Distal renal tubular acidosis that became exacerbated by proton pump inhibitor use

The Effect of Proton Pump Inhibitor Use on the Course of Kidney Function in Patients with Chronic Kidney Disease Stages G3a to G4

BACKGROUND

Proton pump inhibitors (PPI) are widely used and implicated in the progression of chronic kidney disease (CKD). We evaluated the relation between chronic PPI use in veterans with CKD G3a to G4 and the rate of decline in renal function.

METHODS

We accessed the Veteran Affairs Informatics and Computing Infrastructure national database to evaluate the relation between chronic PPI use and rate of decline in renal function in veterans with CKD (eGFR <60 ml/min1.73 m2). We applied Propensity Score Matching to match the PPI group and the no-PPI control group on age, sex, race, and Charlson Comorbidity Index. The final sample included 1406 patients (age: 62.07±7.82, 62.02% Caucasian) in the PPI cohort with a median 4.7 years follow-up and 1425 patients (age: 65.45±6.58, 71.16% Caucasian) in the control cohort with a median 3.9 years follow-up. Kaplan-Meier curve and Cox regression were performed to analyze the associations of PPI use with dialysis, all-cause mortality, metabolic acidosis, and CKD progression.

RESULTS

The PPI group had a significantly increased risk of CKD progression, dialysis and all-cause mortality (aHR, 1.83; 95% CI, 1.53 to 2.19; aHR, 1.84; 95% CI, 1.26 to 2.67; and aHR, 1.34; 95% CI, 1.08 to 1.65, respectively). The PPI cohort also had a trend for development of metabolic acidosis (aHR, 1.34; 95% CI, 0.998 to 1.80), although the difference was not statistically significant.

CONCLUSIONS

The data suggest that chronic PPI use accelerates progression of kidney disease and is associated with increased mortality in CKD patients.

Retrospective analysis of the effect of acid-suppressant therapy on clinicopathologic parameters of cats with chronic kidney disease

Objectives The aim was to retrospectively evaluate the effects of acid-suppressant therapy in a population of cats with chronic kidney disease (CKD). The study objectives were to evaluate the effects of acid-suppressant therapy on clinicopathologic variables and progression of CKD over time. Methods The databases of two institutions were searched over an 11 year time span for cats fitting inclusion criteria for CKD. A total of 89 cats met the criteria for inclusion and were grouped according to either early (ie, stages 1-2) or advanced (ie, stages 3-4) CKD. Variables were statistically analyzed before and after treatment with either: (1) proton pump inhibitors (PPIs; n = 17), (2) histamine-2 receptor antagonists (H2RAs; n = 30), (3) combined acid-suppressant therapy (PPI + H2RA; n = 6) or (4) no acid-suppressant therapy (n = 36). Shapiro-Wilk testing and Q-Q plots were used to assess normality and variance, respectively. A complete randomized design with a mixed-effects repeated measures ANOVA was used to evaluate for differences in stage, treatment and time, as well as the interaction between these effects. Results A significant increase in blood creatinine concentration was found over time independent of severity of CKD and treatment group ( P = 0.0087). A significant increase in blood sodium concentration (change of 3.12 mmol/l) was found independent of stage in cats receiving PPI therapy ( P = 0.0109). A significant decrease in total blood magnesium (change of 0.15 mmol/l) was detected in two cats with early CKD receiving combined acid suppressants ( P = 0.0025). Conclusions and relevance Results of this retrospective study suggest that cats with CKD receiving PPI therapy may develop alterations in blood sodium concentrations but do not experience more rapid progression of CKD.

Acute gouty arthritis induced by proton pump inhibitors: Clinical characteristics and possible mechanisms

AIM

To analyze the clinical characteristics and possible mechanisms of acute gouty arthritis induced by proton pump inhibitors (PPIs).

METHODS

Clinical data for patients with refractory gout after treatment with PPIs from July 2009 to November 2016 in Tianjin Medical University General Hospital were retrospectively analyzed. Eight cases with acute gouty arthritis without usage of diuretics were enrolled for further analysis.

RESULTS

Eight male patients with acute gouty arthritis after treatment with PPIs were initially diagnosed with peptic ulcer (75.0%) or erosive gastritis (25.0%), accompanied by hyperuricemia and urine pH equal to or less than 6. Mean time from PPI prescription to arthritis onset was 6.67 days. Acute gout led to redness, swelling, pain and limited function in the damaged single joint or several joints, which was often accompanied by fever (62.5%). According to laboratory examinations, leukocyte count, percentage of neutrophils, and serum uric acid increased in 6 (75%) patients, while decreased creatinine and urea were found in 7 (87.5%) patients after treatment with PPIs. Serum K⁺ concentrations decreased (P < 0.05) in all the 8 patients, while serum Na⁺ and Cl^- concentrations increased in 5 (62.5%) patients. Pain may be relieved after withdrawal of PPIs, symptomatic treatment, or treatment with nonsteroidal anti-inflammatory drugs or steroids.

CONCLUSION

PPIs can sometimes induce refractory gout, which may result from inhibitory effects of PPIs on H⁺-K⁺-ATPase existing in the kidneys or from the reduction of blood volume.

Kidney biopsy for renal tubular acidosis: when tissue diagnosis makes a difference

Renal tubular acidosis (RTA) is a disorder with variable presentations and oftentimes a nebulous underlying primary diagnosis. We describe a rare cause of RTA as an unusual complication of proton pump inhibitor (PPI) therapy. We report a case of a 33-year-old male with history of hypertension, acid reflux, allergic rhinitis, and low testosterone admitted with complaints of fatigue, weight loss, and unexplained acidosis for ~ 2 months. His medications prior to admission included losartan, omeprazole, potassium chloride, sildenafil, and testosterone propionate injections. His physical exam was unremarkable with a blood pressure of 120/80 mmHg. Initial lab work showed a nonanion gap metabolic acidosis with serum bicarbonate level of 16 mM/L and potassium 3 mM/L. Urine studies showed urine pH of 6.5 and a positive urine anion gap. The serum creatinine was within normal range(1.13 mg/dL). He required massive doses of bicarbonate and potassium supplementation with minimal improvement of serum chemistries achieved. The cause of apparent distal RTA remained elusive despite extensive blood, urine, and imaging testing. Ultimately a renal biopsy was obtained showing mild to moderate tubule-interstitial inflammation with 5% fibrosis. PPI therapy (omeprazole) was stopped, and he was started on prednisone 60 mg per day. Two weeks later, his RTA findings resolved, and he no longer required bicarbonate and potassium supplementation. Our case highlights the importance of recognizing a unique complication of RTA following PPI therapy. It also underscores the possible need for considering a kidney biopsy in the setting of nondiagnostic laboratory work up to uncover the underlying etiology of RTA and suspected allergic interstitial nephritis (AIN).

Distal renal tubular acidosis associated with Sjogren syndrome

Renal tubular acidosis is a common cause of normal anion gap metabolic acidosis but these disorders can be easily missed or misdiagnosed. We highlight the approach to assessing renal tubular acidosis by discussing a case study with a temporal data set collected over more than 5 weeks. We highlight the principles and the necessary information required for a diagnosis of classic distal renal tubular acidosis. We also briefly review several aspects of type 1 renal tubular acidosis related to autoimmune disease, drugs and thyroid disorders.