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

AbstractIntroduction 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 in healthy 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 patients with hypertension according to the degree of hypertension severity.Design and methods Patients with hypertension prescribed ≥2 antihypertensive agents were selected from a multicentre study. Healthy controls were selected from an ongoing study of living kidney donor candidates. Uncontrolled hypertension was defined as systolic daytime ambulatory blood 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) controlled hypertension; (2) uncontrolled hypertension without kidney HMOD; (3) uncontrolled hypertension with kidney HMOD. Fifteen biomarkers were analysed using a Luminex bead-based immunoassay, and nine fell within the specified analytical range.Results Plasma levels of Interleukin 1 receptor antagonist (IL-1RA), neutrophil gelatinase-associated lipocalin (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 uncontrolled hypertension without (n = 59) and with (n = 62) kidney HMOD. In models adjusted for cardiovascular risk factors and eGFR, osteopontin (OPN) was associated with uncontrolled hypertension without kidney HMOD (odds ratio (OR) 1.77 (1.05–2.98), p = 0.03), and regulated upon activation normal T-cell expressed and secreted (RANTES) with uncontrolled hypertension with kidney HMOD (OR 0.57 (0.34–0.95), p = 0.03).Conclusions None of the biomarkers could differentiate our hypertension groups when established risk factors were considered. Plasma OPN may identify patients with uncontrolled hypertension at risk for kidney HMOD

Inotropic responses to serotonin and to isoproterenol in ventricles from foetal and neonatal hearts and left ventricular papillary muscles from 113-day-old, Sham and HF rats.

<p>Positive inotropic response to serotonin (10 µM) in ventricles from foetal and neonatal rats and papillary muscles from normal adult (day 113), Sham and HF rats driven at 1 Hz in the presence of prazosine (0.1 µM), timolol (1 µM) and atropine (1 µM); ketanserin (0.1 µM; A) or GR113808 (1 µM; B) and inotropic response to subsequent addition of isoproterenol (100 µM; C). The contractile response to serotonin or isoproterenol was measured after stabilisation at its maximum within 2–7 minutes as previously demonstrated <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0045489#pone.0045489-Qvigstad1" target="_blank">[13]</a>. Panels show maximum inotropic response in % above basal. *<i>vs</i>. group indicated p<0.05; #HF <i>vs</i>. Sham p<0.05.</p

Expression profiles of mRNA markers of cardiac phenotypes.

<p>Messenger RNA expression in cardiac ventricles from foetal (day 3 and 1 before expected birth; days -3 and -1), neonatal (day 1, 3 and 5 after birth; days 1, 3 and 5), adult (day 113), Sham and HF rats. (A) Expression of ANP mRNA increases at birth and in HF; (B) MHC-α mRNA expression increases at birth and during transition from neonatal to adult and decreases in HF; (C) MHC-β mRNA expression demonstrates a transitional increase at birth and an increase in HF; (D) The ratio of MHC-β over MHC-α mRNA expression confirms transition in phenotype from foetal to adult and from Sham to HF. The results are normalised to the geometric mean of Arbp, Tbp, Rpl4 and Rpl32 and presented relative to day 113 (assigned value 1) for foetal and neonatal, and to Sham (assigned value 1) for HF. *<i>vs</i>. day 113 p<0.05; **<i>vs</i>. day 113 p<0.01; ***<i>vs</i>. day 113 p<0.001; ##HF <i>vs</i>. Sham p<0.01.</p

Animal characteristics of Sham and HF rats.

<p>Animal characteristics are given as mean values ± SEM. LVEDP, left ventricular end diastolic pressure; LVSP, left ventricular systolic pressure; LVDd, left ventricular diameter diastole; LVFS, left ventricular fractional shorting; LAD, left atrial diameter;</p>*<p>HF vs. Sham p<0.05;</p>***<p>HF vs. Sham p<0.001.</p

Correlation between the MHC-β/MHC-α mRNA expression ratio and the 5-HT₄ mRNA expression level in ventricles from foetal and neonatal hearts and left ventricular papillary muscles from 113-day-old, Sham and HF rats.

