Hypertension-nocturia link more robust in Asians, females

Hypertension is associated with a heightened risk of nocturia, and this relationship is more pronounced at a higher nocturia cutoff, in patient-based study samples, among females, and in Black and Asian patients, but appears unrelated to age or body mass index (BMI), according to a study.

“[T]hese findings provide a foundation toward a more individualized approach to the evaluation and management of nocturia in patients with concomitant hypertension,” the researchers said.

Current evidence on the association between nocturia and hypertension as a function of nocturia severity, age, gender, race, BMI, and diuretic use was synthesized. The databases of PubMed, Embase, and Cochrane were searched for studies published up to May 2020. The researchers performed random effects meta-analyses to identify pooled odds ratios (ORs) for nocturia given the presence of hypertension, as well as meta-regression and subgroup analyses to identify differences across study samples.

A total of 1,193 studies were identified, of which 25 met the eligibility criteria. The overall pooled OR for the association between hypertension and nocturia was 1.25 (95 percent confidence interval [CI], 1.21–1.28; p<0.001). Using a 1-void and 2-void cutoff for nocturia, the pooled estimates were 1.20 (95 percent CI, 1.15–1.25; p<0.001) and 1.30 (95 percent CI, 1.25–1.36; p<0.001), respectively (p<0.001 between cutoffs). [J Urol 2021;205:1577-1583]

This association was more robust in patient-based (OR, 1.74, 95 percent CI, 1.54–1.98; p<0.001) than community-based samples (OR, 1.24, 95 percent CI, 1.24–1.29; p<0.001), in females (OR, 1.45, 95 percent CI, 1.32–1.58) than males (OR, 1.28, 95 percent CI, 1.22–1.35; p<0.001), and in Black (OR, 1.56, 95 percent CI, 1.25–1.94) and Asian (OR, 1.28, 95 percent CI, 1.23–1.33) than White subgroups (OR, 1.16, 95 percent CI, 1.08–1.24; p<0.05 for both).

There was no effect seen for age or BMI, and evidence on diuretics was limited.

“Despite the robust correlation between nocturia and age, the association between nocturia and hypertension appears to be independent of age, which can likely be explained by the fact that the prevalence of hypertension also increases with age,” the researchers said. [J Urol 2013;189:S86-S92; JAMA 2003;289:2363-2369; J Urol 2006;175:596-600]

“Although further investigation is required to understand the mechanisms underpinning this association, those studies suggesting that the presence of nocturia is a useful screening tool to identify hypertension would be applicable across age groups,” they added.

With regard to diuretic use, large epidemiologic studies have demonstrated a link between diuretics and nocturia, but other smaller, well-controlled studies have shown diuretics to actually reduce the frequency of nocturia. [BJU Int 2020;125:636-637; Br J Urol 1998;81:215-218]

“The absence of an effect of diuretics on the observed association between nocturia and hypertension suggests that the association between diuretics and nocturia may be attributable to the fact that diuretic use, in and of itself, is a marker of volume overload,” the researchers said.

“[F]uture longitudinal research is still needed to establish causality and determine whether improvement in blood pressure control results in clinically significant improvement in nocturia frequency,” they noted.