Insulin and Its Cardiovascular Effects: What Is the Current Evidence?

Exploration of metformin-based drug combination for mitigating diabetes-associated atherosclerotic diseases

Diabetes mellitus is a substantial global health threat due to its high prevalence and its serious complications. The hyperglycemic state causes damage to vascular endothelial cells and disturbance of lipid metabolism, thus contributing to the development of vascular disorders, especially atherosclerotic diseases. Aggressive glycemic control combined with vascular intervention is critical to the prevention and treatment of diabetes-associated atherosclerosis. It is suggested that metformin should be combined with hypoglycemic agents with proven vascular benefits for treating type 2 diabetes (T2DM) complicated with atherosclerotic diseases. Clinical studies indicates that the preferred combination is metformin with either glucagon-like peptide-1 receptor agonist or sodium/glucose cotransporter-2 inhibitor, which could offer additional vascular benefits and reduce the risk of atherosclerotic complications. Likewise, combination therapy with metformin and hypolipidemic agents has also shown additive effects on glucose control and lipid-lowering in patients with both diabetes and dyslipidemia, whereas extensive clinical trials using atherosclerotic-associated outcomes are required to support the vascular benefits. Moreover, co-administration of metformin with systemic antioxidant or anti-inflammatory therapy may also provide additional vascular benefits as indicated by several animal studies. For instance, a recent study found that additional supplementation of cholecalciferol and taurine enhanced metformin efficacy in controlling diabetes while reducing the risk of associated atherosclerotic complications. However, these potential benefits remain need validation by the evidence from clinical studies. Despite the limitations, such as heterogeneity across different patient populations, and deficiency in long-term outcomes, such efforts can contribute to finding optimal drug combinations to improve the management of T2DM and reduce its atherosclerotic complications.

"NO" controversy?: A controversial role in insulin signaling of diabetic encephalopathy

Insulin, a critical hormone in the human body, exerts its effects by binding to insulin receptors and regulating various cellular processes. While nitric oxide (NO) plays an important role in insulin secretion and acts as a mediator in the signal transduction pathway between upstream molecules and downstream effectors, holds a significant position in the downstream signal network of insulin. Researches have shown that the insulin-NO system exhibits a dual regulatory effect within the central nervous system, which is crucial in the regulation of diabetic encephalopathy (DE). Understanding this system holds immense practical importance in comprehending the targets of existing drugs and the development of potential therapeutic interventions. This review extensively examines the characterization of insulin, NO, Nitric oxide synthase (NOS), specific NO pathway, their interconnections, and the mechanisms underlying their regulatory effects in DE, providing a reference for new therapeutic targets of DE.

Insulin-Heart Axis: Bridging Physiology to Insulin Resistance

Insulin signaling is vital for regulating cellular metabolism, growth, and survival pathways, particularly in tissues such as adipose, skeletal muscle, liver, and brain. Its role in the heart, however, is less well-explored. The heart, requiring significant ATP to fuel its contractile machinery, relies on insulin signaling to manage myocardial substrate supply and directly affect cardiac muscle metabolism. This review investigates the insulin-heart axis, focusing on insulin's multifaceted influence on cardiac function, from metabolic regulation to the development of physiological cardiac hypertrophy. A central theme of this review is the pathophysiology of insulin resistance and its profound implications for cardiac health. We discuss the intricate molecular mechanisms by which insulin signaling modulates glucose and fatty acid metabolism in cardiomyocytes, emphasizing its pivotal role in maintaining cardiac energy homeostasis. Insulin resistance disrupts these processes, leading to significant cardiac metabolic disturbances, autonomic dysfunction, subcellular signaling abnormalities, and activation of the renin-angiotensin-aldosterone system. These factors collectively contribute to the progression of diabetic cardiomyopathy and other cardiovascular diseases. Insulin resistance is linked to hypertrophy, fibrosis, diastolic dysfunction, and systolic heart failure, exacerbating the risk of coronary artery disease and heart failure. Understanding the insulin-heart axis is crucial for developing therapeutic strategies to mitigate the cardiovascular complications associated with insulin resistance and diabetes.

Cardiovascular risk reduction in older people with type 2 diabetes mellitus-a comprehensive narrative review

Metabolic targets are controversial in older people with type 2 diabetes due to functional heterogeneity and morbidity burden. Tight blood pressure and metabolic control appears beneficial in fit individuals who are newly diagnosed with type 2 diabetes and have fewer comorbidities. The benefits of low blood pressure and tight metabolic control is attenuated with the development of comorbidities, especially frailty. Guidelines consider frail older people as one category and recommend relaxed targets. However, sarcopenic obese frail individuals may benefit from tight targets and intensification of therapy due to their unfavourable metabolic profile, accelerated diabetes trajectory and high cardiovascular risk. In addition, the early use of sodium glucose transporter-2 inhibitors and glucagon like peptide-1 receptor agonists may be beneficial in this frailty phenotype due to their cardio-renal protection, which is independent of glycaemic control, provided they are able to engage in resistance exercise training to avoid loss of muscle mass. In the anorexic malnourished frail individual, early use of insulin, due to its weight gain and anabolic properties, is appropriate. In this phenotype, targets should be relaxed with deintensification of therapy due to significant weight loss, decelerated diabetes trajectory and increased risk of medication side effects.

