Impact of Nitrate Ingestion on Protein Synthesis (PRO-Nitrate)

• Plasma amino acids [ Time Frame: every 30 min (from -2 h to + 5 h during the test day) ] [ Designated as safety issue: No ]
  Blood sampling will occur through a catheter placed in an anticubital vein every 30 minutes throughout the test day. We will be using this plasma to measure plasma amino acids to determine the enrichment of labeled amino acids from both the IV tracer and the intrinsically-labeled casein protein. We wish to track the changes in amino acids from the intrinsically-labeled casein protein.
• Plasma nitrate [ Time Frame: every 30 min (from -2 h to + 5 h during the test day) ] [ Designated as safety issue: No ]
  Plasma nitrate will be measured every 30 minutes during the test day through blood sampling from the catheter inserted into an antecubital vein. We want to measure the changes in plasma nitrate after consuming the nitrate or placebo beverage.

A diet rich in leafy green vegetables has been shown to reduce the risk of developing chronic metabolic disease. The health benefits from these particular vegetables may be attributed to their high nitrate content. Recent work suggests that dietary nitrate triggers endogenous nitric oxide release, thereby stimulating vasodilation and improving muscle perfusion in an insulin-independent manner. We hypothesize that in an insulin-resistant state, nitrate co-ingestion will increase muscle perfusion, thereby improving post-prandial delivery of nutrients to skeletal muscle tissue. Specifically, a more efficient delivery of food derived amino acids will stimulate post-prandial muscle protein synthesis and, as such, compensate for a blunted muscle protein synthetic response to food intake in the elderly. This proposal will investigate the efficacy of nitrate co-ingestion as a means to augment muscle protein synthesis in elderly, type 2 diabetes patients and may lead to a novel therapy in the clinical care of type 2 diabetes patients.

• Dietary Supplement: Nitrate
  0.15 mmol/kg body weight sodium nitrate (dissolved in 250 mL water)
• Dietary Supplement: Sodium chloride
  0.15 mmol sodium chloride dissolved in 250 mL water.

• Experimental: Nitrate
  Sodium nitrate ingestion prior to ingesting intrinsically labeled protein
  Intervention: Dietary Supplement: Nitrate
• Placebo Comparator: Sodium chloride
  Sodium chloride placebo group
  Intervention: Dietary Supplement: Sodium chloride

Inclusion Criteria:

• Male
• Aged between 70-85 years
• BMI < 30 kg/m2
• Non insulin-dependent diabetes mellitus type 2 patients (T2DM) ( >1 y since diagnoses)

Exclusion Criteria:

• Smoking
• Hypertension (according to WHO criteria)[29] and/or cardiovascular disease treated with medication containing nitrates and/or having vasodilatory effects
• Use of medication, except for oral blood glucose lowering medication
• Use of insulin
• All co-morbidities interacting with mobility and muscle metabolism of the lower limbs (e.g. arthritis, spasticity/rigidity, all neurological disorders and paralysis).
• HbA1c > 10.0% (86 mmol/mol)
• Donated blood in last 3 months
• Diagnosed impaired renal or liver function
• Myocardial infarction within the last 3 years
• Gastric acid inhibitors
• Use of anti-coagulants