Investigations of the Optimum Serum Bicarbonate Level in Renal Disease.

Not Applicable

Completed

Brief Summary: The purpose of this study is to see if treatment with sodium bicarbonate will lower urine levels of proteins that are indicators of kidney damage in people with diabetes who also have chronic kidney disease.

Detailed Description: Diabetic chronic kidney disease (CKD) is a common problem in Veterans and progresses to end-stage renal disease in many people. It is important to identify treatment strategies that will help prevent the progression of CKD to overt kidney failure. The purpose of this study is to see if sodium bicarbonate reduces urinary markers of kidney damage in Veterans with diabetic CKD and normal serum bicarbonate levels.

Recruitment & Eligibility

Inclusion Criteria

Veteran
Age older than 18 years
Diabetes mellitus
Serum bicarbonate 22 - 28 mmol/L on the most recent measurement within the past six months
Stage 2, 3, or 4 CKD (defined as estimated glomerular filtration rate (eGFR) 15 - 89 ml/min/1.73m2 using the CKD-Epidemiology equation)
Urinary albumin:creatinine ratio > 30 mg/gm on the most recent sample within the past 12 months.

Exclusion Criteria

Lean body weight > 100 kg
Use of oral medications typically prescribed to raise low serum bicarbonate levels (i.e. sodium bicarbonate, sodium citrate, potassium citrate).
Serum potassium < 3.5 meq/L at enrollment visit
Use of 5 or more antihypertensive agents, regardless of the indications of each agent
Systolic blood pressure > 140 mmHg or diastolic blood pressure > 90 mmHg at the enrollment or baseline visit
Diagnosis of congestive heart failure with current, active Class III or IV New York Heart Association symptoms.
Significant fluid overload such that it is unsafe in the opinion of the PI for the patient to participate in the trial
chronic gastrointestinal disorder or any other factors judged to be likely to limit adherence to interventions (i.e. alcoholism, a history of missing clinic visits)
Chronic immunosuppressive therapy for transplanted organs or other indications
Individuals who are currently a member of a vulnerable population (I.e. incarcerated, pregnant).

11.Currently participating in another interventional research study

Arm && Interventions

Group	Intervention	Description
Placebo	Placebo	Participants were prescribed an identical number of placebo tablets had they been assigned to the intervention, and took this daily for six months.
Sodium Bicarbonate	Sodium bicarbonate	Participants were prescribed 0.5 meq of sodium bicarbonate per 1 kilogram of lean body weight daily for six months

Primary Outcome Measures

Name	Time	Method
Change in Urinary Transforming Growth Factor Beta 1 (TGF-b1)	The mean of the 3-month and 6-month urinary TGF-b1 measurement will be compared to the baseline value between the groups.	Urinary TGF-b1 is considered a marker of renal fibrosis

Secondary Outcome Measures

Name	Time	Method
Change in Urinary Albumin Levels	The mean of the 3-month and 6-month measurements will be compared to the baseline values between the groups.	Urinary albumin is a marker of kidney damage
Change in Urinary Levels of Kidney Injury Molecule-1 (KIM-1)	The mean of the 3-month and 6-month measurements will be compared to the baseline values between the groups.	KIM-1 is a marker of of kidney injury.
Change in Urinary Levels of Neutrophil Gelatinase-associated Lipocalin (NGAL)	The mean of the 3-month and 6-month measurements will be compared to the baseline values between the groups.	NGAL is a marker of kidney injury
Change in Urinary Levels of Fibronectin	The mean of the 3-month and 6-month measurements will be compared to the baseline values between the groups.	Fibronectin is a marker of kidney injury.
Change in Estimated Glomerular Filtration (eGFR)	The mean of the 3-month and 6-month measurements will be compared to the baseline values between the groups.	eGFR is a measure of kidney function