N-terminal pro-atrial natriuretic peptide reflects cardiac remodelling in stage 1 hypertension

Sodium accumulation in the skin is associated with higher density of skin lymphatic vessels in patients with arterial hypertension

PURPOSE

Recent studies, conducted mainly on the rodent model, have demonstrated that regulatory pathway in the skin provided by glycosaminoglycans, nuclear factor of activated T cells 5 (NFAT5), vascular endothelial growth factor C (VEGF-C) and process of lymphangiogenesis may play an important role in extrarenal regulation of sodium (Na+) balance, body water volume, and blood pressure. We aimed to investigate the concentrations and relations among the main factors of this pathway in human skin to confirm that this regulatory axis also exists in humans.

PATIENTS AND METHODS

Skin specimens from patients diagnosed with arterial hypertension and from control group were histologically and molecularly examined.

RESULTS

The primary hypertensive and control groups did not differ in Na+ ​concentrations in the skin. However, the patients with hypertension and higher skin Na+ concentration had significantly greater density of skin lymphatic vessels. Higher skin Na+concentration was associated with higher skin water content. In turn, skin water content correlated with factors associated with lymphangiogenesis, i.e. NFAT5, VEGF-C, and podoplanin (PDPN) mRNA expression in the skin. The strong mutual pairwise correlations of the expressions of NFAT5, VEGF-C, vascular endothelial growth factor D (VEGF-D) and PDPN mRNA were noted in the skin in all of the studied groups.

CONCLUSIONS

Our study confirms that skin interstitium and the lymphatic system may be important players in the pathophysiology of arterial hypertension in humans. Based on the results of our study and existing literature in this field, we propose the hypothetical model which might explain the phenomenon of salt-sensitivity.

The diagnostic performance of mid-regional portion of pro-atrial natriuretic peptide for the detection of left ventricular hypertrophy in Caucasian hypertensive patients

Left ventricular hypertrophy (LVH) is predictive of cardiovascular disease. The vasodilator, natriuretic and diuretic actions of atrial natriuretic peptide (ANP) support a role in the pathophysiology of hypertension. Measuring the redundant precursor fragment mid-regional portion of pro-atrial natriuretic peptide (MRproANP) overcomes the technical difficulties of quantifying the bioactive ANP. This study sought to investigate the diagnostic and prognostic utility of MRproANP in a hypertensive Caucasian patient population. A total of 194 hypertensive patients (39 patients with LVH, 69±7.82 years of age, 74% female vs 155 patients without LVH, 68±6.51 years of age, 71% female) were derived from a screening study. Plasma MRproANP concentrations were quantified using immunoluminometric assays. Hypertensive patients with LVH had higher MRproANP concentrations than those without LVH (103.04 (50.58) vs 84.11 pmol l(-1) (44.82); P=0.014). Independent predictors of left ventricular mass index were LogMRproANP (P=0.022), male gender (P<0.001), body mass index (P=0.001) and history of angina or myocardial infarction (P=0.009). The receiver operating curve for MRproANP for the detection of LVH was limited, yielding an area under the curve of only 0.628 (confidence interval 0.523-0.733; P=0.014). Therefore, the role of MRproANP may not lie in the diagnosis of LVH but in monitoring the response to therapy. A nonsignificant trend towards greater mortality in patients with above-median MRproANP levels compared with below-median levels (P=0.167) was observed. Larger studies are required to assess its prognostic utility further.