The association between dietary nitrate, nitrite and total antioxidant capacity with cardiometabolic risk factors: a cross-sectional study among patients with type 2 diabetes

Abstract

Diabetes is a common, chronic, and complex disorder that leads to several disabilities and serious complications. Certain nutrients can be effective in the management of diabetes mellitus. In the present study, we aimed to investigate the effects of dietary nitrate, nitrite, dietary total antioxidant capacity (DTAC), and nitric oxide (NO) index on some cardiometabolic parameters in patients with diabetes. This cross-sectional study was conducted on 100 participants with type 2 diabetes. A validated, semi-quantitative, food frequency questionnaire was collected to evaluate dietary intakes. Anthropometric parameters, blood pressure, and biochemical parameters, including glycemic indices, lipid profile, high-sensitive C-reactive protein (hs-CRP), and serum NO were measured using standard methods. Higher intakes of nitrate and nitrite in our study were primarily attributed to drinking water, vegetables, grains (for nitrate), dairy products, and legumes (for nitrite) rather than higher meat intakes. After adjustment for total energy, MET, BMI, and age, higher intake of nitrate was related to lower HbA1C (p = 0.001) and hs-CRP (p = 0.0.23), and greater HDL-C (p < 0.001) and serum NO (p = 0.008). Moreover, a greater nitrite intake was associated with lower DBP (p = 0.017), HbA1C (p = 0.040), FPG (p = 0.011), and higher serum NO values (p = 0.001). Higher amounts of DTAC and NO index were also related to greater DBP (p < 0.001, and p = 0.004, respectively) and lower hs-CRP (p = 0.004, and p = 0.009, respectively). High intakes of dietary nitrate and nitrite, in the context of high DTAC, are significantly associated with the improvement of some cardiometabolic parameters in patients with diabetes.