Target organ effects in untreated hypertension

The parallel investigation of the renal and cardiac complications of recent and never treated systemic hypertension has only rarely been undertaken. The aim of this study was to define the renal function of never treated hypertensive subjects, separated into white coat hypertensives (HTbb: n = 19, BP at consultation 153/97 mmHg) or permanent hypertensives (HT: n = 49, BP at consultation 169/104 mmHg) as a function of their 24 hour BP. Their renal functions were then compared with those of normotensive subjects (NT: n = 10). The 68 hypertensive subjects seen consecutively underwent renal function investigation (DFG: glomerular filtration rate, DPR: renal plasmatic debit, and muAlb: microalbuminuria over 24 hours), and myocardial echography (measurement of the left ventricular mass index, IMVG). The white coat hypertensives had a normal renal function, while the permanent hypertensives had a significant decrease in DPR and a significantly higher muAlb compared to the normotensives. Compared to the white coat hypertensives, the permanent hypertensives had a significantly lower DFG and DPR, as well as a higher muAlb and IMVG. In all the hypertensives (white coat and permanent) the 24 hour systolic BP was significantly correlated with muAlb (r = 0.51, p < 0.001), filtration fraction (r = 0.30, p < 0.05), and IMVG (r = 0.52, p < 0.001). The renal and myocardial parameters were not significantly correlated. In conclusion, there seems to be a continuum between the level of ambulatory BP and the effect on target organs without a parallel progression of the renal and myocardial effects. From a practical point of view, only ambulatory BP measurement allows differentiation of permanent hypertensives who have a very early renal and/or myocardial effect, while white coat hypertensives are spared.