Ankle-brachial index according to pulse pressure and microalbuminuria in hypertensive patients: a prospective study in family medicine.

INTRODUCTION

Microalbuminuria, as determined by the urinary albumin to creatinine (AC) ratio, is a marker of target organ damage (TOD) in hypertensive patients. Pulse pressure (PP) predicts arterial elasticity and the ankle-brachial index (ABI) is a marker of cardiovascular morbidity. TOD reduction should be achieved through improvements in these indices.

OBJECTIVE

To determine whether ABI, calculated as the ratio between mean PP in the upper and lower limbs, is associated with a reduction in renal damage, as measured by the AC ratio.

METHODS

This was a prospective interventional study based on an intention-to-treat analysis in an opportunity sample of patients treated by three specialists in family medicine, with three-monthly follow-up over a total of six months. Blood pressure was measured in arms and ankles, and PP was calculated and used to determine right and left ABI and mean overall ABI. The AC ratio was determined by urine dipstick test. Descriptive and inferential statistical analysis was performed.

RESULTS

A sample of 75 patients were studied (42.4% women), of whom(42.4% women), of whom 27.6% were diabetic, 46.7% overweight/obese and 49.3% dyslipidemic. overweight/obese and 49 dyslipidemic. There were statistical differences for right ABI (as determined by PP) and for mean overall ABI (as determined by mean PP in lower and upper limbs). Bivariate correlation analysis showed that in the group with improved PP between the first and the third observations, n=23 (40%), there was a statistically significant reduction in AC ratio (r = -0.924, two-tailed p < 0.001); the opposite was observed in the group with reduced PP, in which the AC ratio increased.

DISCUSSION

ABI determined by systolic blood pressure is an excellent predictor of hemodynamic alterations. Increased ABI, based on PP, was accompanied by improved urinary AC ratio. These results are in line with the international literature.

CONCLUSIONS

An improvement in urinary AC ratio--a predictor of TOD--is observed when an improvement in the ankle PP/brachial PP ratio is achieved.