Tissue inhibitor of metalloproteinse-1 is a marker of diastolic dysfunction using tissue doppler in patients with type 2 diabetes and hypertension

Improving Diastolic and Microvascular Function in Heart Transplantation with Donation after Circulatory Death

The impact of the machine perfusion of donation after circulatory death (DCD) hearts with the novel Custodiol-N solution on diastolic and coronary microvascular dysfunction is unknown. Porcine DCD-hearts were maintained four hours by perfusion with normothermic blood (DCD-B), hypothermic Custodiol (DCD-C), or Custodiol-N (DCD-CN), followed by one hour of reperfusion with fresh blood, including microvascular and contractile evaluation. In another group (DCD group), one hour of reperfusion, including microvascular and contractile evaluation, was performed without a previous maintenance period (all groups N = 5). We measured diastolic function with a balloon catheter and microvascular perfusion by Laser-Doppler-Technology, resulting in Laser-Doppler-Perfusion (LDP). We performed immunohistochemical staining and gene expression analysis. The developed pressure was improved in DCD-C and DCD-CN. The diastolic pressure decrement (DCD-C: -1093 ± 97 mmHg/s; DCD-CN: -1703 ± 329 mmHg/s; DCD-B: -690 ± 97 mmHg/s; p < 0.05) and relative LDP (DCD-CN: 1.42 ± 0.12; DCD-C: 1.11 ± 0.13; DCD-B: 1.22 ± 0.27) were improved only in DCD-CN. In DCD-CN, the expression of eNOS increased, and ICAM and VCAM decreased. Only in DCD-B compared to DCD, the pathways involved in complement and coagulation cascades, focal adhesion, fluid shear stress, and the IL-6 and IL-17 pathways were upregulated. In conclusion, machine perfusion with Custodiol-N improves diastolic and microvascular function and preserves the microvascular endothelium of porcine DCD-hearts.

Diabetes Induces Cardiac Fibroblast Activation, Promoting a Matrix-Preserving Nonmyofibroblast Phenotype, Without Stimulating Pericyte to Fibroblast Conversion

Background Interstitial and perivascular fibrosis may contribute to diabetes-associated heart failure. Pericytes can convert to fibroblasts under conditions of stress and have been implicated in the pathogenesis of fibrotic diseases. We hypothesized that in diabetic hearts, pericytes may convert to fibroblasts, contributing to fibrosis and to the development of diastolic dysfunction. Methods and Results Using pericyte:fibroblast dual reporter (NG2^Dsred [neuron-glial antigen 2 red fluorescent protein variant]; PDGFRα^EGFP [platelet-derived growth factor receptor alpha enhanced green fluorescent protein]) mice in a type 2 diabetic db/db background, we found that diabetes does not significantly affect pericyte density but reduces the myocardial pericyte:fibroblast ratio. Lineage tracing using the inducible NG2^CreER driver, along with reliable labeling of fibroblasts with the PDGFRα reporter system, showed no significant pericyte to fibroblast conversion in lean and db/db hearts. In addition, db/db mouse cardiac fibroblasts did not undergo myofibroblast conversion and had no significant induction of structural collagens but exhibited a matrix-preserving phenotype, associated with increased expression of antiproteases, matricellular genes, matrix cross-linking enzymes, and the fibrogenic transcription factor cMyc. In contrast, db/db mouse cardiac pericytes had increased expression of Timp3, without any changes in expression of other fibrosis-associated genes. The matrix-preserving phenotype of diabetic fibroblasts was associated with induction of genes encoding oxidative (Ptgs2/cycloxygenase-2, and Fmo2) and antioxidant proteins (Hmox1, Sod1). In vitro, high glucose partially recapitulated the in vivo changes in diabetic fibroblasts. Conclusions Diabetic fibrosis is not mediated through pericyte to fibroblast conversion but involves acquisition of a matrix-preserving fibroblast program, which is independent of myofibroblast conversion and is only partially explained by the effects of the hyperglycemic environment.

