Ghrelin and leptin levels in obese adolescents. Relationship with body fat and insulin resistance

Abstract

ObJEctIVE: Ghrelin and leptin levels are influenced by body fat (bF%), pubertal stage and possibly insulin resistance (Ir). the aim of our study was: 1) to compare fasting ghrelin and leptin levels between obese and non-obese, adolescents, 2) to investigate possible correlations of these hormones with bF %, as well as Ir. DEsIGN: twenty obese insulin resistant (Ir) adolescents, twenty obese non Ir (NIr) and fifteen healthy non-obese, age-matched adolescents were studied. In all participants, height, weight, body mass index (bMI) and bF % were measured. Fasting glucose, insulin, ghrelin and leptin levels were determined. Ir was assessed using HOMA-Ir index. rEsuLts: bMI, bF %, insulin and HOMA-Ir values were positively correlated with leptin and negatively with ghrelin levels. A negative correlation between circulating leptin and ghrelin levels was found. A suggestive positive correlation between leptin levels and bF %, independent of bMI, was also observed (P=0.075). Ghrelin levels were significantly correlated with insulin levels and HOMA-Ir, independent of bMI (P=0.077). cONcLusIONs: Obesity and Ir may play an important role in the release of ghrelin as well as in the negative correlation between ghrelin and leptin.

Impact of Sustained Weight Loss Achieved through Roux-en-Y Gastric Bypass or a Lifestyle Intervention on Ghrelin, Obestatin, and Ghrelin/Obestatin Ratio in Morbidly Obese Patients

“…Ghrelin levels have been shown to be down-regulated in obese individuals [25, 26] and to increase in response to diet- and/or exercise-induced weight loss [2–4], suggesting that ghrelin plays a role in the long-term regulation of energy balance. An increase in ghrelin levels secondary to weight loss can be seen as a compensatory mechanism to try to restore energy balance by upregulating hunger levels and ultimately energy intake.…”

A Leptin Serum Concentration Less than 10 ng/ml Is a Predictive Marker of Outcome in Patients with Moderate to Severe Secondary Peritonitis

“…It is during this interval that leptin increases to its maximum value postoperatively [14,22] . In nonobese adults the serum reference value of leptin is 11.6 8 1.3 ng/ml, but the leptin levels are influenced by the amount of body fat, age, gender and metabolic diseases such as diabetes mellitus [23,24] . We defined a low leptin serum level as a value of ^ 10 ng/ml.…”

The Relationship between Type 2 Diabetes and Total Ghrelin Level in a Population Sample in the United Arab Emirates

“…On the other hand, conflicting results have been reported [20,21]. Some reports suggested that ghrelin either stimulates [18,19,22] or inhibits insulin secretion depending on the experimental condition [23,24].…”