Clinical signs of autosomal dominant polycystic kidney disease (ADPKD), including indications of vascular dysfunction, can appear as early as childhood. Curcumin, a polyphenol contained in turmeric, lowers vascular dysfunction in humans who do not have ADPKD. Oral curcumin treatment was expected to improve vascular endothelial dysfunction and arterial stiffness in children/young adults with ADPKD. In a 12-month randomized, placebo-controlled, double-blind experiment, 68 children/young adults with ADPKD with an eGFR greater than 80 ml/min per 1.73 m^2 were randomly assigned to either curcumin supplementation (25 mg/kg body weight per day) or placebo delivered in powder form. The key outcomes were aortic pulse-wave velocity and brachial artery flow-mediated dilation. They also used magnetic resonance imaging to look at changes in circulating/urine oxidative stress/inflammation biomarkers and kidney growth (height-adjusted total kidney volume). Vascular oxidative stress was assessed in an 18-year-old subset of participants as the change in brachial artery flow-mediated dilation after an acute ascorbic acid infusion.
Enrolled patients were 185 (mean SD) years old, 54% were females, the baseline brachial artery flow-mediated dilation was 9.3+4.1% change, and the baseline aortic pulse-wave velocity was 512+94 cm/s. The trial was finished by 57 patients. Curcumin had no effect on any of the coprimary endpoints (estimated change [95% CI] for brachial artery flow-mediated dilation [percentage change]: curcumin: 1.14; 95% CI, 0.84 to 3.13; placebo: 0.33; 95% CI, 1.34 to 2.00; estimated difference for change: 0.81; 95% CI, 1.21 to 2.84; P=0.48; aortic pulse-wave velocity [centimeters per second]: curcumin: 0.6; 95% CI, −25.7 to 26.9; placebo: 6.5; 95% confidence interval, −20.4 to 33.5; estimated difference for change: −5.9; 95% CI, −35.8 to 24.0; P=0.67; intent to treat). There were no changes in mechanistic biomarkers or vascular oxidative stress as a result of curcumin use. When compared to the placebo group, height-adjusted total kidney volume did not change. In adolescents and young adults with ADPKD, curcumin administration did not enhance vascular function or reduce kidney development.