PAST ISSUES

Uric Acid Puzzle: Dual Role as Anti-oxidantand Pro-oxidant

Duk Hee Kang, Sung Kyu Ha

Hyperuricemia is known to be associated with the presence of cardiovascular and metabolic syndrome and with the development of incipient kidney disease and an accelerated renal progression. However, an elevated uric acid level was not generally regarded as a true etiology or mediator, but an indicator of these diseases. Uric acid has recently regained the clinical interest and popularity based on emerging data suggesting the causative role of hyperuricemia in cardiovascular and renal disease. Experimental data demonstrates oxidative stress is one of the earliest phenomena observed in vascular, renal, liver cells and adipocytes exposed to uric acid. Since uric acid is one of the major antioxidants of plasma acting as a free radical scavenger and a chelator of transitional metal ion, uric acid-induced oxidative stress seems paradoxical. Data regarding the clinical implication of hyperuricemia is even more confusing, which defines hyperuricemia as a useless parameter to be eliminated from routine follow-up or a major risk factor to be therapeutic target. With a review of experimental and epidemiologic data, the presence of molecular switch to regulate the role of uric acid as anti- or pro-oxidant in different compartment of our body is suggested, which may shed light on understanding the paradoxical role of uric acid and solving the “uric acid debate”.

  • Electrolytes & Blood Pressure Vol.12:1-6, 6 Pages, 2014

Dietary Salt Intake and Hypertension

Sung Kyu Ha

Over the past century, salt has been the subject of intense scientific research related to blood pressure elevation and cardiovascular mortalities. Moderate reduction of dietary salt intake is generally an effective measure to reduce blood pressure. However, recently some in the academic society and lay media dispute the benefits of salt restriction, pointing to inconsistent outcomes noted in some observational studies. A reduction in dietary salt from the current intake of 9-12 g/day to the recommended level of less than 5-6 g/day will have major beneficial effects on cardiovascular health along with major healthcare cost savings around the world. The World Health Organization (WHO) strongly recommended to reduce dietary salt intake as one of the top priority actions to tackle the global non-communicable disease crisis and has urged member nations to take action to reduce population wide dietary salt intake to decrease the number of deaths from hypertension, cardiovascular disease and stroke. However, some scientists still advocate the possibility of increased risk of CVD morbidity and mortality at extremes of low salt intake. Future research may inform the optimal sodium reduction strategies and intake targets for general populations. Until then, we have to continue to build consensus around the grea- test benefits of salt reduction for CVD prevention, and dietary salt intake reduction strategies must remain at the top of the public health agenda.

  • Electrolytes & Blood Pressure Vol.12:7-18, 12 Pages, 2014

Association between Hypophosphatemia and Cardiac Arrhythmias in the Early Stage of Sepsis: Could Phosphorus Replacement Treatment Reduce the Incidence of Arrhythmias?

Andrei Schwartz, Evgeni Brotfain, Leonid Koyfman, Ruslan Kutz, Shaun E. Gruenbaum, Moti Klein, Alexander Zlotnik

It is well known that new-onset arrhythmias are common in septic patients. It is thought that hypophosphatemia in the early stages of sepsis may contribute to the development of new arrhythmias. In this study, we hypothesized that intravenous (IV) phosphorus replacement may reduce the incidence of arrhythmias in critically ill patients. 34 adult septic patients with hypophosphatemia admitted to the general intensive care unit were treated with IV phosphorus replacement per ICU protocol, and the incidence of new arrhythmias were compared with 16 patients from previously published data. IV phosphorus replacement was associated with a significantly reduced incidence of arrhythmias (38% vs. 63%, p=0.04). There were no differences in observed mortality between subgroups, which may be due to the small sample size. This study demonstrated that IV phosphorus replacement might be effective in reducing the incidence of new arrhythmias in septic patients.

  • Electrolytes & Blood Pressure Vol.12:19-25, 7 Pages, 2014

A Case of Post-radiotherapy Urethral Stricture with Spontaneous Bladder Rupture, Mimicking Obstructive Uropathy due to Cancer Metastasis

Jun Young Shin, Sang Min Yoon, Hyuck Jae Choi, Si Nae Lee, Hai Bong Kim, Woo Chul Joo, Joon Ho Song, Moon Jae Kim, Seoung Woo Lee

Non-traumatic, spontaneous urinary bladder rupture is a rare complication of urethral stricture. Furthermore, its symptoms are often nonspecific, and misdiagnosis is common. The authors experienced a case of urethral stricture with spontaneous bladder rupture and bilateral hydronephrosis, mimicking obstructive uropathy attributed to cancer metastasis. A 55-year-old woman was admitted with abdominal pain and distension, oliguria, and an elevated serum creatinine level. She had undergone radical hysterectomy for uterine cervical cancer and received post-operative concurrent chemoradiation therapy 13 years previously. Non-contrast enhanced computed tomography showed massive ascites and bilateral hydronephrosis. The initial diagnosis was acute kidney injury due to obstructive uropathy caused by malignant disease. After improvement of her renal function by bilateral percutaneous nephrostomy catheterization, contrast-enhanced computed tomography and a cytologic examination of ascites showed no evidence of malignancy. However, during retrograde pyelography, a severe urethral stricture was found, and subsequent cystography showed leakage of contrast into the peritoneal cavity and cystoscopy revealed a defect of the posterior bladder wall. After urethral dilatation and primary closure of the bladder wall, acute kidney injury and ascites were resolved.

  • Electrolytes & Blood Pressure Vol.12:26-29, 4 Pages, 2014