The Impact Of Different Periods Of Dynamic Pulse Pressure Index On The Target Organ Damage In Hypertensive Patients

Objective: Observe the relationship between different periods of the dynamic pulse pressure index(PPI) and target organ damage in essential hypertensive patients, and to explore the impact of different periods of PPI on hypertensive target organ damage.Methods: 553 patients with essential hypertension who had never been treated by antihypertensive drug were enrolled in 5th department of Cardiology of Second Hospital of Dalian Medical University from September 2013 to January 2015. The baseline information including age, gender, smoking history, height, weight, and the biochemical testing from blood sample which were cholesterol(CHOL), low-density lipoprotein cholesterol(LDL-C), high density lipoprotein cholesterol(HDL-C), triglyceride(TG) and homocysteine(Hcy) were recorded too. 24-hour, day and night PPI were calculated based on 24-hour ambulatory blood pressure measurement results after recording 24-hour ambulatory blood pressure respectively. Each period of PPI were divided into PPI<0.4 group and PPI≥0.4 group. All enrolled patients were examined by echocardiography, carotid ultrasonography, cranial CT scan, funduscopy and fasting blood tests to get serum cystatin C(Cys C) and collect data related target organ damage. We tested the difference of different periods of PPI between patients with hypertensive target organ and those no corresponding target organ damage. We also compared the incidence of target organ damage in PPI<0.4 group and PPI≥0.4 group of different periods in essential hypertensive patients. Then we analyzed correlation of gender, age, smoking history, CHOL, LDL-C, HDL-C, TRIG, Hcy, BMI and PPI of different periods in different target organ damage in essential hypertensive patients. We also investigated the predictive value of different periods of PPI for different hypertensive target organ damage in essential hypertensive patients.Results: 1. PPI has gender difference. The proportion of male is higher than female in 24-hour PPI<0.4 group, and the proportion of female is higher than male in 24-hour PPI≥0.4 group.The difference is statistically significant. The age, CHOL, LDL-C and Hcy levels in 24-hour PPI≥0.4 group are higher than those in 24-hour PPI<0.4 group and the difference has statistical significance. The HDL-C level in 24-hour PPI≥0.4 group is lower than that in 24-hour PPI<0.4 group and the difference is statistically significant. There is no significant difference between the TG level and BMI in two groups.2. The 24-hour, daytime and nighttime PPI of essential hypertensive patients with cardiac, cerebral, carotid, renal and retinal target organ damage are higher than the patients with corresponding non-target organ damage. The difference is statistically significant.3. The incidence of the target organ damage of heart, brain, carotid, renal and retinal in hypertensive patients in 24-hour, daytime and nighttime PPI≥0.4 group were higher than that of the PPI<0.4 group. The difference was statistically significant(P<0.05).4. Correlation analysis shows that the marker of heart, brain, carotid, renal and retinal damage are positively correlated with 24-hour, day and night PPI. Furthermore, LVMI is positively correlated with age; left ventricular geometry is positively correlated with age, and negatively correlated with gender; IMT are positively correlated with age, CHOL, LDL-C and Hcy; ischemic stroke is positively correlated with age, smoking history, Hcy, but negatively correlated with BMI; Cys C level and funduscopic grade of retina are positively correlated with age.5. Stepwise regression analysis shows that in hypertensive patients increasing daytime PPI is independent risk factor for left ventricular hypertrophy; nighttime PPI increasing is an independent risk factor for increasing of IMT and Cys C.Conclusion: 1. PPI has gender difference. Female is predominant in PPI≥0.4 group.2.The 24-hour, daytime and nighttime PPI of essential hypertensive patients with target organ damage are significantly higher than those without target organ damage.3.The incidence of different hypertensive target organ damage in 24-hour, daytime and nighttime PPI≥0.4 group is higher than that in PPI<0.4 group.4. There are different effects of different periods PPI on hypertensive target organ damage, while increasing daytime PPI is an independent risk factor for left ventricular hypertrophy and increasing nighttime PPI is an independent risk factor for IMT thickening and kidney damage.