Association of microalbuminuria and left ventricular hypertrophy

Sir, We read the interesting article – the association of microalbuminuria and left ventricular hypertrophy – by Dell'Omo et al. [1] for hypertensive non-diabetic men, which is similar to our findings in hypertensive patients with type 2 diabetes mellitus [2, 3]. The hypothesis of humoral factors (cardiac natriuretic peptides, renin, angiotensin II and insulin) as a link between left ventricular hypertrophy and microalbuminuria in hypertensive subjects is attractive. Nevertheless we would like to suggest some additional considerations that focus on the haemodynamic status of these patients. Different left ventricular geometric patterns seem to be related to peculiar conditions of volume and pressure overload; in particular, concentric hypertrophy is associated with elevated total peripheral resistances and high pulse pressure/stroke volume index ratio, an index of arterial stiffening [4, 5]. Pulse pressure is also positively associated with albumin excretion rate [6]; thus a common kind of haemodynamic overload can be found, perhaps with a causative role, both in patients with left ventricular concentric hypertrophy and in subjects with elevated urinary albumin excretion rate. Alternatively, low serum levels of HDL cholesterol, which have been associated both with microalbuminuria [7] and left ventricular hypertrophy [8], could be the determinants of the simultaneous presence of an elevated arterial stiffening and a renal damage with abnormal urinary albumin excretion. In our hypertensive diabetic patients, microalbuminuria was associated with left ventricular concentric hypertrophy and elevated total peripheral resistances but not with an higher pulse pressure/stroke volume index ratio [2]. These findings do not fit with data reported in the article we are commenting, as relative wall thickness could not explain the different distributions of microalbuminuria amongst the different geometric patterns. However, normoalbuminuric hypertensive patients with high-normal albuminuria are characterized by greater relative wall thickness and more frequent left ventricular hypertrophy than those with lower urinary albumin values [9]. We believe that haemodynamic status could be at least one of the links between elevated urinary albumin excretion rate and left ventricular hypertrophy in hypertensive patients. No conflict of interest was declared.