Objective To investigate the relationship between vitamin D and essential hypertension (EH) with impaired glucose tolerance (IGT) by observing the status of serum 25-hydroxyvitamin D3 [25(OH) D3] and to explore the affecting factors.

Methods 499 cases of essential hypertensive inpatients (Oct. 2010 to Sep.2012) were involved. All the subjects are of Han nationality including 259 males and 240 females, with the average age of (53.91 ± 11.85), no oral antihypertensive drugs before hospitalizations. If the fasting plasma glucose (FPG) was normal, then did the oral glucose tolerance test (OGTT). According to the FPG and 2 hours post-load glucose (2hPG), subjects were divided into two groups: (EH, n = 309), (EH+IGT, n = 190). Clinical data were compared between the two groups, and to analyse the serum 25(OH)D3 status differences.

Results EH+IGT patients showed decreased 25(OH)D3 level and increased vitamin D deficiency and insufficient rate as compared with EH cases [(12.01 ± 4.83)ng/ml vs (13.23 ± 5.70)ng/ml, 99.5% vs 98.4%, all P < 0.05]. Serum 25(OH)D3 level was higher among males in both group [EH, (14.24 ± 5.81)ng/ml vs (12.19 ± 5.39)ng/ml, EH+IGT, (12.99 ± 4.99)ng/ml vs (10.88 ± 4.40)ng/ml, P < 0.05]. Serum 25(OH) D3 level and clinic systolic blood pressure (r = –0.321, P < 0.001), clinic diastolic blood pressure (r = –0.343, P < 0.001) were negatively correlated, after the gender, age, duration of hypertension, body mass index, blood lipids and other factors were corrected.

Conclusions Vitamin D deficiency and insufficient exists generally among the Han EH patients with IGT. Serum 25(OH)D3 level decreases much obviously, especial among the female patients.