Evaluation of renal volume by ultrasonography in patients with essential hypertension in Ile-Ife, south western Nigeria

Background and aims: To determine renal volume in adult patients with essential hypertension and correlate it with age, sex, body mass index (BMI), body surface area (BSA) and duration of hypertension. Patients and methods: A total of 150 patients (75 males, 75 females) with essential hypertension and normal renal status were evaluated sonographically in this prospective study. Fifty healthy individuals (25 males, 25 females) without hypertension were also evaluated as control. Renal volume was then calculated from the kidney’s length, width and anterio-posterior diameter using the formula L*W*AP*0.523. Results: The range of renal volume obtained was 51.65-205.02 cm3, with a mean of 114.06±29.78 cm3 for the left kidney and 47.37-177.50 cm3 with a mean of 106.14±25.42 cm3 for the right kidney. The mean volumes of the right and left kidneys in males (112.98±25.56 cm3 and 123.11±32.49 cm3, respectively), were significantly higher than in females (99.31±23.07 cm3 and 105.01±23.77 cm3, respectively). Renal volume correlated significantly with BSA and BMI, but decreased with age. The renal volume showed no correlation with duration of hypertension. Conclusion: Renal volume is higher in the left than the right kidney in hypertensive patients of both sexes and female hypertensive patients have smaller kidney size compared to males. The study also shows that volume of both kidneys decreases with age and positive correlation between renal volume, BSA and BMI. However, there is no correlation between renal size and duration of hypertension.Keywords: essential hypertension; renal volume; ultrasonograph