The Role of the Renin-Angiotensin System and Vitamin D in Keloid Disorder-A Review

Keloid disorder (KD) is a fibroproliferative condition characterized by excessive dermal collagen deposition in response to wounding and/or inflammation of the skin. Despite intensive research, treatment for KD remains empirical and unsatisfactory. Activation of the renin-angiotensin system (RAS) leads to fibrosis in various organs through its direct effect and the resultant hypertension, and activation of the immune system. The observation of an increased incidence of KD in dark-skinned individuals who are predisposed to vitamin D deficiency (VDD) and hypertension, and the association of KD with hypertension and VDD, all of which are associated with an elevated activity of the RAS, provides clues to the pathogenesis of KD. There is increasing evidence implicating embryonic-like stem (ESC) cells that express ESC markers within keloid-associated lymphoid tissues (KALTs) in keloid lesions. These primitive cells express components of the RAS, cathepsins B, D, and G that constitute bypass loops of the RAS, and vitamin D receptor (VDR). This suggests that the RAS directly, and through signaling pathways that converge on the RAS, including VDR-mediated mechanisms and the immune system, may play a critical role in regulating the primitive population within the KALTs. This review discusses the role of the RAS, its relationship with hypertension, vitamin D, VDR, VDD, and the immune system that provide a microenvironmental niche in regulating the ESC-like cells within the KALTs. These ESC-like cells may be a novel therapeutic target for the treatment of this enigmatic and challenging condition, by modulating the RAS using inhibitors of the RAS and its bypass loops and convergent signaling pathways.

The E/e' ratio difference between subjects with type 2 diabetes and controls. A meta-analysis of clinical studies

Type 2 diabetes is associated with an increased risk of heart failure. Left ventricular diastolic dysfunction and type 2 diabetes are frequently associated. Using echocardiography, we know that tissue Doppler imaging E/e’ ratio is a reliable predictor of left ventricular filling pressure. We performed a systematic review and meta-analysis to investigate the averaged E/e’ ratio value in patients with type 2 diabetes compared to non-diabetic controls. In the analysis we included cross-sectional studies providing the averaged E/e’ ratio. Subgroup/sensitivity analyses were conducted according to variables known to influence E/e’ ratio measurements. The analysis included 15 cross sectional studies with 877 type 2 diabetes patients and 1193 controls. The weighted mean difference showed higher values in diabetes (WMD 2.02; 95% CI 1.35, 2.70; p<0.001). The result was consistent in the subgroup/sensitivity analyses. Visual inspection of the funnel plot did not identify substantial asymmetry and the Egger test for funnel plot asymmetry showed a p value of 0.36. In conclusion, our assessment suggests that averaged E/e’ ratio is consistently increased in patients with type 2 diabetes compared to non-diabetic controls in the absence of cardiovascular diseases and complicated hypertension. This alteration may be a precocious diastolic alteration in the diabetic cardiomyopathy.

Utility of Tissue Inhibitor Metalloproteinase-1 and Osteopontin as Prospective Biomarkers of Early Cardiovascular Complications in Type 2 Diabetes

AIM:

This work investigated associations between tissue inhibitor metalloproteinase-1 and diabetic cardiovascular diseases in type 2 diabetic patients; also it investigated the role of osteopontin in the diagnosis of type 2 cardiovascular diabetes complications.

SUBJECTS AND METHODS:

These were examined on eighty subjects, divided into three groups as follows: twenty volunteer healthy control subjects, thirty type 2 diabetes mellitus (DM) patients, and thirty cardiovascular, diabetic patients. Full clinical measurements were carried out, and the expression level of tissue inhibitor metalloproteinase-1 in blood samples was analysed by real-time PCR, using gene-specific primer pairs. Also osteopontin concentrations had been measured by the enzyme-linked immunosorbent assay. Data were tested statistically by parametric tests.

RESULTS:

The concentrations of osteopontin and the expression levels of tissue inhibitor metalloproteinase-1 were significantly increased in diabetic and cardiovascular diabetic groups compared to control group also they were significantly increased in the cardiovascular diabetic group compared to the diabetic group.

CONCLUSION:

Tissue inhibitor metalloproteinase-1 and osteopontin concentrations were significantly increased in diabetic patients with cardiovascular complications than other groups.

