Serum level of insulin-like growth factor-I in type 2 diabetic patients: impact of obesity

Association Between Visceral Fat and Lung Function Impairment in Overweight and Grade I Obese Women: A Cross-Sectional Study

Beyond the common comorbidities related to obesity, such as type 2 diabetes and cardiovascular diseases, impaired lung function is already known, but whether the fat distribution (sub-cutaneous, visceral) affects the lung function and pulmonary immune response are poorly known. Few evidence has shown that visceral fat is associated with insulin resistance, low-grade inflammation, and reduced lung function. In the present study, the body composition and fat distribution were evaluated by multi-frequency octopolar bioimpedance. This study demonstrated a possible association of increased visceral fat with impaired lung function in obesity grade I (n = 28; 45.46 ± 10.38 years old) women that was not observed in normal weight (n = 20; 43.20 ± 10.78 years old) and in overweight women (n = 30; 47.27 ± 10.25 years old). We also identified a negative correlation in FVC% (R2 = 0.9129; p < 0.0236), FEV1% (R2 = 0.1079; p < 0.0134), PEF% (R2 = 0.1673; p < 0.0018), and VC IN% (R2 = 0.1330; p < 0.0057) in the obesity grade I group, clearly demonstrating that higher levels of visceral fat correlate with reduced lung function, but not with sub-cutaneous fat. In addition, for the first time, a negative correlation among anti-fibrotic protein klotho (R2 = 0.09298; p < 0.0897) and anti-inflammatory IL-10 (R2 = 0.1653; p < 0.0487) in plasma was observed, in contrast to increased visceral fat. On the contrary, in breath condensate, a positive correlation for adiponectin (R2 = 0.5665; p < 0.0120), IL1-Ra (R2 = 0.2121; p < 0.0544), and IL1-Beta (R2 = 0.3270; p < 0.0084) was found. Thus, increased visceral fat directly influences the impairment of lung function and the systemic and pulmonary immune response of women with obesity grade I.

The impact of insulin resistance and glycaemic control on insulin-like growth factor-1 in patients with type 2 diabetes: a cross-sectional study

BACKGROUND

Type 2 diabetes mellitus (T2DM) is a multifaceted metabolic disorder. Over the past decade, the potential role of Growth Hormone (GH) and Insulin-like Growth Factor-1 (IGF-1) in the pathogenesis and progression of T2DM has garnered scientific interest. These hormones, while interrelated, exert differential effects on glucose homeostasis; GH elevates blood glucose levels, whereas IGF-1 sustains insulin secretion and augments insulin sensitivity.

OBJECTIVE

The study aimed to investigate the impact of insulin resistance and glycaemic control on IGF-1 levels and to assess other risk factors influencing IGF-1 in T2DM.

METHODS

A cross-sectional study was conducted at the National Diabetes Centre, Baghdad, Iraq, from May 2020 to May 2021. Sixty patients with T2DM were evaluated for fasting plasma glucose (FPG), GH, IGF-1, HbA1c, HOMA-IR, HOMA-B, and anthropometric measures following a comprehensive history and physical examination, focusing on any variables that could influence their metabolic profile. Patients with Type 1 diabetes mellitus, thyroid disease, pituitary disease, chronic kidney disease, hepatic disease, and pregnancy were excluded from the study.

RESULTS

Patients with poorly controlled diabetes (HbA1c > 8) exhibited significantly elevated IGF-1 levels compared to those with HbA1c < 8 (166 vs. 134, P = 0.016). The mean IGF-1 was significantly lower in patients with insulin resistance (IR) compared to those without IR (143 vs. 192, P = 0.001), with a significant negative correlation with Body Mass Index (BMI) and a significant positive correlation with HbA1c and Quantitative Insulin Sensitivity Index (QUICKI). Elevated IGF-1 levels were observed with increasing age, duration of T2DM, higher HbA1c, higher QUICKI, and lower BMI. No significant difference was found in IGF-1 values with regards to HOMA-B, fasting insulin, and waist-hip ratio.

CONCLUSION

Patients with poorly controlled T2DM exhibit higher IGF-1 levels, while those with obesity and high insulin resistance demonstrate lower IGF-1 levels. Further prospective studies are warranted to evaluate the potential of using IGF-1 to reduce insulin resistance and improve metabolic and glycaemic measures in individuals with T2DM and obesity or insulin resistance.

Growth Hormone Mediators and Glycemic Control in Youths With Type 2 Diabetes: A Secondary Analysis of a Randomized Clinical Trial

Importance

Youth-onset type 2 diabetes (T2D) has a more aggressive phenotype than adult-onset T2D, including rapid loss of glycemic control and increased complication risk.

