By Liza Baskin
A crucial part of preventing stroke is to learn more about factors that boost stroke risk. Researchers recently may have pinpointed one such risk factor for women, who tend to die from stroke more often than men.
A recent study found that diabetes was a risk factor associated with stroke for women but not men.
The researchers also discovered that the stroke risk was also tied to age. Women with diabetes over 55 years old had a significantly increased risk of stroke compared to women with diabetes who were younger than 55.
The lead author of this study was Wenhui Zhao, MD, from the Pennington Biomedical Research Center in Baton Rouge, Louisiana.
The study included 30,154 diabetes patients who received care at one of the seven hospitals and clinics operated by LSU Health Care Services Division between January 1, 1999 and December 31, 2009.
All of the participants were newly diagnosed with diabetes upon entering care and did not have a history of stroke or heart disease. There were 10,876 men and 19,278 women, and the average age of the participants was 51 years old.
The researchers conducted follow-up after an average of seven years, and took an HbA1c measurement at baseline (start of study) and at the end of follow-up.
An HbA1c test measures the average level of a person's blood sugar over the previous three months, and indicates whether or not a patient's diabetes is under control. A person is considered to have diabetes once the level rises above 6.5 percent.
The findings showed that 2,949 participants had a stroke during the study period; 1,093 of them were men and 1,856 of them were women.
The incidence rate of stroke for men was 16 cases per 1,000 person-years (number of participants multiplied by number of years in care), and 14 cases per 1,000 person-years for women.
Among the women, the risk of stroke increased as HbA1c increased.
Dr. Zhao and team determined that the women with an HbA1c of 8.0 to 8.9 percent had a 19 percent increased risk of stroke compared to the women with an HbA1c of 6.0 to 6.9 percent.
The women with an HbA1c of 9.0 to 9.9 percent were at a 32 percent increased risk of stroke compared to the women with an HbA1c of 6.0 to 6.9 percent.
An HbA1c of 10.0 percent or more in the women was associated with a 42 percent increased risk of stroke compared to the women with an HbA1c of 6.0 to 6.9 percent.
The findings revealed that there was not a significant association between high HbA1c and increased risk of stroke for the men.
Lastly, the researchers discovered that the women aged 55 years old and older had a significantly increased risk of stroke compared to the women younger than 55 years old.
The authors mentioned a few limitations of their study. First, most of the participants were from minority groups, uninsured and from a low economic standing, so the findings may not be applicable to the general population. Second, the data on stroke cases came from hospital records and were not confirmed by the researchers. Third, only fatal stroke cases were considered. Fourth, the researchers may not have had access to or considered outside factors.
This study was published on February 24 in Diabetologia.
Louisiana State University's Improving Clinical Outcomes Network provided funding.