Changes in Plasma Levels of N-Arachidonoyl Ethanolamine and N-Palmitoylethanolamine following Bariatric Surgery in Morbidly Obese Females with Impaired Glucose Homeostasis

Abstract

Aim. We examined endocannabinoids (ECs) in relation to bariatric surgery and the association between plasma ECs and markers of insulin resistance. Methods. A study of 20 participants undergoing bariatric surgery. Fasting and 2-hour plasma glucose, lipids, insulin, and C-peptide were recorded preoperatively and 6 months postoperatively with plasma ECs (AEA, 2-AG) and endocannabinoid-related lipids (PEA, OEA). Results. Gender-specific analysis showed differences in AEA, OEA, and PEA preoperatively with reductions in AEA and PEA in females postoperatively. Preoperatively, AEA was correlated with 2-hour glucose (r = 0.55, P = 0.01), HOMA-IR (r = 0.61, P = 0.009), and HOMA %S (r = −0.71, P = 0.002). OEA was correlated with weight (r = 0.49, P = 0.03), waist circumference (r = 0.52, P = 0.02), fasting insulin (r = 0.49, P = 0.04), and HOMA-IR (r = 0.48, P = 0.05). PEA was correlated with fasting insulin (r = 0.49, P = 0.04). 2-AG had a negative correlation with fasting glucose (r = −0.59, P = 0.04). Conclusion. Gender differences exist in circulating ECs in obese subjects. Females show changes in AEA and PEA after bariatric surgery. Specific correlations exist between different ECs and markers of obesity and insulin and glucose homeostasis.

Sex difference in brain CB1 receptor availability in man

“…Previous literature on sex difference of endocannabinoid levels in cerebrospinal fluid or peripheral blood is inconclusive with mixed results. Most studies report no major differences of EC levels between males and females [53][54][55][56][57][58][59][60][61][62] but the link between peripheral ECS drive and central CB1 receptor availability is not known 63 . In our sample, females using combined oral contraceptives, a combination of estrogen and progesterone, tended to have lower mean CB1R availability compared to that of females without hormonal contraception.…”

Dysfunctional oleoylethanolamide signaling in a mouse model of Prader-Willi syndrome

“…Indeed, OEA-mediated signaling has been documented throughout vertebrate phylogeny [16–20,23,24] and is likely to exist also in humans [37,38]. Importantly, recent evidence from genetic and human laboratory studies indicates that deficits in the activity of this signaling system may be implicated in human obesity.…”

Endocannabinoids in aqueous humour of patients with or without diabetes

“…The extraction, purification and quantification of endocannabinoids from ocular fluid were performed using a method modified from an established procedure for analysis of endocannabinoids in plasma and mammalian tissues 18–22. Internal standards 30 µL of 2-AG-d8 (5 µM) and 15 µL of AEA-d8 (28 µM) were added to each sample prior to extraction.…”

“…No previous studies have examined the levels of endocannabinoid in the aqueous humour of patients with diabetes compared with patients without diabetes, and whether levels are associated with STDR. Further, in view of previous studies implying that gender and diabetes may affect endocannabinoid concentrations,18–23 we investigated any differences of aqueous endocannabinoid concentration between gender.…”