Associations of ghrelin with eating behaviors, stress, metabolic factors, and telomere length among overweight and obese women: preliminary evidence of attenuated ghrelin effects in obesity?
Ghrelin regulates homeostatic food intake, hedonic eating, and is a mediator in the stress response. In addition, ghrelin has metabolic, cardiovascular, and anti-aging effects. This cross-sectional study examined associations between total plasma ghrelin, caloric intake based on 3day diet diaries, hedonic eating attitudes, stress-related and metabolic factors, and leukocyte telomere length in overweight (n=25) and obese women (n=22). We hypothesized associations between total plasma ghrelin and eating behaviors, stress, metabolic, cardiovascular, and cell aging factors among overweight women, but not among obese women due to lower circulating ghrelin levels and/or central resistance to ghrelin. Confirming previous studies demonstrating lowered plasma ghrelin in obesity, ghrelin levels were lower in the obese compared with overweight women. Among the overweight, ghrelin was positively correlated with caloric intake, giving in to cravings for highly palatable foods, and a flatter diurnal cortisol slope across 3days. These relationships were non-significant among the obese group. Among overweight women, ghrelin was negatively correlated with insulin resistance, systolic blood pressure, and heart rate, and positively correlated with telomere length. Among the obese subjects, plasma ghrelin concentrations were negatively correlated with insulin resistance, but were not significantly correlated with blood pressure, heart rate or telomere length. Total plasma ghrelin and its associations with food intake, hedonic eating, and stress are decreased in obesity, providing evidence consistent with the theory that central resistance to ghrelin develops in obesity and ghrelin's function in appetite regulation may have evolved to prevent starvation in food scarcity rather than cope with modern food excess. Furthermore, ghrelin is associated with metabolic and cardiovascular health, and may have anti-aging effects, but these effects may be attenuated in obesity.
University of California, San Francisco, School of Nursing, United States.
Julia
J
Buss
University of California, Davis, Department of Molecular Biosciences, School of Veterinary Medicine, United States; University of California, Davis, Department of Nutrition, United States.
Peter J
PJ
Havel
University of California, San Francisco, Department of Psychiatry, United States.
Elissa
E
Epel
University of California, San Francisco, Department of Biochemistry and Biophysics, United States.
Jue
J
Lin
University of California, San Francisco, Department of Biochemistry and Biophysics, United States.
Elizabeth
E
Blackburn
University of California, San Francisco, Osher Center for Integrative Medicine, Department of Medicine, United States. Electronic address: Jennifer.Daubenmier@ucsf.edu.
Jennifer
J
Daubenmier
D000328:Adult; D003430:Cross-Sectional Studies; D015930:Diet Records; D002149:Energy Intake; D005247:Feeding Behavior / Q000502:physiology*; D005260:Female; D054439:Ghrelin / Q000097:blood*; D006801:Humans; D007333:Insulin Resistance; D008875:Middle Aged; D009765:Obesity / Q000097:blood*; D050177:Overweight / Q000097:blood*; D016032:Randomized Controlled Trials as Topic; D013315:Stress, Psychological; D016615:Telomere / Q000378:metabolism*
D054439:Ghrelin
Hedonic eating; Leukocyte telomere length; Metabolic factors; Stress; Total plasma ghrelin