Objective

To identify associations of growth hormone mediators with glycemic failure, beta cell function, and insulin sensitivity in youth-onset T2D.

Design, Setting, and Participants

This post hoc secondary analysis of the Treatment Options for Type 2 Diabetes in Adolescents and Youth (TODAY) randomized clinical trial, which enrolled participants from July 2004 to February 2009, included 398 participants from 15 university-affiliated medical centers with available plasma samples from baseline and 36 months. Participants were youths aged 10 to 17 years with a duration of T2D of less than 2 years who were randomized to metformin, metformin plus lifestyle intervention, or metformin plus rosiglitazone. Participants were followed up for a mean (SD) of 3.9 (1.5) years during the trial, ending in 2011. Statistical analysis was performed from August 2022 to November 2023.

Exposure

Plasma insulin-like growth factor-1 (IGF-1), growth hormone receptor (GHR), and insulin-like growth factor binding protein 1 (IGFBP-1).

Main Outcomes and Measures

Main outcomes were (1) loss of glycemic control during the TODAY study, defined as hemoglobin A1c (HbA1c) level of 8% or more for 6 months or inability to wean from insulin therapy, and (2) baseline and 36-month measures of glycemia (fasting glucose, HbA1c), insulin sensitivity (1/fasting C-peptide), high-molecular-weight adiponectin, and beta cell function (C-peptide index, C-peptide oral disposition index).

Results

This analysis included 398 participants (mean [SD] age, 13.9 [2.0] years; 248 girls [62%]; 166 Hispanic participants [42%]; 134 non-Hispanic Black participants [34%], and 84 non-Hispanic White participants [21%]). A greater increase in IGF-1 level between baseline and 36 months was associated with lower odds of glycemic failure (odds ratio [OR], 0.995 [95% CI, 0.991-0.997]; P < .001) and higher C-peptide index per 100-ng/mL increase in IGF-1 (β [SE], 0.015 [0.003]; P < .001). A greater increase in log2 GHR level between baseline and 36 months was associated with higher odds of glycemic failure (OR, 1.75 [95% CI, 1.05-2.99]; P = .04) and lower C-peptide index (β [SE], -0.02 [0.006]; P < .001). A greater increase in log2 IGFBP-1 level between baseline and 36 months was associated with higher odds of glycemic failure (OR, 1.37 [95% CI, 1.09-1.74]; P = .007) and higher high-molecular-weight adiponectin (β [SE], 431 [156]; P = .007).

Conclusions and Relevance

This study suggests that changes in plasma growth hormone mediators are associated with loss of glycemic control in youth-onset T2D, with IGF-1 associated with lower risk and GHR and IGFBP-1 associated with increased risk.

Trial Registration

ClinicalTrials.gov Identifier: NCT00081328.

Clinical investigation of lipoprotein (a) levels in type 2 diabetics for cariovascular diseases prediction and prognosis

OBJECTIVES

We aimed to evaluate the levels of serum lipoprotein a, LP (a), in Jordanian patients with type 2 diabetes mellitus (DM); and to examine its relation to glycemic control, metabolic syndrome (MS) and duration of DM. The LP (a) is considered one of the independent risk factors for coronary artery disease (CAD) in the general population.

METHODS

Fasting blood samples were drawn from 51 diabetic patients with type 2 DM and 31 non-diabetic age and sex control subjects. Serum LP (a) was measured along with other parameters, including triglycerides (TG), total cholesterol (TC), high-density lipoprotein cholesterol (HDL-c), low-density lipoprotein cholesterol (LDL-c) and glycosylated haemoglobin (HbA_1c). Correlation analyses were performed between LP (a) and the various variables measured.

RESULTS

LP (a) measurement showed a skewed distribution towards the lower levels in both groups. Mean LP (a) levels showed a statistically insignificant difference between the two groups. No correlations of LP (a) were observed with age, sex or body mass index (BMI). No correlations of LP (a) with LDL-c, HDL-c, TG, TC, MS, DM duration or HbA_1c were observed. The LP (a) serum levels were significantly higher in type 2 diabetic patients with retinopathy.

CONCLUSIONS

LP (a) serum levels are not increased in type 2 diabetic patients; so, LP (a) may not be a reliable marker for early therapeutic interventions in DM patients, even in high-risk for thrombosis groups.

Reference values for IGF-I serum concentration in an adult population: use of the VARIETE cohort for two new immunoassays

OBJECTIVE

Measurement of IGF-I is important in the management of patients with growth hormone disorders. Here we aim to establish normative data for two new IGF-I assay kits based on a large random sample of the French general adult population.

