A Randomised Controlled Trial of Medical Prophylaxis for the Prevention of Hypertension, Renal Disease and Diabetes in Australian Aborigines

Objective: To evaluate whether the development of albuminuria, hypertension or diabetes can be delayed or postponed in high risk Aboriginal people. Design. Double blind, placebo controlled, randomized trial of a long acting angiotensin converting enzyme inhibitor(ACEi), titrated to full dose where tolerated (active arm) vs placebo. Oversight: A steering committee, an independent audit process and a data analysis group. Eligibility criteria: Consenting Aboriginal adults age 18+ years, with BP = 140/90, urine albumin creatinine ratio < 2.2 gm/mol and without diabetes, who are without contraindications to ACEi. Outcomes: The primary outcome is a composite endpoint for BP>140/90 and/or urine ACR>2.2 gm/mol and or diabetes. Weight, waist, lipids and HbA1c levels will also be followed. Cardiovascular events and natural deaths will be documented. Sample size: A total of 150 candidates is proposed: the Tiwi community. These will represent at least 75 in the active arm and 75 in the placebo arm. The sample size is based on factual incidence data in Tiwi. Duration: Five years of active treatment, with an option to discontinue earlier pending significant results Significance: Delay of onset of features of the vascular/metabolic/renal syndrome in populations where annual incidence rates are as high as 15% per year, and prevalence rates by age 50 years are = 80% could save or prevent much morbidity and mortality from definitive disease. Findings will probably be relevant to other high risk population.