Hypertension: a systemic key to understanding local keloid severity

This study assessed whether hypertension, a circulating factor, influences local keloid severity. This retrospective cross-sectional study involved 304 consecutive patients (13-78 years old) with keloids who were surgically treated in our hospital between January 2011 and August 2013. Their blood pressure (BP), age and gender, and the size and number of their keloids before surgery were recorded. Ordinal logistic regression analyses showed that BP associated significantly with both keloid size and number (all p < 0.0001). Age also associated with keloid size (p < 0.0001). However, a Goodness-of-fit chi-square test showed that the prevalence of hypertension was not higher among keloid patients than in the general Japanese population. This study provides epidemiological evidence for the possibility that primary hypertension may aggravate keloids. We propose that the skin, along with the heart and liver, is a target organ of hypertension. The observations of this study, which require validation with large-scale prospective interventional trials, suggest that keloid patients should be screened for hypertension and that antihypertensive treatments may be of prophylactic and therapeutic value for skin fibrosis.

The link between hypertension and pathological scarring: does hypertension cause or promote keloid and hypertrophic scar pathogenesis?

Pathological scars, namely, keloids and hypertrophic scars (HSs), are caused by excessive cutaneous wound healing that is characterized by histological extracellular matrix (ECM) accumulation, clinically relevant irritating symptoms, and frequent recurrence after surgical excision. To date, there are few effective and specific treatments. This partly reflects the poor understanding of the etiology of these scars and the lack of a suitable animal model. Systemic hypertension has been suggested to participate in pathological scarring. The evidence that supports this hypothesis is reviewed here. Thus, hypertension associates with changes that resemble the aberrant cutaneous wound-healing phases that characterize pathological scar development. It also associates with profibrotic functional changes in the cells that constitute keloids and HSs (endothelial cells, pericytes/myofibroblasts, dermal fibroblasts, and mast cells) and profibrotic ECM remodeling. These hypertension-associated changes are mediated to some extent by inflammation, hypoxia, and the angiotensin/renin-angiotensin-aldosterone system. Thus, hypertension may be an aggravating/risk factor for keloids and HSs. This will help to identify patients who are prone to heavy scars after surgery or postsurgical recurrence. Moreover, pharmacological agents for the prophylaxis and treatment of hypertension-induced fibrosis in other organs may also be useful for keloids/HSs.

Myocardial recovery from ischemia-reperfusion is compromised in the absence of tissue inhibitor of metalloproteinase 4

BACKGROUND

Myocardial reperfusion after ischemia (I/R), although an effective approach in rescuing the ischemic myocardium, can itself trigger several adverse effects including aberrant remodeling of the myocardium and its extracellular matrix. Tissue inhibitor of metalloproteinases (TIMPs) protect the extracellular matrix against excess degradation by matrix metalloproteinases (MMPs). TIMP4 levels are reduced in myocardial infarction; however, its causal role in progression of post-I/R injury has not been explored.

METHODS AND RESULTS

In vivo I/R (20-minute ischemia, 1-week reperfusion) resulted in more severe systolic and diastolic dysfunction in TIMP4(-/-) mice with enhanced inflammation, oxidative stress (1 day post-I/R), hypertrophy, and interstitial fibrosis (1 week). After an initial increase in TIMP4 (1 day post-I/R), TIMP4 mRNA and protein decreased in the ischemic myocardium from wild-type mice by 1 week post-I/R and in tissue samples from patients with myocardial infarction, which correlated with enhanced activity of membrane-bound MMP, membrane-type 1 MMP. By 4 weeks post-I/R, wild-type mice showed no cardiac dysfunction, elevated TIMP4 levels (to baseline), and normalized membrane-type 1 MMP activity. TIMP4-deficient mice, however, showed exacerbated diastolic dysfunction, sustained elevation of membrane-type 1 MMP activity, and worsened myocardial hypertrophy and fibrosis. Ex vivo I/R (20- or 30-minute ischemia, 45-minute reperfusion) resulted in comparable cardiac dysfunction in wild-type and TIMP4(-/-) mice.

CONCLUSIONS

TIMP4 is essential for recovery from myocardial I/R in vivo, primarily because of its membrane-type 1 MMP inhibitory function. TIMP4 deficiency does not increase susceptibility to ex vivo I/R injury. Replenishment of myocardial TIMP4 could serve as an effective therapy in post-I/R recovery for patients with reduced TIMP4.

