PLASMA LEPTIN LEVELS AND A RESTRICTIVE LUNG IN OBESE THAI CHILDREN AND ADOLESCENTS.

Morbid obesity, the most significant risk factor for development of sev- eral respiratory diseases, is linked to decreased pulmonary function. The aim of this study was to determine the relationships between pulmonary function and plasma levels of homeostasis model assessment-insulin resistance (HOMA-IR), insulin, leptin, hs-CRP and fasting glucose. Values were measured in 39 Thai children and adolescents, divided into three groups according to lung function (forced expiratory volume in one second, FEV1); normal (Group A) FEV1 ≥ 80% (n = 19), obese normal (Group B) FEV1 ≥ 80% (n = 14) and obese (Group C) FEV1 < 80% (n = 6). Body mass index was highest in group C. Groups A and B were comparable for FEV1, forced vital capacity (FVC), maximal voluntary ventilation (MVV) and FEV1/FVC, whereas Group C exhibited significantly reduced FEV1, FVC and MVV but a normal FEV1/FVC ratio. All values except the FEV1/FVC ratio were significantly lower than in groups A and B. Group C had significantly higher levels of leptin, insulin, FG and HOMA-IR than Groups A and B (p < 0.001). There was a significant negative correlation between FEV1 and MVV with leptin, insulin and HOMA-IR, but not with high-sensitivity C-reactive protein (hs-CRP). We conclude that FEV1 is reduced in obese children and adolescents and inversely correlates with plasma leptin, insulin and HOMA-IR levels. We have shown that the most important factor in inducing a restrictive lung in these patients may be related to leptin status.

Correlation Between N-Terminal Pro-Brain Natriuretic Peptide Levels and Cardiopulmonary Exercise Testing in Patients With Pre-Capillary Pulmonary Hypertension: A Pilot Study.

BACKGROUND: N-terminal pro-brain natriuretic peptide (NT-proBNP) and cardiopulmonary exercise testing (CPET) are useful for severity assessment in patients with pulmonary hypertension (PH). Correlations between these tests in pre-capillary PH patients is less well studied. METHODS: We studied 23 patients with pre-capillary PH: 8 with idiopathic pulmonary arterial hypertension (IPAH), 6 with systemic sclerosis-associated PAH (SSc-PAH), and 9 with chronic thromboembolic pulmonary hypertension (CTEPH). Clinical evaluation, NT-proBNP levels, six-minute walking test (6MWT), spirometry, and CPET were evaluated on the same day. Correlation between NT-proBNP levels and CPET parameters were investigated. RESULTS: In all patients, NT-proBNP levels were significantly correlated with peak oxygen uptake (VO2) (r = -0.47), peak oxygen pulse (r = -0.43), peak cardiac output (CO) (r = -0.57), peak end-tidal partial pressure of carbon dioxide (PETCO2) (r = -0.74), ventilatory equivalent to carbon dioxide (VE/VCO2) at anaerobic threshold (AT) (r = 0.73), and VE/VCO2 slope (r = 0.64). Significant correlations between NT-proBNP levels and peak PETCO2 and VE/VCO2 were found in IPAH and CTEPH subgroups, and a significant correlation between NT-proBNP levels and VO2 at AT was found in the CTEPH subgroup. No significant correlation was found in the SSc-PAH subgroup. CONCLUSION: NT-proBNP levels were significantly correlated with CPET parameters in patients with IPAH and CTEPH subgroups, but not in SSc-PAH subgroup. A further study with larger population is required to confirm these preliminary findings.