Novel biomarkers in patients with uncontrolled hypertension with and without kidney damage

Abstract

Introduction: estimated glomerular filtration rate (eGFR) and urine albumin/creatinine ratio (acR)are insensitive biomarkers for early detection of hypertension-mediated organ damage (hMOD).in this nationwide cross-sectional study, we assessed potential biomarkers for early hMOD inhealthy persons and patients with hypertension. We hypothesised that plasma levels of biomarkers:(1) are different between healthy controls and patients with hypertension, (2): can classify patientswith hypertension according to the degree of hypertension severity.<p><p>Design and methods: Patients with hypertension prescribed ≥2 antihypertensive agents wereselected from a multicentre study. healthy controls were selected from an ongoing study of livingkidney donor candidates. Uncontrolled hypertension was defined as systolic daytime ambulatoryblood pressure ≥135 mmhg. Kidney hMOD was defined by acR > 3.0 mg/mmol or eGFR < 60 ml/min/1.73 m2. Patients with hypertension were categorised into three groups: (1) controlledhypertension; (2) uncontrolled hypertension without kidney hMOD; (3) uncontrolled hypertensionwith kidney hMOD. Fifteen biomarkers were analysed using a luminex bead-based immunoassay,and nine fell within the specified analytical range.<p>Results: Plasma levels of interleukin 1 receptor antagonist (il-1Ra), neutrophil gelatinase-associatedlipocalin (NGal) and uromodulin were significantly different between healthy controls (n = 39)and patients with hypertension (n = 176). in regression models, with controlled hypertension(n = 55) as the reference category, none of the biomarkers were associated with uncontrolledhypertension without (n = 59) and with (n = 62) kidney hMOD. in models adjusted forcardiovascular risk factors and eGFR, osteopontin (OPN) was associated with uncontrolledhypertension without kidney hMOD (odds ratio (OR) 1.77 (1.05–2.98), p = 0.03), and regulatedupon activation normal t-cell expressed and secreted (RaNtes) with uncontrolled hypertensionwith kidney hMOD (OR 0.57 (0.34–0.95), p = 0.03).<p>Conclusions: None of the biomarkers could differentiate our hypertension groups whenestablished risk factors were considered. Plasma OPN may identify patients with uncontrolledhypertension at risk for kidney hMOD.