Subclinical myocardial inflammation and diffuse fibrosis are common in systemic sclerosis--a clinical study using myocardial T1-mapping and extracellular volume quantification

BACKGROUND

Systemic sclerosis (SSc) is characterised by multi-organ tissue fibrosis including the myocardium. Diffuse myocardial fibrosis can be detected non-invasively by T1 and extracellular volume (ECV) quantification, while focal myocardial inflammation and fibrosis may be detected by T2-weighted and late gadolinium enhancement (LGE), respectively, using cardiovascular magnetic resonance (CMR). We hypothesised that multiparametric CMR can detect subclinical myocardial involvement in patients with SSc.

METHODS

19 SSc patients (18 female, mean age 55 ± 10 years) and 20 controls (19 female, mean age 56 ± 8 years) without overt cardiovascular disease underwent CMR at 1.5T, including cine, tagging, T1-mapping, T2-weighted, LGE imaging and ECV quantification.

RESULTS

Focal fibrosis on LGE was found in 10 SSc patients (53%) but none of controls. SSc patients also had areas of myocardial oedema on T2-weighted imaging (median 13 vs. 0% in controls). SSc patients had significantly higher native myocardial T1 values (1007 ± 29 vs. 958 ± 20 ms, p < 0.001), larger areas of myocardial involvement by native T1 >990 ms (median 52 vs. 3% in controls) and expansion of ECV (35.4 ± 4.8 vs. 27.6 ± 2.5%, p < 0.001), likely representing a combination of low-grade inflammation and diffuse myocardial fibrosis. Regardless of any regional fibrosis, native T1 and ECV were significantly elevated in SSc and correlated with disease activity and severity. Although biventricular size and global function were preserved, there was impairment in the peak systolic circumferential strain (-16.8 ± 1.6 vs. -18.6 ± 1.0, p < 0.001) and peak diastolic strain rate (83 ± 26 vs. 114 ± 16 s-1, p < 0.001) in SSc, which inversely correlated with diffuse myocardial fibrosis indices.

CONCLUSIONS

Cardiac involvement is common in SSc even in the absence of cardiac symptoms, and includes chronic myocardial inflammation as well as focal and diffuse myocardial fibrosis. Myocardial abnormalities detected on CMR were associated with impaired strain parameters, as well as disease activity and severity in SSc patients. CMR may be useful in future in the study of treatments aimed at preventing or reducing adverse myocardial processes in SSc.

Integrating the myocardial matrix into heart failure recognition and management

In contrast to public perception, the morbidity and mortality and the resultant healthcare costs associated with chronic heart failure (HF) are increasing and arguably reaching epidemic proportions. Although basic research efforts have provided unique insights into fundamental processes that govern myocardial extracellular matrix (ECM) growth and function, the translation of these findings to improved diagnostics and therapeutics for HF has not been as forthcoming. The factors that contribute to this relative paucity of new clinical tools for HF are multifactorial but likely include the need to recognize and differentiate HF phenotypes and to couple the use of biomarkers and multimodality imaging in early translational research studies. Recognizing the classification scheme of HF with a reduced ejection fraction (EF) to that of HF with a preserved EF and incorporating unique and differential measurements of ECM remodeling to these specific disease processes are warranted. For example, profiling pathways of ECM degradation such as the matrix metalloproteinases in patients with ischemic heart disease and HF with a reduced EF can provide prognostic information in terms of risk of progression to HF. In patients with chronic hypertensive disease and HF with a preserved EF, plasma profiling indexes of ECM synthesis and turnover, as well as advances in ECM imaging, have been shown to provide diagnostic and prognostic use. In terms of therapeutics, strategies to stabilize the ECM in HF with a reduced EF hold potential, whereas in contradistinction, selective antifibrotic agents may hold promise for HF with a preserved EF.

Changes in plasma profiles of matrix metalloproteinases (MMPs) and tissue inhibitors of MMPs in stress-induced cardiomyopathy

BACKGROUND

Transient changes in the composition of the myocardial extracellular matrix may contribute to the ventricular systolic dysfunction in stress-induced cardiomyopathy (SIC). We examined the changes in plasma matrix metalloproteinases (MMPs) and tissue inhibitors of metalloproteinases (TIMPs) that occur early after the clinical presentation of SIC.

