Hepatic FoxOs link insulin signaling with plasma lipoprotein metabolism through an apolipoprotein M/sphingosine-1-phosphate pathway.

Multiple beneficial cardiovascular effects of HDL depend on sphingosine-1-phosphate (S1P). S1P associates with HDL by binding to apolipoprotein M (ApoM). Insulin resistance is a major driver of dyslipidemia and cardiovascular risk. However, the mechanisms linking alterations in insulin signaling with plasma lipoprotein metabolism are incompletely understood. The insulin-repressible FoxO transcription factors mediate key effects of hepatic insulin action on glucose and lipoprotein metabolism. This work tested whether hepatic insulin signaling regulates HDL-S1P and aimed to identify the underlying molecular mechanisms. We report that insulin-resistant, nondiabetic individuals had decreased HDL-S1P levels, but no change in total plasma S1P. This also occurred in insulin-resistant db/db mice, which had low ApoM and a specific reduction of S1P in the HDL fraction, with no change in total plasma S1P levels. Using mice lacking hepatic FoxOs (L-FoxO1,3,4), we found that hepatic FoxOs were required for ApoM expression. Total plasma S1P levels were similar to those in controls, but S1P was nearly absent from HDL and was instead increased in the lipoprotein-depleted plasma fraction. This phenotype was restored to normal by rescuing ApoM in L-FoxO1,3,4 mice. Our findings show that insulin resistance in humans and mice is associated with decreased HDL-associated S1P. Our study shows that hepatic FoxO transcription factors are regulators of the ApoM/S1P pathway.

Effects on GLP-1, PYY, and leptin by direct stimulation of terminal ileum and cecum in humans: implications for ileal transposition.

BACKGROUND: We do not have a unified, scientifically tested theory of causation for obesity and its co-morbidities, nor do we have explanations for the mechanics of the metabolic/bariatric surgery procedures. Integral to proffered hypotheses are the actions of the hormones glucagon-like peptide-1 (GLP-1), peptide YY (PYY), and leptin. The objective of this study was to obtain blood levels of GLP-1, PYY, and leptin after stimulation of the terminal ileum and cecum by a static infusion of a food hydrolysate in morbidly obese patients undergoing a duodenal switch procedure. SETTING: University Hospital. METHODS: Plasma levels of GLP-1, PYY, and leptin were obtained at 0, 30, 60, 90, and 120 minutes after instillation of 240 mL of a food hydrolysate into the ileum or cecum. RESULTS: The mean±SD GLP-1 values by cecal stimulation for 0, 30, 60, 90, and 120 minutes were: 41.3±23.2; 39.6±21.8; 38.9±19.1; 47.4±22.3; 51.7±27.3 pM, and by ileal stimulation: 55.0±32.8; 83.4±16.1; 78.7±23.8; 84.7±23.5; 76.4±25.6. The mean±SD PYY values by cecal stimulation were: 62.1±24.8; 91.1±32.8; 102.1±39.6; 119.6±37.5; 130.3±36.7, and by ileal stimulation: 73.8±41.6; 138.1±17.7; 149.5±23.3; 165.7±24.3; 155.5±29.1. Percent change in PYY levels increased ~150%, GLP-1 increased ~50%, and leptin decreased ~20%. CONCLUSION: Direct stimulation of the human terminal ileum and cecum by a food hydrolysate elicits significant plasma GLP-1 and PYY elevations and leptin decreases, peaking at 90-120 minutes. The ileal GLP-1 and PYY responses exceed those of the cecum, and the PYY effect is about 3-fold that of GLP-1. The results of this study question the satiety premise for ileal transposition.

Hiatal hernia repair in laparoscopic adjustable gastric banding and laparoscopic Roux-en-Y gastric bypass: a national database analysis.

Hiatal hernia (HH) repairs are commonly done concomitantly with laparoscopic Roux-en-Y gastric bypass (LRYGB) and laparoscopic adjustable gastric banding (LAGB) to decrease gastroesophageal reflux disease (GERD). There is limited evidence about the additional surgical risk these combined procedures engender. We used the United States Nationwide Inpatient Sample 2004-2009 to compare mortality risk, prolonged length of stay (PLOS), and perioperative adverse events using propensity score-matched analysis. We repeated the analysis after removing patients diagnosed with GERD. There were 42,272 weighted patients undergoing LRYGB alone representing 206,559 discharges nationally and an additional 1,945 and 9,060, respectively, undergoing LRYGB + HH repair. For LAGB, there were 10,558 records representing 52,901 LAGB-only discharges and 1,959 representing 9,893 LAGB + HH repair discharges. Thirty-eight percent (95 % CI: 36, 41 %) of the patients in the LRYGB-only group had GERD compared to 55 % (51, 59 %) in the LRYGB + HH repair group. Among the LAGB groups, 31 % (28, 34 %) of LAGB-only patients had GERD compared to 44 % (38, 49 %) in the LAGB + HH repair group. We find that the average treatment effect on the treated (considering the concomitant procedure as treatment and the single procedure as control) for PLOS was -0.12353 (-0.15909, -0.08797) between the LRYGB groups and -0.04353 (-0.07488, -0.01217) for the LAGB groups. We find no evidence of increased risk of perioperative adverse events among patients undergoing concomitant HH repair with LRYGB or LAGB. Patients undergoing the combined procedure appear to be at lower risk of PLOS; this may be due to surgical training norms.

Benefits and complications of the duodenal switch/biliopancreatic diversion compared to the Roux-en-Y gastric bypass.

BACKGROUND: Despite providing superb excess weight loss and increased resolution of comorbid diseases, such as type 2 diabetes mellitus, compared to other bariatric procedures, the duodenal switch/ biliopancreatic diversion (DS/BD) has not gained widespread acceptance among patients and physicians. In this study, we investigated outcomes, symptoms and complications among postsurgical DS patients compared to RYGB patients. METHODS: We used propensity scores to retrospectively match patients who underwent DS/BD between 2005 and 2010 to comparable Roux-en-Y gastric bypass (RYGB) patients. We then reviewed patient charts, and surveyed patients using the University of Minnesota Bariatric Surgery Outcomes Survey tool to track outcomes, comorbid illnesses and complications. RESULTS: One hundred ninety consecutive patients underwent primary DS/BD between 2005 and 2010 at the University of Minnesota Medical Center. There were 178 patients available for follow-up (93.7%) who were matched to 139 RYGB patients. Type 2 diabetes, hypertension, and hyperlipidemia all significantly improved in each group. Improvements were significantly higher in the DS/BD group. Percent total weight loss was not different between groups. Loose stools and bloating symptoms were more frequently reported among DS/BD patients. With the exception of increased emergency department visits among DS/BD patients (P < .01), overall complication rates were not significantly different between DS/BD and RYGB. There was no difference in mortality rates between the groups. CONCLUSION: The DS/BD is a robust procedure that engenders both superior weight loss and improvement of major comorbidities. Complication and adverse event rates are similar to those of RYGB.