Morning Hypertension as a Factor Independently Associated with Renal Dysfunction in Hypertensive Patients with Chronic Kidney Disease

Abstract

Background and Objectives: Hypertension is highly prevalent among individuals with chronic kidney disease (CKD) and contributes substantially to both cardiovascular morbidity and progressive renal dysfunction. Ambulatory blood pressure monitoring (ABPM) provides superior diagnostic accuracy compared with office measurements and is recommended for evaluating blood pressure patterns and hypertension-mediated organ damage in CKD. Morning blood pressure, in particular, has gained increasing attention due to its association with adverse cardiovascular and renal outcomes. However, evidence regarding the independent impact of morning hypertension in CKD remains limited. This study aimed to determine the prevalence of morning and nocturnal hypertension phenotypes in hypertensive CKD patients and to evaluate their associations with renal and cardiac target organ damage. Materials and Methods: A total of 132 patients with CKD stages 1–5 underwent 24-h ABPM, transthoracic echocardiography, and comprehensive biochemical evaluation. Morning and nocturnal hypertension were defined according to ESC 2024 guidelines. Demographic, clinical, echocardiographic, and renal parameters were compared between groups. Correlation analyses were performed to explore associations between blood pressure phenotypes and markers of target organ damage. Multivariable regression models were used to assess independent predictors of renal and cardiac structural alterations. Results: Morning hypertension was present in 42.4% of patients, whereas nocturnal hypertension was detected in 78%. Patients with morning hypertension exhibited significantly lower eGFR and higher UACR levels (both p < 0.001). Morning hypertension showed positive correlations with creatinine, urea, PTH, ESR, and UACR, and negative correlations with eGFR, albumin, calcium, hemoglobin, and TAPSE. In multivariable regression, morning hypertension was independently associated with lower eGFR (β = −0.26; p = 0.002). Nocturnal hypertension was positively associated with IVSd (β = 0.19; p = 0.024) and UACR, supporting its role in cardiac remodeling and renal injury. Conclusions: Morning hypertension may represent a clinically relevant blood pressure phenotype in CKD and may be associated with markers of renal dysfunction; however, longitudinal studies are needed to determine its prognostic significance. The strong associations of nocturnal hypertension with IVSd and albuminuria further highlight the importance of evaluating 24-h blood pressure patterns. Incorporating ABPM into routine clinical practice may enhance risk stratification and guide individualized treatment strategies in CKD.