Fewer Old People, But More Younger Ones, Having Strokes

Neurology Today
15 April 2010; Volume 10(8); p 16

LAINO, CHARLENE

A study of stroke rates in Ohio and Kentucky shows the average age of stroke patients dropped by nearly three years from 1993–1994 to 2005.

SAN ANTONIO, TX—Fewer old people are having strokes, researchers report. But strokes are on the rise among younger people, a group not traditionally considered at high risk for the condition, they said.

A study of stroke rates in Ohio and Kentucky shows the average age of stroke patients dropped by nearly three years from 1993–1994 to 2005. During the same period, the percentage of stroke patients aged 20 to 45 years increased from 4.5 percent to 7.3 percent, said Brett M. Kissela, MD, associate professor, co-director of the Neurology Residency Program, and vice chair of education and clinical services at the University of Cincinnati Neuroscience Institute in Ohio.

Speaking here at the American Stroke Association International Stroke Conference 2010, Dr. Kissela said that rising rates of obesity, high blood pressure, and diabetes are likely driving the trend.

For example, he said his group has previously reported that for people under age 65, diabetes is associated with a five-fold greater risk of stroke. In contrast, it is “commonly accepted that diabetes confers about a three-fold higher risk of stroke among patients in general,” Dr. Kissela said.

For the current study, the researchers examined data from five counties in the Greater Cincinnati and northern Kentucky region, which includes about 1.3 million people. The region is representative of the United States in terms of age, income, and education levels and percentage of African Americans, Dr. Kissela said.

Using discharge diagnoses, medical reviews, and information from nursing homes and physician offices, the researchers determined the mean age of stroke and stroke rates by race and age for three time periods: 1993–1994, 1999, and 2005.

Results showed that the mean age at which patients had a stroke in 1993–1994 was 71.3 years, compared with 70.9 years in 1999 and 68.4 years in 2005. The trend is statistically significant, he said.

The percentage of all strokes occurring in patients aged 20 to 45 years increased from 4.5 percent in 1993–1994 to 5.5 percent in 1999 and 7.3 percent in 2005.

Even among people under 45, strokes are still a “low frequency event,” affecting 25 of every 100,000 whites and 55 of every 100,000 blacks in 2005, Dr. Kissela said. (See “More Data on Stroke Rates.”)

The researchers were unable to address stroke incidence among other races, as they were not well represented in the study cohort. As for risk factors, the prevalence of hypertension, diabetes, and high cholesterol all increased among young adults, while increasing among middle-aged persons, the study showed.

Figure. DR. BRETT M. KISSELA said because stroke is thought of as an older person's disease, younger people are falling through the cracks, adding: “If we don't reverse this trend, there will be many years of productive life lost.”

[ Click here to enlarge ]

So why would strokes and stroke risk factors be increasing in younger people, while decreasing in older persons? There is increased awareness of stroke among [older] patients, Dr. Kissela said. Additionally, stroke prevention efforts aimed at controlling high blood pressure, diabetes, and obesity have largely been aimed at older people, Dr. Kissela said.

Because stroke is thought of as an older person's disease, younger people are falling through the cracks, he said. “If we don't reverse this trend, there will be many years of productive life lost. Not just years of work lost; it can be as simple as a young mother no longer being able to hold her baby,” he said.

Among responses, Dr. Kissela said, clinicians need to “promote a healthy lifestyle among patients of all ages and let younger people know that they too are at risk.” Younger people tend to skip an annual exam if they're feeling OK, he noted. “Everyone should be checked regularly for treatable problems,” he said.

Asked to comment on the findings, Brian Silver, MD, assistant professor of neurology at Wayne State University of Medicine and a vascular neurologist at Henry Ford Hospital in Detroit, agreed the data are representative of the entire nation. Anecdotally, he added, “myself and colleagues nationwide are treating a lot more patients in their 30s and 40s. In the last few weeks, I can think of four or five patients in their 30s and 40s who I've seen with a stroke.”

Like Dr. Kissela, Dr. Silver said rising rates of obesity, hypertension, and diabetes among younger patients are most likely to blame for their rising stroke rates.

Because the change occurred in just over a decade, “that would rule out some freak genetic change in the population,” he said.

Obesity, Dr. Silver said, may be the biggest problem as it is tied to other risk factors. He suggested that preventive efforts start at a very young age, with even elementary school students encouraged adopt a healthy lifestyle, including regular physical activity and nourishing food choices.

Weighing in on the topic, Daniel T. Lackland, MD, professor of epidemiology and neurosciences at the Medical University of South Carolina in Charleston, said, “Most people don't think of stroke as a younger person's condition. But strokes do occur in young adults and they occur for the same reasons as in older people.”

Dr. Lackland said that while there are many campaigns aimed at increasing awareness of myocardial infarction among people in their 40s and 50s, “we're not doing as much with stroke.”

He suggested that stroke campaigns be modeled after the American Heart Association's and other groups' efforts to raise awareness of heart attacks among younger persons. •

Among other data on stroke rates, investigators reported:

* When looked at by race, stroke rates decreased significantly only among blacks over age 85 years: from 1910 per 100,000 in 1993–1994 to 1029 per 100,000 in 2005.

* Among whites, the rate began to decrease significantly at age 65. Specifically, the incidence of stroke in those aged 65 to 74 years dropped from 530 per 100,000 in 1993–94 to 451 per 100,000 in 2005. Among white people aged 75 to 84 years, it decreased from 1039 to 778 per 100,000, and among those 85 years and older, it dropped from 1680 to 1263 per 100,000.

* The incidence rates in people aged 20 to 45 increased in both blacks and whites. However, the increase was statistically significant only among whites, increasing from 12 per 100,000 people in 1993–1994 to 25 per 100,000 in 2005.

* The prevalence of hypertension among persons aged 20 to 44 increased from 38 percent in 1995 to 41 percent in 2005, the study showed. Among persons aged 45 to 54, it dropped from 54 percent to 50 percent.

* The prevalence of diabetes did increase significantly in the younger age group, from 0 in 1995 to five percent in 2005. Among those aged 45 to 54, there was a nonsignificant increase in diabetes, from three to five percent.

* The prevalence of hyperchesterolemia showed similar trends to that of hypertension. Among younger adults, it increased from 13 percent in 1995 to 16 percent in 2005, the study showed. Among persons aged 45 to 54, it dropped from 23 percent to 20 percent in those time periods.