We controlled the hemodilution and electrolyte levels during coronary artery revascularization in chronic hemodialysis patients by hemofiltration during the period of extracorporeal circulation. Subjects comprised 7 chronic hemodialysis patients (males, average age 53) undergoing coronary artery revascularization in our department from January 1988 to December 1989. All patients had been undergoing hemodialysis for chronic renal failure and in one patient, after admission, continuous ambulatory peritoneal dialysis (CAPD) was additionally performed. During surgery, the dialyzer was equipped with an extracorporeal circulation circuit and the electrolyte level and hemodilution were adjusted using transfusion (1, 270±372ml). A large infusion volume (12, 657± 3, 966ml) was maintained and removal of water was carried out by ultrafiltration. After surgery, all patients underwent hemodialysis twice or more by the 3rd day of recovery. Concentrations of electrolytes were maintained at appropriate levels throughout the day of surgery except for one case of postoperative hypokalemia, but no marked changes in hemodynamics were observed during and after surgery. Hemofiltration during extracorporeal circulation is safe and useful in coronary surgery because it is simpler and requires less time than hemodialysis.

OBJECTIVESThe purposes of this paper were to evaluate the serum leptin levels in healthy adolescents and to establish standard age variation curves.

METHODSNine hundred six (414 boys and 492 girls) healthy adolescents were investigated. The maximum increment age in height (MIA) was identified in 124 boys and 130 girls. The menarcheal age (MA) was obtained for 130 girls. Fasting leptin levels were measured by enzyme immunoassay. The MIA was calculated by proportional allotment of yearly height increments.

RESULTSSerum leptin levels did not change in boys and girls from the ages of 9 to 11. They decreased after the age of 11 in boys, while they increased in girls. Stepwise multiple regression analysis revealed that serum leptin levels were closely related to pubertal stage. The levels decreased remarkably after MIA in boys and increased remarkably after MA in girls. We drew standard age variation curves of serum leptin levels by calculating the 25th, 50th and 75th percentiles for each age in both boys and girls. The percentile curves for boys were divided into pre-MIA and post-MIA curves. Those for girls were divided into pre-MA and post-MA curves.

CONCLUSIONWe have devised a potentially useful method for evaluating serum leptin levels in adolescents considering the effects of gender and growth.