Assessment of 25-Hydroxyvitamin D Levels in Patients with Resistant Hypertension.
OBJECTIVE
To investigate the possible correlation between serum 25-hydroxyvitamin D levels and resistant hypertension (RH).


METHODS
Patients who had undergone ambulatory blood pressure measurements (ABPM) during outpatient controls were enrolled. Fifty subjects with RH, 50 with controlled hypertension (CHT) and 50 normotensive subjects (NT) were included in the study. RH was defined as 'suboptimal blood pressure control despite using 3 antihypertensive agents including a diuretic or need for 4 or more drugs to control blood pressure'. The 25-hydroxyvitamin D and parathormone levels were compared between the groups. Pearson's correlation coefficient test was applied to assess the correlation between 25-hydroxyvitamin D levels and office blood pressure (BP) and ABPM. Logistic regression analysis was used to determine the independent correlates of RH.


RESULTS
The 25-hydroxyvitamin D level was significantly lower in the RH group (17.02 ± 5.4 ng/ml) compared to the CHT (24.9 ± 4.8 ng/ml) and NT groups (28.0 ± 5.7 ng/ml, p < 0.001). In univariate correlation analysis, 25-hydroxyvitamin D levels had a significant negative correlation with office systolic BP (r = -0.329, p < 0.001), office diastolic BP (r = -0.395, p < 0.001), systolic ambulatory BP (r = -0.844, p = 0.004), and diastolic ambulatory BP (r = -0.567, p = 0.005). ROC analysis revealed that 25-hydroxyvitamin D levels <21.50 ng/ml predicted the presence of RH with a sensitivity of 78% and a specificity of 79% (AUC = 0.89, 95% CI 0.83-0.94). In the multivariate logistic regression analysis, 25-hydroxyvitamin D level was independently correlated with the presence of RH (β 0.660, 95% CI 0.572-0.760, p < 0.001).


CONCLUSIONS
There was an independent correlation between lower 25-hydroxyvitamin D levels and presence of RH.
Department of Cardiology at Okmeydanx0131; Training and Research Hospital, Istanbul, Turkey.
Erdal
E
Belen
İrfan
İ
Şahin
Barış
B
Güngör
Burak
B
Ayça
İlhan İlker
İİ
Avcı
Murat
M
Avşar
Suleyman Sezai
SS
Yıldız
Fatih
F
Akın
Emrah
E
Bozbeyoglu
Ertugrul
E
Okuyan
D000959:Antihypertensive Agents / Q000627:therapeutic use; D018660:Blood Pressure Monitoring, Ambulatory; D003430:Cross-Sectional Studies; D004351:Drug Resistance; D005260:Female; D006801:Humans; D006973:Hypertension / Q000188:drug therapy*; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D010281:Parathyroid Hormone / Q000097:blood; D011446:Prospective Studies; D012372:ROC Curve; D012680:Sensitivity and Specificity; D014807:Vitamin D / Q000031:analogs & derivatives* / Q000097:blood
D000959:Antihypertensive Agents; D010281:Parathyroid Hormone; D014807:Vitamin D; C104450:25-hydroxyvitamin D