Effects of Improving Glycemic Control with Insulin on Leptin, Adiponectin, Ghrelin and Neuropeptidey Levels in Patients with Type 2 Diabetes Mellitus: a Pilot Study

Abstract

Objective:Insulin therapy is associated with weight gain in patients with type 2 diabetes mellitus (T2DM). Several peptides are implicated in appetite control. We evaluated the effects of insulin-induced improved glycaemic control on leptin, adiponectin, ghrelin, neuropeptide Y (NPY) levels and patient characteristics. Method:Consecutive T2DM patients (n = 90) were divided into 2 groups: Group A: 45 insulin-naïve uncontrolled (glycosylated haemoglobin A1c; HbA1c >7%) patients on oral hypoglycaemic agents (OHAs) who converted to insulin monotherapy. Group B: 45 well-controlled (HbA1c <7%) patients on OHAs. Both groups were monitored at baseline, 3 and 6 months. Males and females were analyzed separately because some hormone levels differ between genders. Results:In both genders, insulin therapy (Group A) was associated with significant (p = 0.003 to <0.001) increases in weight, body mass index and leptin levels and significant decreases in glucose, HbA1c and NPY levels. In male insulin-treated patients a significant increase in adiponectin levels (p = 0.008) was observed. There were significant correlations (p = 0.016 to <0.001) between leptin levels, waist circumference and body fat in all patient groups, except group B males. Conclusion:Changes in leptin, adiponectin and NPY levels may occur after insulin-induced improved glycaemic control. These changes may be influenced by gender, weight, body fat and HbA1c.

Weight gain and changes in plasma adiponectin and leptin concentrations after 12-month insulin intensive therapy for Chinese male patients with newly diagnosed type 2 diabetes

“…In contrast, plasma LMW adiponectin concentrations were not significantly changed. These insulin-associated changes agree with previous reports of adiponectin and leptin concentrations in type 2 diabetes on insulin therapy [14,[23][24][25][26][27][28][29][30]. However, we were able to add some information.…”

“…One reason of this discrepancy may be physiological concentration in patients receiving insulin injection dose in our study. In addition, changes in glycaemia and HbA1c were not significantly associated with adiponectin and leptin, as previously reported [15,23,27,33]. These results suggest that adiponectin and leptin levels were primarily regulated by factors other than glycaemic control in type 2 diabetes.…”

“…Therefore, an elevation in blood adiponectin concentration after IIT in type 2 diabetes might lead to suppression of weight gain through effects on lipid and glucose metabolism in the body. In addition, the inability of increased leptin concentrations inhibit weight gain after IIT in type 2 diabetes patients may be partly explained by the presence of leptin resistance [13,[23][24][25][26][27]. To the best of our knowledge, this is the first study to demonstrate the elevated increments of total and HMW adiponectin after IIT in male patients with newly diagnosed type 2 diabetes were associated with less subsequent body weight gain.…”

“…However, plasma leptin concentrations were shown to be elevated in obese individuals, implying the presence of leptin resistance, which is characterised by deficient regulation of energy balance of leptin [21] and can lead to aggravated weight gain in the condition of exposure to a highfat diet [22]. Many studies have revealed that elevated leptin levels and body weight may occur after insulin-induced improved glycaemic control in subjects with type 2 diabetes, and the increments in leptin levels were correlated with the increments in weight and body mass index (BMI) in patients on insulin monotherapy [23][24][25][26][27]. Aas et al suggested that the increase in serum leptin-levels (so called hyperleptinemia) observed during insulin treatment in type 2 diabetes may induce leptin resistance, contributing to weight gain [23].…”

The Role of Psychobiological and Neuroendocrine Mechanisms in Appetite Regulation and Obesity

“…leptin, insulin, ghrelin and NPY) [109]. For example, insulin treatment was shown to increase leptin and decrease NPY levels in diabetic patients; body weight was also increased in insulin-treated patients [110]. This was probably due to other mechanisms such as the anabolic effects of insulin, stimulation of lipogenesis, suppression of hepatic glucose production, reduction of basal metabolic rate and elimination of glycosuria.…”