Effects of basal insulin application on serum visfatin and adiponectin levels in type 2 diabetes

Development of an isotope dilution mass spectrometry assay for the quantification of insulin based on signature peptide analysis

An isotope dilution mass spectrometry (IDMS) method that involves peptide-based protein analysis was developed to accurately quantify insulin. In this study, a signature peptide (GFFYTPK) obtained from tryptic digestion of insulin was selected as a surrogate for insulin. Then, the optimal conditions for signature peptide analysis through mass spectrometry detection and enzymatic digestion were determined. The analytical performance of this method was assessed and validated using porcine insulin-certified reference material. The linear range of the insulin calibration curve ranged from 0.05 ~ 2 mass ratios, with recoveries ranging from 96.15 to approximately 101.15%. The limit of detection was 0.19 ng/mL, and the limit of quantification was 0.63 ng/mL. The quantitative results corresponded well with a certified value that was obtained from measuring a porcine insulin reference material with amino acid-based IDMS. In addition, the target peptide GFFYTPK can be found in other species of insulin. This method was also applied for the quantification of human insulin-certified reference material. Finally, we applied the method to quantify the concentrations of simulated serum insulin. These findings suggested that this signature peptide-based IDMS approach can accurately quantify insulin levels, can assign a certified value to insulin reference materials, and has the potential to quantify serum insulin with traceable measurements.

The Molecular Basis of Male Infertility in Obesity: A Literature Review

The rising incidence of obesity has coincided with rising levels of poor reproductive outcomes. The molecular basis for the association of infertility in obese males is now being explained through various mechanisms. Insulin resistance, hyperglycemia, and changes in serum and gonadal concentrations of adipokines, like leptin, adiponectin, resistin, and ghrelin have been implicated as causes of male infertility in obese males. The effects of obesity and hypogonadism form a vicious cycle whereby dysregulation of the hypothalamic-pituitary-testicular axis-due to the effect of the release of multiple mediators, thus decreasing GnRH release from the hypothalamus-causes decreases in LH and FSH levels. This leads to lower levels of testosterone, which further increases adiposity because of increased lipogenesis. Cytokines such as TNF-α and interleukins, sirtuins, and other inflammatory mediators like reactive oxygen species are known to affect fertility in obese male adults. There is evidence that parental obesity can be transferred through subsequent generations to offspring through epigenetic marks. Thus, negative expressions like obesity and infertility have been linked to epigenetic marks being altered in previous generations. The interesting aspect is that these epigenetic expressions can be reverted by removing the triggering factors. These positive modifications are also transmitted to subsequent generations.

Obesity: A Doorway to a Molecular Path Leading to Infertility

The dramatic rise in obesity has recently made it a global health issue. About 1.9 billion were overweight, and 650 million global populations were obese in 2016. Obese women suffer longer conception time, lowered fertility rates, and greater rates of miscarriage. Obesity alters hormones such as adiponectin and leptin, affecting all levels within the hypothalamic-pituitary-gonadal axis. Advanced glycation end products (AGEs) and monocyte chemotactic protein-1 (MCP-1) are inflammatory cytokines that may play an important role in the pathophysiology of ovarian dysfunction in obesity. In obese males, there are altered sperm parameters, reduced testosterone, increased estradiol, hypogonadism, and epigenetic modifications transmitted to offspring. The focus of this article is on the possible adverse effects on reproductive health resulting from obesity and sheds light on different molecular pathways linking obesity with infertility in both female and male subjects. Electronic databases such as Google Scholar, Embase, Science Direct, PubMed, and Google Search Engine were utilized to find obesity and infertility-related papers. The search strategy is detailed in the method section. Even though multiple research work has shown that obesity impacts fertility in both male and female negatively, it is significant to perform extensive research on the molecular mechanisms that link obesity to infertility. This is to find therapeutics that may be developed aiming at these mechanisms to manage and prevent the negative effects of obesity on the reproductive system.

