BACKGROUND Type 2 diabetes (T2D) is a metabolic disease with significant medical complications. Roux-en-Y gastric bypass (RYGB) surgery is one of the few interventions that remit T2D in ~60% of patients. However, there is no accurate method for predicting preoperatively the probability for T2D remission. METHODS A retrospective cohort of 2,300 RYGB patients at Geisinger Clinic was used to identify 690 patients with T2D and complete electronic data. Two additional T2D cohorts (N=276, and N=113) were used for replication at 14 months following RYGB. Kaplan-Meier analysis was used in the primary cohort to create survival curves until remission. A Cox proportional hazards model was used to estimate the hazard ratios on T2D remission. FINDINGS Using 259 preoperative clinical variables, four (use of insulin, age, HbA1c, and type of antidiabetic medication) were sufficient to develop an algorithm that produces a type 2 diabetes remission (DiaRem) score over five years. The DiaRem score spans from 0 to 22 and was divided into five groups corresponding to five probability-ranges for T2D remission: 0–2 (88%–99%), 3–7 (64%–88%), 8–12 (23%–49%), 13–17 (11%–33%), 18–22 (2%–16%). The DiaRem scores in the replication cohorts, as well as under various definitions of diabetes remission, conformed to the DiaRem score of the primary cohort. INTERPRETATION The DiaRem score is a novel preoperative method for predicting the probability (from 2% to 99%) for T2D remission following RYGB surgery. FUNDING This research was supported by the Geisinger Health System and the National Institutes of Health.

OBJECTIVERoux-en-Y gastric bypass (RYGB) in humans can remit type 2 diabetes, but the operative mechanism is not completely understood. In mice, fibroblast growth factor (FGF) 15 (FGF19 in humans) regulates hepatic bile acid (BA) production and can also resolve diabetes. In this study, we tested the hypothesis that the FGF19–BA pathway plays a role in the remission of human diabetes after RYGB surgery.RESEARCH DESIGN AND METHODSCohorts of diabetic and nondiabetic individuals of various body weights were used. In addition, RYGB patients without diabetes (No-Diabetes), RYGB patients with diabetes who experienced remission for at least 12 months after surgery (Diabetes-R), and RYGB patients with diabetes who did not go into remission after surgery (Diabetes-NoR) were studied. Circulating FGF19 and BA levels, hepatic glycogen content, and expression levels of genes regulating the FGF19–BA pathway were compared among these groups of patients using pre- and postoperative serum samples and intraoperative liver biopsies.RESULTSPreoperatively, patients with diabetes had lower FGF19 and higher BA levels than nondiabetic patients, irrespective of body weight. In diabetic patients undergoing RYGB, lower FGF19 levels were significantly correlated with increased hepatic expression of the cholesterol 7alpha-hydroxylase 1 (CYP7A1) gene, which modulates BA production. Following RYGB surgery, however, FGF19 and BA levels (particularly cholic and deoxycholic acids) exhibited larger increases in Diabetic-R patients compared with nondiabetic and Diabetic-NoR patients.CONCLUSIONSTaken together, the baseline and postoperative data implicate the FGF19–CYP7A1–BA pathway in the etiology and remission of type 2 diabetes following RYGB surgery.

OBJECTIVE Gastric bypass surgery is an effective therapy for extreme obesity. However, substantial variability in weight loss outcomes exists that remains largely unexplained. Our objective was to determine whether any commonly collected pre-operative clinical variables were associated with weight loss following Roux-en-Y gastric bypass surgery. DESIGN The analysis was based on a prospectively recruited observational cohort of 2365 patients who underwent Roux-en-Y gastric bypass surgery from 2004-2009. Weight loss was stratified into three major phases, early (0-6 months), nadir, and long-term (>36 months). Multivariate regression models were constructed using a database of over 350 variables. RESULTS A total of 12-14 pre-operative variables were independently associated (p<0.05) with each of the temporal weight loss phases. Pre-operative variables associated with poorer nadir and long-term weight loss included: higher baseline BMI, higher pre-operative weight loss, iron deficiency, use of any diabetes medication, non-use of bupropion medication, no history of smoking, aged >50 years, and the presence of fibrosis on liver biopsy. CONCLUSIONS Several variables previously associated with poorer weight loss after RYGB surgery including age, baseline BMI, and type 2 diabetes were replicated. Several others suggest possible clinical interventions for post-operative management of RYGB patients to improve weight loss outcomes.

