Study of the relation between serum leptin and malnutrition in patients with chronic obstructive pulmonary disease

Objective To explore the significance of serum leptin and tumor necrosis factor in malnutrition of chronic obstructiov pulmonary disease(COPD).Methods Serum leptin and tumor necrosis factor-α (TNF-α) concentrations of 68 COPD patients in stationary phase and 22 healthy volunteers were measured by radioimmunoassay.The body mass index(BMI),ideal body weight percentage(BW%),triceps skin-fold thickness(TSF),min-upper arm circumference(MAC),serum albumin(ALB) and total lymphocytes count(LYM) were determined in all subjects.The correlation between leptin,nutritional parameters and TNF-α was analysed.Results ①Serum leptin concentrations in 68 patients with COPD were lower than in 22 healthy controls( 9.95± 7.63ng/ml VS 23.52± 14.10ng/ml,P 0.05); Serum leptin concentrations in 35 malnourished patients with COPD were lower than both in 33 non-malnourished patients and 22 healthy control ( 5.61± 3.56ng/ml VS 14.70± 8.10ng/ml,P 0.05; 5.61± 3.56ng/ml VS 23.52± 14.10 ng/ml,P 0.05).Serum leptin concentrations in non-malnourished patients were lower than in healthy controls( 14.70± 8.10ng/ml VS 23.52± 14.10ng/ml,P 0.05).②Serum TNF-α concentrations in patients with COPD were higher than in healthy controls( 1.37± 0.48ng/ml VS 0.95± 0.22ng/ml,P 0.05).Serum TNF-α concentrations in malnourished patients with COPD were higher than in non-malnourished patients( 1.55± 0.55ng/ml VS 1.19± 0.30ng/ml,P 0.05).③Serum leptin concentrations were significantly positive correlated with BMI and NW% in all groups.Serum leptin concentrations were significantly positive correlated with TSF、MAC、ALB and LYM in patients with COPD.Serum leptin concentrations were significantly positive correlated with TSF in malnourished patients with COPD and healthy controls.Serum leptin concentrations were not significantly correlated with serum TNF-α concentrations in all groups.④Serum leptin concentrations in female patients with COPD were significantly higher than in male ones ( 13.92± 10.47ng/ml VS 7.91± 4.62ng/ml,P 0.05); and in healthy volunteers,Serum leptin concentrations in female ones were higher than in male ones( 28.45± 14.23ng/ml VS 20.49± 13.68ng/ml,P= 0.217).Conclusions Serum leptin concentrations correlate with nutritional parameters and gender in COPD patients and the physiologic regulation of leptin is not controlled by TNF-α system.leptin may contribute to the malnutrition in COPD patients.