Relationship between body mass index and mean arterial pressure in normotensive and chronic hypertensive pregnant women: a prospective, longitudinal study

Abstract

BackgroundBeing overweight is associated with both higher systolic blood pressure (SBP) and diastolic blood pressure (DBP) during pregnancy and increased risk of gestational hypertensive disorders. The objective of this study was to determine and quantify the effect of body mass index (BMI) on mean arterial pressure (MAP) at several time points throughout pregnancy in normotensive (NT) and chronic hypertensive pregnant (HT) women.MethodsA prospective longitudinal study was carried out in 461 singleton pregnancies (429 low-risk and 32 with chronic arterial hypertension), with measurements taken at the 1st, 2nd, and 3rd trimesters and at delivery. Linear mixed-effects regression models were used to evaluate the time-progression of BMI, SBP, DBP and MAP during pregnancy (NT vs. HT). The longitudinal effect of BMI on MAP, adjusted for the hypertensive status, was investigated by the same methodology.ResultsBMI consistently increased with time in both NT and HT women. In contrast, MAP decreased during the first half of pregnancy, after which it increased until the moment of delivery in both groups. A 5-unit increase in BMI was predicted to produce an increase of approximately 1 mmHg in population MAP values. This effect is independent from the time period and from hypertensive status.ConclusionsIn both NT and HT pregnant women, MAP is strongly (and significantly) influenced by increases in BMI.

Does pre-pregnancy BMI determine blood pressure during pregnancy? A prospective cohort study

“…In this study, SBP and DBP were increased by 0.25 and 0.18 mm Hg per BMI unit, respectively. These findings were similar to those in a previous study 28 which reported an increased mean arterial pressure (MAP) of 0.21 mm Hg per BMI unit, but were smaller compared with another study 5 which reported the mean differences of blood pressure in the first, second and third trimesters of 1.03, 0.98 and 0.89 mm Hg for SBP per BMI unit and 0.83, 0.81 and 0.74 mm Hg for DBP per BMI unit. These discrepancies could be attributed to differences in variables included in the adjustment model, where in the latter study gestational weight gain was taken into account in the adjusted model but not in our analysis.…”

“…It was in accordance with the reports from previous studies. 5 14 15 28 Almost similar to our findings, a study which explored the relation between blood pressure during pregnancy with gestational age and pre-pregnancy BMI as continuous scale measurements also found that SBP and DBP levels generally increased with higher pre-pregnancy BMI at any gestational age. 16 …”

“… 52 This is supported by a study which showed that women's pre-pregnancy BMI strongly influenced women's MAP throughout pregnancy in normotensive and chronic hypertensive women alike. 28 …”

The association between maternal anthropometry and blood pressure in pregnancy – results from the Croatian islands’ birth cohort study (CRIBS)

“…This effect was present consistently over the course of pregnancy, in accordance with the reports from previous studies. 8,20,21 Elevated pregnancy blood pressure associated with maternal pre-pregnancy BMI is also in accordance with a large body of literature that documents increased pre-eclampsia risk among overweight and obese women. 19,22,23 As a change in body composition and an accretion of water occurs differently in women during pregnancy, body weight gain might not be the best and only measure reflecting changes in fat storage.…”

Frequency of hypertension and the correlation between body mass index and level of hypertension among patients in different categories of obesity

“…Сложеност патофизиолошких дешавања огледа се у сазнању да хипертензивне особе могу да развију општи пад у бета-адренергичком одговору, који модулира развој гојазности у хипертензији. Сходно томе, претерана сим-патичка активација доводи до хипертензије и повећања телесне тежине, а даље повећање телесне тежине погор-шава хипертензију 31 . Сматра се да студије пресека дају реалније подат-ке од лонгитудиналних, јер није могуће да се директно процени утицај телесне тежине на крвни притисак на различитим нивоима крвног притиска и различитим ка-тегоријама гојазности 7 .…”