SUBJECTS AND METHODS

We measured IGF-I in 911 healthy adults (18-90 years) with two immunoassays (ROCHE Elecsys® and IMMULITE-2000 calibrated against the new IS 02/2547). We compared the data with those of the six immunoassays (iSYS, LIAISON XL, IMMULITE-2000 calibrated against the first IS 87/518, IGF-I RIACT, Mediagnost ELISA, and Mediagnost RIA) that we reported previously. The pairwise concordance among the eight assays was assessed with Bland-Altman plots for both the IGF-1 raw data and the standard deviation scores (SDS), as well as with the percentage of observed agreement and the weighted Kappa coefficient for categorizing IGF-I SDS (ClinicalTrials.gov Identifier: NCT01831648).

RESULTS

The normative data included the range of values (2.5-97.5 percentiles) given by the two new IGF-I assays according to age group and sex. A formula for the SDS calculation is provided. As for the previous six assays, the lower limits of the reference intervals of the two new assays were similar, but the upper limits varied markedly. The pairwise concordances were only moderate (kappa 0.57).

CONCLUSIONS

Data obtained for these two new IGF-I immunoassays confirm that despite being obtained in the same large healthy population, the reference intervals of the eight commercial IGF-1 assay kits showed noteworthy differences. The agreement among the various methods was moderate to good.

Effect of Anthocyanins Supplementation on Serum IGFBP-4 Fragments and Glycemic Control in Patients with Fasting Hyperglycemia: A Randomized Controlled Trial

BACKGROUND

Insulin-like growth factor binding protein-4 (IGFBP-4) fragments have been shown to be associated with cardiometabolic diseases. Anthocyanins as a subgroup of natural polyphenols could have benefits on treating cardiometabolic diseases. The aim of this study was to examine the effects of purified anthocyanins on serum IGFBP-4 fragments and glycemic control in patients with fasting hyperglycemia.

METHODS

A set of 121 participants with elevated fasting glucose (≥5.6 mmol/L), who were originally randomly assigned to anthocyanins (320 mg/day) or placebo groups, were included in this study. Serum IGFBP-4 fragments, fasting and postload glucose, insulin, and C-peptide after a three-hour oral glucose tolerance test (OGTT) were measured at baseline and at the end of 12 weeks.

RESULTS

Compared with placebo, anthocyanins increased serum IGFBP-4 fragments (net change 8.33 ng/mL, 95% CI [1.2, 15.47], p=0.023) and decreased fasting glucose (-0.4 mmol/L [-0.71, -0.1], p=0.01), 2-hour C-peptide (-1.02 ng/mL [-1.99, -0.04], p=0.041) and the 3-hour area under the curve (AUC) of C-peptide (-2.19 [-4.11, -0.27], p=0.026). No other significant difference in parameters for glycemic control and insulin resistance was observed.

CONCLUSION

Anthocyanins supplementation for 12 weeks improved serum IGFBP-4 fragments and decreased fasting glucose and postload C-peptide in patients with fasting hyperglycemia. Further studies are needed to confirm our findings and clarify the potential mechanism.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT02689765. Registered on 6 February 2016, https://clinicaltrials.gov/ct2/show/NCT02689765.

Altered GH-IGF-1 Axis in Severe Obese Subjects is Reversed after Bariatric Surgery-Induced Weight Loss and Related with Low-Grade Chronic Inflammation

Endocrine disorders are common in obesity, including altered somatotropic axis. Obesity is characterized by reduced growth hormone (GH) secretion, although the insulin-like growth factor-1 (IGF-1) values are controversial. The aim of this study was to evaluate the effect of weight loss after bariatric surgery in the GH–IGF-1 axis in extreme obesity, in order to investigate IGF-1 values and the mechanism responsible for the alteration of the GH–IGF-1 axis in obesity. We performed an interventional trial in morbidly obese patients who underwent bariatric surgery. We included 116 patients (97 women) and 41 controls (30 women). The primary endpoint was circulating GH and IGF-1 values. Circulating IGF-1 values were lower in the obese patients than in the controls. Circulating GH and IGF-1 values increased significantly over time after surgery. Post-surgery changes in IGF-1 and GH values were significantly negatively correlated with changes in C-reactive protein (CRP) and free T4 values. After adjusting for preoperative body mass index (BMI), free T4 and CRP in a multivariate model, only CRP was independently associated with IGF-1 values in the follow-up. In summary, severe obesity is characterized by a functional hyposomatotropism at central and peripheral level that is progressively reversible with weight loss, and low-grade chronic inflammation could be the principal mediator.