The Cholestyramine-induced Decrease of PYY Postprandial Response is Negatively Correlated with Fat Mass in Obese Women

Abstract

Obese patients have decreased fasting and postprandial levels of peptide YY (PYY), an anorexigenic peptide produced by the L cells of the gastrointestinal mucosa. Fatty nutrients are the most powerful stimulus for PYY release. Cholestyramine, an anion exchanger which adsorbs bile salts, reduces digestion of lipids. The aim of the present study was to investigate the effects of cholestyramine or placebo on PYY secretion in obese women administered a high-fat meal [n=8; age: 30.9±2.7 years; BMI: 47.3±3.3 kg/m2]. Postprandial PYY levels in obese women given placebo significantly increased in plasma at 30, 60, 90, and 120 min after meal ingestion. Cholestyramine administration significantly reduced postprandial PYY response at 15, 30, and 60 min. Percent fat mass (FM%) was negatively correlated with the percent increment of plasma PYY concentrations induced by meal administration at 30 min; conversely, there was a positive correlation between FM% and the percent decrement of plasma PYY concentrations induced by cholestyramine at the same time interval. These correlations failed to reach statistical significance when related to BMI. This study implies that in the obese state the altered PYY response to food consumption is a consequence of a dysfunction of L cells, which become less sensitive to the positive feedback effect of lipids.

Anorexigenic postprandial responses of PYY and GLP1 to slow ice cream consumption: preservation in obese adolescents, but not in obese adults

“…In addition, a negative correlation has been reported between circulating levels of these anorexigenic peptides and adiposity, evaluated as BMI and FM (26,27). In this study, despite a significant difference in BMI between the two groups, there was no correlation between postprandial responses in GLP1 and PYY and BMI or FM.…”

Different Effects of Cholestyramine on Postprandial Secretions of Cholecystokinin and Peptide YY in Women with Bulimia Nervosa

“…A previous study of our group showed a suppressant effect of cholestyramine on postprandial PYY secretion also in patients with simple obesity [27]. The mechanism by which cholestyramine reduces the plasma PYY response to the high-fat meal is presumably different from that responsible for the increase of postprandial CCK release.…”

“…The drug (3 packets, each containing 4 g of the drug) was dissolved in the same volume as the placebo. The dose of cholestyramine was chosen on the basis of a previous work of ours [27]. No significant difference emerged among subjects in the mean time required to consume the meal in the two tests.…”

“…One further variable could be represented by individual differences in the concentrations of bile salts in pancreaticobiliary secretion. Indeed, intraduodenal bile acids are potent suppressors of CCK secretion at physiological concentrations [21] and bile salts seem to play a modulatory role in both CKK and PYY secretion after food ingestion, as demonstrated by the cholestyramine-induced increase of plasma CCK levels and gallbladder responses to an orally or intraduodenally administered mixed meal [22,23,24,25,26] and by the decrease of PYY response to a high-fat meal in obese women [27]. …”

Decrease in hunger and desire to eat: taste effect or the osmolar concentration?

“…I also have some comments about the study design and statistical analysis used by van Avesaat et al First, it may be possible that hormone release or hormone response on the receptor area is affected by fat mass (2). We know that fat mass in individuals with normal BMI may exceed the range that is usually classified as normalweight obesity or latent obesity.…”