Safety and glycemic control with insulin degludec use in clinical practice: results from a 3-year Japanese post-marketing surveillance study

Introduction

Insulin degludec (degludec) is a basal insulin with a long duration of action. This post-marketing surveillance study monitored safety and glycemic control during use of degludec for 3 years in normal clinical practice in Japan.

Materials and methods

This multicenter, open-label, observational study included patients with diabetes receiving degludec in Japan between 2013 and 2019. The primary outcome was incidence of adverse events occurring over 3 years of treatment. The pre-specified, secondary outcomes were severe hypoglycemic episodes and changes in HbA1c and fasting plasma glucose levels.

Results

Of 4167 patients enrolled, 4022 were included in the safety assessments and 3918 in the assessments of glycemic control. Mean age was 58.9 years; 74.1% of patients had type 2 diabetes, and mean HbA1c at baseline was 8.7%. Adverse events and serious adverse events were observed in 19.1% and 8.9% of patients, respectively. Cardiac disorders and neoplasms were reported in 2.0% and 1.8% of patients, respectively, with the majority of these incidents reported as serious adverse events. Adverse drug reactions were seen in 8.0% of patients, mainly hypoglycemia. Hypoglycemic events were observed in 5.6% of patients, and severe hypoglycemic events in 1.7%. No serious allergic or injection-site reactions were seen. Respective changes (from baseline to 3 years' observation) in HbA1c and fasting plasma glucose levels were - 0.55% and - 36.3 mg/dL, and 19.6% of patients reached HbA1c < 7.0%.

Conclusions

Using degludec for 3 years in normal clinical practice had a good safety and tolerability profile. Improvements in glycemic control were also seen.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13340-023-00657-7.

A Novel Peptide COX52-69 Inhibits High Glucose-induced Insulin Secretion by Modulating BK Channel Activity

BACKGROUND

Excessive insulin is the leading cause of metabolic syndromes besides hyperinsulinemia. Insulin-lowering therapeutic peptides have been poorly studied and warrant urgent attention.

OBJECTIVES

The main purpose of this study, was to introduce a novel peptide COX52-69 that was initially isolated from the porcine small intestine and possessed the ability to inhibit insulin secretion under high-glucose conditions by modulating large conductance Ca2+-activated K+ channels (BK channels) activity.

METHODS AND RESULTS

Enzyme-linked immunosorbent assay results indicate that COX52-69 supressed insulin release induced by high glucose levels in pancreatic islets and animal models. Furthermore, electrophysiological data demonstrated that COX52-69 can increase BK channel currents and hyperpolarize cell membranes. Thus, cell excitability decreased, corresponding to a reduction in insulin secretion.

CONCLUSION

Our study provides a novel approach to modulate high glucose-stimulated insulin secretion in patients with hyperinsulinemia.

Influence of age on the association between the triglyceride-glucose index and all-cause mortality in patients with cardiovascular diseases

BACKGROUND

In patients with cardiovascular diseases, it is reported that the triglyceride-glucose index (TGI) potentially indicates prognosis. However, the results are controversial. Moreover, whether age has an impact on the predictive value of TGI remains unclear.

METHODS

Participants with cardiovascular diseases were enrolled using the China Health and Retirement Longitudinal Study (CHARLS) registry. TGI was calculated as ln (triglyceride×glucose/2). The survival status was recorded every 2 years in the follow-up waves. Multivariate regression analysis was carried out to determine the relationship between TGI levels and long-term all-cause mortality in patients grouped by different age. Patients younger than 65 years old were regarded as middle-aged group. Otherwise, they were classified as old group.

RESULTS

In total, 2923 patients with cardiovascular diseases and baseline blood test results were included. After 7 years of follow-up, 242 (8.91%) patients died. Cox regression analysis revealed that higher TGI levels were associated with a higher risk of long-term all-cause mortality in middle-aged participants (hazard ratio [HR], 3.64; 95% confidence interval [CI] 1.44-9.22, P = 0.006) but not in old participants (HR 1.20, 95% CI 0.62-2.32, P = 0.594, P for interaction = 0.017), after adjusting physical activity and other factors. Kaplan-Meier estimate analysis and restricted cubic spline curves showed similar results.

