Abstract: Objective To explore the change of nicotinamide adenine dinucleotide（NAD⁺） in aorta and peripheral blood mononuclear cells（PBMCs） in hypertensive patients and its relationship with blood pressure and vascular function. Methods Aortic tissues were collected from 3 patients with hypertension and 3 healthy controls. The NAD⁺ level in aorta was determined by high performance liquid chromatography-mass spectrometry（HPLC-MS）. Thirty patients with essential hypertension and 30 healthy subjects were recruited. The concentration of NAD⁺ in PBMCs was measured. Brachial-ankle pulse wave velocity（baPWV） and flow-mediated dilation（FMD） were used to evaluate vascular function. The concentrations of NAD⁺ in aortic tissue and PBMCs between patients with essential hypertension and healthy controls were compared. Pearson correlation analysis and multivariate logistic regression analysis were used to analyze the correlation between NAD⁺ level in PBMCs and blood pressure, baPWV and FMD. Results Compared with the control group, the NAD⁺ level in aortic tissue was significantly decreased in the hypertensive group （12.71±3.62） vs（31.28±6.69） pmol/mg tissue, t=4.228, P=0.013. The concentration of NAD⁺ in PBMCs of hypertensive patients was also significantly lower （7.76±5.43） vs（16.15±8.70） pmol/mg protein, t=2.752, P=0.009, accompanied by increased baPWV （1 653.00±271.80） vs（1 279.00±196.80） cm/s, t=6.114, P＜0.001 and decreased FMD （5.43±2.41）% vs（7.04±1.95）%, t=1.974, P=0.004. Linear correlation analysis showed that NAD⁺ in PBMCs was negatively correlated with systolic blood pressure（r=-0.508, P＜0.001）, diastolic blood pressure（r=-0.460, P＜0.001）, baPWV（r=-0.559, P＜0.001） and positively correlated with FMD（r=0.528, P＜0.001）. Multivariate logistic regression analysis showed that NAD⁺ levels in PBMCs were independently correlated with FMD（OR=0.877, 95%CI 0.799-0.963, P=0.006）, baPWV（OR=0.906, 95%CI 0.836-0.982, P=0.017）, systolic blood pressure（OR=0.823, 95%CI 0.733-0.924, P=0.001） and diastolic blood pressure（OR=0.878, 95%CI 0.792-0.973, P=0.013）. Conclusion NAD⁺ levels in the aorta and PBMCs are decreased in hypertensive patients, and the NAD⁺ level in PBMCs is closely related to hypertensive vascular dysfunction.