BackgroundAcanthosis nigricans (AN) has a close relationship with obesity. It is believed that obesity and AN have the common pathophysiological basis such as hyperinsulinism. This study is aimed to observe the effect of laparoscopic sleeve gastrectomy (LSG) on body composition and insulin resistance in Chinese obese patients with acanthosis nigricans.MethodsA total of 37 obese patients who underwent LSG in our hospital were selected for analysis. They were divided into simple obesity (OB n = 14) and obesity with acanthosis nigricans (AN n = 23) group respectively. Body composition was measured by dual-energy X-ray absorptiometry (DEXA). Anthropometric measurements and glucolipid metabolism before and 3 months post LSG were collected for analysis.ResultsPatients with AN got noticeable improvement in skin condition and their AN score was significantly decreased (3.52 ± 0.79 vs. 1.48 ± 0.73, P < 0.001).Alleviated insulin resistance and more trunk fat loss than limbs’ were observed in both groups (P value < 0.01). In AN group, preoperative android fat mass (FM) was positively correlated with fasting insulin and natural logarithm of HOMA-IR (LNIR) (r = 0.622, 0.608, respectively; all P < 0.01). Besides, changes in android FM and visceral adipose tissue (VAT) also showed significantly positive correlation with changes in LNIR (r = 0.588, r = 0.598, respectively; all P < 0.01).ConclusionsLSG had a positive impact on body composition and skin condition in Chinese obese patients with AN. Loss of android FM and VAT might result in the alleviation of insulin resistance in AN patients. Android fat distribution seems to be a potential indicator of postoperative metabolic benefits for obese patients with AN.

Background and Objective The stomach plays an important role in obesity and obesity‐related diabetes; yet, little is known about key pathways in the gastric mucosa associated with obesity and diabetes. Methods We performed gene microarray and real time‐polymerase chain reaction (RT‐PCR) on gut mucosa samples from control subjects (CON), patients with simple obesity (OB), and patients with obesity and comorbid diabetes (OD) (n = 3 per group). Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses were used to predict the functional significance of differentially expressed genes. Results In total, 262 genes were upregulated and 265 genes were downregulated in the OB group whereas 1756 genes were upregulated and 1053 genes were downregulated in the OD group compared with the CON group. Of these, 23 were co‐regulated in both comparisons. Seven differentially expressed genes were validated by RT‐PCR (NRIP3, L1CAM, TPO, P2RY1, OR8A1, ADAMTS19, and ASIC3). A functional analysis revealed that genes differentially expressed between the OB or OD and CON groups played crucial roles in metabolic, T cell, and G‐protein coupled receptor biological processes, and primarily participated in the PI3K‐Akt and AGE‐RAGE signaling pathways. Conclusions Obesity and obesity‐related diabetes are associated with important gene expression and pathway alterations in the stomach.

Gastric mucosal injury is a less well known complication of obesity. Its mechanism remains to be further elucidated. Here, we explored the protective role of lipocalin 2 (LCN2) against endoplasmic reticulum stress and cell apoptosis in gastric mucosa in patients and mice with obesity. Through molecular and genetic analyses in clinical species, LCN2 secreted by parietal cells expression is elevated in obese. Immunofluorescence, TUNEL, and colorimetry results show that a more significant upregulation of pro-inflammatory factors and increased amount of apoptotic cells in gastric tissue sections in obese groups. Loss- and gain-of-function experiments in gastric epithelial cells demonstrate that increased LCN2 protected against obesity associated gastric injury by inhibiting apoptosis and improving inflammatory state. In addition, this protective effect was mediated by repressing ER stress. Our findings identify LCN2 as a gastric hormone could be a compensatory protective factor against gastric injury in obese.