CONCLUSION

TGI was a promising marker for predicting all-cause mortality in middle-aged patients after cardiovascular diseases. Patients younger than 65 years old who have a higher level of TGI may develop a higher risk of all-cause mortality, and they are encouraged to control vascular risk factors and take more physical activity to improve their prognosis. Additionally, whether intervention in regulating TGI levels is beneficial for the prognosis of these patients needs further investigation.

The dietary and lifestyle indices of insulin resistance are associated with increased risk of cardiovascular diseases: A prospective study among an Iranian adult population

BACKGROUND AND AIMS

Previous studies have introduced insulin resistance (IR) as a major risk factor for poor cardiovascular diseases (CVDs) outcomes. Diet, body weight, and physical activity are three key pillars of lifestyle that can significantly impact the IR status. We aimed to assess the possible link between the empirical dietary index for IR (EDIR) and the empirical lifestyle index for IR (ELIR) with the risk of chronic heart disease (CHD) and CVDs.

METHODS AND RESULTS

This study was conducted on 4980 participants aged ≥30 years (follow-up rate: 99.85%). Dietary intake data was collected using a validated food frequency questionnaire. Cox proportional hazard regression was used to estimate the hazard ratio and 95% confidence intervals (HRs and 95% CIs) of CVDs and CHD across tertiles of EDIR and ELIR scores. In the final model, after adjusting for all potential confounding variables, participants in the highest tertile of EDIR had a higher risk of CVD (HR:1.36, 95%CI:1.03-1.80, P-trend = 0.016) and CHD (HR:1.36, 95% CI:1.01-1.83, P-trend = 0.023) compared to the lowest tertile. Also, participants with a higher score of ELIR had a higher risk of CVD (HR: 1.64, 95%CI:1.24-2.16, P-trend=<0.001) and CHD (HR: 1.72, 95%CI:1.28-2.32, P-trend=<0.001).

CONCLUSION

A greater adherence to the lifestyle and diet with a higher EDIR and ELIR may be associated with an increased risk of CVD and CHD outcomes in the adult population.

Obesity and Diabetic Complications: A Study from the Nationwide Diabetes Report of the National Program for Prevention and Control of Diabetes (NPPCD-2021) Implications for Action on Multiple Scales

BACKGROUND

Obesity plays a major role in the pathogenesis and development of macro- and microvascular complications of type 2 diabetes (T2D) and type 1 diabetes (T1D). We aimed to assess the association between obesity and macrovascular and microvascular complications of diabetes.

METHODS

This study consisted of 111,830 patients (age range: 1-106) with diabetes including 10,641 T1D (3187 obese [38.2% men] and 7454 non-obese [45.5% men]) and 101,189 T2D (51,873 obese [27.5% men] and 49,316 non-obese [33.4% men]) from the National Program for Prevention and Control of Diabetes (NPPCD-2021) in Iran, who attended academic tertiary care outpatient clinics from February 2016 to April 2021. A pooled logistic regression model was used to examine the association between obesity and diabetic complications.

RESULTS

Among patients with T1D, a significant association was found between obesity and cardiovascular disease (CVD), neuropathy, nephropathy and retinopathy (OR= 1.75, 1.56, 1.80 and 1.92, P-value= 0.001, 0.004, 0.001 and <0.001, respectively). In T2D, a statistically significant association was found between obesity and CVD, neuropathy and nephropathy (OR= 1.63, 1.98, 1.21, respectively, P-values <0.001).

CONCLUSION

Obesity was independently associated with CVD, neuropathy and nephropathy in patients with T1D and T2D and with retinopathy only in T1D, to different degrees. The association between obesity and retinopathy and neuropathy was the strongest among T1D and T2D, respectively. Findings from this study suggest that obesity affects diabetic complications differently among the two types of diabetes, in terms of epidemiology and pathophysiology. This signifies the importance of different preventive and therapeutic approaches to obesity in T1D compared to T2D, on a national and global scale.

Red Blood Cell Distribution Width Predicts Myocardial Infarction and Mortality After Vascular Surgery-A Prospective Cohort Study

BACKGROUND

This study aims to investigate the association between preoperative Red blood cell Distribution Width (RDW) and postoperative outcomes, including myocardial infarction (MI), and mortality.

METHODS

A prospective cohort including all patients submitted to elective vascular arterial surgery at a university hospital. The primary and secondary outcomes were 30-day mortality and 30-day MI, respectively.

