Study of Circulating fibroblast growth factor – 21 and insulin resistance in patients with impaired fasting, impaired glucose tolerane and type 2 diabetes

Abstract

Fibroblast growth factor 21 (FGF21), a member of the FGF family, has recently emerged as a novel regulator of metabolism. FGF21 is mainly produced by the liver, and functions as a potent activator of glucose uptake in adipocytes. FGF21 causes paracrine effects, such as induction of hepatic ketogenesis, and endocrine actions, such as the promotion of lipolysis in white adipose tissue. Circulating FGF21 concentrations have been found elevated in insulin-resistant states, such as impaired glucose tolerance and type 2 diabetes(DM2). FGF21 also seems to be involved in the regulation of body fat mass. Circulating FGF21 concentrations are significantly elevated in obesity in rodents responding poorly to exogenous FGF21, indicating that obesity could be an FGF21-resistant state. The aim of this study is to assess the relationship between plasma level of FGF- 21& Insulin resistance in cases with impaired fasting glucose, impaired glucose tolerance and type 2 diabetes mellitus. The study was conducted on 80 subjects who were selected from Tanta University hospital outpatient clinic of diabetes. They were divided into 4 groups: The first group (group I) included 20 patients who were diagnosed as type 2 diabetes mellitus, excluding those with any other chronic illness.

The second group (II) included 20 impaired fasting glucose subjects. The third group (III) included 20 impaired glucose tolerance subjects. The fourth group (IV) included 20 normal subjects as a control group. These cases were subjected to:- 1. Full clinical history including: name, age, history suggestive of diabetic complications and other associated illnesses. 2. Full clinical examination including: • Body mass index. • Waist circumference. • Hip circumference. 3. Lab investigations including: • Liver enzymes(ALT,AST), • Serum creatinine. • Fasting plasma glucose. • 2h postprandial plasma glucose. • Fasting plasma insulin. • HbA1C. • Assessment of HOMA-IR. • Lipid profiles (cholesterol, TG, LDL and HDL). • Serum fibroblast growth factor 21. • Estimation of GFR using Cockcroft Gault equation[ml/min] eCcr ═ (140-age)×Mass(in kilograms)×(0,85 if female)/ 72× serum creatinine (in mg/dl) Our results showed FGF21 to be positively correlated with insulin resistance according to HOMA equation.