FOREARM BLOOD-FLOW RESERVE AND CARDIAC AND RENAL INDEXES OF PRESSURE LOAD IN NORMOTENSIVE AND HYPERTENSIVE INDIVIDUALS

In response to hypertension, arterioles remodel their structure, the h eart develops myocardial hypertrophy? and the kidney reduces creatinin e clearance and increases albuminuria. To better understand the interr elations among the target organs involved in hypertension, we evaluate d minimal forearm vascular resistances - a hemodynamic index of arteri olar structure derived from mean blood pressure and maximal postischem ic forearm blood flow-the echocardiographic indexes of cardiac structu re, and urinary albumin excretion and creatinine clearance in 29 male mild to moderate non-macroalbuminuric essential hypertensive patients on no drugs and 11 age- and sex-matched normotensive control subjects. Minimal forearm resistances were elevated in hypertensive patients an d correlated with left ventricular mass, wall thickness, and mean arte rial pressure. Patients with abnormal minimal forearm resistances (2 S D above normal) were characterized by higher pressure, greater wall th ickness, lower creatinine clearance, and higher albumin excretion, sug gesting that maximal forearm flow capacity does relate to the hemodyna mic load exerted on both the kidney and heart. However, the correlatio n with cardiac structure and mean arterial pressure explained only par t of the variability of minimal forearm resistances. Furthermore, no c orrelation among these parameters was found when hypertensive patients were evaluated separately from normotensive subjects, possibly becaus e of heterogeneous factors active on arteriolar structure and unrelate d to the presser load. Overall, the data suggest that the development of abnormal minimal forearm resistances in the course of the hypertens ive process is related to the presser load, but its details need furth er understanding.