Comparison of Associations of Reduced Estimated Glomerular Filtration Rate With Stroke Outcomes Between Hypertension and No Hypertension

Background and purpose: We compared the association of low estimated glomerular filtration rate (eGFR) with stroke outcomes among patients with hypertension and without hypertension.

Methods: We used the China stroke registry to identify patients on discharge with the diagnosis of stroke in 2012 and 2013. Low eGFR was defined as <60 mL/min/1.73 m². Multivariable analysis was used to evaluate the association of low eGFR with 1-year all-cause mortality, recurrent stroke, poor functional outcome defined as 3 to 6 in modified Rankin Scale (mRS), and ordinal mRS, where the interaction of eGFR category and hypertension status was investigated.

Results: Of 5082 patients without hypertension, 221 patients (4.4%) had low eGFR, as compared with 1378 patients (8.6%) previously diagnosed with hypertension. In patients without hypertension, the adjusted odds ratios with 95% confidence interval of low eGFR was 1.88 (1.23-2.88) for all-cause mortality, 1.36 (0.66-2.83) for recurrent stroke, 2.14 (1.45-3.16) for poor functional outcome, and 2.07 (1.58-2.70) for ordinal mRS. In patients with hypertension, low eGFR was associated with all stroke outcomes: 1.80 (1.50-2.16) for all-cause mortality, 1.52 (1.20-1.91) for recurrent stroke, 1.30 (1.11-1.52) for poor functional outcome, and 1.31 (1.18-1.46) for ordinal mRS. The significant interaction between eGFR categories and hypertension was only found for poor functional outcome (P=0.046) and ordinal mRS (P=0.002).

Conclusions: Effect of low eGFR on all-cause mortality and recurrent stroke in patients without hypertension was not significantly different from that in patients with hypertension, but low-eGFR patients without hypertension had a higher risk of stroke-related disability than those with hypertension.