This study is examining the effectiveness of adding folic acid to enalapril maleate (Vasotec) for patients with high blood pressure. The main outcome that will be measured is the decrease in homocysteine levels, a marker of high blood pressure.
The details
High blood pressure or hypertension can lead to other illnesses such as heart disease and stroke. There are many causes of hypertension including genetics. Some patients have an abnormal gene (mutation) called MTHFR C677T. This means that they do not break down homocysteine (an amino acid) into folic acid (vitamin B9). This causes hypertension.
Previous studies have suggested that patients with this mutation that are given folic acid have reduced levels of homocysteine and lower blood pressure. However, it is not known which dose is the best for patients and if it is more effective when used with a commonly used blood pressure-lowering medication such as enalapril.
This study will examine the best dose of folic acid to use with enalapril to reduce homocysteine levels. The main outcome to be measure will be a decrease in homocysteine levels after 8 weeks of treatment.
Who are they looking for?
This study is recruiting 3600 patients aged 45 or older with hypertension. Patients must be taking blood pressure-lowering medication for at least 2 weeks. Patients who are not taking medication can also participate if they have at least two blood pressure readings of 90 mmHg (diastolic) or more or 140 mmHg (systolic) or more. Female participants must be willing to use birth control during the trial. Patients must test positive for the MTHFR C677T mutation. Patients must have good tolerance for enalapril.
Patients must not be allergic to enalapril or folic acid supplements. Patients must not have hypertension caused by another condition such as kidney or endocrine disease. Patients with certain conditions including heart disease, certain digestive disorders, diabetes, uncontrolled hyperthyroidism, certain lung diseases, stroke within the previous 3 months, nerve disorders, cancer, and other diseases cannot participate. Participants taking folic acid or other B vitamin supplements in the previous 3 months cannot participate. Participants who participated in a clinical trial for a drug that is not yet approved within the previous month cannot participate. Female participants must not be pregnant or breastfeeding.
How will it work
Participants will be divided into 8 groups. All participants will receive enalapril. One group will receive a placebo for folic acid and the other 7 will receive different doses of folic acid (ranging from 0.4 mg to 2.4 mg).
The decrease in blood homocysteine levels will be measured for 8 weeks. The increase in blood folic acid levels will be measured for 8 weeks.
