Serum Leptin Concentrations in Young Insulin-Sensitive and Insulin-Resistant Volunteers

Abstract

The aim of this study was to compare metabolic profiles and serum leptin concentrations between young insulin-sensitive and insulin-resistant subjects. A cross-sectional study was performed in 32 healthy, non-obese, young volunteers. Assessing of insulin sensitivity, serum leptin concentration, serum uric acid, creatinine levels and lipid profile were done on all subjects.An insulin suppression test modified with octreotide was performed to assess insulin sensitivity. Steady state glucose (SSG) and steady state insulin concentrations were calculated. Based on the SSG data, the volunteers were divided into four quartiles, considering as insulin-sensitive individuals those from quartile 1 to quartile 3, and insulin-resistant subjects those in quartile 4. Characteristics of both groups were compared, including metabolic profile and leptin levels. After dividing SSG into quartiles, 24 subjects were considered as insulin-sensitive individuals, and 8 were assessed as insulin-resistant subjects. Total cholesterol and low-density lipoprotein (LDL) cholesterol were significantly higher in the insulin-resistant group than in the insulinsensitive group. Serum leptin concentration was significantly higher (p=0.05) in insulin-resistant women (6.1 nglml) than those considered as insulin-sensitive (3.7±2.3ng/ml). In conclusion, insulin-resistant subjects had higher concentrations of total cholesterol and LDL-cholesterol compared to insulinsensitive individuals. Serum leptin level was higher in insulin-resistant women than those considered as insulin-sensitive.

Effect of Surgically Removing Subcutaneous Fat by Abdominoplasty on Leptin Concentrations and Insulin Sensitivity

“…These findings suggest that hyperinsulinemia induces leptin resistance and hyperleptinemia. 8,19,20 Abdominoplasty did not show a significant effect on insulin sensitivity in this study, contrary to results published by our group after surgical removal of subcutaneous fat by large-volume liposuction in obese women. In that study, we observed an improvement in insulin sensitivity and suggested, as in other investigations, that subcutaneous fat is an important predictor of insulin resistance and is independent from visceral fat.…”

“…6,7 A strong association has been reported between insulin resistance and leptin resistance. 5,8 The practice of cosmetic body contour has increased in the last few years, in particular abdominoplasty, which consists of a surgical intervention with resection of skin and subcutaneous tissue from the umbilicus to the pubic symphysis and attaching the remaining skin portion to the pubic symphysis line. 9,10 The effects of removing fat by abdominoplasty on insulin sensitivity and leptin concentrations are unknown, and the same effects after liposuction are scarce and controversial.…”

Leptin Levels in Type 2 Diabetes: Associations with Measures of Insulin Resistance and Insulin Secretion

“…This persisted after adjustment for fat mass. Previous studies also using this model found an independent association with insulin sensitivity in non-diabetic subjects [4,7,12], but not always in diabetic subjects [6].…”

Effect of Insulin Therapy on Plasma Leptin and Body Weight in Patients with Type 2 Diabetes

“…Female subjects exhibited higher plasma leptin levels and a greater increase with insulin therapy. Insulin-resistant women have previously been reported to have higher leptin levels than insulin-sensitive women [13]. Fig.…”