Bilirubin levels inversely associated with new-onset hypertension in perimenopause

Among perimenopausal women, lower total bilirubin concentrations may indicate an increased likelihood of new-onset hypertension, as reported in a cross-sectional study.

The study included 196 perimenopausal women, among whom 85 had new-onset hypertension. All participants underwent 24-hour ambulatory blood pressure monitoring and a clinical assessment including anthropometrics.

Questionnaires were used to obtain sociodemographic and lifestyle data, as well as menopausal symptoms (modified Kupperman Index [mKI]). Researchers also collected fasting blood samples from the participants to measure a wide range of biomarkers and hormone levels.

Compared with normotensive women, hypertensive women had significantly lower total bilirubin levels (11.15 vs 12.55 μmol/L; p=0.046). Restricted cubic spline regression showed a nonsignificant nonlinear relationship between total bilirubin and new-onset hypertension (p=0.339).

However, in a multivariable logistic and robust linear regression model adjusted for minimal sufficient adjustment sets, higher total bilirubin levels were associated with lower odds of new-onset hypertension (odds ratio, 0.91 per μmol/L, 95 percent confidence interval [CI], 0.84–0.98; p=0.019). 

Total bilirubin was inversely associated with average 24-hour diastolic blood pressure (β = −0.36 mm Hg per μmol/L, 95 percent CI, −0.62 to −0.10; p=0.008) but not with 24-hour systolic blood pressure (β = −0.37 mm Hg per μmol/L, 95 percent CI, −0.79 to 0.06; p=0.090).

There was evidence of stronger inverse associations of total bilirubin with hypertension and 24-hour blood pressure in women with fewer menopausal symptoms (mKI ≤10), although the total bilirubin–mKI interaction was not significant.