RESULTS

Atrial fibrillation, chronic kidney disease (CKD), and dependent functional status were more prevalent in deceased patients. After multivariable analysis, age (adjusted OR 1.08, 95% Confidence Interval [1.01-1.15], p = 0.027) and RDW-standard deviation (RDW-SD) (1.08 [1.01-1.16], p = 0.032) remained independent predictors of mortality. Patients with MI had higher rates of diabetes, CKD, dependent functional status, ASA physical status IV, and insulin medication. After multivariable analysis, dependent functional status (4.8 [1.6-15.0], p = 0.007), insulin medication (4.4 [1.5-12.6], p = 0.007) and RDW-SD (1.10 [1.02-1.19], p = 0.020) were independent predictors of MI.

CONCLUSION

RDW-SD independently predicted postoperative MI and mortality, and may provide valuable information for prevention and early management of adverse outcomes.

The effect of select systemic medications on outcomes in diabetics with central retinal vein occlusion

BACKGROUND

Diabetes mellitus is a risk factor for central retinal vein occlusion (CRVO); however, it is unclear whether certain commonly used medications among diabetics or glycemic control impact visual outcomes in diabetic eyes with CRVO.

PURPOSE

To evaluate the effect of select systemic medications and glycemic control on presenting features, treatment burden, and outcomes in patients with diabetes who develop a central retinal vein occlusion (CRVO).

METHODS

Retrospective longitudinal cohort study at a single tertiary academic referral center from 2009-2017 investigating eyes of patients being treated for diabetes mellitus at CRVO onset. Eyes with a prior history of anti-vascular endothelial growth factor (anti-VEGF) therapy or laser treatment within the year prior to CRVO onset were excluded. Main outcomes and measures were visual acuity (VA), central subfield thickness (CST), cystoid macular edema (CME), and number of intravitreal injections and laser treatment throughout follow-up.

RESULTS

We identified 138 eyes of 138 participants who were diabetic at CRVO onset. Of these, 49% had an ischemic CRVO. Median follow-up time was 25.5 months. Fifty-five eyes (40%) had a HbA1c within 6 months of CRVO presentation. HbA1c was positively correlated with both presenting CST (p = 0.04) and presence of CME (p < 0.01). In all 138 eyes, mean presenting VA was 20/246, and mean final VA was 20/364. Better-presenting VA was significantly associated with aspirin 325 mg use (p = 0.04). Lower CST at presentation was significantly associated with metformin use (p = 0.02). Sitagliptin use at CRVO onset was associated with a lower prevalence of CME at final follow-up (p < 0.01). Lower final CST was significantly associated with glipizide use at CRVO onset (p = 0.01). There were no significant associations between systemic medications or HbA1c and treatment burden or final VA (p > 0.05).

CONCLUSION

Although aspirin 325 mg, metformin, sitagliptin, and glipizide were associated with better-presenting VA, lower-presenting CST, lower prevalence of macular edema at final visit, and lower final CST, respectively, none of these systemic agents or glycemic control were associated with decreased treatment burden or improved visual outcomes in diabetics with CRVO.

Vascular effects following intensification of glycemic control in poorly controlled patients with long-standing type 2 diabetes mellitus

PURPOSE

The aim of the present study was to investigate the effect of intensive antidiabetic therapy on vascular indices in type 2 diabetes mellitus (T2DM) patients.

METHODS

Poorly controlled T2DM patients (n = 62, mean age 64 years, T2DM duration 14 years, HbA1c ≥ 7.5%) were studied at baseline and following intensive treatment to achieve optimal glycemic control. Brachial artery flow-mediated dilation, carotid-femoral pulse wave velocity, central augmentation index, large and small (C2) artery compliance, carotid intima-media thickness (cIMT), and ankle-brachial index were assessed at baseline and follow-up.

RESULTS

HbA1c decreased from 8.8% (8.1, 10.1) (median, interquartile range-IQ) to 7.4% (6.9, 7.8), p < 0.001. Triglycerides and high-sensitivity C-reactive protein levels were decreased by ~ 10% and 50%, respectively (p < 0.05). Maximum cIMT and C2 increased at follow-up (0.97 ± 0.25 to 1.03 ± 0.27 mm and 3.3 (2.7, 4.2) to 4.2 (3.2, 5.4) ml/mmHg × 10, respectively, p < 0.05). In subgroup analysis, the observed changes in vascular indices were not affected by diabetes duration, presence of cardiovascular disease, or insulin treatment.

CONCLUSION

In patients with long-standing T2DM, short-term aggressive glycemic control was associated with an improvement of microvascular function (C2) and deterioration of carotid atherosclerosis (IMT) without any effect on the elastic properties of large arteries.

Hepatic fibrosis of any origin in a large population of type 2 diabetes patients

BACKGROUND AND AIMS

Excess morbidity and mortality from chronic liver disease in type 2 diabetes (T2DM) is recognized; however, the clinical features associated with liver fibrosis (LF) of any origin are poorly known. Metabolic status and/or coexisting complications over time may play a role.

