Bathing in hot springs at night could help ward off hypertension

Habitual nighttime hot spring bathing appears to exert a significant protective effect against hypertension, reports a recent Japan study.

The study included 4,001 adults, all aged ≥65 years, in whom hot spring habits were assessed through a questionnaire. All participants had a history of hypertension and 55.9 percent were women.

Unadjusted analyses found that those who were 85 years of age or older were significantly more likely to have hypertension, as were those with a history of arrhythmia, stroke, diabetes mellitus, and gout. Hyperlipidaemia and past renal disease likewise aggravated hypertension risk.

In contrast, women were significantly less likely to develop hypertension than men. Bathing in hot springs daily, as well as doing so beyond 7 pm, also had significant protective effects against hypertension.

In multivariable logistic regression analysis, age ≥85 years remained a significant risk factor for hypertension (odds ratio [OR], 1.410, 95 percent confidence interval [CI], 1.170–1.680; p<0.001), as did histories of various cardiovascular conditions and comorbidities.

Of note, taking a bath at a hot spring at 7 pm or later likewise continued to be a protective factor against hypertension, reducing such risk by 15 percent (OR, 0.85, 95 percent CI, 0.768–0.940; p=0.001).

“In this study, we found that habitual nighttime hot spring bathing was significantly associated with a lower prevalence of hypertension in older adults,” the researchers said. “Randomized controlled trials on habitual nighttime hot spring bathing as a treatment for hypertension are warranted.”