Dyslipidemia, oral contraceptive use ‘raise hypertension risk’
MedWire News: Dyslipidemia and long-term use of oral contraceptives are risk factors for hypertension in Chinese women, study results show.
The study also found that the two risk factors interact with each other in a multiplicative manner, report Ying Li (Jiangsu Institute of Planned Parenthood Research, Nanjing, China) and team in the Journal of Human Hypertension.
Li's team undertook a case-control study involving 665 women with hypertension and 665 normotensive women matched for age and region. The groups were compared to identify potential risk factors for the development of hypertension.
Dyslipidemia was significantly more prevalent among hypertensive women than controls (68.1% vs 57.0%), as was the use of combined oral contraceptives (61.5% vs 58.7%).
Mean levels of total cholesterol, triglycerides, low-density lipoprotein cholesterol, and Lipoprotein (a) were all significantly higher in hypertensive women than in controls. By contrast, levels of high-density lipoprotein cholesterol, apolipoprotein A1, and apolipoprotein B did not differ between the groups.
After adjusting for confounders, the risk for hypertension increased gradually with the increasing cumulative duration of oral contraceptive use, Li et al report. Compared with never-users, the risk for hypertension was increased 1.46 fold in women reporting 15-20 years of use and 1.49 fold in women with more than 20 years of use.
The risk for hypertension gradually decreased from stopping use of COC.
Logistic regression analysis identified age, family history of hypertension, dyslipidemia, and more than 15 years' use of combined oral contraceptives as significant independent predictors for hypertension.
Interestingly, dyslipidemia and 15 or more years' contraceptive use showed a multiplicative interaction, such that the risk for hypertension was increased 1.74 fold, 1.77 fold, and 2.82 fold if women had dyslipidemia, 15 or more years' contraceptive use, and both risk factors, respectively.
Li et al say that their study raises concerns over the use of oral contraceptives in women with dyslipidemia and recommend that women should be monitored closely for changes in blood pressure after starting such therapy.
"The onset of hypertension is a reason to stop using combined oral contraceptives or consider other forms of contraception," they conclude.
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By Joanna Lyford