METHODS AND RESULTS

We interrogated the database of the diabetes unit network of Piedmont (Italy) (71,285 T2DM patients) and calculated a fibrosis-4 score (FIB-4) from data recorded between 2006 and 2019. Comorbidities were obtained by linkage with hospital data. The study population was subdivided by aetiology of LF (alcoholic, viral, metabolic). Associations between upper level of FIB-4 and demographic and clinical variables were evaluated separately for each group using robust Poisson models and presented as prevalence ratios. Nearly one-quarter (24%) of T2DM patients had some form of LF: viral (0.44%) and alcoholic (0.53%) forms were far less frequent than metabolic ones (22.7%). Only 1 out of 5 of these patients had a history of known cirrhosis. Age, male sex, duration of diabetes, coronary disease, hyperuricemia, renal failure, and features of liver failure (e.g., lower body-mass index, lipid and HbA1c levels) were positively associated with metabolic LF. More intensive treatments with insulin and segretagogue emerged as a significant predictive indicators of LF of metabolic origin.

CONCLUSION

A sizeable proportion of T2DM patients has some degree of LF, mainly of metabolic origin and often undiagnosed. There is a need to clarify whether the link between insulin therapy and advanced LF is causal or not.

Bioactive Foods and Medicinal Plants for Cardiovascular Complications of Type II Diabetes: Current Clinical Evidence and Future Perspectives

Cardiovascular diseases (CVDs) are the main cause of mortality in type 2 diabetes mellitus (T2DM); however, not all patients are fully satisfied with the current available treatments. Medicinal plants have been globally investigated regarding their effect in CVD, yet the field is far from getting exhausted. The current paper aims to provide an evidence-based review on the clinically evaluated medicinal plants and their main therapeutic targets for the management of CVD in T2DM. Electronic databases including PubMed, Cochrane, Embase, Scopus, and Web of Science were searched from 2000 until November 2019, and related clinical studies were included. Lipid metabolism, glycemic status, systemic inflammation, blood pressure, endothelial function, oxidative stress, and anthropometric parameters are the key points regulated by medicinal plants in T2DM. Anti-inflammatory and antioxidant properties are the two most important mechanisms since inflammation and oxidative stress are the first steps triggering a domino of molecular pathological pathways leading to T2DM and, subsequently, CVD. Polyphenols with potent antioxidant and anti-inflammatory effects, essential oil-derived compounds with vasorelaxant properties, and fibers with demonstrated effects on obesity are the main categories of phytochemicals beneficial for CVD of T2DM. Some medicinal plants such as garlic (Allium sativum) and milk thistle (Silybum marianum) have strong evidences regarding their beneficial effects; however, others have low level of evidence which reveals the need for further clinical studies with larger sample sizes and longer follow-up periods to confirm the safety and efficacy of medicinal plants for the management of CVD in T2DM.

Identification of Potential Bioactive Ingredients and Mechanisms of the Guanxin Suhe Pill on Angina Pectoris by Integrating Network Pharmacology and Molecular Docking

The Guanxin Suhe pill (GSP), a traditional Chinese medicine, has been widely used to treat angina pectoris (AP) in Chinese clinical practice. However, research on the bioactive ingredients and underlying mechanisms of GSP in AP remains scarce. In this study, a system pharmacology approach integrating gastrointestinal absorption (GA) evaluation, drug-likeness (DL) evaluation, target exploration, protein-protein-interaction analysis, Gene Ontology (GO) enrichment analysis, network construction, and molecular docking was adopted to explore its potential mechanisms. A total of 481 ingredients from five herbs were collected, and 242 were qualified based on GA and DL evaluation. Target exploration identified 107 shared targets between GSP and AP. Protein-protein interaction identified VEGFA (vascular endothelial growth factor A), TNF (tumor necrosis factor), CCL2 (C-C motif chemokine ligand 2), FN1 (fibronectin 1), MMP9 (matrix metallopeptidase 9), PTGS2 (prostaglandin-endoperoxide synthase 2), IL10 (interleukin 10), CXCL8 (C-X-C motif chemokine ligand 8), IL6 (interleukin 6), and INS (insulin) as hub targets for GSP, which were involved in the inflammatory process, ECM proteolysis, glucose metabolism, and lipid metabolism. GO enrichment identified top pathways in the biological processes, molecular functions, and cell components, explaining GSP's potential AP treatment mechanism. Positive regulation of the nitric oxide biosynthetic process and the response to hypoxia ranked highest of the biological processes; core targets that GSP can regulate in these two pathways were PTGS2 and NOS2, respectively. Molecular docking verified the interactions between the core genes in the pathway and the active ingredients. The study lays a foundation for further experimental research and clinical application.

IGFBP-1 and IGFBP-2 are associated with a decreased pulse-wave velocity in young, healthy adults

Background and aims

In healthy, young adults we analyzed a panel of cardiovascular disease related proteins in plasma and compared them with the vascular health of the subjects. The aim was to identify proteins with a relationship to the early atherosclerotic process in healthy individuals.

Methods

We employed the proximity extension assay from OLINK proteomics to analyze 92 cardiovascular disease (CVD) related proteins on 833 subjects (men and women, ages 18–26). The women were further divided into an estrogen-using group and non-users. Protein expression was analyzed using principal component analysis (PCA). The following vascular examinations were performed: Pulse-wave velocity (PWV), augmentation index (AIX), carotid-intima media thickness (cIMT).

Results

Three principal components were obtained using PCA to analyze the protein expression. None of the obtained principal components correlated significantly with AIX or cIMT. One of the components, explaining 6% of the total variance of the data, was significantly correlated with PWV. Upon examination of the proteins with the highest factor loadings on this component independently in a multivariable model, adjusting for established CVD risk biomarkers, insulin-like growth factor-binding protein 1 (IGFBP-1) and insulin-like growth factor-binding protein 2 (IGFBP-2) were found to independently, negatively correlate with PWV. Among the established risk factors included in the multivariable model, age was significantly and adversely correlated with all vascular measurements.

Conclusions

In this population of healthy, young adults, groups of CVD related proteins correlate with PWV, but not AIX or cIMT. This group of proteins, of which IGFBP-1 and IGFBP-2 were independently, negatively correlated in a multivariable model with PWV, could have benificial effects on vascular stiffness. The robust association between age and PWV, AIX and cIMT provide insight into the impact of aging on the vasculature, which is detectable even in a population of young, healthy, non-smoking individuals of ages spanning only 8 years.

Supplementary information

The online version contains supplementary material available at 10.1186/s12872-021-01914-w.

Effect of long-term growth hormone replacement on glucose metabolism in adults with growth hormone deficiency: a systematic review and meta-analysis

PURPOSE

This systematic review and meta-analysis was performed to summarize the long-term (more than 6 months) effect of growth hormone (GH) replacement therapy (GHRT) on glucose metabolism among adults growth hormone deficiency (AGHD) patients.

METHODS

We searched MEDLINE, EMBASE and the Cochrane Library databases from inception till March 2020 for relevant studies evaluating the effect of GHRT on glucose metabolism in AGHD patients. Results were stratified into two periods (6-12 months and more than12 months) according to the length of follow-up.

RESULTS

Thirty-three studies including 11 randomized controlled trials (RCTs) and 22 prospective open-label studies (POLs) were included in the meta-analysis. The findings of this meta-analysis showed that GH supplementation with a duration of 6-12 months among adults with growth hormone deficiency (GHD) significantly increased fasting plasma glucose (FPG) (SMD 0.37; 95% CI 0.25 to 0.49; I² = 0%; P < 0.00001), fasting insulin (FI) (SMD 0.2; 95% CI 0.08 to 0.33; I² = 9%; P = 0.001), glycated hemoglobin (HbA1c) (SMD 0.31; 95% CI 0.17 to 0.46; I² = 10%; P < 0.0001) and homeostasis model of assessment-insulin resistance (HOMA-IR) (SMD 0.28; 95% CI 0.08 to 0.47; I² = 13%; P = 0.006). Notably, GH intervention with a duration of more than 12 months showed no significant effect on FI (SMD 0.14; 95% CI - 0.09 to 0.37; I² = 0%; P = 0.24), HbA1c (SMD - 0.02; 95% CI - 0.3 to 0.26; I² = 72%; P = 0.89) and HOMA-IR levels (SMD 0.04; 95% CI - 0.24 to 0.31; I² = 0%; P = 0.80) in adults with GHD. However, FPG levels in AGHD were still significantly increased with more than one year intervention period (SMD 0.41; 95% CI 0.29 to 0.53; I² = 0%; P < 0.00001).

CONCLUSION

Overall, the current meta-analysis demonstrated that GHRT with a shorter duration (6-12 months) led to a deterioration in glucose metabolism including FPG, FI, HbA1c and HOMA-IR in AGHD patients. However, the negative effects of GH therapy on these glucose homeostasis parameters were not seen in longer duration of GHRT, except for FPG.

Pulse wave velocity, augmentation index, and carotid intima-media thickness are each associated with different inflammatory protein signatures in young healthy adults: The lifestyle, biomarkers and atherosclerosis study

BACKGROUND AND AIMS

We aimed to identify plasma protein biomarkers related to inflammation that correlated with physiological measurements of vascular function and structure in healthy individuals.

METHODS

We used the OLINK proteomics panel, which measures 92 inflammatory proteins, in 834 young, healthy non-smokers (ages 18-26). Principal component analysis (PCA) was employed to identify patterns of proteins. The following measurements were used: pulse-wave velocity (PWV), carotid intima-media thickness (cIMT) and augmentation index (AIX). Established cardiovascular risk factors were included in multivariable models.

RESULTS

PCA showed four principal components (PC 1, PC 2, PC 3, PC 4). PC 3, comprising proteins related to hemostasis, was significantly and inversely correlated with PWV. Among the proteins with the highest factor loadings on PC 3, uPA was negatively correlated with PWV in multivariable regression models. AIX was significantly correlated with PC 2, comprising inflammatory cytokines. Among the proteins with the highest factor loadings on PC 2, interleukin-6 was significantly correlated with AIX in the multivariable model. cIMT was significantly correlated with PC 4, comprising proteins related to chemotaxis. Among the proteins with the highest factor loadings on PC 4, fractalkine was significantly correlated with cIMT in the multivariable model.

CONCLUSIONS

In young, healthy individuals, OLINK inflammatory proteins correlated with measures of vascular status. Each of the three measures PWV, AIX, and cIMT, which target different parts of the vasculature, correlated with its own specific protein signature, indicating that different subsets of inflammatory mediators affect different parts of the vasculature and are detectable already in young healthy adults.

Insulin Therapy in Pregnancy Hypertensive Diseases and its Effect on the Offspring and Mother Later in Life

Pregnancy hypertensive disorders such as Preeclampsia (PE) are strongly correlated with insulin resistance, a condition in which the metabolic handling of D-glucose is deficient. In addition, the impact of preeclampsia is enhanced by other insulin-resistant disorders, including polycystic ovary syndrome and obesity. For this reason, there is a clear association between maternal insulin resistance, polycystic ovary syndrome, obesity and the development of PE. However, whether PE is a consequence or the cause of these disorders is still unclear. Insulin therapy is usually recommended to pregnant women with diabetes mellitus when dietary and lifestyle measures have failed. The advantage of insulin therapy for Gestational Diabetes Mellitus (GDM) patients with hypertension is still controversial; surprisingly, there are no studies in which insulin therapy has been used in patients with hypertension in pregnancy without or with an established GDM. This review is focused on the use of insulin therapy in hypertensive disorders in the pregnancy and its effect on offspring and mother later in life. PubMed and relevant medical databases have been screened for literature covering research in the field especially in the last 5-10 years.

New Insight into Diabetes Management: From Glycemic Index to Dietary Insulin Index

BACKGROUND

Despite efforts to control hyperglycemia, diabetes management is still challenging. This may be due to focusing on reducing hyperglycemia and neglecting the importance of hyperinsulinemia; while insulin resistance and resultant hyperinsulinemia preceded diabetes onset and may contribute to disease pathogenesis.

OBJECTIVE

The present narrative review attempts to provide a new insight into the management of diabetes by exploring different aspects of glycemic index and dietary insulin index.

RESULTS

The current data available on this topic is limited and heterogeneous. Conventional diet therapy for diabetes management is based on reducing postprandial glycemia through carbohydrate counting, choosing foods with low-glycemic index and low-glycemic load. Since these indicators are only reliant on the carbohydrate content of foods and do not consider the effects of protein and fat on the stimulation of insulin secretion, they cannot provide a comprehensive approach to determine the insulin requirements.

CONCLUSION

Selecting foods based on carbohydrate counting, glycemic index or glycemic load are common guides to control glycemia in diabetic patients, but neglect the insulin response, thus leading to failure in diabetes management. Therefore, paying attention to insulinemic response along with glycemic response seems to be more effective in managing diabetes.

Sex-specific Mendelian randomization study of genetically predicted insulin and cardiovascular events in the UK Biobank

Insulin drives growth and reproduction which trade-off against longevity. Genetically predicted insulin, i.e., insulin proxied by genetic variants, is positively associated with ischemic heart disease, but sex differences are unclear, despite different disease rates and reproductive strategies by sex. We used Mendelian randomization in 392,010 white British from the UK Biobank to assess the sex-specific role of genetically predicted insulin in myocardial infarction (MI) (14,442 cases, 77% men), angina (21,939 cases, 65% men) and heart failure (5537 cases, 71% men). Genetically predicted insulin was associated with MI (odds ratio (OR) 4.27 per pmol/L higher insulin, 95% confidence interval (CI) 1.60 to 11.3) and angina (OR 2.93, 1.27 to 6.73) in men, but not women (MI OR 0.80, 95% CI 0.23 to 2.84, angina OR 1.10, 95% CI 0.38 to 3.18). Patterns were similar for insulin resistance and heart failure. Mitigating the effects of insulin might address sexual disparities in health.

Efficacy and safety of the second generation basal insulin analogs in type 2 diabetes mellitus: A critical appraisal

Type 2 diabetes mellitus is a progressive disease, which requires insulin treatment when other management is no longer effective. Although, insulin plays a vital role in the treatment of diabetes, conventional basal insulins have certain limitations, which have led to the development of more stable and peak less analogues.

OBJECTIVES

To analyze the efficacy and safety of second generation vs. first generation basal insulins, and the efficacy and safety of second generation vs. second generation basal insulins, in patients with type 2 diabetes mellitus, from the evidence provided by head-to-head randomized controlled trials.

METHODS

The following electronic databases were searched: PubMed and MEDLINE, Scopus, BIOSIS, Embase, ClinicalTrials.gov, Google Scholar, and Springer Online Archives Collection, from January 1966 to October 2018. Articles resulting from these searches and relevant references cited in those articles were examined.

RESULTS

The efficacy among insulins evaluated was similar, however, second generation insulins cause a lower risk of hypoglycemia compared to first generation insulins. A single study showed similar metabolic control with subtle differences in the risk of hypoglycemia among second generation insulins.

CONCLUSIONS

The second-generation basal insulins result in metabolic control similar to first generation insulins, with lower risk of hypoglycemia. Second-generation insulins have comparable efficacy, with some differences in the risk of hypoglycemia.

Toward a panoramic perspective of the association between environmental factors and cardiovascular disease: An environment-wide association study from National Health and Nutrition Examination Survey 1999-2014

OBJECTIVES

An environment-wide association study (EWAS) may be useful to comprehensively test and validate associations between environmental factors and cardiovascular disease (CVD) in an unbiased manner.

APPROACH AND RESULTS

Data from National Health and Nutrition Examination Survey (1999-2014) were randomly 50:50 spilt into training set and testing set. CVD was ascertained by a self-reported diagnosis of myocardial infarction, coronary heart disease or stroke. We performed multiple linear regression analyses associating 203 environmental factors and 132 clinical phenotypes with CVD in training set (false discovery rate < 5%) and significant factors were validated in the testing set (P < 0.05). Random forest (RF) model was used for multicollinearity elimination and variable importance ranking. Discriminative power of factors for CVD was calculated by area under the receiver operating characteristic (AUROC). Overall, 43,568 participants with 4084 (9.4%) CVD were included. After adjusting for age, sex, race, body mass index, blood pressure and socio-economic level, we identified 5 environmental variables and 19 clinical phenotypes associated with CVD in training and testing dataset. Top five factors in RF importance ranking were: waist, glucose, uric acid, and red cell distribution width and glycated hemoglobin. AUROC of the RF model was 0.816 (top 5 factors) and 0.819 (full model). Sensitivity analyses reveal no specific moderators of the associations.

CONCLUSION

Our systematic evaluation provides new knowledge on the complex array of environmental correlates of CVD. These identified correlates may serve as a complementary approach to CVD risk assessment. Our findings need to be probed in further observational and interventional studies.

Association between single nucleotide polymorphism rs11057401 of CCDC92 gene and the risk of coronary heart disease (CHD)

Background

Given that the CCDC92 (coiled-coil domain containing 92) was important in insulin resistance, we sought to investigate whether the CCDC92 rs825476 SNP is associated with the risk of CHD in Chinese Han population.

Methods

Rs11057401 was genotyped for 817 patients with CHD and 724 age- and sex-matched controls using PCR-based Invader assay with the probe sets designed and synthesized by third wave.

Results

Patients were found to have a significantly higher frequency of AA than the controls (23.5% vs. 14.7%, OR = 1.60, p = 0.000), and the frequency of allele A was found to be remarkably higher in the patients than the controls (48.1% vs. 40.3%, OR = 1.19, p = 0.000). Multivariate logistic analysis showed that the incidence of CHD was positively correlated with hyperlipidemia, T2D and rs11057401 AA/AT genotypes. The FPG, TC, and ApoA1 levels in the CHD patients were different among the AA, AT and TT genotypes (P < 0.05), the A allele carriers had higher FPG, TC and lower ApoA1 levels than the A allele non-carriers (P < 0.05).

Conclusion

The genotypic and allelic frequencies of the rs11057401 SNP were significantly different between the patients with CHD and controls. Subjects with AA genotype or A allele were associated with an increased risk of CHD. The AA/AT genotypes were also associated with increased serum FPG, TC and decreased ApoA1 in CHD.