In the present study, we sought to identify lncRNA expression profiles in NASH patients with histological evidence of lobular inflammation and advanced fibrosis. We profiled lncRNA expression using RNA-sequencing of wedge liver biopsies from 24 NAFLD patients with normal liver histology, 53 NAFLD patients with lobular inflammation, and 65 NAFLD patients with advanced fibrosis. Transcript profiling identified 4432 and 4057 differentially expressed lncRNAs in comparisons of normal tissue with lobular inflammation and fibrosis samples, respectively. Functional enrichment analysis revealed lncRNA participation in TGFB1 and TNF signaling, insulin resistance, and extracellular matrix maintenance. Several lncRNAs were highly expressed in fibrosis relative to normal tissue, including nuclear paraspeckle assembly transcript 1 (NEAT1), hepatocellular carcinoma upregulated lncRNA (HULC), and metastasis-associated lung adenocarcinoma transcript 1 (MALAT1). Two potential target mRNAs, syndecan 4 (SDC4) and C-X-C motif chemokine ligand 5 (CXCL5) were identified for HULC and MALAT1, respectively, but only CXCL5 showed differential expression among the different histological classes. Knockdown of MALAT1 expression reduced CXCL5 transcript and protein levels by 50% and 30%, respectively, in HepG2 cells. Expression of MALAT1 and CXCL5 was upregulated in activated hepatic stellate (LX-2) cells compared to cells in the quiescent state, and MALAT1 expression was regulated by hyperglycemia and insulin in HepG2 cells, but only by insulin in LX-2 cells. Dysregulated lncRNA expression is associated with inflammation and fibrosis in NASH. Functionally relevant differences in MALAT1 expression may contribute to the development of fibrosis in NASH through mechanisms involving inflammatory chemokines.

Genome‐wide association and linkage studies have identified multiple susceptibility loci for obesity. We hypothesized that such loci may affect weight loss outcomes following dietary or surgical weight loss interventions. A total of 1,001 white individuals with extreme obesity (BMI >35 kg/m2) who underwent a preoperative diet/behavioral weight loss intervention and Roux‐en‐Y gastric bypass surgery were genotyped for single‐nucleotide polymorphisms (SNPs) in or near the fat mass and obesity‐associated (FTO), insulin induced gene 2 (INSIG2), melanocortin 4 receptor (MC4R), and proprotein convertase subtilisin/kexin type 1 (PCSK1) obesity genes. Association analysis was performed using recessive and additive models with pre‐ and postoperative weight loss data. An increasing number of obesity SNP alleles or homozygous SNP genotypes was associated with increased BMI (P < 0.0006) and excess body weight (P < 0.0004). No association between the amounts of weight lost from a short‐term dietary intervention and any individual obesity SNP or cumulative number of obesity SNP alleles or homozygous SNP genotypes was observed. Linear mixed regression analysis revealed significant differences in postoperative weight loss trajectories across groups with low, intermediate, and high numbers of obesity SNP alleles or numbers of homozygous SNP genotypes (P < 0.0001). Initial BMI interacted with genotype to influence weight loss with initial BMI <50 kg/m2, with evidence of a dosage effect, which was not present in individuals with initial BMI ≥50 kg/m2. Differences in metabolic rate, binge eating behavior, and other clinical parameters were not associated with genotype. These data suggest that response to a surgical weight loss intervention is influenced by genetic susceptibility and BMI.