Type 1 diabetes associated with higher risk for ischemic, hemorrhagic stroke

Compared with the general population, patients with type 1 diabetes with or without maintaining target HbA1c levels were at increased risk for ischemic and hemorrhagic stroke, which intensified with worse glycemic control, according to research published in the Journal of Internal Medicine.

“Diabetes mellitus is an established risk factor for cardiovascular disease,” C. Hedén Ståhl, of the department of molecular and clinical medicine at the University of Gothenburg in Sweden, and colleagues wrote. “The results from a growing number of studies in the last decade have indicated that type 1 diabetes is a risk factor for stroke. Age and blood pressure level are examples of factors that predict stroke in individuals with type 1 diabetes as well as in those without diabetes. However, chronic hyperglycemia is a risk factor specific amongst individuals with diabetes but has not been widely investigated as a risk factor for stroke in those with type 1 diabetes.”

Hedén Ståhl and colleagues sought to determine whether excess risk for stoke is associated with glycemic control in patients with type 1 diabetes compared with the general population. They evaluated data from the Swedish National Diabetes register from 1998 to 2011 on 33,453 adult patients with type 1 diabetes (mean age, 35.5 years; mean diabetes duration, 20.2 years). Participants were matched to 159,924 control participants based on age, sex and county of residence. Follow-up was a median of approximately 8 years. The researchers used Cox hazard regression to estimate the risk for ischemic and hemorrhagic stroke.

Data indicated 2.3% (n = 762) of patients with type 1 diabetes were diagnosed with stroke — a threefold increase compared with the controls (0.7%; n = 1,122). For ischemic stroke, the overall multiple-adjusted HR for type 1 diabetes compared with control subjects was 3.29 (95% CI, 2.96-3.66), while it was 2.49 (95% CI, 1.96-3.16) for hemorrhagic stroke. As HbA1c levels increased, the risk of ischemic and hemorrhagic stroke also increased. There was a significant increase in ischemic stroke risk with HbA1c within the recommended target ( 6.9% [52 mmol mol^-1]; multiple-adjusted HR = 1.89 [95% CI, 1.44 –2.47]). In addition, there was a distinct increase in both ischemic and hemorrhagic stroke risk for patients with HbA1c levels of at least 9.7% (83 mmol mol^-1), with a multiple adjusted HR of 7.94 (95% CI, 6.29-10.03) for ischemic stroke and 8.17 (95% CI, 5-13.35) for hemorrhagic stroke.

“[Continuous] efforts to improve glycemic control in individuals with type 1 diabetes are of major importance to protect this group against a disease with potentially devastating effects on daily life,” Hedén Ståhl and colleagues concluded.

Another study by Hedén Ståhl and colleagues determined that adults with type 2 diabetes and a healthy BP have a similar stroke risk compared with the general population. – by Alaina Tedesco

References:

Hedén Ståhl C, et al. J Intern Med. 2016;doi:10.1111/joim.12572.

Hedén Ståhl C, et al. Diabet Med. 2016;doi:10.1111/dme.13292.

Disclosure: The researchers report funding from the Swedish state, the Novo Nordisk Foundation, the Swedish Society of Physicians, the Health and Medical Care Committee of the Regional Executive Board, Region Västra Götaland, the Swedish Heart and Lung Foundation, Diabetes Wellness and the Swedish Research Council.