Unexplained weight loss is common in patients with chronic obstructive
pulmonary disease (COPD). Leptin not only is a critical regulator of body weight and
appetite, but also serves as an immune-modulator. Nitric oxide (NO) is a potent
relaxant of bronchial and pulmonary artery and leptin has a regulatory role in its
synthesis. In the present study, the association of serum leptin levels with nitric oxide
metabolites (NO) in COPD was investigated. Methods: Serum leptin and NO levels
were measured in COPD patients [males (n=18) and females (n=15)] above forty
years old compared with control group (n=30) in the same age matched group.
Serum leptin levels were measured by enzyme linked immune sorbant assay (ELISA)
technique. NO level was measured by spectrophotometric method. Results: Serum
mean leptin level was significantly lower in COPD male group (9.7 ± 4.1 pg/ml) and
female group (11.1 ± 3.7pg/ml) than corresponding control group (male: 12.7 ±1.4
pg/ml and female: 15.1 ± 1.5pg/ml) ( p <0.01 in both). Also, serum nitric oxide
(nitrite and nitrate) in COPD male (18.4 ± 3.7μmol/L) and female group (15.9 ± 5.6
μmol/L) which was lower than corresponding control group (male: 21.2 ±1.9μmol/L
and female: 24.2 ± 2.5μmol/L) (p <0.01 in both). Conclusions: low serum leptin
associated with COPD is related with low BMI. Associated low nitric oxide serum
level may be related to the pathogenesis of COPD.