Effect of Urinary Alkalinization on Urine Uric Acid Precipitation and Crystallization in Adults With Type 1 Diabetes (Alk-UA)
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|ClinicalTrials.gov Identifier: NCT02502071|
Recruitment Status : Completed
First Posted : July 20, 2015
Results First Posted : November 20, 2018
Last Update Posted : November 20, 2018
|Condition or disease||Intervention/treatment||Phase|
|Type 1 Diabetes Diabetic Nephropathy Diabetic Kidney Disease||Drug: sodium bicarbonate||Phase 4|
Diabetic nephropathy is characterized not only by glomerular disease but also tubulointerstitial injury. The tubular changes associated with diabetic nephropathy, include basement membrane thickening, tubular hypertrophy, epithelial-mesenchymal transition, glycogen accumulation and interstitial inflammation. Although glomerular changes has received significantly more attention from researchers and clinicians than tubulointerstitial changes in diabetes, tubular injury is known to associate better with renal function than glomerular injury. In fact, tubular proteinuria may precede microalbuminuria with type 1 diabetes, suggesting that tubular damage may be induced earlier than glomerular injury in the course of diabetic nephropathy.
Serum uric acid (SUA) is lower in adolescents and adults with type 1 diabetes compared to non-diabetic peers. Despite lower levels SUA remains an important risk factor for diabetic nephropathy in type 1 diabetes, with a large clinical trial underway examining the ability of allopurinol to prevent early renal loss. Several mechanisms have been proposed to explain the lower levels of SUA in type 1 diabetes including glucosuria induced uricosuria leading to spilling of urine uric acid (UUA) and lowering of SUA, and the notion that intracellular uric acid (IUA) and/ or UUA rather than SUA may be responsible for the development of complications. Animal studies have demonstrated that blocking uric acid production protects the kidney from tubulointerstitial injury, which suggests a causal role for uric acid in the development of diabetic tubular injury. Relative dehydration, secondary to glucosuria, exercise or inadequate liquid intake, may lead to concentrated and acidic urine, which may cause UUA to precipitate and crystallize in type 1 diabetes. The UUA precipitation and crystallization is thought to induce inflammation and injury of the tubules with possible retrograde glomerular injury. Moreover, it was recently shown that UUA promoted apoptosis in human proximal tubular cells by oxidative stress and activation of NADPH Oxidase NOX 4.
Oral alkali replacements are readily available, safe and include the following formulations sodium bicarbonate, BiCitra (sodium citrate and citric acid), PolyCitra (citric acid, sodium citrate, and potassium citrate), polycitra-K (potassium citrate and citric acid). In contrast to sodium bicarbonate, citrate is converted to bicarbonate in the liver and thus this conversion is affected by liver disease. Usual adult doses for urinary alkalinization are 325 to 2000 mg orally 1 to 4 times a day. One gram provides 12 mEq (mmoL) each of sodium and bicarbonate, and is titrated to a goal of urine pH of 8.0. In a prospective open-label trial 4 g of sodium bicarbonate was administered orally 3 times daily to 9 healthy volunteers for 24 hours, and after 10 hours all participants had a urine pH ≥ 7 and after 20 hours all participants had urine pH ≥ 8. No adverse effects or abnormal blood results were documented during the 24-hour follow-up. Urinary alkalinization should solubilize UUA thereby increasing the concentration of uric acid in urine and decreasing precipitation and crystallization of UUA. It is unknown whether alkalinization of urine reduces UUA precipitation and crystallization in type 1 diabetes.
With diabetic nephropathy being the leading cause of end-stage renal disease in the Western world, it is critical to develop a better understanding of the determinants of risk and progression of early diabetic nephropathy, to improve outcomes in patients with type 1 diabetes. UUA is a particularly attractive therapeutic target due to the potential to reduce tubular injury with sodium bicarbonate. Accordingly, the investigators propose a pilot experimental study examining the effect of urine alkalinization with oral sodium bicarbonate on UUA precipitation and crystallization in adults with type 1 diabetes.
|Study Type :||Interventional (Clinical Trial)|
|Actual Enrollment :||45 participants|
|Intervention Model:||Single Group Assignment|
|Masking:||None (Open Label)|
|Official Title:||Effect of Urinary Alkalinization on Urine Uric Acid Precipitation and Crystallization in Adults With Type 1 DiabetesL a Open-label Trial|
|Study Start Date :||January 2017|
|Actual Primary Completion Date :||July 2017|
|Actual Study Completion Date :||August 2017|
Experimental: Sodium Bicarbonate
All participants will receive 2 doses of 1950mg Sodium Bicarbonate
Drug: sodium bicarbonate
All participants will receive 2 doses of 1950mg sodium bicarbonate
Other Name: NaHCO3
- Change in Urine Uric Acid Concentration (Increased Solubility) by Assay [ Time Frame: Day 1 (pre-therapy) and Day 2 (post-therapy) ]
- Change in Number of Participants With Urine Uric Acid Precipitation by Polarized Microscopy [ Time Frame: Day 1 (pre-therapy) and Day 2 (post-therapy) ]
To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.
Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT02502071
|United States, Colorado|
|Barbara Davis Center for Diabetes|
|Aurora, Colorado, United States, 80045|