Is Angiotensinogen Gene Polymorphism Associated with Hypertension in Pregnancy?

Abstract

Objective: To determine whether a state of hypertension in pregnancy in the Japanese can be predicted in the early period based on detection of the M235T variant of the angiotensinogen gene, alone or with other factors.

Methods: A total of 313 Japanese pregnant women were divided into 3 groups on the basis of their angiotensinogen genotype: TT, MT, and MM. Hypertension in pregnancy was diagnosed for 33 patients in all. For each group, we sought to determine what factors increased the risk of the disease.

Main Outcome Measures: The angiotensinogen M235T variant, mean arterial pressure (MAP) before the 12th gestational week, body mass index (BMI) before pregnancy, age at delivery, parity, a familial history of hypertension, and development of preeclampsia or gestational hypertension were considered.

Results: The frequencies of the allele T were the same among preeclampsia, gestational hypertension, and normal subjects. In TT subjects, a high incidence of gestational hypertension was found for women with MAP ^•90 mm Hg, high or low BMI before pregnancy ^•22.0 or <18.0, and maternal history of hypertension. In MT subjects, women who showed MAP ^•90 mm Hg or who were above 36 years old at delivery had a high incidence of gestational hypertension. Preeclampsia could not be predicted in either group.

Conclusions: Hypertension in pregnancy cannot be predicted on the basis of the M235T variant of angiotensiogen gene alone. However, gestational hypertension is associated with combinations of other factors. In contrast, it is virtually impossible to predict the development of preeclampsia.

Key Words:

• Angiotensinogen M235T variant
• Preeclampsia
• Gestational hypertension