Background and aims: Different bariatric procedures have been associated with variable weight loss and decrease in serum levels of lipids and lipoproteins. This variation could be partly related to the length of the small intestinal bypass. We evaluated the association of the small intestinal length with the non-alcoholic fatty liver disease (NAFLD) at baseline and with lipid metabolism before and after laparoscopic Roux-en-Y gastric bypass (LRYGB).
Methods: Seventy consecutive morbidly obese patients were recruited to this prospective study. A standard 60-cm biliopancreatic limb (BPL) and 120-cm alimentary limb (AL) was performed, and thereafter, the common channel (CC) length was measured during elective LRYGB. Histological analysis of liver biopsy to diagnose NAFLD was performed. The mRNA expression of genes participating in the cholesterol and fatty acid metabolism in the liver was analyzed.
Results: Female sex (p = 0.006), serum triglycerides (TG, p = 0.016), serum alanine aminotransferase (ALT, p = 0.007), and liver steatosis (p = 0.001) associated with the small intestinal length (BPL + AL + CC) at baseline. Association remained significant between levels of serum TG and CC length (p = 0.048) at 1-year follow-up. Liver mRNA expression of genes regulating cholesterol synthesis and bile metabolism did not associate with the baseline small intestinal length.
Conclusions: Our findings support the suggestions that small intestinal length regulates TG metabolism before and after LRYGB. Therefore, modification of the length of bypassed small intestine based on measured total small intestinal length could optimize the outcomes of the elective LRYGB.
Keywords: Common channel; LRYGB; Obesity; Small intestinal length; TG; Weight loss.