Sodium Bicarbonate and Mitochondrial Energetics in Persons With CKD

Inclusion Criteria:

* Moderate-severe CKD determined by eGFR \<50ml/min per 1.73m2 by CKD EPI equation on at least 2 consecutive occasions.
* Metabolic acidosis defined as bicarbonate level\<24 on two consecutive occasions. Bicarbonate level of 24 or less allowed if eGFR\<=45ml/min per 1.73m2
* Age 21 to 85 years old

Exclusion Criteria:

* Type 1 diabetes
* Poorly controlled diabetes (HgbA1c\>10%)
* History of persistent hyperkalemia (K\>5.4)
* History of persistent hypokalemia (K\<3.3)
* Uncontrolled blood pressure (\>170/100)
* Chronic treatment with renal replacement therapy
* History of aortic dissection or severe valvular heart disease
* Exercise induced angina
* Uncontrolled cardiac dysrhythmia
* Oxygen dependent chronic obstructive pulmonary disease (COPD)
* Symptomatic claudication
* End stage liver disease
* Mobility disability defined as inability to walk without human assistance
* Dementia or psychosis
* Patients who cannot consent
* Active use of intraveneous drugs
* Non-english speaking
* History of transplant
* Implants that prohibit MRI measurements or trauma involving metal fragments
* Pacemaker
* Expectation to start dialysis during the course of study.
* Women who are breastfeeding, pregnant, or are wanting to become pregnant
* Any condition which in the judgement of the clinical investigator places the participant at risk from participation in the study.

Exclusion criteria for optional muscle biopsy

* Drugs- anticoagulants or antiplatelets:

  * Anticoagulants, any 1 (coumadin, rivaroxaban, apixaban, dabigatran, edoxaban)
  * Antiplatelets, any 2 (aspirin, cilostazol, clopidogrel, dipyridamole, prasugrel, ticragrelor, ticlopidine, vorapaxar)
* Platelet count \<100,000
* International normalized ratio (INR)\>1.4