dimethylarginine and Postoperative-Complications

Levels of the endogenous nitric oxide synthase inhibitor asymmetrical dimethylarginine (ADMA) are elevated and endothelial progenitor cells (EPCs) decreased in patients undergoing renal transplantation (Tx) and may contribute to cardiovascular complications. In this study, we tested the hypothesis that elevated ADMA and decreased EPC can be positively influenced with regular physical exercise early after Tx. Blood samples for analysis of ADMA and EPC were obtained from randomly selected 64 patients after Tx who agreed to participate in a supervised aerobic exercise program for 6 months (group I). Samples were collected before the training began, 1 month after surgery (with stabilized renal function), and at 6 months after initiation. Sixty-two age, sex, human leukocyte antigens (HLA) typing, duration of previous dialysis, history of cardiovascular disease, and immunosupression regimen-matched transplant patients who did not exercise regularly were examined as controls (group II). There were no differences in ADMA levels and EPC count between both groups before the training program began. After 6 months of exercise, ADMA concentration in the group I decreased (3.50 ± 0.45 vs. 2.11 ± 0.35 μmol/L; P < .01) and was also lower comparing with group II (2.11 ± 0.23 vs. 3.25 ± 0.35 μmol/L; P < .01). In the same period, EPC cells increased from 2.085 ± 650 cells/mL versus 3.991 ± 560 cells/mL, P < .01 in group I; but in group II, changes were nonsignificant (P = .11). Blood lipids, HbA1c, insulin, and systolic blood pressure were also affected by the training program. Elevated ADMA level and decreased EPC count were significantly influenced by early regular exercise in patients after Tx.

Topics: Adult; Aged; Arginine; Endothelial Progenitor Cells; Exercise Therapy; Female; Follow-Up Studies; Humans; Kidney Transplantation; Male; Middle Aged; Postoperative Complications; Prospective Studies

Cancer and surgical stress interact to aggravate insulin resistance, protein catabolism, and glutamine depletion in skeletal muscle. We compared the effects of insulin-mediated euglycemia and moderate hyperglycemia on kinetics of protein and selected amino acids in skeletal muscle of female cancer patients after major surgery.. In each patient, a 24-hr period of insulin-mediated tight euglycemia (mean blood glucose, 5.8 +/- 0.4 mmol/L) preceded or followed a 24-hr control period of moderate hyperglycemia (mean blood glucose, 9.6 +/- 0.6 mmol/L) on the first and second day after surgery, in randomized order, according to a crossover experimental design.. Intensive care unit, cancer hospital.. Cancer patients after abdominal radical surgery combined with intraoperative radiation therapy.. Intensive (57 +/- 11 units/24 hrs) and conventional (25 +/- 5 units/24 hrs) insulin treatment during total parenteral nutrition.. Muscle metabolism was assessed at the end of each 24-hr period of euglycemia and of hyperglycemia by leg arteriovenous catheterization with stable isotopic tracers. We found that euglycemia as compared with hyperglycemia was associated with higher (p < .05) fractional glucose uptake (16% +/- 4% vs. 9% +/- 3%); higher (p < .05) muscle protein synthesis and neutral net protein balance (-3 +/- 3 vs. -11 +/- 3 nmol phenylalanine x 100 mL(-1) x min(-1), respectively); lower (-52% +/- 12%, p < .01) muscle nonprotein leucine disposal (an index of leucine oxidation) and higher (p < .05) plasma leucine concentrations; and higher (3.6 +/- 1.7 times, p < .01) net de novo muscle glutamine synthesis and plasma glutamine concentrations (p < .05). Euglycemia was associated with higher (23% +/- 7%, p < .05) plasma concentrations of arginine but did not affect either arginine release from muscle or plasma concentration and muscle flux of asymmetrical dimethylarginine. Rate of muscle proteolysis correlated (p < .05) with muscle release of asymmetrical dimethylarginine.. Treating hyperglycemia improves skeletal muscle protein and amino acid metabolism in cancer patients after major surgery.

Topics: Abdominal Neoplasms; Amino Acids; Arginine; Blood Glucose; Cancer Care Facilities; Combined Modality Therapy; Critical Care; Cross-Over Studies; Energy Metabolism; Female; Glutamine; Humans; Hyperglycemia; Insulin; Insulin Resistance; Leucine; Middle Aged; Muscle Proteins; Muscle, Skeletal; Overweight; Parenteral Nutrition, Total; Phenylalanine; Postoperative Complications; Radiotherapy, Adjuvant

Topics: Adult; Arginine; Female; Heart Atria; Humans; Male; Natriuretic Peptide, Brain; Peptide Fragments; Postoperative Complications; Transposition of Great Vessels; Ventricular Dysfunction

Asymmetrical dimethylarginine (ADMA), an endogenous competitive inhibitor of nitric oxide synthase, is elevated in vascular pathologies such as hypertension and chronic kidney disease. Children undergoing cardiac surgery are at high risk of poor hemodynamic and renal outcomes secondary to cardiopulmonary bypass (CPB). This study tested the hypothesis that elevated preoperative ADMA levels are associated with overall worse clinical outcomes after pediatric CPB.. This was a prospective, observational study of 100 patients aged from 2 weeks to 18 years who underwent cardiac surgery involving CPB. Serum ADMA levels were obtained preoperatively and on postoperative days zero through four. Clinical outcomes measured included acute kidney injury (AKI) by pRIFLE criteria, low cardiac output syndrome (LCOS), length of mechanical ventilation, hospital and ICU length of stay, unplanned reoperation, and mortality.. The 29 patients with an elevated preoperative ADMA were more likely to have prolonged mechanical ventilation, increased ICU and hospital length of stay, unplanned reoperation, and LCOS than those with a normal preoperative level. ADMA levels inversely correlated with estimated glomerular filtration rate (eGFR), but did not differ between patients with and without AKI after CPB. Preoperative ADMA levels correlated with hospital length of stay (r(s) = 0.289), ICU length of stay (r(s) = 0.308), and length of mechanical ventilation (r(s) = 0.402); [all p < 0.05]. ADMA levels before surgery had good predictive power for prolonged mechanical ventilation (AUC-ROC 0.809; 95 % CI 0.704, 0.914; p < 0.001).. Patients with elevated ADMA before surgery were more likely to have prolonged mechanical ventilation, develop LCOS, require an extended length of stay, and require reoperation. ADMA levels inversely correlated with eGFR, but did not predict AKI. Preoperative serum ADMA appears to identify pediatric cardiac surgery patients at risk of poor postoperative outcomes following CPB.

Topics: Acute Kidney Injury; Adolescent; Arginine; Cardiac Output, Low; Cardiopulmonary Bypass; Child; Child, Preschool; Female; Humans; Infant; Infant, Newborn; Intensive Care Units, Pediatric; Length of Stay; Male; Postoperative Complications; Preoperative Period; Prospective Studies; Respiration, Artificial; Risk Factors; Treatment Outcome