Hepatic, Renal and Inflammatory Biomarkers are Positively Associated with Blood Pressure Changes in Healthy Pregnant Women: A Prospective Cohort

This article evaluates the association of hepatic, renal, and inflammatory biomarkers with changes in systolic (SBP) and diastolic (DBP) blood pressure (BP) during healthy pregnancies. A prospective cohort study with 225 healthy pregnant women was conducted in Rio de Janeiro, Brazil. SBP and DBP were evaluated throughout pregnancy (5th–13th, 20th–26th, and 30th–36th gestational weeks) and were the outcomes. The following biomarkers were measured at the first trimester and analyzed according to tertiles of the sample distribution and were considered the main independent predictors: alkaline phosphatase (ALP), alanine aminotransferase (ALT), aspartate aminotransferase (AST), uric acid (UA), creatinine (Cr), and C-reactive protein (CRP) concentrations. The statistical analysis included 3 stages of modeling with the longitudinal linear mixed-effects procedures: Model 1 was adjusted for gestational age and quadratic gestational age; Model 2 included interactions between the biomarkers and gestational age; and Model 3 was adjusted for self-reported skin color, education, parity, early-pregnancy body mass index (BMI) (under/normal <25; overweight/obese ≥25 kg/m(2)), smoking habit, and leisure-time physical activity. Additional models were performed for CRP and UA with the inclusion of interaction terms between the biomarkers and BMI. Women classified in the third tertile of the ALP (≥61.1 U/L; β(SBP) = 3.474; 95% confidence interval [CI]: 0.955–5.992; β(DBP) = 3.291; 95% CI: 1.098–5.485), ALT (≥14.3 U/L; β(SBP) = 2.232; 95% CI: 0.221–4.242; β(DBP) = 2.355; 95% CI: 0.721–3.989), and Cr values (≥48.6 μmol/L; β(DBP) = 1.927; 95% CI: 0.347–3.508) presented higher BP levels during pregnancy compared to those in the first and second tertiles. Women in the highest tertile of the ALP concentration distribution presented a lower rate of change in SBP and DBP during pregnancy (interaction term with gestational age β(SBP) = −0.004; 95% CI: −0.007 to −0.001; P = 0.02; β(DBP) = −0.003; 95% CI: −0.006 to −0.001; P = 0.01). Higher UA concentrations were associated with higher SBP levels only in overweight/obese women (β = 3.878; 95% CI: 0.687–7.068), whereas higher CRP concentrations (≥2.6 mg/L) were associated with higher DBP in under/normal weight women (β =2.252; 95% CI: 0.267–4.236). ALP, ALT, and Cr concentrations were positively associated with BP levels, whereas ALP was associated with a lower rate of change in BP. The associations of UA and CRP with BP differ according to the early-pregnancy BMI.