Hyperfiltration in lean essential hypertension.
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Adult↗
Biomedical subjects
G DuCailar
Publications and source records attributed to G DuCailar.
Contrasting effect of antihypertensive treatment on the renal response to L-arginine.
We assessed the renal hemodynamic response to L-arginine infusion (30 g within 60 minutes) in normotensive subjects, patients with never-treated essential hypertension, and hypertensive patients controlled by long-term (more than 2 years) treatment with or without an angiotensin-converting enzyme inhibitor. The renal vasodilator response to L-arginine observed in normotensive subjects (15 +/- 4% increase in effective renal plasma flow) was abolished in untreated hypertensive patients and restored only in the group treated by angiotensin-converting enzyme inhibition. In the whole population a positive correlation between the change in effective renal plasma flow and the change in urinary cGMP was obtained. It is suggested that abnormalities of the renal nitric oxide pathway not corrected by increased availability of L-arginine and reversible only on long-term treatment by angiotensin-converting enzyme inhibition may underlie the abnormal renal resistance observed in essential hypertension.
Adrenergic beta-Antagonists↗
Is microalbuminuria a marker of early intrarenal vascular dysfunction in essential hypertension?
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 high-density 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 glomerular filtration rate or a fall in filtration fraction was observed in normoalbuminuric patients only. In contrast, the renal vasodilator response was abolished in microalbuminuric subjects, together with blunting of the rise in plasma renin activity associated with captopril. This occurred despite similar indexes of activity of the endogenous renin-angiotensin system. It is suggested that microalbuminuria may be a marker of early functional or fixed intrarenal vascular dysfunction in never-treated lean patients with essential hypertension.
Adolescent↗
[Arterial hypertension, hyperinsulinism and insulin resistance].
The incidence of hypertension is increased in obesity, a state associated with an insulin resistance syndrome. By using an euglycemic clamp method, Ferrannini et al. demonstrated the existence of an insulin resistance state in patients with essential hypertension. However, the body mass index of the subjects studied appeared to be slightly excessive. This abnormality has not been observed in patients with secondary hypertension. Insulin resistance is probably localized to peripheral tissues such as muscles and may be associated with other cellular abnormalities. Can insulin resistance, characterized by a raised circulating insulin concentration in the presence of normal blood glucose, be responsible for certain "modifications" associated with essential hypertension? Insulin induces sodium retention and increases the aldosterone-secreting effect of angiotensin II. These effects are likely to promote a rise in blood pressure and an increase in the sensitivity of vessels to endogenous substances. Moreover, insulin is a known growth factor and is involved in lipoprotein metabolism. If insulin resistance plays an important role in the maintenance of complications of essential hypertension, it is important that the treatments used tend to correct this anomaly. Thiazide diuretics and beta-blockers aggravate insulin resistance while angiotensin converting-enzyme inhibitors correct this condition.
Adult↗
Converting enzyme inhibitors and renal function in essential and renovascular hypertension.
Converting enzyme inhibitors (CEI) are useful in the treatment of hypertension. However, acute renal deterioration may occur in some conditions in association with the crucial role of angiotensin in the regulation of glomerular filtration rate (GFR), such as volume depletion, severe stenosis of both renal arteries, and stenosis of a single functioning kidney. CEI-induced acute renal failure can develop in the absence of a fall in systemic pressure, is facilitated by prior sodium depletion, and is reversible upon discontinuation of treatment. In a personal study conducted in 28 patients with CEI-induced renal dysfunction (reversible after discontinuation of CEI), the incidence of stenosis of large renal vessels was 61%, whereas 39% of these subjects had no significant renal artery abnormalities. Although the occurrence of such a complication is not a convincingly accurate predictor of the existence of renovascular hypertension, angiographic detection of renal artery stenosis (bilateral or on a single-functioning kidney) may be justified in some of these patients.
Angiotensin-Converting Enzyme Inhibitors↗
Albuminuria in normals and essential hypertension.
The prevalence and determinants of urinary albumin excretion rate (AER) were assessed in lean and overweight normotensive subjects (NT) and patients with essential hypertension (EH). In NT and EH, the presence of overweight was associated with a significant exacerbation of AER. In the normotensive population, AER was higher in subjects with a positive family history of hypertension. An important role for smoking was observed in the hypertensive population; in fact, the prevalence of microalbuminuria (MA) was almost twofold in lean hypertensive smokers when compared to nonsmokers. Among other determinants of AER, a major influence of systolic arterial pressure, urinary excretion of urea (an estimate of protein intake), and high-density lipoprotein (HDL) cholesterol (inversely correlated with AER) was observed mainly in lean EH patients. The significance of microalbuminuria is unclear. Is it a marker of cardiovascular risk and/or a predictor of the future development of renal disease in EH?
Adolescent↗
Angiotensin II receptor antagonists and hypertension.
Over recent years, a number of imidazole derivatives that specifically bind to the angiotensin II type 1 receptor, thereafter called sartans, have been developed and made available to the clinician. Whether targeting antihypertensive treatment with such a high specificity within the renin cascade may carry major clinical advantage over inhibiting angiotensin converting-enzyme remains to be demonstrated. In short-term studies, the efficacy of these drugs at reducing blood pressure was similar to that of established comparators, whereas overall side effect profile was comparable to that of placebo.
Angiotensin II↗