DIabetic Retinopathy Candesartan Trials. (DIRECT)

The primary objective is to determine whether candesartan, compared to placebo reduces the progression of diabetic retinopathy in normotensive, normoalbuminuric type 1 diabetic patients with retinopathy.

The secondary objective is to determine whether candesartan, compared to placebo, reduces the incidence of clinically significant macular oedema (CSME) and/or proliferative diabetic retinopathy (PDR) and beneficially influences the rate of change in urinary albumin excretion rate (UAER).

This study is part of the DIRECT Programme also including a primary prevention study of diabetic retinopathy in type 1 diabetes and a secondary prevention study in type 2 diabetes. The primary objective for all three pooled studies is to determine whether candesartan, compared to placebo, reduces the incidence of microalbuminuria in type 1 and type 2 diabetic patients.

• No Intervention: 1
  Placebo
• Experimental: 2
  Candesartan cilexetil
  Intervention: Drug: Candesartan Cilexetil

• Sjølie AK, Klein R, Porta M, Orchard T, Fuller J, Parving HH, Bilous R, Aldington S, Chaturvedi N. Retinal microaneurysm count predicts progression and regression of diabetic retinopathy. Post-hoc results from the DIRECT Programme. Diabet Med. 2011 Mar;28(3):345-51.
• Porta M, Hainer JW, Jansson SO, Malm A, Bilous R, Chaturvedi N, Fuller JH, Klein R, Orchard T, Parving HH, Sjølie AK; DIRECT Study Group. Exposure to candesartan during the first trimester of pregnancy in type 1 diabetes: experience from the placebo-controlled diabetic retinopathy candesartan trials. Diabetologia. 2011 Jun;54(6):1298-303. Epub 2011 Jan 12.
• Bilous R, Chaturvedi N, Sjølie AK, Fuller J, Klein R, Orchard T, Porta M, Parving HH. Effect of candesartan on microalbuminuria and albumin excretion rate in diabetes: three randomized trials. Ann Intern Med. 2009 Jul 7;151(1):11-20, W3-4. Epub 2009 May 18.
• Chaturvedi N, Porta M, Klein R, Orchard T, Fuller J, Parving HH, Bilous R, Sjølie AK; DIRECT Programme Study Group. Effect of candesartan on prevention (DIRECT-Prevent 1) and progression (DIRECT-Protect 1) of retinopathy in type 1 diabetes: randomised, placebo-controlled trials. Lancet. 2008 Oct 18;372(9647):1394-402. Epub 2008 Sep 25.

Inclusion Criteria:

• Male or female aged 18 - 55 years with type 1 diabetes diagnosed before age of 36 years and in need for continuous insulin treatment within 1 year of diagnosis of diabetes are included.
• Duration of diabetes for > 1 year and < 20 years with stable diabetic therapy within last 6 months.
• Patients with untreated resting mean sitting SBP < 130 mmHg, mean sitting DBP < 85 mmHg and with retinal photograph grading level > 20/10 up to < 47/47 (on ETDRS severity scale).

Exclusion Criteria:

• Patients with the following conditions are excluded from participation on the study:
• Cataract or media opacity of a degree which precludes taking gradable retinal photographs
• Angle closure glaucoma, which precludes pharmacological dilatation of the pupil
• History or presence of proliferative retinopathy
• History or presence of clinical significant macular oedema (CSME)
• History or evidence of photocoagulation of the retina
• Other retinal conditions which may mask assessment, eg, retinal vein occlusion
• Positive micral dipstick test
• Presence of secondary diabetes
• Pregnant or lactating women or women of child bearing potential not practicing an adequate method of contraception
• Need of treatment with ACE-inhibitor
• Haemodynamically significant aortic or mitral valve stenosis
• Known renal artery stenosis or kidney transplantation
• Hypersensitivity to study drug
• Severe concomitant disease which may interfere with the assessment of the patient, eg, malignancy, as judged by the investigator