Synergistic effect of gestational hypertension and postpartum incident hypertension on cardiovascular health: a nationwide population study.
BACKGROUND
Gestational hypertension (GH) is a common complication of pregnancy and is associated with increased risk of incident hypertension in later life (IH) and cardiovascular events. However, the interactive effect of GH and IH on postpartum cardiovascular health remains unclear.


RESULTS
A nationwide population-based study was conducted using 1 million individuals from the Taiwan National Health Insurance database. Records from 1998 to 2009 were used to identify 1260 pregnant women with GH and without previous cardiovascular disease. The control group comprised 5040 pregnant women without GH, matched for age and date of delivery. During the follow-up period (median duration, 5.8 years), 182 cardiovascular events developed. Women with GH had significantly higher risk of cardiovascular events (hazard ratio [95% CI], 2.44 [1.80 to 3.31]) and IH (8.29 [6.30 to 10.91]) than controls. Compared with women without GH and IH, there was a significantly higher risk of cardiovascular events for women without GH but with IH (relative risk [95% CI], 2.89 [1.27-6.58]), women with GH but without IH (1.66 [1.16-2.39]), and women with GH and IH (8.11 [5.36-12.30]). The synergy index was 2.91 (95% CI 1.11 to 7.59), suggesting a positive interaction between GH and IH.


CONCLUSIONS
GH increased the risk of subsequent IH. Women with both GH and IH were at a substantially higher cardiovascular risk than were women with either GH or IH. The synergistic adverse effect of GH and IH on postpartum cardiovascular health indicates that more attention should be paid to this special population.
Cardiology Division, Internal Medicine Department, Taipei Medical University Wan-Fang Hospital, Taipei, Taiwan (J.S.Y.) Department of Medicine, Taipei Medical University, Taipei, Taiwan (J.S.Y.).
Jong Shiuan
JS
Yeh
Department of Medicine, Taipei Veterans General Hospital, Taipei, Taiwan (H.M.C., S.H.S.) Department of Medical Education, Taipei Veterans General Hospital, Taipei, Taiwan (H.M.C.) Department of Medicine, National Yang-Ming University, Taipei, Taiwan (H.M.C., P.F.H., S.H.S.).
Hao-Min
HM
Cheng
Healthcare and Management Center, Taipei Veterans General Hospital, Taipei, Taiwan (P.F.H.) Department of Medicine, National Yang-Ming University, Taipei, Taiwan (H.M.C., P.F.H., S.H.S.).
Pai-Feng
PF
Hsu
Department of Medicine, Taipei Veterans General Hospital, Taipei, Taiwan (H.M.C., S.H.S.) Department of Medicine, National Yang-Ming University, Taipei, Taiwan (H.M.C., P.F.H., S.H.S.).
Shih-Hsien
SH
Sung
Institute of Population Health Sciences, National Health Research Institutes, Miaoli, Taiwan (W.L.L., H.L.F., S.Y.C.).
Wen-Ling
WL
Liu
Institute of Population Health Sciences, National Health Research Institutes, Miaoli, Taiwan (W.L.L., H.L.F., S.Y.C.).
Hsin-Ling
HL
Fang
Institute of Population Health Sciences, National Health Research Institutes, Miaoli, Taiwan (W.L.L., H.L.F., S.Y.C.).
Shao-Yuan
SY
Chuang
D000328:Adult; D001794:Blood Pressure; D002318:Cardiovascular Diseases / Q000175:diagnosis / Q000453:epidemiology* / Q000503:physiopathology; D016022:Case-Control Studies; D005260:Female; D006304:Health Status; D006801:Humans; D006973:Hypertension / Q000175:diagnosis / Q000453:epidemiology* / Q000503:physiopathology; D046110:Hypertension, Pregnancy-Induced / Q000175:diagnosis / Q000453:epidemiology* / Q000503:physiopathology; D015994:Incidence; D011247:Pregnancy; D018570:Risk Assessment; D012307:Risk Factors; D013624:Taiwan / Q000453:epidemiology; D013997:Time Factors
cardiovascular events; gestational hypertension; incident hypertension