Relationship between 25(OH) vitamin D and the number of antihypertensive drugs in hypertensive patients in the area of Blida (Algeria)

Abstract

The purpose of the study was to evaluate the relationship between 25(OH) vitamin D and the number of antihypertensive drugs (AHTs) used in hypertensive patients. A total of 1145 patients were enrolled in the study between January 2017 and June 2018 in specialized consultation at the department of internal medicine at the Blida university hospital (65.8% female, 34.2% male, age: 52 ± 13 years old). The initial serum 25 (OH) vitamin D level was determined by the enzyme immunoassay for all patients. Antihypertensive therapy was supplemented with 200000 IU/month cholecalciferol for all the patients. A follow-up visit was performed 12 months later. In total, 22.4% of patients received 1 antihypertensive drug, 47.7% of patients 2 drugs, 19.7% of patients 3 drugs, 8.8% of patients 4 drugs, and 1.4% were treated with 5 antihypertensive drugs. The mean number of antihypertensive drugs was 2.5. Glomerular filtration measured by CKD-EPI was 49.3 ± 7.2 ml/min. The mean level of baseline plasma vitamin D was 10.6 ± 5.4 ng/ml. One year later, the mean plasma level of vitamin D increased to 28.3 ± 10.8. Sixty seven percent of the patients were still under vitamin D supplementation at follow-up whereas 32.8% had stopped the treatment. In the former, plasma vitamin D increased to 29.0 ng/ml versus 15.3 ng/ml in the latter group. There was a significant relationship between the 25(OH) vitamin D plasma level and blood pressure ( P = 0.05) and the number of antihypertensive drugs used ( P = 0.013). The difference between those patients who kept the treatment and those who stopped was highly significant ( P < 0.05). The action of diuretics on BP is more synergistic in combination with vitamin D (95.5% vs. 76.4% without vitamin D), followed respectively by calcium channel blockers (67.8% vs. 57.4%), beta-blockers (66.2% vs. 46.5%), converting enzyme inhibitors (50.3% vs. 34.4%) and finally angiotensin II receptor blockers (45.1% vs. 36.2%). The number of antihypertensive drugs have a less significant effect on PA in compared to groups with vitamin D ( P < 0.001). Supplementation with vitamin D improved the control of BP in our studied population. It seems desirable to encourage the prescription of a dual therapy containing a diuretic in hypertensive patients with supplementation in vitamin D. Further studies are necessary to better explore the plasma level of vitamin D and the efficiency of different classes of antihypertensive treatment.