Effect of inorganic nitrate on metabolic parameters in patients with type 2 diabetes: A 24-week randomized double-blind placebo-controlled clinical trial.

Aim: In this randomized placebo-controlled clinical trial, effect of oral inorganic nitrate (NO ₃ ^- ) on metabolic parameters was assessed in patients with type 2 diabetes mellitus (T2DM).
Methods: Seventy-four eligible patients with T2DM were randomly assigned to NO ₃ ^- -rich beetroot powder (5 g/d contains ~250 mg NO ₃ ^- ) and placebo groups to complete intervention over a 24-week period. Blood HbA1c, fasting serum glucose, insulin, C-peptide, as well as lipid profile were assessed at baseline and again at weeks 4, 12, and 24; indices of insulin resistance were also calculated. To assess safety of long-term oral NO ₃ ^- , liver and renal function tests were measured. An intention-to-treat approach was used for data analysis. To compare effect of intervention over time between the groups (time×group), repeated measures generalized estimating equation (GEE) linear regression models were used.
Results: Mean age of the participants was 54.0 ± 8.5 (47.9% were male) and mean duration of diabetes was 8.5 ± 6.1 years. A total of 64 patients (n = 35 in beetroot group and n = 29 in placebo group) completed at least two visits and were included in the analyses. No significant difference was observed between the groups for glycemic and lipid parameters over time. Liver and renal function tests, as safety outcome measures, showed no undesirable changes during the study follow-up.
Conclusion: Supplementation with inorganic NO ₃ ^- had no effect on metabolic parameters in patients with T2DM.
(Copyright © 2020 Elsevier Inc. All rights reserved.)