagnosis of cardiovascular disease or an invasive cardiovascular procedure. They then linked information from death certificates to the hospitalization records.

For adults from 35 to 84 years old, the rate of stroke decreased from 314.1 strokes per 100,000 person-years during 1995 to 1999 to 271.0 strokes per 100,000 person-years during 2010 to 2014. Meanwhile, the rate of STEMI declined more than 60 percent from 206.4 per 100,000 person-years to 84.7 per 100,000 person-years.

Among adults from 35 to 39 years old, the rate of stroke more than doubled from 1995 to 1999 and 2010 to 2014. Adults from 40 to 44 years old, 45 to 49 years old and 50 to 54 years old also had increased rates of stroke, while those older than 55 years old had decreased rates of stroke.

After adjusting for age, adults born from 1925 to 1934 had a 26 percent higher rate of stroke compared with those born from 1945 to 1954. Meanwhile, adults born from 1965 to 1974 had a 43 percent higher rate of stroke compared with those born from 1945 to 1954.

The study had a few limitations, according to the researchers, including the possibility of coding errors. During the study, there were also changes in the use of magnetic resonance imaging, which could lead to ascertainment bias in stroke diagnoses. In addition, the researchers did not have data on emergency services response time for stroke patients.

“The results from this study beg the question: ‘Has the stroke-healthiest generation come and gone?'" the researchers wrote. “Based on our findings, there appears to a trend toward increasing rates of ischemic stroke in those born after 1954. We also found a slowing of the trend of decreasing STEMI rates, particularly in those younger than 50 years. These trends may have significant implications for health outcomes and the overall healthcare burden in the future. Further analyses of these outcomes in persons younger than 55 years should be done in other populations to assess their reproducibility. Examination of cohorts that have been under close observation for proven or suspected stroke, regardless of hospitalization, is also needed. The present finding of increasing stroke rates in persons younger than 55 years is unsettling and merits vigorous inquiry.”