A 45-year-old woman with poorly controlled hypertension and diabetes mellitus presented with left iliac fossa pain, constipation alternating with diarrhea, and weight loss. She had been diagnosed with idiopathic cardiomyopathy five years previously. Echocardiogram had shown a left ventricular ejection fraction (LVEF) of 35%; coronary angiogram was normal. Colonoscopy revealed sigmoid colitis with stenosis. Abdominal computed tomography revealed a 5 cm right adrenal tumor. Twenty-four hour urinary free catecholamines and fractionated metanephrine excretion values were elevated, confirming pheochromocytoma. Her colitis resolved after one month of adrenergic blockade. Repeat echocardiogram showed improvement of LVEF to 65%. After laparoscopic right adrenalectomy, the patient's hypertension resolved, and diabetic control improved. Timely management avoided further morbidity and potential mortality in our patient.
INTRODUCTION: Blockade of the renin-angiotensin-aldosterone system (RAAS) by either the angiotensin converting enzyme inhibitor (ACE-I) or the angiotensin II receptor blocker (ARB) has been shown to reduce albuminuria and delay the progression of diabetic nephropathy. This study evaluated the effect of dual blockade of the RAAS by adding an ACEI or an ARB to the administration of either drug alone on albuminuria in Asian type 2 diabetic patients with nephropathy.
METHODS: 34 patients were randomly assigned to receive either enalapril 20 mg or losartan 100 mg once daily for eight weeks. Following this, all patients received a combination of enalapril 10 mg and losartan 50 mg daily for eight weeks, followed by enalapril 20 mg and losartan 100 mg daily for another eight weeks. The blood pressure and 24-hour urinary albumin excretion (UAE) were monitored.
RESULTS: Following monotherapy with enalapril, there was a mean and standard error (SE) reduction in the UAE and mean arterial pressure (MAP) of 9.8 (SE 6.8) percent (p-value is 0.061) and 5.3 (SE 2.2) mmHg (p-value is 0.026), respectively; the reduction in UAE and MAP following monotherapy with losartan was by 10.9 (SE 14.1) percent (p-value is 0.053) and 4.5 (SE 1.9) mmHg (p-value is 0.034), respectively. Combination therapy with enalapril and losartan further reduced the UAE (11.2 [SE 8.7] percent, p-value is 0.009] despite there being no significant change in the MAP (-1.2 [SE 1.47] mmHg, p-value is 0.42). The adverse effects included dry cough (seven [19.4 percent] patients, resulting in the withdrawal of medication in two patients), and transient hyperkalaemia (two [six percent] patients).
CONCLUSION: Dual blockade of the RAAS is safe and effective in reducing albuminuria in Asian type 2 diabetic patients with nephropathy.