Pattern of urinary sediments and comparison with dipstick urinalysis in hypertensive Nigerians

Urinary sediment examination and dipstick urinalysis are an integral part in evaluating hypertensive patients. This study aims to determine the prevalence of urinary sediment abnormalities and compare this result with dipstick urinalysis in hypertensive Nigerians.

138 newly diagnosed, adult, hypertensive Nigerians were studied. They were compared with an age- and sex-matched non-hypertensive control group from the general population. The subjects' urine samples were analyzed by dipstick test and microscopy (bright field), enhanced by Sternheimer's stain. Significant sediments were defined as =3/hpf and dipstick proteinuria or hematuria as =1+.

Mean age was 43.21±9.64 yrs and 43.19±9.55 yrs in patients and controls respectively with 76 (55%) males in the patients and 80 (58%) in controls. Microscopic hematuria (=3/hpf) was detected in 15.2% of the patients and 3.6% of the control group (p=0.0009).Other elements present in insignificant quantities in patients and controls, respectively, were: leukocytes (7.2%, 9.4%, p=0.513); hyaline casts (5.8%, 8%, p=0.476), granular casts (1.4%, 0%) and crystals (6.5%, 5.1%, p=0.606). Dipstick proteinuria with hematuria was found in 6.55% and proteinuria alone in 1.45% of cases, while the control group showed 2.2% and 1.45% of hematuria and proteinuria, respectively; 47.6% of hypertensive patients with urinary sediment hematuria were not detected by dipstick test.

Hypertensive Nigerians showed a high prevalence of microscopic hematuria which may be suggestive of sub-clinical kidney damage at diagnosis. There is a high false-negative rate with dipstick urinalysis, underscoring the need for routine examination of urinary sediment in the assessment of hypertensive patients.