Randomised Double-Blind Placebo-Controlled Study of Folic Acid Adjunct for 8 Weeks in Hyperhomocysteinaemic Hypertensive Patients in Zaria, Nigeria

Abstract

Objectives: This study was aimed at determining the effect of folic acid adjunct therapy on homocysteine (HCY) and blood pressure (BP) levels in hypertensive subjects.
 Method: The study was a double blind placebo-controlled trial on 100 hypertensive patients randomised into 50 folate and 50 placebo groups, where the folate group had 5 mg folic acid daily for 8 weeks. Fasting plasma homocysteine, folate and blood pressure levels were determined at baseline, at 4 and at 8 weeks. The Mixed Model Repeated Measures analysis of variance was applied for data analysis.
 Results: Hyperhomocysteinaemia was found at baseline in the folate (21.3 ± 5.7 µmol/L) and placebo (21.6 ± 4.9 µmol/L) groups which did not differ statistically (p > 0.05). Folic acid adjunct therapy, reduced homocysteine levels at 4 weeks by 2.0 µmol/L (9.2 %, p < 0.05) and at 8 weeks by 1.2 µmol/L (5.6 %, p < 0.05), with no significant (p > 0.05) systolic and diastolic blood pressure lowering effect. High base-line folate levels were found in both folate (113.8 ± 51.2 ng/ml) and placebo groups (109.5 ± 51.4 ng/ml) with no statistically significant difference (p > 0.05).
 Conclusion: Short-term daily folic acid supplementation over 8 weeks had a significant homocysteine reduction effect with no significant reduction in systolic and diastolic blood pressures of hypertensive subjects in Zaria, Nigeria. Hyperhomocysteinaemia could not be accounted for by suboptimal folate levels.
 Keywords: Hypertension, Homocysteine, Blood pressure, Folate, Placebo, Nigeria.

Relationship between plasma homocysteine and blood pressure in hypertensive Northern-Nigerians

“…These they also add to their staple diet as these are readily available and cheaper 43,44 . Additionally, deficiencies in other B vitamins like B 12 and B 6 which can result in hyperhomocysteinemia will require further investigation in subsequent studies as they were not assayed in the present study; however some study done in Nigeria had shown that B 12 deficiency was rare in Nigerians 30,45,46 .…”

“…It becomes imperative that other non-traditional vascular risk factors should be looked out for. Also, lifestyle modification inclusive of increased consumption of high fibre, fruits & vegetables, exercise and avoidance of smoking /alcohol should be emphasized, as part of the cardiovascular disease preventive strategy 30,50 . Traditional vascular risk factors associated with hyper-tension like hyperlipidaemia were not determined in this study.…”

Prevalence of hyperhomocysteinaemia, selected determinants and relation to hypertension severity in Northern-Nigerian hypertensives: the ABU homocysteine survey

“…20 However, a study by Vander Jagt on adolescent girls in Northern-Nigeria showed that folate levels were within satisfactory limits despite high mean homocysteine levels and this was attributed to their marginal vitamin B12 status. 33 This may not extrapolate for an adult population as adolescent girls were studied 20 but previous study by Flemming et al 20,40,50 showed that vitamin B12 deficiency was rare in Northern-Nigerians. 20,40 This was confirmed by a recent study done in Zaria comparing stroke patients with normal healthy subjects which showed that vitamin B12 deficiency is not the problem of healthy Nigerians as the levels were well within normal reference range.…”

“…33 This may not extrapolate for an adult population as adolescent girls were studied 20 but previous study by Flemming et al 20,40,50 showed that vitamin B12 deficiency was rare in Northern-Nigerians. 20,40 This was confirmed by a recent study done in Zaria comparing stroke patients with normal healthy subjects which showed that vitamin B12 deficiency is not the problem of healthy Nigerians as the levels were well within normal reference range. 43 Further studies on hypertensive subjects should be done to determine if there are any such deficiencies in them which is currently on-going.…”

“…Laboratory analysis was by the laboratory scientist in 2 batches under the same prevailing condition of storage and in the presence of the lead author. 40…”