Fiber intake predicts ghrelin levels in overweight and obese postmenopausal women.
BACKGROUND
Ghrelin levels are decreased upon food intake, but the impact of specific diet-derived macronutrients on its regulation remains unclear. In addition, because of ghrelin's association with body weight regulation, it is important to understand the mechanisms regulating its levels in obese individuals.


OBJECTIVE
To examine the effect of specific macronutrients on ghrelin levels in overweight and obese postmenopausal women.


METHODS
Thirty-five subjects underwent a euglycemic/hyperinsulinemic clamp (EHC) to examine glucose disposal and total ghrelin (TotG) and acylated ghrelin (AG) levels. Macronutrient intake was evaluated with a 3-day food questionnaire.


RESULTS
Under fasting conditions, positive associations were observed between fiber intake and TotG and AG levels. Fasting AG also correlated positively with the intake of total energy, as well as monounsaturated and polyunsaturated lipids. Importantly, fiber consumption explained up to 26 and 23% of the variation in TotG and AG respectively. During the EHC, TotG levels were significantly reduced at all times, while AG was decreased at 60 min only. TotG area under the curve (AUC) values were positively associated with fiber and polyunsaturated lipid intake, while AG AUC values correlated positively with fiber, total energy, carbohydrate, and lipid intake. Interestingly, fiber intake explained up to 21% of the variation in TotG AUC, while total energy intake predicted up to 21% of the variation in the AG AUC.


CONCLUSIONS
The present study suggests that fiber intake is an important regulator of ghrelin levels both in fasting and in hyperinsulinemic conditions. Overall, these results reinforce the importance of the intimate association between eating habits and gastrointestinal hormonal regulation.
Département de, Nutrition et de Médecine, Université de Montréal, Montréal, Québec, Canada.
David H
DH
St-Pierre
Rémi
R
Rabasa-Lhoret
Marie-Eve
ME
Lavoie
Antony D
AD
Karelis
Irene
I
Strychar
Eric
E
Doucet
Lise
L
Coderre
D000368:Aged; D001786:Blood Glucose / Q000378:metabolism; D004043:Dietary Fiber / Q000008:administration & dosage*; D005215:Fasting / Q000502:physiology; D005247:Feeding Behavior / Q000502:physiology; D005260:Female; D054439:Ghrelin / Q000097:blood*; D015309:Glucose Clamp Technique; D006801:Humans; D006946:Hyperinsulinism / Q000378:metabolism; D008875:Middle Aged; D015596:Nutrition Assessment; D009765:Obesity / Q000378:metabolism*; D050177:Overweight / Q000378:metabolism*; D017698:Postmenopause / Q000378:metabolism*; D011237:Predictive Value of Tests
D001786:Blood Glucose; D004043:Dietary Fiber; D054439:Ghrelin