Study design and procedures
CKD
CoQ10 and NR in CKD (CoNR trial) is a placebo-controlled, double-blind, randomized crossover trial with 3 arms: placebo, CoQ10, and NR (Clinicaltrials.gov NCT03579693). The trial was conducted from November 2018 to April 2021. There were 3 phases in the study, each 42 (6 weeks) days separated by a 1-week washout period. Subjects received 1,000 mg/day of NR (Niagen) or 1,200 mg/day of CoQ10 (Tishcon) for 6 weeks (Adherence to the study treatment was assessed by phone call from the study coordinator midway through each treatment arm to confirm adherence and inventory method to assess remaining pills at the end of the study. Participants were asked to bring in unused study pills at each visit to return to The University of Washington Investigational Drug Services (IDS), which managed the study drugs. Adherence was defined as consumption of at least 75% of the prescribed regimen.There were 4 study visits in total for this trial: 1 baseline visit followed by 3 more at the end of each treatment period. The baseline visit was the same as visits 2, 3, and 4, with an addition of medical history and anthropometrics testing. Participants underwent baseline evaluation including a detailed assessment of demographics, smoking history, medical history, medication inventory, and vital signs. Independent functional status was obtained using an ADL score. These were collected using the Lawton-Bowdy Instrumental Activities of Daily Living (IADL) scale (A brief screening process to evaluate eligibility criteria and to obtain informed consent took place approximately 1 month before the baseline visit. The screening visit included verification of inclusion and exclusion criteria, measuring vital signs, anthropometrics, 6-minute walking distance, screening labs (renal panel and complete blood count), and bicycle ergometry practice to familiarize participants with the equipment. Qualified participants were randomized to a supplementation sequence (