Effect of vitamin D on the variability of blood pressure in premenopausal and menopausal hypertensive women in the area of Blida (Algeria).

OBJECTIVE: To evaluate the effect of 25 (OH) vitamin D supplementation on blood pressure (BP) variability in hypertensive women in the pre-menopausal and post-menopausal periods.

MATERIALS AND METHODS: 881 hypertensive women prospectively followed for an interventional study between January 2016 and September 2017, in specialized consultation at the department of internal medicine at the Blida University Hospital (Algeria). Four hundred and thiry nine premenopausal women (group I) and 442 menopausal women (group II). The initial serum 25 (OH) D level for each group was determined by the enzyme immunoassay. In groups I and II, we identified 2 subgroups, A: insufficiency (vit D between 29 and 20ng/ml) and B: deficiency (vit D less than 20ng/L). Antihypertensive therapy was supplemented with an additional 200000IU/month cholecalciferol for the two B subgroups. The variability in BP was calculated as the ratio of mean systolic and diastolic BP during daytime and nighttime, with performing ambulatory BP measurement at baseline, 3, 6, and 12 months of follow-up.

RESULTS: At inclusion, the level of 25 (OH) D was lower (P<0.05) in subgroups IB (19.3±8.5ng/ml) and IIB (18.2±9, 5ng/ml) compared to subgroups IA (28.1±10.7ng/ml) and IIA (25.2±10.1ng/ml). After supplementation, the level of 25 (OH) D increased in subgroup IB (38.3±11.9ng/ml) and in subgroup IIB (37.3±10, 5ng/ml) and became higher (P<0.001) than in subgroups IA and IIA. Between subgroups IA and IB, at inclusion, there is no difference (P>0.05) in the SBP and DBP variability during the day and at night. After treatment, the variability of the SBP at night became lower (P<0.02) in group IB compared to group IA. In subgroup IIB, daytime variability indices were higher (P=0.04) at inclusion than in group IIA. After treatment, the variability of SBP during the day decreased but remained the highest (P<0.05) in subgroup IIB (14.8±10.8mmHg) compared to subgroup IB (12.0±8.1mmHg), as well as to subgroups IIA (10.9±9.8mmHg) and IA (10±8.1mmHg). We found a significant correlation of cholecalciferol with the variability of SBP during the day.

CONCLUSIONS: Vitamin D deficiency appears to be a factor of BP variability. Although the variability of the postmenopausal group remains higher than that of the other groups, the correction of the level of 25 (OH) D by the supply of cholecalciferol 200000 IU per month leads to a reduction in the variability of BP in the studied hypertensive women could help to prevent morbimortal complications.