Division of Maternal-Fetal Medicine, Department of Obstetrics and Gynecology, Duke University Health System, Durham, North Carolina.
Duke University School of Medicine, Duke University, Durham, North Carolina.
Am J Perinatol. 2023 Apr;40(5):467-474. doi: 10.1055/a-1925-1532. Epub 2022 Aug 16.
N-terminal pro-brain natriuretic peptide (NT-proBNP), a marker of ventricular dysfunction, varies by body mass index (BMI) outside of pregnancy. This study aimed to determine whether obesity affects NT-proBNP levels in pregnancy.
This was a prospective observational study of healthy pregnant people in the third trimester (3TM) and postpartum (PP). Patients were excluded if they had significant medical comorbidities or if their fetuses had anomalies, growth restriction or aneuploidy. NT-proBNP was measured at 28 weeks (3TM), predelivery (PD), 1 to 2 days PP (immediate postpartum [IPP]), and 4 to 6 weeks PP (delayed postpartum [DPP]). LogNT-proBNP levels were analyzed using linear mixed effects models, including BMI < or ≥30, time, and time-by-BMI interactions.
Fifty-five people (28 [51%] with BMI ≥ 30 and 27 [49%] with BMI < 30) were enrolled. A greater proportion of obese than nonobese subjects developed hypertensive disorders of pregnancy (50 vs. 15%, = 0.010) and obese patients had higher systolic blood pressures at all time points ( < 0.05). NT-proBNP levels (median [interquartile range] in pg/mL) were 18 (6-28) versus 26 (17-48) at 3TM, 16 (3-38) versus 43 (21-60) at PD, 58 (20-102) versus 63 (38-155) at IPP, and 33 (27-56) versus 23 (8-42) at DPP for obese compared with nonobese patients. In linear mixed effects models, logNT-proBNP was lower in obese patients at 3TM (β = -0.89 [95% confidence interval, CI: -1.51, -0.26]) and PD (β = -1.05 [95% CI: -1.72, -0.38]). The logNT-proBNP trends over time differed by BMI category, with higher values in obese patients at both PP time points compared with the 3TM (IPP β = 1.24 [95% CI: 0.75, 1.73]; DPP β = 1.08 [95% CI: 0.52, 1.63]), but only IPP for nonobese patients (β = 0.87 [95% CI: 0.36, 1.38]).
Obese patients had lower NT-proBNP levels than nonobese patients during pregnancy but not PP. The prolonged PP elevation in NT-proBNP in obese patients suggests that their PP cardiac recovery may be more prolonged.
· NT-proBNP levels are lower in obese than nonobese patients during pregnancy.. · Levels remain elevated in obese, but not nonobese, patients up to 4 to 6 weeks' postpartum.. · A lower threshold for concern regarding NT-proBNP levels may be needed in obese pregnant people..
脑钠肽前体（NT-proBNP）是心室功能障碍的标志物，其水平在妊娠以外的情况下会因体重指数（BMI）而变化。本研究旨在确定肥胖是否会影响妊娠期间 NT-proBNP 的水平。
这是一项对孕晚期（3TM）和产后（PP）的健康孕妇进行的前瞻性观察性研究。如果患者存在严重的合并症，或者其胎儿存在异常、生长受限或非整倍体，则将其排除在外。在 28 周（3TM）、分娩前（PD）、产后 1-2 天（即刻产后[IPP]）和产后 4-6 周（延迟产后[DPP]）测量 NT-proBNP。使用线性混合效应模型分析 LogNT-proBNP 水平，包括 BMI<30 和 BMI≥30。
共纳入 55 人（28 人[51%]BMI≥30，27 人[49%]BMI<30）。与非肥胖患者相比，肥胖患者更易发生妊娠高血压疾病（50%比 15%，=0.010），且所有时间点的收缩压均较高（<0.05）。与非肥胖患者相比，肥胖患者的 NT-proBNP 水平（pg/mL）在 3TM 时为 18（6-28）比 26（17-48），PD 时为 16（3-38）比 43（21-60），IPP 时为 58（20-102）比 63（38-155），DPP 时为 33（27-56）比 23（8-42）。在线性混合效应模型中，肥胖患者在 3TM（β=-0.89[95%置信区间：-1.51，-0.26]）和 PD（β=-1.05[95%置信区间：-1.72，-0.38]）的 LogNT-proBNP 水平较低。BMI 类别随时间的 LogNT-proBNP 趋势不同，与 3TM 相比，PP 时间点的肥胖患者的 LogNT-proBNP 值更高（IPP β=1.24[95%置信区间：0.75，1.73]；DPP β=1.08[95%置信区间：0.52，1.63]），而非肥胖患者仅在 IPP 时更高（β=0.87[95%置信区间：0.36，1.38]）。
与非肥胖患者相比，肥胖患者在妊娠期间 NT-proBNP 水平较低，但在产后期间并非如此。肥胖患者在产后的 NT-proBNP 水平持续升高，提示其产后心脏恢复可能更为缓慢。
·肥胖患者 NT-proBNP 水平低于非肥胖患者。
·肥胖患者的 NT-proBNP 水平在产后持续升高，但非肥胖患者的水平没有升高。
·肥胖孕妇 NT-proBNP 水平可能需要降低以引起关注。
