Reduction in diastolic blood pressure linked to nocturia improvement

Modest decreases in diastolic blood pressure were associated with a statistically significant reduction in nocturnal voids, according to a retrospective analysis presented during the 2021 AUA Annual Meeting.¹

For their study, the researchers assessed the voiding diaries of patients who underwent treatment for lower urinary tract symptoms (LUTS) at a Veterans Affairs urology clinic. The goal of the study was to assess whether there were any changes in nocturnal micturition resulting from a reduction in a patient’s blood pressure.

Providing background for the study, Connelly Miller, MPH, first author of the paper, said, “A recent systematic review demonstrated that hypertensive patients were 1.2 to 1.3 times more likely to report nocturia; however, there is a gap in understanding in both the mechanism behind the relationship between nocturia and hypertension and the clinical applications of that relationship.”

Miller is a fourth year medical student at SUNY Downstate Health Sciences University, Brooklyn, New York, who has been conducting retrospective analyses to understand features of nocturia using information from a prospectively kept database of men seen for LUTS at the outpatient clinic of the Veteran Affairs New York Harbor Healthcare System, Brooklyn.

The retrospective analysis included adult male patients who had at least 2 voiding diaries separated by ≥30 days and who had a reduction in systolic and/or diastolic blood pressure of ≥10% from baseline to follow-up. The researchers used nonparametric statistical testing to compare nocturnal and 24-hour void number, total volume, and maximum voided volume from baseline to follow-up.

Overall, there were 53 patients who had a ≥10% decrease in systolic blood pressure after ≥30 days: average of 139 mm Hg lowered to an average of 118 mm Hg (P <.0001). The mean age of these patients at their initial visit was 69 years, 47% were White, 36% were Black, and 17% were Hispanic/other. Seventeen percent had diabetes, 23% had peripheral edema, 21% had obstructive sleep apnea (OSA), and 6% had chronic kidney disease (CKD). By the time of their initial visit, 60% had been prescribed antihypertensive treatment.

There were 68 patients who had ≥10% decreased in diastolic blood pressure after ≥30 days: average of 82 mm Hg lowered to an average of 68 mm Hg (P <.0001). The mean age at initial visit was 68 years, 46% White, 37% Black, and 18% were Hispanic or other. Sixteen percent of patients had diabetes, 21% had peripheral edema, 25% had OSA, and 1% had CKD. Sixty percent had been prescribed antihypertensive treatment by the time of their initial visit.

There were 33 patients had a reduction in both systolic and diastolic blood pressure.

Among the patients with a decrease in diastolic blood pressure, there was a significant reduction in nocturnal voids from a median of 2.5 (interquartile range [IQR], 2-4) to a median of 2 (IQR, 1-3; P = .02). There was not a significant reduction in nocturnal voids in the patients with a decrease in systolic blood pressure: median of 2 both before (IQR, 2-3.5) and after (IQR, 2-4) the reduction (P = .97).

Miller noted that the patients with a decrease in systolic blood pressure had an increase in their 24-hour maximum voided volume, from a median of 200 mL (IQR, 200-360) to a median of 300 mL (IQR, 210-290; P = .04). This did not occur in the diastolic reduction group: median of 268 mL (IQR, 200-385) to median of 261 mL (IQR, 200-400; P = .83).

“In a diverse, representative setting, patients who recorded modest decreases in diastolic blood pressure experienced a statistically significant reduction in nocturnal voids,” Miller said in his concluding remarks. “A possible explanation might be related to early versus late diuresis, such that patients with increased diastolic blood pressure have lower volumes of first nocturnal void; however, this did not change significantly after reduction.”

Miller added, “Patients with decreased systolic blood pressure experienced increases in max voided volume. This has been used as a corollary for bladder capacity, and prior work has similarly demonstrated that increased cardiovascular risk scores are associated with decreased bladder capacity.”

Reference

1. Miller C, Monaghan T, Robins D, et al. Diastolic blood pressure reduction is associated with improvement in nocturia. Presented at: 2021 American Urological Association Annual Meeting; September 10-13, 2021; virtual. Abstract MP63-06.