Renal Impairment and Risk of Acute Stroke: The INTERSTROKE Study.

Area of Science:

• Nephrology
• Neurology
• Epidemiology

Background:

• Previous research indicates a link between impaired kidney function and stroke.
• However, uncertainties remain regarding the nature and strength of this association.

Purpose of the Study:

• To investigate whether shared risk factors explain the association between renal impairment and stroke, or if it is an independent risk.
• To explore regional variations and differences across stroke subtypes.

Main Methods:

• The INTERSTROKE study, a large international case-control study, analyzed data from 21,127 participants across 27 countries.
• Estimated glomerular filtration rate (eGFR) was calculated to define renal impairment (eGFR <60 mL/min/1.73 m2).
• Multivariable conditional logistic regression models were employed to assess the association between renal function and stroke risk.

Main Results:

• Renal impairment was more prevalent in stroke cases (22.9%) than controls (17.7%) and varied by region.
• Lower eGFR was independently associated with increased odds of all stroke types (OR 1.35), with higher odds for intracerebral hemorrhage than ischemic stroke.
• The association was strongest in younger participants and those from Africa, South Asia, or South America. Renal impairment also correlated with worse clinical outcomes, including a nearly threefold increased risk of death within one month.

Conclusions:

• Renal impairment is a significant independent risk factor for stroke.
• The impact of renal impairment on stroke risk and severity is particularly pronounced in younger populations and specific geographic regions.
• Addressing renal health is crucial for stroke prevention and improving patient outcomes.