Diabetes Mellitus Associated With Increased Intracerebral Hemorrhage Risk in Younger Patients

Emma Hitt, PhD

July 6, 2007 — Patients with diabetes mellitus (DM) appear to be at a 3- to 4-fold increased risk of intracerebral hemorrhage (ICH) compared with patients without DM, findings from a population-based study suggest. The association was especially strong in black patients younger than 55 years, the researchers found.
Brett Kissela, MD, associate professor of neurology at the University of Cincinnati, Ohio, and colleagues presented their findings at the American Diabetes Association 67th Scientific Sessions in Chicago, Illinois.
"The degree of risk changes substantially with age — and diabetes appears to be a more powerful mediator of risk for ICH at younger ages," Dr. Kissela told Medscape. "We have also previously found this to be true for ischemic stroke as well."
According to the researchers, however, many studies have failed to demonstrate an association between diabetes and ICH, despite the fact that DM is associated with many risk factors that can increase ICH risk.
To further evaluate this issue, the researchers assessed data sets from 2 time periods (one data set from 1993 to 1994 and one from 1999) in a population-based study of more than 1.35 million residents of 5 counties. Cases of ICH that occurred during the study period were noted, and medical records were abstracted for each case.
A total of 258 cases of ICH developed during the 1993 to 1994 study period, and 313 developed during the 1999 study period. Among patients with incident ICH, 13% and 21%, respectively, had DM. During both study periods, blacks were significantly more likely than whites to develop ICH at younger age: 63 vs 70 years in 1993 to 1994 (P = .002) and 61 vs 70 years in 1999 (P = .0002).
A pooled analysis of results from both study periods indicated that among black patients younger than 55 years, 50 patients per 100,000 developed ICH, and of those, 40 had DM and 10 did not, indicating a risk ratio of 4.0 (95% confidence interval [CI], 1.5 – 8.4). Among white patients younger than 55 years, the risk ratio was 2.8 (95% CI, 1.1 – 6.2), and the ratio remained similar as age increased (2.5, 1.2, and 1.8 for the 55- to 64-year, 65- to 74-year, and ≥75-year age groups, respectively). However, among black patients, the rate ratios declined with age (1.4, 0.7, and 0.6 for the 55- to 64-year, 65- to 74-year, and ≥75-year age groups, respectively), suggesting a strong influence for young age on the association between DM and ICH.
"Our results demonstrate why DM has been thought not increase the risk of ICH," noted Dr. Kissela. "When viewed over the lifespan, this higher risk in younger patients is mitigated by the lower risk in older age groups, especially among black patients. However, our population-based study was large enough to collect a large number of ICH cases over the 2 study periods and thus allowed us to evaluate the risk in an age- and race-specific fashion."
Ralph Sacco, MD, professor and chairman of the Department of Neurology at the University of Miami, Florida, noted that the findings are feasible, because many of the macrovascular and microvascular complications associated with diabetes could be expected to increase stroke risk.
"These findings add to our knowledge of ICH risk in this population and underscore the need for clinicians to prevent these and other complications of diabetes through adequate glycemic control, with particular awareness about which subgroups might be at increased risk."
Dr. Kissela also pointed out that most patients have little knowledge about the symptoms/signs that accompany stroke or of the need to get immediate medical attention by calling 911. Tissue plasminogen activator, for example, can be given within 3 hours of a stroke, and similar treatments are being developed for ICH. "Patients with DM should be made aware of this information."
This study was funded by a grant from the National Institutes of Neurological Disorders and Stroke. The authors report no relevant financial relationships.
American Diabetes Association 67th Scientific Sessions: Abstract 0687-P. Presented June 23, 2007.