Objective:To explore the correlation between lean nonalcoholic fatty liver disease (NAFLD) and metabolic indicators in a young and middle-aged population undergoing physical examination.Methods:It was a cross-sectional study. A total of 8 250 individuals who underwent routine physical examinations at the Health Medical Center of the Second Affiliated Hospital of Chongqing Medical University from January to December 2021 and met the inclusion and exclusion criteria were selected as the research subbjects. The general examination, fasting blood glucose, blood lipids, liver function, renal function, and fasting color ultrasound examination results were analyzed retrospectively to assess the correlation between lean NAFLD and major metabolic indicators using independent sample t-test, chi-square test, and multivariable logistic regression. Results:The prevalence of lean NAFLD was higher in men than in women (50.7% vs. 49.3%, χ2=97.261, P<0.001). After stratifying the age of onset of lean NAFLD, the peak age of onset was found to be between 45 and 59 years, with the prevalence gradually increasing with age. When stratified by body mass index (BMI), the peak incidence of lean NAFLD was observed in individuals with a BMI of ≥20 and <23 kg/m 2, with the prevalence showing a significant upward trend as BMI increased. The systolic blood pressure, diastolic blood pressure, total cholesterol, triglyceride, low-density lipoprotein, fasting blood glucose, alanine aminotransferase, aspartate aminotransferase, γ-glutamyltransferase, and serum uric acid in lean NAFLD groupwere all significantly higher than those in lean non-NAFLD group (all P<0.01), and the level of high density lipoprotein was significantly lower than that of lean non-NAFLD group ( t=23.755, P<0.001). The logistic analysis showed that systolic blood pressure ( OR=1.258, 95% CI: 1.081-1.465), diastolic blood pressure ( OR=1.282, 95% CI: 1.056-1.557), total cholesterol ( OR=1.712, 95% CI: 1.525-1.923), triglyceride ( OR=4.115, 95% CI: 3.621-4.676), alanine aminotransferase ( OR=1.467, 95% CI: 1.104-1.950), γ-glutamyltransferase ( OR=1.482, 95% CI: 1.242-1.769), fasting blood glucose ( OR=2.479, 95% CI: 2.092-2.939) and serum uric acid ( OR=1.390, 95% CI: 1.236-1.563) were independent metabolic risk factors for lean NAFLD (all P<0.05). Conclusions:The levels of various metabolic markers in young and middle-aged patients with lean NAFLD increase, and the risk of lean NAFLD increases. Metabolic markers are helpful to screen people at risk of lean NAFLD.

Objective:To investigate the application value of optical coherence tomography (OCT) and intravascular ultrasound (IVUS) in evaluating flow diverter (FD) apposition and endothelialization in aneurysm animal models, and analyze the effect of incomplete stent apposition (ISA) on aneurysm lumen healing and stent endothelialization.Methods:Lateral common carotid artery aneurysm models in swines were established by surgical method and then FD was implanted. Immediately after surgery, OCT and IVUS were used to evaluate the locations and degrees of ISA, and difference between these 2 methods in evaluating FD apposition was compared. DSA was performed at 12 weeks after surgery to evaluate the aneurysm occlusion (Kamran grading) and stent patency. OCT and IVUS were used again to observe the stent endothelial situation; by comparing with histopathologic results, effect of ISA on aneurysm healing and stent endothelialization was analyzed.Results:Lateral common carotid artery aneurysm models in 6 swines were established, and 6 Tubridge FDs were successfully implanted. Compared with IVUS (3 stents, 4 locus), OCT could detect more ISA (6 stents, 14 locus); and the vascular diameter change area (7 locus), aneurysm neck area (4 locus) and the head and tail of FD (3 locus) were the main sites of FD malapposition; average distance between stent wire and vessel wall was (560.14±101.48) μm. At 12 weeks after surgery, DSA showed that 1 patient had a little residual contrast agent at the aneurysm neck (Kamran grading 3), and the remaining 5 had complete aneurysm occlusion (Kamran grading 4). One FD had moderate lumen stenosis, and the other 5 FDs had lumen patency. OCT indicated mostly disappeared acute ISA; ISA proportion decreased to 21.4 % (3/14), including 2 in the aneurysm neck and 1 in the partial stent. Histopathological results showed bare stent woven silk, without obvious endothelial coverage; in one FD with luminal stenosis, intimal hyperplasia was mainly composed of vascular smooth muscle cells.Conclusion:In carotid artery aneurysm model with FD implantation, OCT can detect more ISA than IVUS; most acute ISA have good outcome at 12 th week of follow-up, while severe ISA can cause delayed FD endothelialization and delayed aneurysm occlusion.