Mohammed, Abdulelah M. Taha. Measurement of paraoxonase-1, visfatin levels in Iraqi diabetic and diabetic with hypothyroidism

Introduction and Aim: This study is to evaluate the levels of paraoxonase-1 and visfatin in diabetic and diabetic with hypothyroidism patients and to discover the relationship of paraoxonase-1 and visfatin levels in these patients. Materials and Methods: The study included 35 subjects in control group (G1), 35 with diabetes (G2), and 35 diabetes with hypothyroidism (G3), aged ranging 25-50 years for all the study groups and BMI with (20.5-25.4) Kg/m2. Serum and whole blood were used for estimating F.B.S., HbA1c%, lipid profile, T4, TSH, paraoxonase-1 and visfatin. Results: The results revealed a significant elevation in F.B.S., HbA1c%, TC, TG, VLDL and LDL in G2 and G3 compared to G1.   The HDL levels showed a significant decrease in G2, G3 compared to G1. Also, showed significant reduction in T4 in G3 compared to G2 and G1. A significant elevation in TSH in G3 compared to G2 and G1 and a significant decrease in paraoxonase-1 but increase in visfatin for G3 more than G2 when compared to G1 were observed. Conclusion:  The study concluded that paraoxonase -1 and visfatin are suggestive reliable markers for the diagnosis of thyroid disorder in diabetics with hypothyroidism depending on their relation with T4 and TSH.

Molecular Mechanisms Underlying the Relationship between Obesity and Male Infertility

In recent decades, the worldwide prevalence of obesity has risen dramatically and is currently estimated to be around 20%. Obesity is linked to an increased risk of comorbidities and premature mortality. Several studies have shown that obesity negatively impacts male fertility through various mechanisms. This review aims to investigate the molecular mechanisms through which obesity impairs male reproduction, including obesity-associated hypogonadism and its effects on spermatogenesis, chronic inflammation, and oxidative stress. Obesity negatively impacts both conventional and biofunctional sperm parameters, and it also induces epigenetic changes that can be transferred to offspring. Moreover, obesity-related diseases are linked to a dysregulation of adipocyte function and micro-environmental inflammatory processes. The dysregulated adipokines significantly influence insulin signaling, and they may also have a detrimental effect on testicular function. Sirtuins can also play an important role in inflammatory and metabolic responses in obese patients. Understanding the molecular mechanisms that are involved in obesity-induced male infertility could increase our ability to identify novel targets for the prevention and treatment of obesity and its related consequences.

Prevalence and Risk Factors of Type 2 Diabetes and Prediabetes Among 53,288 Middle-Aged and Elderly Adults in China: A Cross-Sectional Study

BACKGROUND

Diabetes is a metabolic disorder that causes a heavy burden on healthcare systems worldwide. The aim of this study was to determine the prevalence of type 2 diabetes and prediabetes and its associated factors among eight communities in Nanchong, China.

METHODS

This was an observational cross-sectional study conducted throughout eight communities in Nanchong, China. The participants were 53,288 individuals aged 45 years or older. The participants' characteristics, comorbidities, health behaviors, family history, and dietary intake were assessed. Multinomial logistic regression models were fitted to identify factors associated with type 2 diabetes and prediabetes.

RESULTS

The prevalence of diabetes and prediabetes was 13.9% (95% confidence interval [CI], 13.6-14.2) and 3.1% (95% CI, 2.9-3.2) of the population, respectively. After adjusting for other risk factors, advanced age, overweight, obesity, abdominal obesity, comorbidities, smoking, a family history of diabetes, and Chinese cooking vegetable intake were associated with an increased risk of type 2 diabetes and prediabetes.

CONCLUSION

The prevalence of type 2 diabetes in the Chinese population is rising compared with data from the past. The risk factors of type 2 diabetes and prediabetes identified in this study will aid the identification of individuals at a high-risk of diabetes and the implementation of effective health promotion programs and campaigns.

CLINICAL TRIAL REGISTRY NUMBER

ChiCTR-HOC-17013200.