<p>The ratio of MHC-β to MHC-α mRNA levels and 5-HT₄ mRNA level showed a proportional relationship with a slope which significantly deviated from zero, p<0.0001 (linear regression analysis).</p

Expression of 5-HT_4(b), 5-HT_2A, 5-HT_2B and 5-HTT mRNA in left ventricular myocardium.

<p>Messenger RNA expression in cardiac ventricles from foetal (day 3 and 1 before expected birth; days -3 and -1), neonatal (day 1, 3 and 5 after birth; days 1, 3 and 5), adult (day 113), Sham and HF rats. (A) 5-HT_4(b) mRNA levels decreased with foetal and neonatal development and the level in adult myocardium was one tenth of that at day -3 but reappeared in HF; (B) 5-HT_2A mRNA expression increased at birth (day 1), decreased during neonatal development and was unaltered in HF; (C) 5-HT_2B mRNA expression was transiently increased at birth (day 1) compared to adult (day 113) and not changed in HF; (D) 5-HTT mRNA expression was lower in foetal hearts compared to neonatal, adult, Sham and HF which all showed a similar expression level. The results are normalised to the geometric mean of Arbp, Tbp, Rpl4 and Rpl32 and presented relative to day 113 (assigned value 1) for foetal and neonatal or to Sham (assigned value 1) for HF. *<i>vs</i>. day 113 p<0.05; **<i>vs</i>. day 113 p<0.01; ***<i>vs</i>. day 113 p<0.001; ##HF <i>vs</i>. Sham p<0.01.</p

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

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 in healthy 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 patients with hypertension according to the degree of hypertension severity. Patients with hypertension prescribed ≥2 antihypertensive agents were selected from a multicentre study. Healthy controls were selected from an ongoing study of living kidney donor candidates. Uncontrolled hypertension was defined as systolic daytime ambulatory blood pressure ≥135 mmHg. Kidney HMOD was defined by ACR > 3.0 mg/mmol or eGFR 2. Patients with hypertension were categorised into three groups: (1) controlled hypertension; (2) uncontrolled hypertension without kidney HMOD; (3) uncontrolled hypertension with kidney HMOD. Fifteen biomarkers were analysed using a Luminex bead-based immunoassay, and nine fell within the specified analytical range. Plasma levels of Interleukin 1 receptor antagonist (IL-1RA), neutrophil gelatinase-associated lipocalin (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 uncontrolled hypertension without (n = 59) and with (n = 62) kidney HMOD. In models adjusted for cardiovascular risk factors and eGFR, osteopontin (OPN) was associated with uncontrolled hypertension without kidney HMOD (odds ratio (OR) 1.77 (1.05–2.98), p = 0.03), and regulated upon activation normal T-cell expressed and secreted (RANTES) with uncontrolled hypertension with kidney HMOD (OR 0.57 (0.34–0.95), p = 0.03). None of the biomarkers could differentiate our hypertension groups when established risk factors were considered. Plasma OPN may identify patients with uncontrolled hypertension at risk for kidney HMOD. In order to tailor individualised hypertension treatment, a risk assessment for cardiovascular disease (CVD) must be performed. This includes evaluation of established hypertension-mediated organ damage (HMOD), such as the presence of kidney damage and associated risk factors. Today, kidney function is assessed by blood and urine samples. However, today’s blood and urine samples are not sensitive enough to capture kidney damage due to hypertension at a stage when prevention may be most effective. In this study, we evaluated plasma levels of biomarkers related to endothelial and kidney cell pathology, inflammation and fibrosis in healthy patients and patients with hypertension. We hypothesised that plasma levels of biomarkers could differentiate between different degrees of hypertension severity. Healthy controls had lower Interleukin 1 receptor antagonist (IL-1RA) and neutrophil gelatinase-associated lipocalin (NGAL) levels, but higher uromodulin compared to patients with hypertension. Except for osteopontin (OPN), all biomarkers showed significant trends in median biomarker levels across study groups. However, as hypertension severity increased, the median plasma OPN levels also rose. None of the biomarker could consistently differentiate the hypertension severity groups after considering established risk factors. However, OPN may be an early biomarker for kidney damage in hypertension. Biomarkers for early detection of organ damage in hypertension may guide targeted treatment. Plasma OPN may have potential to identify those at risk for hypertensive kidney damage. However, the studied biomarkers lack consistent discrimination across hypertension severity levels.</p