Early Renal Damage in Young Hypertensive Subjects: Link With Office and 24-Hour Ambulatory Systolic and Diastolic Blood Pressure

Abstract

Objective: Hypertension (HTN) and target organ damage rate in young subjects is underestimated in clinical practice according to latest population studies and treatment strategy of HTN is not well defined due to minor and controversial data of clinical studies. As a part of cohort study of HTN detection and evaluation in young population we investigated renal function in untreated hypertensive subjects with primary diagnosed essential hypertension. Design and method: We performed office BP evaluation and ambulatory blood pressure monitoring with oscillometric cuff-based device in 102 young subjects with untreated essential hypertension defined with ESH criteria of HTN according to office and ambulatory blood pressure monitoring (age 26.2 ± 7.7 (M ± SD) years, 88.3% male, office SBP 134.7 ± 15.8 mm Hg, office DBP 73.2 ± 12.4 mm Hg). Serum creatinine and albumin/creatinine ratio in urine were measured. GFR was calculated with CKD-EPI. For comparison of variables in quartiles of blood pressure we used one-way ANOVA for parametric ones and Kruskal-Wallis test – for non-parametric variables. Results: We compared glomerular filtration rate (GFR) and albumin/creatinine ratio (ACR) in quartiles of office and 24 h systolic and diastolic blood pressure. Significant difference in GFR was registered in office SBP quartiles: GFR in 1st and 4th quartiles was 105,1 ± 21,7 vs 90,3 ± 14 ml/min/1,73m2, with F 4.035, P value 0,0097 while there was no any significant difference of ACR levels according to office BP levels. ACR was significantly different in quartiles of mean nighttime DBP: ACR median in 1st quartile – 4 [0,75; 5,0] vs 8 [3,0; 29,0] in last quartile, P value 0,0056 with no significant difference for daytime DBP and daytime and nighttime SBP. Significant correlation between mean nighttime DBP and ACR was observed: r 0,243, P value 0,023. R for office SBP and GFR was (-0,325) with P value 0,002. Conclusions: In young untreated hypertensive subjects elevation of office SBP is associated with GFR decline while ACR has association with nighttime DBP elevation.