Korean Journal of Nephrology 2000;19(4):724-730.

복막투석 환자에서 혈청 Leptin과 Leptin의 발현에 관한 전향적 연구 (A Prospective Study on Changes of Serum Leptin and Its Expression in CAPD Patients)

오동진(Dong Jin Oh),김대중(Dae Joong Kim),강우현(Woo Hyun Kang),이방훈(Bang Hoon Lee),박진아(Jin A Park),허우성(Woo Sung Hur),김윤구(Yoon Goo Kim),오하영(Ha Young Oh),강순아(Soon Ah Kang)

Abstract

The ob gene product leptin is thought to be an adipostatic hormone through the regulation of food intake and energy expenditure. There are many reports that serum leptin concentration was increased in CRF patients, especially CAPD patients. The causes of elevated serum leptin concentration in CRF are believed to be multifactorial. Increased body fat mass, decreased residual renal function, active inflammation and hyperinsulinemia all are suggested to influence serum leptin concentration in CAPD patients. In this study, in order to investigate the pathogenic mechanism of increased serum leptin level in CAPD patients, we observed the changes of serum leptin concentration, leptin expression in the abdominal subcutaneous fat tissue, body fat composition, residual renal function, serum insulin concentration and CRP. Thirteen patients(7 men and 6 women, mean age 53±14 years) were enrolled in this study. Serum leptin concentration was measured by RIA before start of CAPD(baseline data), 5 days and 1, 3 months after start of CAPD. Simultaneously, fat tissues were aspirated from the abdominal subcutaneous fat tissues for analysis of ob gene expression. Ob mRNA expression was measured by semiquantitative RT-PCR method. The changes of serum insulin concentration, C-reactive protein, residual renal function were measured. All studies were done immediately before starting CAPD, 5 days, 1 month and 3 months after starting CAPD. Total body fat was estimated by dual energy X-ray absorptiometry and abdominal visceral and parietal fat area measured by computed tomography were done at 1-3 days(baseline data), 1 month, 3 months after start of CAPD. Serum leptin concentration increased significantly as early as 5 days after start of CAPD and maintained high up to 3 months(4.3±2.6→8.2±7.6→7.4±6.5→10.8±13.8ng/mL), while leptin expression in the abdominal subcutaneous fat tissue did not change during the study period(0.24±0.06→0.25±0.08→0.20±0.07→0.34±0.21ng/mL). No significant changes of body fat composition, residual renal function and serum insulin concentration were observed during the study period. These results suggest that increase of serum leptin concentration after CAPD may be due to increase of local leptin production, especially from the peritoneum, as has also been suggested by several reports of relatively higher dialysate leptin.