Acute exercise may exacerbate oxidative stress response in hemodialysis patients.

BACKGROUND/AIMS: Hemodialyzed patients (HD) demonstrate elevated oxidative stress (OXS) levels. Exercise effects on OXS response and antioxidant status of HD was investigated in the present study. METHODS: Twelve HD and 12 healthy controls (HC) performed a graded exercise protocol. Blood samples, collected prior to and following exercise, were analyzed for lactate, thiobarbituric acid-reactive substances (TBARS), protein carbonyls (PC), reduced (GSH) and oxidized glutathione (GSSG), total antioxidant capacity (TAC), catalase, and glutathione peroxidase (GPX) activity. RESULTS: HC demonstrated higher time-to-exhaustion (41%), lactate (41%) and VO2 peak (55%) levels. At rest, HD exhibited higher TBARS, PC, and catalase activity values and lower GSH, GSH/GSSG, TAC, and GPX levels. Although exercise elicited a marked change of OXS markers in both groups, these changes were more pronounced (p < 0.05) in HD patients. After adjusting for VO2 peak, differences between groups disappeared. VO2 peak was highly correlated with GSH/GSSG, TBARS, TAC and PC at rest and after exercise. CONCLUSIONS: These results imply that HD demonstrate higher OXS levels and a lower antioxidant status than HC at rest and following exercise. Acute exercise appears to exacerbate OXS response in hemodialyzed patients probably due to diminished antioxidant defense. However, aerobic capacity level seems to be related to OXS responses in this population.

Acid-base and electrolyte disorders in patients with diabetes mellitus.

Diabetes mellitus is the most common metabolic disorder in the community. The diabetics may suffer from acid-base and electrolyte disorders due to complications of diabetes mellitus and the medication they receive. In this study, acid-base and electrolyte disorders were evaluated among outpatient diabetics in our hospital. The study consisted of patients with diabetes mellitus who visited the hospital as outpatients between the period January 1, 2004 to December 31, 2006. The patients' medical history, age and type of diabetes were noted, including whether they were taking diuretics and calcium channel blockers or not. Serum creatinine, proteins, sodium, potassium and chloride and blood gases were measured in all patients. Proteinuria was measured by 24-h urine collection. Two hundred and ten patients were divided in three groups based on the serum creatinine. Group A consisted of 114 patients that had serum creatinine < 1.2 mg/dL, group B consisted of 69 patients that had serum creatinine ranging from 1.3 to 3 mg/dL and group C consisted of 27 patients with serum creatinine > 3.1 mg/dL. Of the 210 patients, 176 had an acid-base disorder. The most common disorder noted in group A was metabolic alkalosis. In groups B and C, the common disorders were metabolic acidosis and alkalosis, and metabolic acidosis, respectively. The most common electrolyte disorders were hypernatremia (especially in groups A and B), hyponatremia (group C) and hyperkalemia (especially in groups B and C). It is concluded that: (a) in diabetic outpatients, acid-base and electrolyte disorders occurred often even if the renal function is normal, (b) the most common disorders are metabolic alkalosis and metabolic acidosis (the frequency increases with the deterioration of the renal function) and (c) the common electrolyte disorders are hypernatremia and hypokalemia.