Introduction
Microalbuminuria is considered an early marker of glomerular injury in patients with
diabetes, but tubular injury can precede glomerular injury and cannot be detected
by microalbumin. We need a new and early marker of kidney injury in
normoalbuminuric diabetic patients. Urinary heme oxygenase-1 (uHO-1) is an
enzyme that is produced in tubules in response to oxidative stress and can be a
marker of tubular injury.
Aim
To investigate the clinical implication of uHO-1 as an early diagnostic marker in
diabetic nephropathy (DN).
Patients and methods
A total of 65 diabetic patients, comprising 20 microalbuminuric patients and 45
normoalbuminuric patients, and 20 healthy participants as a control group were
included in this study. Level of uHO-1 was detected by enzyme-linked
immunosorbent assay.
Results
uHO-1 was highly significantly elevated (P<0.000) in microalbuminuric group
compared with normoalbuminuric group and control group, respectively.
Normoalbuminuric group was highly significantly elevated (P<0.000) in uHO-1
compared with the control group. uHO-1 was positively correlated with
albumin–creatinine ratio but was not correlated with estimated glomerular
filtration rate. Receiver operating characteristic curve analysis of uHO-1 levels
for early diagnosis of DN revealed that the cutoff value of uHO-1 was 5.8 ng/ml
(sensitivity 80% and specificity 71%) for early diagnosis of DN.
Conclusion
The findings of this study indicate that elevated levels of uHO-1 can be detected in
normoalbuminuric diabetic patients and revealed renal tubular damage. uHO-1
may be used as an early biomarker for DN.