Although the optimal time to initiate hemodialysis is not well defined, it is necessary to start extracorporeal ultrafiltration methods (ECUM) earlier in uremic diabetic patients to avoid life-threatening events, such as anasarca, heart failure, and lung congestion. These patients frequently manifest the poor response to the administration of high dosage of loop diuretics. To investigate the effectiveness of concomitant usage of synthetic human atrial natriuretic peptide (hANP) with loop diuretics, we administered carperitide (hANP) in a case with diabetic nephropathy and nephrotic syndrome.
A 44-year-old woman with 10-year history of type 2 diabetes was referred to our hospital because of oliguria, generalized edema, repeated vomiting, and severe diarrhea. She developed overt proteinuria 3 years ago and has been treated with glimepiride. She presented severe anasarca and gained >15 kg body wt during the past 2 months. Blood pressure was 147/87 mmHg, and Achilles tendon reflex and vibrating sense of lower extremities disappeared. She had diabetic retinopathy and received photocoagulation 3 years before. Serum albumin was 1.9 g/dl, serum creatinine 1.92 mg/dl, total cholesterol 419 mg/dl, daily urinary protein secretion 12.4 g, and creatinine clearance 18.4 ml/min. Cardio-thoracic ratio was 51% in chest X-ray, and pleural effusion and ascites were seen in computed tomography. We started oral and intravenous administration of furosemide (200 mg/day) and infusion of albumin. However, she became anuric at the 7th hospital day, 250–300 ml/day. Before we performed ECUM, we started continuous infusion of carperitide from a dose of 0.025 μg · kg−1 · min−1 and maintained at 0.08 μg · kg−1 · min−1. The concomitant use of furosemide brought prominent diuresis reaching 2,000 ml/day, and we gradually tapered the dosage and continued for 25 days. Finally, she maintained the daily urine volume of 1,000–1,500 ml/day with the oral administration of furosemide (120 mg/day) without deterioration of renal functions. Edema, ascites, vomiting, and diarrhea disappeared, and her body weight returned to 56 kg (Fig. 1).
Although the remission and regression of nephrotic syndrome due to diabetic nephropathy was reported (1), the massive proteinuria is usually intractable, and most patients finally manifested end-stage renal disease. The use of a high dosage of diuretics also accelerates intravascular dehydration, elevation of creatinine and uric acid levels, and impaired renal function. Synthetic hANP elevates glomerular filtration rate by increasing renal blood flow and relaxation of the mesangial cells. It also increases the medullary blood flow and inhibits reabsorption of sodium and water of collecting duct cells. The concomitant use of synthetic hANP and loop diuretics enhances the diuretic action and may suppress furosemide-induced aldosterone activation (2). Instead of ECUM, the administration of synthetic hANP in nephrotic patients with diabetic nephropathy is useful to avoid life-threatening anasarca and may prevent the progressive deterioration of renal function.
