Ghrelin and Leptin May Be Early Biomarkers for Exocrine Pancreatic Insufficiency

A small study of children with cystic fibrosis suggests that leptin and ghrelin levels may predict the development of exocrine pancreatic insufficiency.

Researchers from Poland collected blood samples from 34 patients whose ages ranged from 3 months to 18 years (mean age: 4.5 years) and looked for relationships between the concentrations of the 2 hormones and a wide range of factors: CFTR gene mutations, exocrine pancreas function, abnormal lipid metabolism, liver cell function, and overall diet quality.

Their analysis found a statistically significant positive correlation between ghrelin levels and amylase activity, along with a statistically significant negative correlation between ghrelin levels and serum lipase.

Ghrelin concentrations were significantly lower than average in patients with salt wasting syndrome (p<0.05) and in patients who had yet to reach 1 year of age.

The researchers also found statistically lower serum leptin levels in patients with growth deficiency and increased parameters of cholestasis, particularly in the youngest age group.

“Leptin and ghrelin are peptide hormones which, working antagonistically, regulate the energy balance of the body,” the researchers wrote in the Journal of Cystic Fibrosis. “Ghrelin and leptin levels in children with cystic fibrosis correlate with the nutritional status and can be an early marker of exocrine pancreatic insufficiency.”

Previous research has documented a link between leptin and ghrelin levels and pancreatic insufficiency caused by cystic fibrosis.

A 2007 study that also appeared in the Journal of Cystic Fibrosis, for example, matched 20 healthy adolescents with 14 teens whose cystic fibrosis impaired pancreatic function. Fasting leptin levels were significantly higher in the cystic fibrosis patients than in the controls (p=0.030) and significantly lower in males with cystic fibrosis than in females with the same condition (p=0.01). Fasting ghrelin levels, on the other hand, were significantly lower in males with cystic fibrosis than in control males (p<0.001), though they were comparable in females from both patient groups.

Study team members, who hailed from universities and hospitals in Greece, hypothesized that the differences in hormone levels might explain (or, at least, help explain) the fact that weight, body mass index and body fat percentage were all significantly lower for the cystic fibrosis group than for the control group.

“As the overall clinical outcome of cystic fibrosis patients is related to the nutritional status and body weight,” they wrote, “the role of ghrelin and leptin in these patients needs to be elucidated.”

In general, ghrelin makes people want to eat. Studies show that levels of the peptide rise slowly between meals and then jump significantly when subjects expect to begin eating in the near future. As soon as subjects actually begin to eat, however, plasma ghrelin levels tend to fall rapidly.

Leptin produces nearly the opposite effect, a feeling of satiation and a desire to stop eating. The body begins secreting it shortly after food consumption begins and keeps on doing so throughout the course of a meal and shortly after its conclusion.

The 2 peptides effectively work together to ensure that people eat enough (and are willing to exert enough effort to procure food) but also that they don’t eat to excess.

Some researchers have speculated that ghrelin could prove an effective treatment for people who need to gain weight, but it has not been tried as a regular treatment for patients with exocrine pancreatic insufficiency.