ScienceDaily (Aug. 23, 2008) — The incidence of strokes among
diabetics in Northern Sweden declined between 1985 and 2003, according to a
population-based study published in Stroke: Journal of the American Heart
Association.
Researchers also found that survival rates improved leading to a rapid
decline in the number of fatal events among diabetic people.
“Prior research has suggested that the trend in strokes was increasing, but
our study shows declining incidence in stroke for non-diabetic men, both for
first and recurrent stroke, and in recurrent strokes in non-diabetic women,”
said Mats Eliasson, M.D., Ph.D., co-author of the study and a senior
lecturer in the Department of Public Health and Clinical Medicine at Umeå
University and the Department of Medicine at Sunderby Hospital in Luleå,
Sweden.
The reasons for the overall decline of strokes among diabetics are
uncertain. The decline may be the result of more intensive treatment of
hypertension in diabetics and smoking cessation and cholesterol-lowering
efforts, Eliasson said.
“The impressive decline in smoking and large decreases in cholesterol
levels, and to a lesser degree blood pressure levels, in the population of
northern Sweden may have contributed to the declining incidence in both
diabetic and non-diabetic subjects over the study period,” he said. “On the
other hand, we found more recurrent events among diabetic subjects than
non-diabetic subjects, indicating a need for even more intensive secondary
prevention among diabetic patients.”
Researchers examined data on 15,382 stroke patients, 35- to 74-years-old,
who were part of the Northern Sweden MONICA (Multinational Monitoring of
Trends and Determinants in Cardiovascular Disease) Project Stroke Registry,
an international collaboration sponsored by the World Health Organization.
Over the 19 years, 11,605 subjects suffered a first stroke and 3,777 had a
recurrent stroke. Twenty-two percent of the men and women had previously
been diagnosed with diabetes.
Although the total number of strokes per 100,000 in diabetics was
significantly greater than in non-diabetics, researchers found no
significant difference in the rate of decline over time and death rates
between the two groups.
Among the major findings:
* Diabetic women had a yearly decrease in incidence of first-ever stroke of
1.5 percent, while incidence remained unchanged over the observation period
for non-diabetic women.
* Non-diabetic men had a significant declining trend in incidence rates of
first-ever stroke of .8 percent per year, while there was an insignificant
decline in diabetic men.
* All groups, except diabetic women with first-ever stroke, had a
significant decline in deaths over time.
* Incidence rates per 100,000 of all strokes among male diabetics fell from
1,961 to 1,815.
* The incidence rates per 100,000 of all stroke in women fell from 1,921 to
1,176.
* In non-diabetics, the incidence rates per 100,000 fell from 358 for men
and 204 for women to 284 and 183, respectively.
* For recurrent strokes, the decline was significant for all but diabetic
men, with the greatest decline (5.4 percent a year) in diabetic women.
Non-diabetic women showed a 2.7 percent yearly drop.
Researchers found no apparent explanation for the gender differences. An
earlier study in the United States didn’t find gender differences in care or
treatment adherence between male and female diabetics.
“The fact that patients with diabetes, to a great extent, had favorable time
trends similar to those of non-diabetics is particularly interesting
considering that diabetic patients with heart attack, from the same
population, did not show any positive trends over the 19-year study,”
Eliasson said.
Control of hypertension may have a greater impact in stroke than in coronary
heart disease, he said.
Co-authors are Aslak Rautio, M.D., and Birgitta Stegmayr, Ph.D. Individual
author disclosures can be found on the manuscript.
Adapted from materials provided by American Heart Association.