METHODS AND RESULTS

Ten patients with SIC were enrolled. Plasma concentrations of the 6 major MMPs (1, 2, 3, 7, 8, and 9) and all 4 TIMPs (1, 2, 3, and 4) were analyzed and compared with data from 15 control subjects. Within 24 hours of the clinical presentation, SIC patients had lower MMP-1 levels (0.41 ± 0.13 vs 0.70 ± 0.13 pg/mL; P = .048) and MMP-8 levels (1.61 ± 0.34 vs 4.84 ± 1.38 pg/mL; P = .001) and higher TIMP-4 levels (3.06 ± 0.40 vs 2.16 ± 0.18 pg/mL; P = .05) compared with control. Seven of 9 SIC patients had elevated LV end-diastolic pressures, and all had normal LV end-diastolic dimensions and volumes.

CONCLUSIONS

Patients afflicted with SIC had MMP and TIMP profiles similar to those described in hypertensive heart disease and diastolic heart failure and different from the profiles following myocardial infarction. Our findings uncovered a unique biomolecular profile in SIC during the first 24 hours of presentation.

Plasma levels of matrix metalloproteinases and their inhibitors in hypertension: a systematic review and meta-analysis

BACKGROUND

Hypertension is a major cause of cardiovascular remodeling. In the cardiovascular system, the remodeling of the extracellular matrix is controlled by the matrix metalloproteinases (MMPs) and the tissue inhibitors of MMPs (TIMPs). The aim of this meta-analysis is to elucidate the behavior of plasma MMP and TIMP levels in hypertension and their relationship to cardiovascular remodeling.

METHODS

MEDLINE and EMBASE databases were searched up to July 2011. Studies were considered eligible if they provided values of plasma MMPs and TIMPs in hypertensive patients. Given the high variability of the plasma biomarker values among studies, the standardized mean difference (SMD) was calculated.

RESULTS

Ten studies provided plasma MMP-9; the SMD between 778 hypertensive patients and 669 controls was 1.95 units (P < 0.05). Thirteen studies provided plasma TIMP-1; the SMD between 851 hypertensive patients and 646 normotensive individuals was 1.92 units (P < 0.01). Three studies investigated whether plasma TIMP-1 predicted left ventricular (LV) remodeling; the SMD between 92 hypertensive patients with and 88 hypertensive patients without LV hypertrophy was 5.81 units (P < 0.05). As for diastolic heart failure (HF), five studies provided data for plasma MMP-2; the SMD between 321 hypertensive patients with and 334 hypertensive patients without HF was 2.36 units (P < 0.01). The heterogeneity among studies was high.

CONCLUSIONS

These results suggest that MMP-2, MMP-9 and TIMP-1 may have a role as biomarkers of cardiovascular remodeling in hypertension. If these results are confirmed in prospective clinical studies, they could provide new tools to stratify cardiovascular risk in hypertensive patients.

Metalloproteinase-3 genotype as a predictor of cardiovascular risk in hypertensive adolescents

Background and Objectives

Hypertension develops as a result of cardiac hypertrophy and fibrosis or as a result of exchange of the extracellular matrix. In particular, matrix metalloproteinase (MMP)-3 is a major enzyme involved in the reconstruction of the arterial intima through activation of other MMPs. We analyzed MMP-3 genotypes in hypertensive and normotensive adolescents and sought to determine if a particular genotype is a predictor of cardiovascular complications.

Subjects and Methods

Forty-four hypertensive adolescents and 59 healthy adolescents were included in this study. Serum aldosterone, renin, insulin, angiotensin converting enzyme (ACE), insulin, homocysteine, vitamin B₁₂, folate, MMP-1, MMP-2, MMP-3, MMP-9, tissue inhibitors of matrix metalloproteinases (TIMP)-1, and TIMP-2 were measured. MMP-3 genotypes were analyzed using a polymerase chain reaction (PCR) primer. The carotid intima media thickness (IMT), diameter, and brachial ankle pulse wave velocity (baPWV) were evaluated using ultrasound.

Results

In hypertensive adolescents, blood pressure, anthropometric data, carotid IMT, baPWV, serum pro-MMP-1, MMP-2, MMP-9, TIMP-1, and TIMP-2 were no different between the 6A/6A group and the 5A/6A group. Serum MMP-9 was higher in the 5A/6A group than in the control group. Aldosterone, insulin, and homocysteine were higher in the 6A/6A group than in the control group, and vitamin B₁₂ and folate were lower in the 6A/6A group than in the control group.

Conclusion

In conclusion, serum MMP-3 levels were not significantly different in different MMP-3 genotypes in hypertensive adolescents. However, few patients were included in this study. Further investigation is necessary to clarify the relationship between MMP-3 genotype and cardiovascular risk.

Fibrosis in diabetes complications: pathogenic mechanisms and circulating and urinary markers

Diabetes mellitus is characterized by a lack of insulin causing elevated blood glucose, often with associated insulin resistance. Over time, especially in genetically susceptible individuals, such chronic hyperglycemia can cause tissue injury. One pathological response to tissue injury is the development of fibrosis, which involves predominant extracellular matrix (ECM) accumulation. The main factors that regulate ECM in diabetes are thought to be pro-sclerotic cytokines and protease/anti-protease systems. This review will examine the key markers and regulators of tissue fibrosis in diabetes and whether their levels in biological fluids may have clinical utility.

Matrix metalloproteinases 2 and 9 and their tissue inhibitors 1 and 2 in premenopausal obese women: relationship to cardiac function

BACKGROUND

Myocardial fibrosis is one of the mechanisms underlying left ventricular (LV) dysfunction in obese patients and may result from dysregulation of extracellular matrix (ECM) turnover. Matrix metalloproteinases (MMPs) and their tissue inhibitors (TIMPs) represent a regulatory system playing a crucial role in ECM metabolism.

OBJECTIVES

We sought to assess plasma levels of MMP-2, MMP-9, TIMP-1 and TIMP-2 in obese young women and to evaluate the association between MMP/TIMP system components and LV function in this population.

DESIGN

Prospective, cross-sectional study.

SETTING

University hospital.

PATIENTS

Seventy-one women aged < 35 years with body mass index > 30 kg m(-2) and 30 healthy slim female controls.

MAIN OUTCOME MEASURES

Plasma MMP-2, MMP-9, TIMP-1 and TIMP-2 measurements and echocardiographic studies, including LV strain/strain rate evaluation.

RESULTS

We demonstrated increased levels of MMP-9 and TIMP-1 and decreased MMP-2 in the obese population. LV dysfunction shown in patients with obesity was characterized by significantly lower values of strain/strain rate parameters. Plasma MMP-2 correlated positively and TIMP-1 negatively with systolic strain (r = 0.39, P < 0.001 and r = -0.40, P < 0.001, respectively), peak systolic strain rate (r = 0.38, P < 0.001 and r = -0.27, P < 0.03, respectively) and peak early diastolic strain rate (r = 0.40, P < 0.001 and r = -0.24, P < 0.05, respectively). Plasma MMP-2, fasting insulin and body mass index proved the only independent determinants of strain/strain rate parameters of LV systolic and diastolic performance in obese subjects.

CONCLUSIONS

In premenopausal obese women (1) plasma MMP/TIMP profile is altered, (2) abnormalities of LV function are related to the changes in the MMP/TIMP system that might promote attenuated ECM degradation, mainly to the downregulation of MMP-2.

Matrix metalloproteinases/tissue inhibitors of metalloproteinases: relationship between changes in proteolytic determinants of matrix composition and structural, functional, and clinical manifestations of hypertensive heart disease

BACKGROUND

Chronic hypertension may cause left ventricular (LV) remodeling, alterations in cardiac function, and the development of chronic heart failure (CHF). Changes in the composition of the extracellular matrix (ECM) known to occur in hypertension are believed to be causally related to these structural, functional, and clinical outcomes. However, whether the determinants of ECM composition, such as the balance between ECM proteases (matrix metalloproteinases [MMPs]) and their tissue inhibitors [TIMPs]), are altered in hypertensive heart disease is unknown.

METHODS AND RESULTS

Plasma MMP-2, -9, and -13 values, TIMP-1 and -2 values, and Doppler echocardiography images were obtained for 103 subjects divided into 4 groups: (1) reference subjects (CTL) with no evidence of cardiovascular disease, (2) hypertensive (HTN) subjects with controlled blood pressure and no LV hypertrophy, (3) hypertensive subjects with controlled blood pressure and with LV hypertrophy (HTN+LVH) but no CHF, and (4) hypertensive subjects with controlled blood pressure, LVH, and CHF (HTN+LVH+CHF). Compared with CTL, patients with HTN had no significant changes in any MMP or TIMP. Patients with HTN+LVH had decreased MMP-2 and MMP-13 values and increased MMP-9 values. Only patients with HTN+LVH+CHF had increased TIMP-1 values. A TIMP-1 level >1200 ng/mL was predictive of CHF.

CONCLUSIONS

Patients with hypertension but normal LV structure and function had normal MMP/TIMP profiles. Changes in MMP profiles that favor decreased ECM degradation were associated with LVH and diastolic dysfunction. An increased TIMP-1 level predicted the presence of CHF. Although these findings should be confirmed in a larger prospective study, these data do suggest that changes in the MMP/TIMP balance may play an important role in the structural, functional, and clinical manifestations of hypertensive heart disease.

Collagen type-I degradation is related to arterial stiffness in hypertensive and normotensive subjects

Although arterial stiffness is an independent cardiovascular risk factor associated with both aging and hypertension, relatively little is known regarding the structural changes in the vessel wall that occur with vessel stiffening. We determined if collagen type-I metabolism is related to arterial stiffening in both hypertensive and normotensive subjects. Arterial stiffness was assessed by aortic pulse wave velocity (PWV) and augmentation index (AIx) in 46 subjects (48.7 +/- 2 years, 32 hypertensives) and related to circulating markers of collagen type-I turnover. Collagen synthesis was assessed by the measurement of carboxy-terminal peptide of procollagen type-I (PIP) and collagen degradation by the measurement of carboxy-terminal telopeptide of collagen type-I (ICTP), by quantitative immunoassay. Matrix metalloproteinase-1 (MMP-1) and the tissue inhibitor of metalloproteinase-1 (TIMP-1) were also quantified by immunoassay. The ratio of collagen type-I synthesis to degradation was negatively correlated with both PWV (P<0.05) and AIx (P<0.05), whereas plasma MMP-1 levels displayed a positive correlation with both PWV (P<0.01) and AIx (P<0.01), after adjustment for age and mean arterial pressure. The relationship between collagen type-I turnover and arterial stiffness was similar in both the normotensive and hypertensive subjects. Although circulating markers of collagen synthesis were increased in the hypertensive subjects, this was not related to arterial stiffness. Collagen type-I degradation is increased in relation to collagen type-I synthesis in subjects with stiffer arteries. Matrix metalloproteinase-1, the enzyme responsible for collagen type-I degradation, is positively related to both large elastic and muscular artery stiffness in normotensive and hypertensive subjects.

Type 2 diabetes mellitus: a cardiovascular perspective

Diabetes mellitus is a disease, which is at the epitome of cardiovascular risk factors causing considerable morbidity and mortality. In addition to microvascular complications, there is two- to six-fold increased risk of macrovascular diseases, such as coronary artery disease, peripheral artery disease and stroke. While the mortality from coronary artery disease in patients without diabetes has declined over the past 20 years, the mortality in men with type 2 diabetes mellitus has not changed. Furthermore, the prevalence of diabetes in the UK has increased by 30% since 1991 and the same among the world population in 2010 is expected to be twice in 1990. This dramatic increase has serious implications from a cardiovascular perspective and thus the aggressive management of blood pressure, dyslipidaemia and blood glucose in diabetes is of vital importance. The aim of this review is to evaluate the current evidence and to discuss the implications of type 2 diabetes and its relevance to clinical practice in cardiology. We address this broad subject in discussing (i) the pathophysiology of cardiovascular disease in the setting of type 2 diabetes and (ii) the prevalence of cardiovascular risk, complications and prognostic implications in type 2 diabetes, with a discussion of current therapeutic interventions for the prevention or delay of these consequences where relevant.