Is microalbuminuria a marker of early intrarenal vascular dysfunction in essential hypertension?

Abstract

The relation between basal intrarenal hemodynamics and the renal response to acute inhibition of angiotensin-converting enzyme by captopril and albuminuria was assessed in 106 lean patients with essential hypertension without detectable proteinuria. It was observed that the microalbuminuric group (24.5% of the total population) was characterized by a higher systemic arterial pressure, a lower level of highdensity lipoprotein cholesterol, and similar mean values of age, duration of hypertension, glomerular filtration rate, renal plasma flow, filtration fraction, and plasma renin activity when compared with normoalbuminuric subjects. In response to captopril, a significant renal vasodilatation without a change in M icroalbuminuria (urinary excretion of albumin lower than 200 /xg/min) was proposed as a reliable predictor of the development of overt (proteinuric) nephropathy in patients with insulin-dependent diabetes 1 and of cardiovascular morbidity and mortality in diabetic 2 -3 and nondiabetic 4 populations. The mechanisms and significance of microalbuminuria observed in some patients with essential hypertension are not clearly elucidated because of the lack of simultaneous assessment of the relation between albuminuria and intrarenal hemodynamics and long-term follow-up studies. In the present studies, an attempt was made to evaluate the systemic and renal determinants of microalbuminuria in a population of never-treated patients with mild to moderate hypertension of rather short duration. In addition, the renal response to acute blockade of angiotensin-converting enzyme was assessed to detect contrasting effects in microalbuminuric (MA+) and normoalbuminuric (MA-) patients. Only lean patients were included to eliminate the possible exacerbating influence of overweight in association with high blood pressure on the urinary excretion of albumin. 5 Methods PatientsOne hundred six lean patients (34 women and 72 men) with mild to moderate essential hypertension were included in this study. Age range was 16 to 64 years, and body mass index was lower than 26 kg/m 2 in women and 27 kg/m 2 in men. All subjects had never received antihypertensive medication before participating in the studies. Women on oral contraceptives as well as patients with albustix-positive proteinuria were

Microalbuminuria is associated with unfavourable cardiac geometric adaptations in essential hypertensive subjects

“…Furthermore, it has been hypothesised that microalbuminuria is a marker of Journal of Human Hypertension endothelial dysfunction and increased vascular permeability that might predispose to greater penetration of atherogenic lipoprotein particles into arterial wall. 20,21 Towards this end, we have previously reported that microalbuminuria is associated with excess impairment of large arteries mechanics in essential hypertension, 7 a state which is closely related with LV structural and functional changes. 22 So, it is reasonable to suggest that microalbuminuria is closely related with unfavorable LV geometric patterns through its widespread damage of the arterial tree.…”

Microalbuminuria, an integrated marker of cardiovascular risk in essential hypertension

“…In contrast to diabetic patients in whom microalbuminuria is frequently accompanied by hyperfiltration and anticipates a decline in renal function, 128 hypertensive microalbuminuria is characterised by unchanged glomerular filtration rate, reduced renal plasma flow, increased filtration fraction, elevated vascular resistance [129][130][131][132] and exhaustion of the renal functional reserve. 133 Recent cross-sectional reports in non-diabetic populations 51 do, however, suggest a more complicated picture.…”

Microalbuminuria in urban Zimbabwean women

“…[14][15][16][17][18][19][20] In addition, MAU is a marker of early intrarenal vascular dysfunction in lean essential hypertensives. 21,22 It is also associated with the inflammatory processes that occur in a variety of diseases including trauma and sepsis. 23 An elevated level of ␤ 2 -microglobulin in the urine is also associated with a variety of diseases and may be caused by disruption of tubular function rather than glomerular function.…”