Clinical trial NCT00729365
Conditions: Type 1 Diabetes
Keywords: Urine albumin excretion rates Nighttime and daytime blood pressure Endothelial Dysfunction
Sponsor: Northwestern University
Start date: 2008-07-01; Completion date: 2010-06-01
Enrollment: 65 participants; Allocation: RANDOMIZED; Intervention model: PARALLEL

Brief summary:
The purpose of this study is to determine if the early treatment with a blood pressure medication (an ACE Inhibitor) can prevent or delay the development of kidney disease (microalbuminuria) in patients with Type 1 diabetes who have normal blood pressure and urine albumin levels.

Detailed description:
Only a fraction of persons with Type 1 diabetes (less than 40%) develop diabetic kidney disease (nephropathy). When the urinary albumin (a protein normally excreted in small amounts) is within the normal range, the prevalence of high blood pressure (hypertension) based on office blood pressure readings is very low. Many of these persons, however, develop nocturnal hypertension (high nighttime blood pressure) before the development of abnormally high urinary albumin excretion (a condition referred to as microalbuminuria). Currently, early treatment with medications called ACE inhibitors is only recommended after there is an indication of kidney damage, as reflected by the presence of microalbuminuria. Beginning ACE inhibitor therapy is currently not recommended prior to the development of microalbuminuria, unless patients have high blood pressure, because it would result in over-treatment of many people. By the time that microalbuminuria develops, however, kidney damage may be present and many patients will develop kidney disease. It would therefore be beneficial to identify those subjects who will develop microalbuminuria, so that treatment could be started early for those individuals. Persons who may go on to develop protein in their urine and eventual kidney disease perhaps could be identified on the basis of an abnormal fall (too little) in blood pressure at night. This pattern should not be confused with high blood pressure, but instead seen as an early indication present before the development of high blood pressure and microalbuminuria.

The purpose of the current study is therefore aimed at demonstrating that it is possible to prevent kidney disease in patients with type 1 diabetes and normal office blood pressure and urine protein excretion by selecting them on the basis of an abnormal fall in blood pressure at night. Moreover, this clinical trial will reveal the impact of long-term administration of an ACE inhibitor on nighttime blood pressure and also assess changes in the relative stiffness of blood vessels(endothelial dysfunction) in persons with type 1 diabetes over time.

Arms: arm 1: Subjects with normal nighttime blood pressure profile that decreases at night (Dippers). This group are all given placebo. arm 2: Subjects with nighttime blood pressure that does not drop during the night (non-dippers). This group will be given placebo. arm 3: Subjects with nighttime blood pressure that does not drop during the night (non-dippers). This group will be given ACE inhibitor (study medication).
Interventions: intervention 1: Ramipril intervention 2: Placebo intervention 3: Placebo
Intervention descriptions: intervention 1: ACE inhibitor known as Ramipril

Subjects with nighttime blood pressure that does not drop during the night ("non-dippers") maybe randomized into this group and given an ACE inhibitor (study medication). Therefore, the "Non-Dippers" groups II and III will be randomized to receive either drug or placebo. intervention 2: Dippers (category of subjects with a nighttime dip in blood pressure) will all be given Placebo. Control group. intervention 3: Subjects with nighttime blood pressure that does not drop during the night ("non-dippers") maybe randomized into the control group and given Placebo.

Protocol documents: