The relationship between adrenomedullin, metabolic factors, and vascular function in individuals with type 2 diabetes

Adipokines in the Crosstalk between Adipose Tissues and Other Organs: Implications in Cardiometabolic Diseases

Adipose tissue was previously regarded as a dormant organ for lipid storage until the identification of adiponectin and leptin in the early 1990s. This revelation unveiled the dynamic endocrine function of adipose tissue, which has expanded further. Adipose tissue has emerged in recent decades as a multifunctional organ that plays a significant role in energy metabolism and homeostasis. Currently, it is evident that adipose tissue primarily performs its function by secreting a diverse array of signaling molecules known as adipokines. Apart from their pivotal function in energy expenditure and metabolism regulation, these adipokines exert significant influence over a multitude of biological processes, including but not limited to inflammation, thermoregulation, immune response, vascular function, and insulin sensitivity. Adipokines are pivotal in regulating numerous biological processes within adipose tissue and facilitating communication between adipose tissue and various organs, including the brain, gut, pancreas, endothelial cells, liver, muscle, and more. Dysregulated adipokines have been implicated in several metabolic diseases, like obesity and diabetes, as well as cardiovascular diseases. In this article, we attempted to describe the significance of adipokines in developing metabolic and cardiovascular diseases and highlight their role in the crosstalk between adipose tissues and other tissues and organs.

Higher serum adrenomedullin concentration is associated with an increased risk of gestational diabetes mellitus: A nested case-control study in Wuhan, China

Adrenomedullin (ADM) is thought to play a significant role in regulating insulin secretion and glucose metabolism. However, studies on the relationship between ADM and gestational diabetes mellitus (GDM) are limited. We hypothesized that a higher serum ADM concentration would be associated with an increased risk of GDM. Therefore, a nested case-control study of 65 GDM cases and 130 prepregnancy body mass index, age, parity, and gestational age of blood collection-matched controls was conducted to prospectively evaluate the association between circulating ADM concentrations in early pregnancy and the risk of GDM in pregnant women based on the Tongji Birth Cohort. Serum ADM concentrations in the GDM group were higher than those in the control group (2125.04 ± 644.97 vs 1880.76 ± 581.13 pg/mL) (P = .008). Serum ADM concentration was positively associated with the risk of developing GDM (P_trend < .05). The adjusted odds ratio (OR) comparing the highest tertile of ADM with the lowest was 2.74 (95% CI, 1.17-6.43). The risk of GDM increased by 49% (OR, 1.49; 95% CI, 1.05-2.12) for each SD increment of serum ADM. Moreover, serum ADM concentration was positively correlated with circulating total cholesterol (r = 0.204), triglycerides (r = 0.197), and systolic blood pressure (r = 0.173), but negatively correlated with circulating high-density lipoprotein cholesterol concentration (r = -0.176). Pregnant women with higher serum ADM concentrations have a markedly increased risk of developing GDM. Further studies are warranted to explore the possible thresholds of ADM that increase the risk of GDM and to confirm and elucidate the underlying mechanisms.

Associations of the vasoactive peptides CT-proET-1 and MR-proADM with incident type 2 diabetes: results from the BiomarCaRE Consortium

BACKGROUND

Endothelin-1 (ET-1) and adrenomedullin (ADM) are commonly known as vasoactive peptides that regulate vascular homeostasis. Less recognised is the fact that both peptides could affect glucose metabolism. Here, we investigated whether ET-1 and ADM, measured as C-terminal-proET-1 (CT-proET-1) and mid-regional-proADM (MR-proADM), respectively, were associated with incident type 2 diabetes.

METHODS

Based on the population-based Biomarkers for Cardiovascular Risk Assessment in Europe (BiomarCaRE) Consortium data, we performed a prospective cohort study to examine associations of CT-proET-1 and MR-proADM with incident type 2 diabetes in 12,006 participants. During a median follow-up time of 13.8 years, 862 participants developed type 2 diabetes. The associations were examined in Cox proportional hazard models. Additionally, we performed two-sample Mendelian randomisation analyses using published data.

RESULTS

CT-proET-1 and MR-proADM were positively associated with incident type 2 diabetes. The multivariable hazard ratios (HRs) [95% confidence intervals (CI)] were 1.10 [1.03; 1.18], P = 0.008 per 1-SD increase of CT-proET-1 and 1.11 [1.02; 1.21], P = 0.016 per 1-SD increase of log MR-proADM, respectively. We observed a stronger association of MR-proADM with incident type 2 diabetes in obese than in non-obese individuals (P-interaction with BMI < 0.001). The HRs [95%CIs] were 1.19 [1.05; 1.34], P = 0.005 and 1.02 [0.90; 1.15], P = 0.741 in obese and non-obese individuals, respectively. Our Mendelian randomisation analyses yielded a significant association of CT-proET-1, but not of MR-proADM with type 2 diabetes risk.

CONCLUSIONS

Higher concentrations of CT-proET-1 and MR-proADM are associated with incident type 2 diabetes, but our Mendelian randomisation analysis suggests a probable causal link for CT-proET-1 only. The association of MR-proADM seems to be modified by body composition.

Associations of Plasma Bioactive Adrenomedullin Levels with Cardiovascular Risk Factors in BRCA1/2 Mutation Carriers

Background Cardiovascular disease (CVD) is an important cause of morbidity and mortality in breast cancer survivors. Effective screening modalities to identify CVD risk are lacking in this population. Adrenomedullin (ADM) has been suggested as a biomarker for subclinical cardiac dysfunction in the general population. Levels of ADM have been proven to be responsive to lifestyle changes that lead to improved cardiovascular health. As BRCA1/2 mutation carriers are deemed to be at an increased risk for CVD, the aim of this study was to examine plasma ADM levels in a cohort of BRCA mutation carriers and to assess their association with cardiovascular risk factors.

Methods Plasma ADM concentrations were measured in 292 female BRCA1/2 mutation carriers with and without a history of breast cancer. Subjects were classified into high versus low ADM levels based on the median ADM level in the entire cohort (13.8 pg/mL). Logistic regression models were used to estimate the odds ratios (OR) of having elevated ADM levels by several cardiovascular risk factors.

Results Of all women (median age: 43 years), 57.5% had a previous diagnosis of breast cancer. The median time between diagnosis and study entry was three years (range: 0 – 32 years). Women presenting with metabolic syndrome had 22-fold increased odds of having elevated ADM levels (p < 0.001). Elevated ADM levels were associated with lower cardiorespiratory fitness (OR = 0.88, p < 0.001) and several parameters of obesity (p < 0.001). ADM levels were higher in women who have ever smoked (OR = 1.72, p = 0.02). ADM levels were not associated with a previous diagnosis of breast cancer (p = 0.28).

Conclusions This is the first study in BRCA mutation carriers that has linked circulating ADM levels to traditional cardiovascular risk factors. The long-term clinical implications of these findings are yet to be determined.

Proadrenomedullin in Patients with Preserved Left Ventricular Systolic Function Undergoing Coronary Artery Bypass Grafting

Introduction

A potentially new marker of cardiovascular diseases — proadrenomedullin is the precursor of adrenomedullin, which is a multifunctional peptide hormone, produced in most of the tissues in response to cellular stress, ischemia, and hypoxia.

Methods

Ninety-three people, aged 51-79 years, were included in the study. Exclusion criteria were severe or corrected valvular disease, acute coronary syndrome, age ≥ 80 years, glomerular filtration rate < 45 ml/min, active infectious diseases, and cancer. The subjects were observed for adverse events, including reduced left ventricular ejection fraction (LVEF) by ≥ 10%, first incidence of atrial fibrillation (AF), and the necessity of using dopamine during hospitalization.

Results

Use of pressure amines, occurrence of the first AF episode, and left ventricular dysfunction defined by a decrease in LVEF by at least 10% compared to the value before surgery were reported in the perioperative period. No death, sudden cardiac arrest with effective resuscitation, non-ST-elevation myocardial infarction, ST-elevation myocardial infarction, or heart failure were observed. Significantly higher proadrenomedullin concentration was observed in the group with reduced postoperative LVEF (1.68 vs. 0.77 nmol/l, P=0.005). The relative risk of a decrease in ejection fraction in the group of patients with proadrenomedullin concentration ≥ 0.77 nmol/l was more than twelve-fold higher (95% confidence interval 1.69-888.33; P=0.013) than in the group of patients with a concentration of proadrenomedullin < 0.77 nmol/l.

Conclusion

The higher baseline concentration of proadrenomedullin has a predominantly predictive value of postoperative left ventricular systolic dysfunction.

Mid-regional pro-adrenomedullin is a novel biomarker for arterial stiffness as the criterion for vascular failure in a cross-sectional study

We investigated the potential of mid-regional pro-adrenomedullin (MR-proADM) for use as a novel biomarker for arterial stiffness as the criterion for vascular failure and cardiometabolic disease (obesity, hypertension, dyslipidemia, diabetes, and metabolic syndrome) compared with high-sensitivity C-reactive protein (hsCRP). Overall, 2169 individuals (702 men and 1467 women) were enrolled. Multiple regression analysis was performed to assess the association of MR-proADM and hsCRP with brachial-ankle pulse wave velocity (baPWV), adjusting for other variables. The diagnostic performance (accuracy) of MR-proADM with regard to the index of vascular failure was tested with the help of receiver operating characteristic curve analysis in the models. MR-proADM was significantly higher in participants with vascular failure, as defined by baPWV and/or its risk factors (obesity, hypertension, dyslipidemia, diabetes, and metabolic syndrome), than in control groups. Independent of cardiovascular risk factors (age, drinking, smoking, body mass index, systolic blood pressure, lipid and glycol metabolism), MR-proADM was significantly associated with baPWV, and MR-proADM showed higher areas under the curve of baPWV than hsCRP showed. MR-proADM is more suitable for the diagnosis of higher arterial stiffness as the criterion for vascular failure than hsCRP. Because vascular assessment is important to mitigate the most significant modifiable cardiovascular risk factors, MR-proADM may be useful as a novel biomarker on routine blood examination.

Associations of cardiac stress biomarkers with incident type 2 diabetes and changes in glucose metabolism: KORA F4/FF4 study

BACKGROUND

High N-terminal pro-brain-type natriuretic peptide levels have been associated with a lower risk of type 2 diabetes mellitus (T2D). However, less is known about other cardiac stress biomarkers in this context. Here we evaluated the association of mid-regional pro-atrial natriuretic peptide (MR-proANP), C-terminal pro-arginine vasopressin (copeptin), C-terminal pro-endothelin-1 (CT-proET-1) and mid-regional pro-adrenomedullin (MR-proADM) with incident T2D and changes in glucose metabolism.

METHODS

We performed a prospective cohort study using data from the population-based KORA F4/FF4 study. 1773 participants (52.3% women) with MR-proANP measurements and 960 (52.7% women) with copeptin, CT-proET-1 and MR-proADM measurements were included. We examined associations of circulating plasma levels of MR-proANP, copeptin, CT-proET-1 and MR-proADM with incident T2D, the combined endpoint of incident prediabetes/T2D and with fasting and 2 h-glucose, fasting insulin, HOMA-IR, HOMA-B and HbA1c at follow-up. Logistic and linear regression models adjusted for age, sex, waist circumference, height, hypertension, total/HDL cholesterol ratio, triglycerides, smoking, physical activity and parental history of diabetes were used to compute effect estimates.

RESULTS

During a median follow-up time of 6.4 years (25th and 75th percentiles: 6.0 and 6.6, respectively), 119 out of the 1773 participants and 72 out of the 960 participants developed T2D. MR-proANP was inversely associated with incident T2D (odds ratio [95% confidence interval]: 0.75 [0.58; 0.96] per 1-SD increase of log MR-proANP). Copeptin was positively associated with incident prediabetes/T2D (1.29 [1.02; 1.63] per 1-SD increase of log copeptin). Elevated levels of CT-proET-1 were associated with increased HOMA-B at follow-up, while elevated MR-proADM levels were associated with increased fasting insulin, HOMA-IR and HOMA-B at follow-up. These associations were independent of previously described diabetes risk factors.

CONCLUSIONS

High plasma concentrations of MR-proANP contributed to a lower risk of incident T2D, whereas high plasma concentrations of copeptin were associated with an increased risk of incident prediabetes/T2D. Furthermore, high plasma concentrations of CT-proET-1 and MR-proADM were associated with increased insulin resistance. Our study provides evidence that biomarkers implicated in cardiac stress are associated with incident T2D and changes in glucose metabolism.

Midregional Proadrenomedullin Can Reflect the Accumulation of Visceral Adipose Tissue-A Key to Explaining the Obesity Paradox

Background: The aim of this study was to investigate whether plasma midregional proadrenomedullin (MR-proADM) reflected body composition, such as body mass index (BMI), visceral adipose tissue (VAT), subcutaneous adipose tissue (SAT), VAT/SAT ratio, body fat mass (BFM), and skeletal muscle mass (SMM). Methods: A total of 2244 individuals (727 men and 1517 women) were included in the study. Multiple regression analysis was performed to assess the combined influence of variables: age, daily alcohol consumption, Brinkman index, sleeping time, metabolic equivalents, anamnesis for hypertension, dyslipidemia, diabetes, and body composition of MR-proADM, by using a stepwise forward selection method. Results: MR-proADM was significantly related to all anthropometric indices (BMI, VAT, SAT, VAT/SAT ratio, BFM, and SMM) in men and women. On the basis of a stepwise forward selection method, VAT (men: beta = 0.184, p < 0.001, women: beta = 0.203, p < 0.001) and BFM (beta = 0.181, p < 0.001) in women, were found to be significantly associated with MR-proADM. Conclusion: This study suggests that plasma MR-proADM concentration is a more reliable indicator of VAT for fat distribution, and thus, MR-proADM may help better understand the obesity paradox. Changes in circulating levels of MR-proADM could possibly reflect changes in body composition, endocrine, and metabolic milieu.

Copeptin, myeloperoxidase and pro-adrenomedullin for acute coronary syndrome in patients with chronic kidney disease

Objectives:

Copeptin, myeloperoxidase and pro-adrenomedullin have emerged as potential biomarkers for diagnosis and prognosis of acute coronary syndrome (ACS). However, their applicability in patients with chronic kidney disease (CKD) remains unknown as these patients were excluded from previous studies. Our objective was to determine the superior novel cardiac marker to predict 30-day and six-month adverse cardiac events (ACEs) defined as cardiac-related death, myocardial infarction and ventricular fibrillation.

Methods:

A prospective observational study was carried out. Patients were included if they presented to the emergency department with symptoms suggestive of ACS and had CKD as defined as a serum creatinine of more than 130 µmol/l. Copeptin, myeloperoxidase and pro-adrenomedulin assays were performed. Occurrence of ACE was traced from review of the patients’ case records and the registry of deaths.

Results:

A total of 724 patients were recruited: 60.6% were male and 68.6% were Chinese. The median age was 67 years. Among those recruited, 88.3% had CKD stages 4 and 5, with 33.5% on dialysis. The rates of ACE at 30 days and six months were 15.1% and 21.7%, respectively. All readings of the three biomarkers were not significantly different in patients with ACE compared with those without both at 30 days and six months. The areas under the curve for copeptin, myeloperoxidase and pro-adrenomedullin were 0.53, 0.50 and 0.45, respectively ( p > 0.05).

Conclusions:

The poor performance of the biomarkers may be attributable to lack of specificity for ACS, as elevated levels could be from other causes in CKD patients. Routine testing cannot be recommended.

Microvascular endothelial function is an independent predictor for albuminuria progression among Asians with type 2 diabetes-A prospective cohort study

OBJECTIVE

We aim to investigate whether microvascular endothelial dysfunction is an independent predictor for future albuminuria progression in T2DM cohort.

METHODS

A total of 1098 patients with T2DM were clinically assessed at baseline and 3.2-year follow-up. Progression was defined as transition from normoalbuminuria (ACR <30 mg/g) to microalbuminuria (ACR = 30-299 mg/g) or macroalbuminuria (ACR >300 mg/g), or microalbuminuria to macroalbuminuria. Microvascular endothelial vasodilation at baseline was quantified using LDF. The increase in perfusion in response to ACh and NaNP was calculated. Logistic regression model was used to estimate the OR for albuminuria progression.

RESULTS

Albuminuria progression occurred in 226 (20.6%) patients. Baseline ACh was significantly higher in nonprogression than progression group (80.0 ± 53.2% vs 72.0 ± 49.7%, P = .04). There is no significant difference in NaNP between the two groups (111.1 ± 80.3% vs 121.1 ± 87.4%, P = .12). After multivariable adjustment, 1-SD increase in ACh was marginally associated with albuminuria progression (OR = 0.87, 95% CI, 0.72-1.02, P = .08) in all patients. When stratified by baseline albuminuria, 1-SD increase in ACh was significantly associated with albuminuria progression in normoalbuminuria (OR = 0.76, 95% CI, 0.59-0.97, P = .03), but not in microalbuminuria patients (OR = 1.18, 95% CI, 0.81-1.70, P = .39).

CONCLUSIONS

Impaired endothelial-dependent microvascular reactivity predicts the onset of albuminuria progression among T2DM patients with normoalbuminuria.

Plasma adrenomedullin level in children with obesity: relationship to left ventricular function

BACKGROUND

Obese children are at increased risk for abnormal cardiac structure and function. Little is known about adrenomedullin (AM), a cytokine produced in various organs and tissues, as a biomarker of cardiac hypertrophy in obese children. This study aimed to assess the plasma AM levels in a cohort of obese children and its relationship to left ventricular (LV) functions.

METHODS

The study included 60 obese children and 60 non-obese children matched for age and gender as control group. Blood pressure, serum lipid profile, fasting glucose, insulin and plasma AM and the homeostatic model assessment of insulin resistance (HOMA-IR) were measured. Cardiac dimensions and LV functions were assessed using conventional echocardiography.

RESULTS

Compared to control subjects, obese children had higher blood pressure (P = 0.01), insulin (P = 0.001), HOMA-IR (P = 0.001), and AM (P = 0.001). Moreover, obese children had higher LV mass index (LVMI) (P = 0.001), indicating LV hypertrophy; prolonged isovolumic relaxation times (P = 0.01), prolonged mitral deceleration time (DcT) (P = 0.01) and reduced ratio of mitral E-to-mitral A-wave peak velocity (P = 0.01), indicating LV diastolic dysfunction. Laboratory abnormalities were only present in children with LV hypertrophy. In multivariate analysis in obese children with LV hypertrophy, AM levels were positively correlated with LVMI [odds ratio (OR) 1.14, 95% confidence interval (Cl) 1.08-1.13, P = 0.0001] and mitral DcT (OR 2.25, 95% CI 1.15-2.05, P = 0.01) in the presence of higher blood pressure and HOMA-IR. A cut-off value of AM at 52 pg/mL could differentiate obese children with and without left ventricular hypertrophy at a sensitivity of 94.32% and specificity of 92.45%.

CONCLUSIONS

Plasma AM levels may be elevated in obese children particularly those with LV hypertrophy and is correlated with higher blood pressure and insulin resistance. Measurement of plasma AM levels in obese children may help to identify those at high risk of developing LV hypertrophy and dysfunction.

Atrial natriuretic peptide, copeptin and adrenomedullin levels in polycystic ovary syndrome: a case-control study

BACKGROUND

Polycystic ovary syndrome (PCOS) defined by the Rotterdam criteria does not take into account the unhealthy metabolic profile of the syndrome with increased insulin resistance (IR) and overweight favoring development of type 2 diabetes, hypertension and cardiovascular disease (CVD). We assess three vasoactive peptides associated with CVD in women with PCOS.

METHOD

Plasma levels of mid-regional pro-atrial natriuretic peptide (MR-proANP), copeptin and mid-regional pro-adrenomedullin (MR-proADM) were measured in 98 PCOS patients and 46 age- and BMI-matched healthy women.

RESULTS

We found no difference in levels of MR-proANP, copeptin and MR-proADM between the PCOS and control group. Multiple regression analyses on a combined group of PCOS and control subjects demonstrated an inverse correlation between MR-proANP and IR (measured by fasting C-peptide) and a positive correlations between copeptin and IR as well as MR-proADM and BMI. We found no association between peptide levels and different Rotterdam phenotypes.

CONCLUSION

Plasma concentrations of MR-proANP, copeptin and MR-proADM were not increased in PCOS compared to age- and BMI-matched controls. Thus, these peptides cannot be used to detect increased risk of CVD in a young PCOS cohort.

Association of metabolic complications with plasma mid-regional pro-adrenomedullin level in stable kidney transplant recipients

BACKGROUND

Recently, increased plasma mid-regional pro-adrenomedullin (MR-proADM) concentrations have been demonstrated in patients with chronic renal failure. In this study, we attempted to identify significant clinical factors associated with MR-proADM concentration in stable kidney transplant recipients.

METHODS

Forty-seven Japanese kidney transplant recipients who underwent transplantation >180days prior to the study were analyzed. To facilitate comparability of anti-hypertensive regimens across recipients taking different drugs, we calculated the treatment intensity score of anti-hypertensive drugs in each recipient. Morning blood samples were collected and plasma MR-proADM concentrations were measured using an enzyme immunoassay.

RESULTS

Multiple regression analysis identified treatment intensity score for anti-hypertensive drugs, serum albumin, creatinine clearance and use of lipid-lowering agents as significant independent factors associated with plasma MR-proADM concentration. Adjusted coefficient of determination for this model was 0.46.

CONCLUSION

Apart from indicating lowered renal function, plasma MR-proADM concentration may be a useful biomarker for metabolic disorders, especially hypertension and hyperlipidemia, in stable kidney transplant patients.

Plasma Adrenomedullin and Allelic Variation in the ADM Gene and Kidney Disease in People With Type 2 Diabetes

Production of adrenomedullin (ADM), a vasodilator peptide, increases in response to ischemia and hypoxia in the vascular wall and the kidney. This may be an adaptive response providing protection against organ damage. We investigated the hypothesis that ADM has a nephroprotective effect in two prospective cohorts of patients with type 2 diabetes recruited in France. The highest tertile of plasma MR-proADM (a surrogate for ADM) concentration at baseline was associated with the risk of renal outcomes (doubling of plasma creatinine concentration and/or progression to end-stage renal disease) during follow-up in both cohorts. Four SNPs in the ADM gene region were associated with plasma MR-proADM concentration at baseline and with eGFR during follow-up in both cohorts. The alleles associated with lower eGFR were also associated with lower plasma MR-proADM level. In conclusion, plasma MR-proADM concentration was associated with renal outcome in patients with type 2 diabetes. Our data suggest that the ADM gene modulates the genetic susceptibility to nephropathy progression. Results are consistent with the hypothesis of a reactive rise of ADM in diabetic nephropathy, blunted in risk alleles carriers, and with a nephroprotective effect of ADM. A possible therapeutic effect of ADM receptor agonists in diabetic renal disease would be worth investigating.

The influence of diabetes mellitus on midregional proadrenomedullin concentrations and prognostic value in heart failure outpatients

BACKGROUND

Diabetes mellitus (DM) is associated with an adverse outcome in heart failure (HF). Increased concentrations of midregional proadrenomedullin (MR-proADM) have been associated with DM and are predictors of mortality in HF patients. The aim of this study was to elucidate the impact of DM on MR-proADM concentrations and the prognostic value regarding all-cause mortality and hospitalization among HF patients.

METHODS AND RESULTS

We included 366 patients from an HF clinic; 69 (19%) had a history of DM and 40 (11%) had newly diagnosed DM (HbA1c ≥48 mmol/mol). The median MR-proADM concentration was unaffected by DM status (P = .20) but increased in HF patients with impaired renal function (P < .001). During a median follow-up of 55 months, 189 died, and 292 either died or were hospitalized. After adjustment for clinically relevant parameters, MR-proADM was associated with all-cause mortality (hazard ratio [HR] 1.3, 95% confidence interval [CI] 1.1-1.4; P = .01) and the combined end point of death and hospitalization (HR 1.2, 95% CI 1.1-1.4; P = .02) per 1 SD increment of ln-transformed variable. No interaction between DM and MR-proADM was found regarding mortality or hospitalization.

CONCLUSIONS

Diabetes status had no impact on MR-proADM concentrations or in the predictive ability of MR-proADM in HF patients.

Adrenomedullin and tumour microenvironment

Adrenomedullin (AM) is a regulatory peptide whose involvement in tumour progression is becoming more relevant with recent studies. AM is produced and secreted by the tumour cells but also by numerous stromal cells including macrophages, mast cells, endothelial cells, and vascular smooth muscle cells. Most cancer patients present high levels of circulating AM and in some cases these higher levels correlate with a worst prognosis. In some cases it has been shown that the high AM levels return to normal following surgical removal of the tumour, thus indicating the tumour as the source of this excessive production of AM. Expression of this peptide is a good investment for the tumour cell since AM acts as an autocrine/paracrine growth factor, prevents apoptosis-mediated cell death, increases tumour cell motility and metastasis, induces angiogenesis, and blocks immunosurveillance by inhibiting the immune system. In addition, AM expression gets rapidly activated by hypoxia through a HIF-1α mediated mechanism, thus characterizing AM as a major survival factor for tumour cells. Accordingly, a number of studies have shown that inhibition of this peptide or its receptors results in a significant reduction in tumour progression. In conclusion, AM is a great target for drug development and new drugs interfering with this system are being developed.

Cardiac natriuretic peptides in plasma increase after dietary induced weight loss in obesity

Background

Cardiac natriuretic peptides are established biomarkers in heart disease, but are also affected by body mass index (BMI). The purpose of the present study was to examine the impact of weight loss and changes in body composition following dietary intervention on plasma concentrations of the prohormones to A- and B-type natriuretic peptides (proANP and proBNP) and adrenomedullin (proADM).

Results

A total of 52 healthy obese subjects, 47 women and 5 men (BMI 36.5 ± 5.6 kg/m²) were randomised to either an intensive weight reduction programme using a combination of very low calorie diet (810 kcal/day) and conventional hypo-energetic diet (1200 kcal/day) for 52 weeks, or to a control group that was offered diet-related counselling. N-terminal proBNP (NT-proBNP), mid-regional proANP (MR-proANP) and proADM (MR-proADM) and body composition using dual-energy x-ray absorptiometry (DEXA) scanning were determined at baseline and after 52 weeks. Comparisons between groups were analysed using t-tests. Changes from the baseline within the groups were analysed with paired tests. Changes in the variables, delta (∆), were calculated as 52 weeks minus the baseline.

In the intervention group, BMI decreased by almost 20% (31.6 ± 6.2 vs. 37.1 ± 6.1 kg/m²; P <0.001) with a loss of body fat of 23.5 ± 15.5% (P < 0.001). Plasma concentrations of NT-proBNP and MR-proANP increased (from 55 ± 31 to 97 ± 55 pg/ml; P < 0.001, and from 59 ± 21 to 74 ± 26 pmol/L; P < 0.001), whereas MR-proADM decreased (from 573 ± 153 to 534 ± 173 pmol/L; P <0.001). Changes (Δ) in MR-proANP correlated with Δfat mass (r = −0.359; P = 0.011) and Δglucose (r = −0.495; P <0.001), while increases in NT-proBNP were primarily associated with reduced plasma glucose (r = −0.462; P <0.001). A modest but significant weight loss of 6% (P < 0.001) was found in the control group with no changes in plasma concentrations of NT-proBNP or MR-proANP, and a minor change in MR-proADM.

Conclusions

Plasma NT-proBNP and MR-proANP concentrations increase and MR-proADM concentration decreases during weight loss, underlining the dynamic impact of BMI, body composition and glucose metabolism on these cardiovascular biomarkers.

Adrenomedullin and diabetes

Adrenomedullin (ADM) is a peptide hormone widely expressed in different tissues, especially in the vasculature. Apart from its vasodilatatory and hypotensive effect, it plays multiple roles in the regulation of hormonal secretion, glucose metabolism and inflammatory response. ADM regulates insulin balance and may participate in the development of diabetes. The plasma level of ADM is increased in people with diabetes, while in healthy individuals the plasma ADM concentration remains low. Plasma ADM levels are further increased in patients with diabetic complications. In type 1 diabetes, plasma ADM level is correlated with renal failure and retinopathy, while in type 2 diabetes its level is linked with a wider range of complications. The elevation of ADM level in diabetes may be due to hyperinsulinemia, oxidative stress and endothelial injury. At the same time, a rise in plasma ADM level can trigger the onset of diabetes. Strategies to reduce ADM level should be explored so as to reduce diabetic complications.

Adrenomedullin, periodontitis, diabetes-unraveling the equivocal relationship: A clinicobiochemical cross-sectional study

Context:

Antimicrobial proteins and peptides constitute a diverse class of host-defense molecules that act early to combat invasion and infection with bacteria and other microorganisms. Among the various antimicrobial peptides in the oral cavity, adrenomedullin (ADM), a cationic peptide, is found in gingival crevicular fluids (GCFs) in amounts twice as high in periodontal disease sites as healthy sites. Studies have also shown that plasma levels of ADM increased in patients with type 2 diabetes mellitus as compared with controls.

Aims:

This clinico-biochemical study was undertaken to try to decipher the probable link between ADM, diabetes and periodontitis.

Materials and Methods:

The study comprised of 90 patients who were divided into three groups based on community periodontal index scores and diabetes status. Probing pocket depth and clinical attachment level were measured in all subjects. GCF was collected from all the participants using micropipettes and blood samples were collected from subjects in Groups III, for analysis of glycated hemoglobin. ADM levels were measured in GCF samples by the enzyme-linked immunosorbent assay.

Statistical Analysis Used:

The data obtained were subjected to analysis of variance, Bonferroni test and Pearson's correlation.

Results:

An increase in GCF levels of ADM from periodontal health to disease and in periodontitis patients with type 2 diabetes was noted.

Conclusions:

Increase in GCF levels of ADM from periodontal health to disease and in periodontitis patients with type 2 diabetes reinforces the perio-systemic interlink concept.

Plasma levels of IL-17, VEGF, and adrenomedullin and S-cone dysfunction of the retina in children and adolescents without signs of retinopathy and with varied duration of diabetes

The study objective was to assess chosen biochemical parameters of blood and bioelectric function of the retina in patients with T1DM. The study group consisted of 41 patients with T1DM with no signs of diabetic retinopathy. The control group included 21 pediatric patients. We performed (1) S-cone ERG testing with retina response stimulation in both eyes at the luminance of 0.1, 0.2, and 0.5 (cd × s/m²) with the 440 nm blue flash and light application of the amber background (300 ph cd/m², 495 nm wavelength), (2) anthropometric measurements, (3) biochemical investigations: IL-17, VEGF, and ADM by the ELISA method. A comparison of the ERG results with biochemical investigations indicates a likely correlation between the worsening of retinal bioelectric function and VEGF levels growing with diabetes duration. We showed a negative correlation between ADM and HbA1c and described possible causes of ADM reduction observed in subgroup I. We demonstrated the presence of bioelectric retinal dysfunction already before the diagnosis of diabetic retinopathy, which provides new possibilities in the diagnosis of preclinical chronic complications of diabetes. The changes observed in the levels of IL-17, ADM, and VEGF suggest their involvement in the diabetic pathogenesis of eye diseases.

Plasma level of adrenomedullin is influenced by a single nucleotide polymorphism in the adiponectin gene

Objective

Adrenomedullin (ADM) and adiponectin are both involved in inflammation and cardiovascular diseases. The plasma levels of these peptides are influenced by single nucleotide polymorphisms (SNPs) in the ADM and ADIPOQ genes respectively. There is some evidence that ADM may regulate adiponectin gene expression, but whether adiponectin can regulate ADM expression is unclear, and was therefore investigated.

Methods

Plasma ADM level was measured in 476 subjects in the Hong Kong Cardiovascular Risk Factor Prevalence Study-2 (CRISPS2). We genotyped them for 2 ADIPOQ SNPs that are known to be associated with plasma adiponectin level.

Results

The minor allele frequencies of ADIPOQ SNPs rs182052 and rs12495941 were 40.6% and 42.2% respectively. Plasma ADM level was significantly associated with rs182052 after adjusting for age and sex (β = 0.104, P = 0.023) but not with rs12495941 (β = 0.071, P = 0.120). In multivariate analysis, plasma ADM level increased with the number of minor alleles of rs182052 (P = 0.013). Compared to subjects with GG genotype, subjects with AA genotype had 17.7% higher plasma ADM level (95% CI: 3.6%–33.7%). Subgroup analysis revealed that the association was significant in diabetic patients (β = 0.344, P = 0.001) but not in non-diabetic subjects.

Conclusion

Plasma ADM level is related to SNP rs182052 in the ADIPOQ gene. Our findings provide new evidence of the interplay between these two important peptides in cardiovascular disease and diabetes. Knowing the genotype may help to refine the interpretation of these biomarkers.

Adrenomedullin attenuates vascular calcification in fructose-induced insulin resistance rats

AIM

To determine the therapeutic effects of adrenomedullin (ADM) on vascular calcification and related molecular mechanism in fructose-induced insulin resistance rats.

METHODS

Rats received ordinary drinking water or 10% fructose in drinking water for 12 weeks and subcutaneous injection of normal saline or ADM (3.6 μg kg(-1) ) twice a day for the last 4 weeks. Levels of ADM, calcitonin receptor-like receptors (CRLR), receptor activity-modifying proteins (RAMP) as well as calcium content, alkaline phosphatase (ALP) activity, osteoblastic and contractile smooth muscle markers in aortic media were measured.

RESULTS

The levels of ADM, CRLR, RAMP2 and RAMP3 in aortic media were increased in fructose-fed rats. ADM treatment attenuated the fructose-induced insulin resistance, increased blood pressure, fasting glucose, insulin, triglycerides and cholesterol levels. It improved VSMCs proliferation and disordered arrangement and hyperplasia of elastic fibres in fructose-fed rats. Calcium deposits, calcium content and ALP activity in the aortic media were increased in fructose-fed rats, which were attenuated by ADM treatment. The osteoblastic markers such as osteopontin (OPN), bone morphogenetic protein 2 (BMP2) proteins and core binding factor alpha-1 (Cbfα-1) protein and mRNA expressions were increased in fructose-fed rats. ADM treatment increased the OPN protein expression, but reduced the BMP2 protein, Cbfα-1 protein and mRNA expression. Contractile smooth muscle markers such as α-actin and smooth muscle 22α (SM-22α) were downregulated in fructose-fed rats, which were recovered by ADM treatment.

CONCLUSION

Administration of ADM attenuates insulin resistance, calcium deposition and osteogenic transdifferentiation in aortic media in fructose-fed rats.

Adrenomedullin is up-regulated in patients with pancreatic cancer and causes insulin resistance in β cells and mice

BACKGROUND & AIMS

New-onset diabetes in patients with pancreatic cancer is likely to be a paraneoplastic phenomenon caused by tumor-secreted products. We aimed to identify the diabetogenic secretory product(s) of pancreatic cancer.

METHODS

Using microarray analysis, we identified adrenomedullin as a potential mediator of diabetes in patients with pancreatic cancer. Adrenomedullin was up-regulated in pancreatic cancer cell lines, in which supernatants reduced insulin signaling in beta cell lines. We performed quantitative reverse-transcriptase polymerase chain reaction and immunohistochemistry on human pancreatic cancer and healthy pancreatic tissues (controls) to determine expression of adrenomedullin messenger RNA and protein, respectively. We studied the effects of adrenomedullin on insulin secretion by beta cell lines and whole islets from mice and on glucose tolerance in pancreatic xenografts in mice. We measured plasma levels of adrenomedullin in patients with pancreatic cancer, patients with type 2 diabetes mellitus, and individuals with normal fasting glucose levels (controls).

RESULTS

Levels of adrenomedullin messenger RNA and protein were increased in human pancreatic cancer samples compared with controls. Adrenomedullin and conditioned media from pancreatic cell lines inhibited glucose-stimulated insulin secretion from beta cell lines and islets isolated from mice; the effects of conditioned media from pancreatic cancer cells were reduced by small hairpin RNA-mediated knockdown of adrenomedullin. Conversely, overexpression of adrenomedullin in mice with pancreatic cancer led to glucose intolerance. Mean plasma levels of adrenomedullin (femtomoles per liter) were higher in patients with pancreatic cancer compared with patients with diabetes or controls. Levels of adrenomedullin were higher in patients with pancreatic cancer who developed diabetes compared those who did not.

CONCLUSIONS

Adrenomedullin is up-regulated in patients with pancreatic cancer and causes insulin resistance in β cells and mice.

Vasoregulatory peptides pro-endothelin-1 and pro-adrenomedullin are associated with metabolic syndrome in the population-based KORA F4 study

BACKGROUND

Metabolic alterations and endothelial dysfunction are interrelated processes in type 2 diabetes (T2D) and metabolic syndrome (MetS) that often develop in parallel. We assessed the association of vasoactive precursor peptides (VPPs) with MetS and T2D.

DESIGN AND METHODS

Plasma levels of C-terminal pro-endothelin-1 (CT-proET-1) and midregional pro-adrenomedullin (MR-proADM) were measured by novel sensitive assays in 1590 participants of the population-based KORA F4 study. The association of the VPPs with T2D, MetS defined by IDF criteria, the components of MetS, and insulin resistance (IR) was assessed in logistic regression models.

RESULTS

Elevated levels of CT-proET-1 and MR-proADM were associated with T2D, MetS, and IR in age- and sex-adjusted models. After adjustment for age, sex, former vascular complications, lifestyle factors, high-sensitive C-reactive protein, and serum creatinine, significant associations with MetS were found for MR-proADM (OR=5.94, 95% CI 3.78-9.33) and CT-proET-1 (OR=5.18, 95% CI 3.48-7.71) (top quartile vs bottom quartile). CT-proET-1 and MR-proADM were strongly associated with all components of MetS as defined by IDF criteria. After multivariable adjustment, association of CT-proET-1 and MR-proADM with pathological glucose tolerance and T2D disappeared and a borderline association with IR was found only for CT-proET-1 (OR=1.34, 95% CI 0.96-1.87).

CONCLUSIONS

We here demonstrate for the first time that plasma levels of both MR-proADM and CT-proET-1 levels are related to MetS and its components, thus suggesting that they possibly have a role as a surrogate biomarker for the disease and its complications.

Adrenomedullin: possible predictor of insulin resistance in women with polycystic ovary syndrome

The aim of the study was to investigate adrenomedullin (ADM) levels and its relation with insulin resistance in women with polycystic ovary syndrome (PCOS). Twenty-nine women with PCOS and 29 age- and body mass index (BMI)- matched control subjects were included in the study. PCOS was defined according to criteria by the Rotterdam European Society of Human Reproduction and Embryology/American Society for Reproductive Medicine (ESHRE/ASRM)-sponsored PCOS consensus workshop group. A full clinical and biochemical examination including basal hormones and metabolic profile was performed. Insulin resistance was calculated by using the homeostasis model assessment of insulin resistance index (HOMA-IR). Plasma ADM levels were measured by high performance liquid chromatographic (HPLC) method. Plasma ADM, fasting insulin levels and HOMA-IR were significantly higher in patients with PCOS than the control group. ADM levels were positively correlated with insulin levels and HOMA-IR index. The best cut-off value of ADM levels to identify the presence of insulin resistance (HOMA-IR≥2.7) was 30.44 ng/ml. Calculated odds ratio of insulin resistance by using logistic regression analysis, as predicted by ADM, was 0.15 (95% confidence interval, 0.037-0.628; p=0.009). In multiple regression analysis, ADM level was an independent predictor of HOMA-IR index. Our finding indicated that ADM levels increased in women with PCOS in accordance with HOMA-IR. ADM could be a significant independent determinant of insulin resistance in women with PCOS.

Midregional Proadrenomedullin for Prediction of Cardiovascular Events in Coronary Artery Disease: Results from the AtheroGene Study

BACKGROUND

Midregional proadrenomedullin (MR-proADM) is a newly identified prognostic marker in heart failure. We evaluated the prognostic impact of MR-proADM in a cohort of patients with symptomatic coronary artery disease according to their clinical presentation.

METHODS

We measured baseline MR-proADM concentrations in 2240 individuals from the prospective AtheroGene study and evaluated the prognostic impact on future fatal and nonfatal cardiovascular events during a follow-up period of 3.6 (1.6) years.

RESULTS

The sample comprised 1355 individuals with stable angina pectoris (SAP) and 885 with acute coronary syndrome (ACS). A cardiovascular event occurred in 192 people. Individuals presenting with SAP had only slightly lower plasma MR-proADM concentrations than those with ACS (0.53 vs 0.55 nmol/L, P = 0.006). MR-proADM showed a moderate association with age, serum N-terminal pro–B-type natriuretic peptide (NT-proBNP), glomerular filtration rate, serum C-reactive protein, hypertension, diabetes, and prevalent multivessel disease (all P &lt; 0.0005). Individuals suffering from a cardiovascular event had higher MR-proADM concentrations at baseline in both groups (SAP 0.63 vs 0.53 nmol/L and ACS 0.65 nmol/L vs 0.55 nmol/L, both P &lt; 0.0005). Cox regression analysis incorporating various variables of cardiovascular risk and NT-proBNP revealed a hazard ratio of 1.4 (95% CI 1.2–1.6; P &lt; 0.0005) per increment of MR-proADM by 1SD. In risk models for secondary prevention, MR-proADM provided information comparable to that of NT-proBNP.

CONCLUSIONS

MR-proADM is an independent predictor for future cardiovascular events in patients with symptomatic coronary artery disease, providing information comparable to NT-proBNP for secondary risk stratification.

Imbalance of the autonomic nervous system at night in women with gestational diabetes

AIMS

Autonomic nervous system dysfunction is observed in Type 2 diabetes. As gestational diabetes is a potent risk factor of later Type 2 diabetes, we set out to determine whether autonomic nervous system imbalance could already be observed in women with this condition. Because activity of the sympathetic nervous system tends to be relatively stable in the nocturnal hours, we performed the study at night.

RESEARCH DESIGN AND METHODS

We studied 41 women with gestational diabetes, 22 healthy pregnant controls and 14 non-pregnant controls. We assayed plasma noradrenaline at 24.00, 04.00 and 07.00 h and performed an overnight Holter recording for heart rate variability analysis. In addition, we assayed plasma adrenomedullin, a cardiovascular protective hormone.

RESULTS

Compared with non-pregnant controls, plasma noradrenaline levels were increased at 04.00 and 07.00 h in the gestational diabetic (P = 0.003) and pregnant control (P = 0.002) groups, with no difference between them. Heart rate variability, very-low-frequency and low-frequency power were lower in pregnant groups compared to the non-pregnant controls. Heart rate variability remained unchanged between specified sampling times in the gestational diabetic group, in contrast to fluctuation seen in the control groups.

CONCLUSIONS

Gestational diabetes, compared with normal pregnancy, seems not to be a state of overall sympathetic nervous system activation. At the heart level, however, an inhibitory effect on autonomic nervous system modulation was seen. Plasma noradrenaline and heart rate variability correlated well, supporting the use of this function in future studies of overall sympathetic activity during pregnancy.

Plasma adrenomedullin level in Egyptian children and adolescents with type 1 diabetes mellitus: relationship to microvascular complications

BACKGROUND

Adrenomedullin (AM) is known to be elevated in different clinical situations including diabetes mellitus (DM), but its potential role in the pathogenesis of vascular complications in diabetic children and adolescents is to be clarified. Hence, the study aimed at assessment of plasma adrenomedullin levels in children and adolescents with type 1 DM and correlation of these levels with metabolic control and diabetic microvascular complications (MVC).

METHODS

The study was performed in the Diabetes Specialized Clinic, Children's Hospital of Ain Shams University in Cairo, Egypt. It included 55 diabetic children and adolescents (mean age 13.93 +/- 3.15 years) who were subdivided into 40 with no MVC and 15 with MVC. Thirty healthy subjects, age-and sex-matched, were included as control group (mean age 12.83 +/- 2.82 years). Patients and controls were assessed for glycosylated hemoglobin (HbA1c) and plasma adrenomedullin assay using ELISA technique.

RESULTS

Mean plasma AM levels were significantly increased in patients with and without MVC compared to control group, (110.6 pg/mL, 60.25 pg/mL and 39.2 pg/mL respectively) (P < 0.01) with higher levels in those with MVC (P < 0.05). Plasma AM levels were positively correlated with both duration of diabetes (rho = 0.703, P < 0.001) and glycemic control (HbA1c) (rho = 0.453, P < 0.001).

CONCLUSION

Higher plasma AM levels in diabetics particularly in those with MVC & its correlation with diabetes duration and metabolic control may reflect the role of AM in diabetic vasculopathy in the pediatric age group.

Endothelial markers may link kidney function to cardiovascular events in type 2 diabetes

OBJECTIVE

The increased cardiovascular risk in diabetes has been linked to endothelial and renal dysfunction. The aim of this study was to investigate the role of stable fragments of the precursors of adrenomedullin, endothelin-1, vasopressin, and atrial natriuretic peptide in progression of cardiovascular disease in patients with diabetes.

RESEARCH DESIGN AND METHODS

This was a prospective, observational study design with a composite end point (death or unexpected admission to hospital due to a cardiovascular event) on 781 patients with type 2 diabetes (54 events, median duration of observation 15 months). The four stable precursor peptides midregional adrenomedullin (MR-proADM), midregional proatrial natriuretic peptide (MR-proANP), COOH-terminal proendothelin-1 (CT-proET-1), and COOH-terminal provasopressin or copeptin (CT-proAVP) were determined at baseline, and their association to renal function and cardiovascular events was studied using stepwise linear and Cox logistic regression analysis and receiver operating characteristic analysis, respectively.

RESULTS

MR-proADM, CT-proET-1, CT-proAVP, and MR-proANP were all elevated in patients with future cardiovascular events and independently correlated to serum creatinine. MR-proADM and MR-proANP were significant predictors of a future cardiovascular event, with MR-proANP being the stronger (area under the curve 0.802 +/- 0.034, sensitivity 0.833, specificity 0.576, positive predictive value 0.132, and negative predictive value 0.978 with a cutoff value of 75 pmol/l).

CONCLUSIONS

The four serum markers of vasoactive and natriuretic peptides are related to both kidney function and cardiovascular events, thus linking two major complications of diabetes, diabetic nephropathy and cardiovascular disease.

Plasma MR-proADM correlates to BMI and decreases in relation to leptin after gastric bypass surgery

Adrenomedullin (ADM) is a vasoactive peptide found to be related to obesity and its comorbidities: type 2 diabetes, hypertension, atherosclerosis, and coronary heart disease. ADM is increased both in plasma and in adipose tissue of obese individuals when compared to lean subjects and is considered as a member of the adipokine family. We determined plasma midregional proadrenomedullin (MR-proADM) concentrations in a cohort of 357 subjects with BMI ranging from 17.5 to 42.3 kg/m2 and no additional medical history. In parallel, 28 severely obese patients scheduled to undergo laparoscopic Roux-en-Y gastric bypass (RYGB) surgery were studied at two time points: before and 1 year after surgery. Outcome measurements were: MR-proADM, cortisol, leptin, C-reactive protein (CRP) thyroid-stimulating hormone (TSH), creatinine and metabolic parameters. BMI correlated significantly to plasma MR-proADM levels (r=0.714, P<0.001), also after adjustment for age and gender (r=0.767, P<0.001). In obese subjects, there was a positive relationship between MR-proADM and leptin (r=0.511, P=0.006). Following RYGB, plasma MR-proADM decreased from 0.76+/-0.03 to 0.62+/-0.02 pg/ml (P<0.0001). RYGB-induced changes in MR-proADM correlated significantly to changes in leptin (r=0.533, P=0.004) and in CRP (r=0.429, P=0.023). We conclude that BMI is an independent predictor of circulating MR-proADM levels. Weight loss after RYGB is associated with a significant decrease in plasma MR-proADM, which is related to surgery-induced changes in both circulating leptin and systemic inflammation.