Adipokines and Obesity. Potential Link to Metabolic Disorders and Chronic Complications

The World Health Organization (WHO) has recognized obesity as one of the top ten threats to human health. It is estimated that the number of obese and overweight people worldwide exceeds the number of those who are undernourished. Obesity is not only a state of abnormally increased adipose tissue in the body, but also of increased release of biologically active adipokines. Adipokines released into the circulating blood, due to their specific receptors on the surface of target cells, act as classic hormones affecting the metabolism of tissues and organs. What is more, adipokines and cytokines may decrease the insulin sensitivity of tissues and induce inflammation and development of chronic complications. Certainly, it can be stated that in an era of a global obesity pandemic, adipokines may gain more and more importance as regards their use in the diagnostic evaluation and treatment of diseases. An extensive search for materials on the role of white, brown and perivascular fatty tissue and obesity-related metabolic and chronic complications was conducted online using PubMed, the Cochrane database and Embase.

Gingival crevicular fluid levels of visfatin in patients with chronic periodontitis and polycystic ovary syndrome

Objective

Recently, the association between periodontal diseases and polycystic ovary syndrome (PCOS) has been established, and it has been revealed that visfatin levels increase in chronic periodontitis (CP) and PCOS. However, there was no study comparing the mean visfatin levels between advanced CP and PCOS. Therefore, the probable role of visfatin linking these diseases remains unknown, and this study was conducted to address this gap.

Methods

In this age- and weight-matched case-control study (cases with PCOS disease and controls without it), 110 female participants were divided into 4 groups based on clinical findings. The 1st group participants had both PCOS and advanced CP (n=30), 2nd group participants had only PCOS (n=25), 3rd group participants had only advanced CP (n=23), and 4th group comprised of healthy participants (n=32). Enzyme-linked immunosorbent assay was used to investigate visfatin levels in the gingival crevicular fluid (GCF). Data were collected and analyzed using Stata software (version 11).

Results

The results revealed the significant effect of both PCOS and advanced CP on visfatin levels in the GCF (P<0.05).

Conclusion

According to the results of this study, the visfatin level in the GCF could be the probable link of association between PCOS and advanced CP.

Adipose tissue-derived cytokines and their correlations with clinical characteristics in Vietnamese patients with type 2 diabetes mellitus

BACKGROUND

Adipokines are involved in the pathogenesis of metabolic disorders including obesity and type 2 diabetes mellitus (T2DM). This study investigates the levels of leptin, resistin, visfatin, secreted frizzled-related protein 5 (SFRP5), monocyte chemoattractant protein-1 (MCP-1) and retinol-binding protein 4 (RBP4) and their correlations with clinical parameters of overweight and T2DM.

METHODS

We recruited overweight 50 patients with T2DM, 88 non-overweight patients with T2DM, 29 overweight and 100 non-overweight individuals devoid of T2DM for this study. The levels of studied adipokines were measured by enzyme-linked immunosorbent assay and correlated with clinical parameters.

RESULTS

The levels of MCP-1 and SFRP5 were decreased while visfatin and RBP4 levels were increased in patients with T2DM compared to those in the control individuals (P < 0.01). Among patients with T2DM, leptin and resistin levels were higher while RBP4 levels were lower in patients with overweight T2DM compared to those in patients with non-overweight T2DM (P < 0.0001, 0.019 and 0.05, respectively). Leptin and MCP-1 levels were correlated with HOMA-IR, QUICKI and HOMA-β. Leptin/MCP-1 ratio was correlated with insulin levels, HOMA-IR and HOMA-β indexes. Resistin/RBP4, visfatin/MCP-1 and MCP-1/RBP4 ratios were strongly correlated with the levels of fasting glucose, HbA1c and HOMA-β. In addition, ROC curve analyses indicated a diagnostic potential of resistin/RBP4 and MCP-1/RBP4 indexes for T2DM (AUC = 0.81 and 0.83, respectively) and β-cell function (AUC = 0.76 and 0.74, respectively).

CONCLUSIONS

Adipokines (leptin, resistin, visfatin, SFRP5, MCP-1, and RBP4) are associated with overweight and T2DM and may serve as a potential prognostic marker and therapeutic intervention for overweight-related T2DM.