A clinical analysis of the association between vitamin D level and morning blood pressure surge in elderly hypertensive patients

Objectives To explore the relationship of vitamin D level with the parameters of ambulatory blood pressure and morning blood pressure surge in elderly hypertensive patients. Methods 102 elderly hypertensive patients aged 60~81 years with 59male and 43female were included.25-hydroxy vitamin D levels in the patients were categorized into sufficiency group(≥50 nmol/L)and deficient group(<50 nmol/L). The biochemistry and ambulatory and office blood pressure parameters were compared between the two groups.The simple correlations of 25-hydroxy vitamin D with ambulatory and office blood pressure parameters and blood glucose were analyzed.The relative factors of morning blood pressure surge and association of different 25-hydroxy vitamin D levels with morning blood pressure surge were observed. Results Compared with sufficient group, deficient group had higher levels of body mass index, office systolic blood pressure, 24 h systolic blood pressure, day systolic blood pressure, night systolic blood pressure and morning blood pressure surge, but showed lower night blood pressure decrement.25-hydroxy vitamin D level showed an negative correlation with fasting plasma glucose, body mass index, office systolic blood pressure, 24 h systolic blood pressure, day diastolic blood pressure, night systolic blood pressure and morning blood pressure surge, but a positive correlation with night blood pressure decrement(P<0.05). Multiple logistic regression analysis showed that 25(OH)D3 and body mass index were risk factors for morning blood pressure surge(P<0.01)in the elderly hypertensive patients.With the decrease of 25-hydroxyvitamin D level, the incidence of morning blood pressure surge was increased(OR=3.306, 95%CI: 1.075-10.168, P=0.037; OR=4.019, 95%CI: 1.519-10.634, P=0.005). Conclusions 25-hydroxyvitamin D level shows a negative correlation with fasting plasma glucose, body mass index, office systolic blood pressure, 24 h systolic blood pressure, day diastolic blood pressure, night systolic blood pressure, and a positive correlation with night time blood pressure decrease.The incidence of morning blood pressure surge increases as 25-hydroxyvitamin D level decreases. Key words: Hypertension; Vitamin D; Blood pressure determination