Correlation between serum leptin and other variables.

<p>As shown, leptin was positively correlated with BMI, serum IL-6, PaO₂^POST, and ΔPaO₂ and negatively correlated with PaO₂^PRE, PaCO₂^PRE, PaCO₂^POST, and ΔPaCO₂. BMI, body mass index; IL-6, interleukin 6; PaCO₂^POST, postoperative arterial partial pressure of carbon dioxide (PaCO₂); PaCO₂^PRE, preoperative PaCO₂; ΔPaCO₂, PaCO₂^POST minus PaCO₂^PRE; PaO₂^POST, postoperative arterial partial pressure of oxygen (PaO₂); PaO₂^PRE, preoperative PaO₂; ΔPaO₂, PaO₂^POST minus PaO₂^PRE; r, Bravais-Pearson correlation coefficient.</p

Dual effects of leptin in perioperative gas exchange of morbidly obese patients

<div><p>Leptin has shown positive effects on respiratory function in experimental settings. The role of leptin on perioperative respiratory function in morbidly obese patients has not been established. We performed a retrospective analysis of morbidly obese patients undergoing laparoscopic sleeve gastrectomy. Fasting serum leptin and interleukin (IL)-6 were measured preoperatively, and arterial blood gases were obtained pre- and postoperatively. Outcome variables were arterial partial pressure of oxygen (PaO₂), arterial partial pressure of carbon dioxide (PaCO₂), and differences in PaO₂ and PaCO₂ between pre- and postoperative values (ΔPaO₂, ΔPaCO₂; postoperative minus preoperative). Patients with lower (<40 μg/L) and higher (≥40 μg/L) leptin levels were compared. Bravais-Pearson’s correlation, multiple linear regression, and logistic regression analysis were performed. A total of 112 morbidly obese patients were included. Serum leptin was significantly higher in females than in males (42.86±12.89 vs. 30.67±13.39 μg/L, p<0.0001). Leptin was positively correlated with body mass index (<i>r</i> = 0.238; p = 0.011), IL-6 (<i>r</i> = 0.473; p<0.0001), and ΔPaO₂ (<i>r</i> = 0.312; p = 0.0008). Leptin was negatively correlated with preoperative PaO₂ (<i>r</i> = -0.199; p = 0.035). Preoperative PaO₂ was lower, ΔPaCO₂ was smaller, and ΔPaO₂ was greater in the high leptin group than in the low leptin group. In multiple regression analysis, leptin was negatively associated with preoperative PaO₂ (estimate coefficient = -0.147; p = 0.023). In logistic regression analysis, leptin was associated with improved ΔPaO₂ (odds ratio [OR] = 1.104; p = 0.0138) and ΔPaCO₂ (OR = 0.968; p = 0.0334). Leptin appears to have dual effects related to perioperative gas exchange in obese patients undergoing bariatric surgery. It is associated with worse preoperative oxygenation but improved respiratory function after surgery.</p></div

Correlation between body mass index and other variables.

<p>As shown, BMI was positively correlated with PaCO₂^PRE, PaCO₂^POST, and ΔPaO₂ and negatively correlated with PaO₂^PRE, PaO₂^POST, and ΔPaCO₂. BMI, body mass index; PaCO₂^POST, postoperative arterial partial pressure of carbon dioxide (PaCO₂); PaCO₂^PRE, preoperative PaCO₂; ΔPaCO₂, PaCO₂^POST minus PaCO₂^PRE; PaO₂^POST, postoperative arterial partial pressure of oxygen (PaO₂); PaO₂^PRE, preoperative PaO₂; ΔPaO₂, PaO₂^POST minus PaO₂^PRE; r, Bravais-Pearson correlation coefficient.</p

Logistic regression analysis between leptin and BMI and variation of gas exchange parameters.

<p>Logistic regression analysis between leptin and BMI and variation of gas exchange parameters.</p

Characteristics of 112 morbidly obese patients included in the study.

<p>Characteristics of 112 morbidly obese patients included in the study.</p

Vessel cell proliferation in IPF lung tissue.

<p>Strong Ki-67 immunostaining was observed both in endothelial (A, arrows) and in smooth muscle cells (B, arrows) of remodelled pulmonary arteries adjacent to metaplastic epithelial cells (well seen in A, arrowhead). Bar scale: 10 µm.</p

TGF-β expression in IPF lung tissue.

<p>A) Significantly increased TGF-β median score values of epithelial cells are seen in virus positive cases. B) TGF-β median score values of macrophages in virus positive and virus negative cases. Stronger and more extensive TGF-β immunostaining well seen in virus positive (C) than virus negative case (D). Bar scale: 5 µm.</p

Vascular remodelling in IPF lung tissue.

<p>Significantly increased arterial thickening (A) particularly of the intimal layer (B) is seen in virus positive cases. Elastic Van Gieson stained sections showed increased wall thickening (increased elastic and collagen fibers) especially of the intimal layer (arrow) in virus positive (C) compared to virus negative cases (D). Bar scale: 100 µm. L = lumen.</p

In situ hybridization for EBV.

<p>EBER transcripts well seen in the nuclei of two alveolar epithelial cells (arrows). Bar scale: 10 µm.</p

Study subjects (IPF patients and non-IPF DPLDs).

<p>Data are number of patients (%) or mean (sd). IPF: idiopathic pulmonary fibrosis;</p><p>DPLDs: Diffuse parenchymal lung diseases; BMI: body mass index; CHD: coronary heart disease.</p