Circulating Levels of Betatrophin and Irisin Are Not Associated with Pancreaticβ-Cell Function in Previously Diagnosed Type 2 Diabetes Mellitus Patients

Abstract

Betatrophin and irisin are two recently identified hormones which may participate in regulating pancreatic β-cell function. However, the associations of these two hormones with β-cell function remain unclear. The present study aims to demonstrate the associations of circulating betatrophin and irisin levels with β-cell function, assessed by the area under the curve (AUC) of C-peptide, and the possible correlation between these two hormones in previously diagnosed type 2 diabetes mellitus (T2DM) patients. In total, 20 age-, sex-, and body mass index- (BMI-) matched normal glucose tolerance (NGT) subjects and 120 previously diagnosed T2DM patients were included in this study. Partial correlation analysis was used to evaluate the relationships between these two hormones and indexes of β-cell function and insulin resistance. Our results showed that betatrophin levels were significantly elevated, while irisin levels were significantly decreased, in patients with T2DM compared with NGT subjects. However, partial correlation analysis showed that betatrophin levels did not correlate with β-cell function-related variables or insulin resistance-related variables before or after controlling multiple covariates, while irisin correlated positively with insulin sensitivity but is not associated with β-cell function-related variables. Besides, no correlation was observed between betatrophin and irisin levels. Hence we concluded that betatrophin and irisin were not associated with β-cell function in previously diagnosed T2DM patients.

Irisin is a biomarker for metabolic syndrome in prepubertal children

“…However, the direct effect of irisin on insulin is not fully understood. Some reports suggested that irisin is not correlated with β-cell function (HOMA-β), fasting C-peptide, or fasting insulin levels [34]. Nevertheless, it is notable that irisin was significantly associated with MetS, although irisin was not correlated with insulin and HOMA-IR in our study.…”

Physiology and role of irisin in glucose homeostasis

“…In humans, irisin is positively associated with circulating levels of insulin and HOMA of β-cell function (HOMA-β) in individuals with normal glucose tolerance ( n = 254), indicating that irisin might be involved in the regulation of β-cell function 90 . However, in another study, irisin correlated neither with HOMA-β nor with fasting C-peptide or fasting insulin levels 91 .…”

The relationship between circulating irisin, retinol binding protein-4, adiponectin and inflammatory mediators in patients with metabolic syndrome

“…The concentration of RBP-4 was found to be elevated in obesity and type 2 DM, MetS and CVD (5). Many authors found that RBP-4 levels were associated with MetS parameters and HOMA-IR, the duration of diabetes and carotid atherosclerosis as determined by CIMT (26)(27)(28)(29). There are conflicting results about the association of RBP-4 and CRP levels, probably due to methodological differences (30,31).…”