Quercetin supplementation prevents kidney damage and improves long-term prognosis in hypertensive patients

Quercetin has shown potential antihypertensive-like activities in several studies. The present study aimed to test the effect of quercetin supplementation on kidney damage and long-term prognosis in hypertensive patients. The data of enrolled hypertensive patients were acquired from the NHANES dataset. The flavanol intake data was extracted from the FNDDS flavonoid database. Information regarding mortality was extracted from the NCHS. A total of 5801 hypertensive patients were included in this study. Preliminary analysis found that the total flavanols intake dosage was the independent influence factor of the kidney damage prevalence in hypertension, and it was found that only the quercetin supplementation was the protective factor for kidney damage after stratification analysis. For every 10 mg/d increase in quercetin intake, the kidney damage prevalence decreased by 8% [OR = 0.92, 95% CI: 0.85-0.99, p = 0.032]. The comprehensive analysis results suggested that hypertensive patients in the quercetin-high group had a lower kidney damage prevalence and a higher survival probability than those in the quercetin-low group. The urine microalbumin of hypertensive patients in the quercetin-high group was significantly lower than that of hypertensive patients in the quercetin-low group. In addition, at a median follow-up time of 122 months, the mortality decreased by 9% [HR = 0.91, 95% CI: 0.84-0.99, p = 0.031] for every 10 mg/d increase in quercetin intake. The findings suggested that high quercetin intake was associated with low kidney damage prevalence and high survival probability. Based on the existing evidence, promoting quercetin supplementation as a supplementary treatment for hypertensive patients was warranted.