Inmaculada Colina

Prothrombin Fragment 1+2 Is Associated With Carotid Intima-Media Thickness in Subjects Free of Clinical Cardiovascular Disease

Background and Purpose— Thrombin, a central enzyme in the clotting cascade, plays a role not only in thrombosis but also in the progression of atherosclerosis. We studied the relationship between prothrombin fragment 1+2 (F1+2), a specific marker of thrombin generation in vivo, and carotid intima-media thickness (IMT), an index of subclinical atherosclerosis. Methods— We examined 181 asymptomatic middle-aged subjects (mean age 55.6 years, 76.7% men) free of overt clinical atherosclerotic disease. F1+2 was measured by enzyme-linked immunosorbent assay and IMT by duplex ultrasonography of carotid artery. Multiple linear regression analysis was used to assess the relationship between the 2 parameters. Results— Compared with individuals in the lowest tertile of F1+2, those in the upper tertile (>0.55 nmol/L) showed significantly higher IMT (P <0.01). In correlation analysis, a positive relationship was found between plasma F1+2 and carotid IMT. F1+2 also correlated positively with cholesterol (P <0.008) and low-density lipoprotein cholesterol (P <0.005), but not with blood pressure or body mass index. In the multivariate analysis, the association of F1+2 with carotid IMT remained significant (P <0.001) after adjustment for age, sex, body mass index, systolic blood pressure, cholesterol, diabetes, and smoking. Conclusions— In a population sample of adults without clinically overt atherosclerotic disease, the plasma levels of F1+2 were significantly associated with carotid IMT, suggesting a relationship between thrombin generation and the development atherosclerosis.

Increased Synthesis of Systemic Prostacyclin in Cirrhotic Patients

Urinary excretion of two prostacyclin metabolites was investigated in 48 subjects: 8 controls and 40 cirrhotics (9 without ascites, 22 with ascites and preserved renal function, and 9 with functional renal failure). Urinary 6-keto-prostaglandin F1 alpha (6-keto-PGF1 alpha), believed to reflect renal prostacyclin production, was significantly increased in patients without ascites and in ascitic patients with preserved renal function, but cirrhotics with renal failure showed rates similar to controls. Excretion of 2,3-dinor-6-keto-PGF1 alpha (PGI-M), the major urinary metabolite of systemic prostacyclin, was increased in all groups of patients, including those with renal failure. A single dose of sulindac, a renal-sparing prostaglandin synthesis inhibitor, reduced PGI-M but not 6-keto-PGF1 alpha in 5 cirrhotic patients. This would be consistent with the predicted renal origin of the latter and the systemic origin of the former. Ascitic patients with high urinary excretion of PGI-M (above the median value) showed significantly lower mean arterial pressure and higher plasma renin activity and aldosterone than patients with excretion below the median. Urinary 6-keto-PGF1 alpha was higher in patients with low PGI-M. Finally, creatinine clearance corrected excretion of PGI-M, as an estimation of relative plasma levels correlates both with plasma renin activity and plasma aldosterone in the 31 subjects who presented with ascites. It is suggested that enhanced synthesis of systemic prostacyclin may influence hemodynamic changes in patients with liver cirrhosis. Overproduction of systemic prostacyclin in the absence of increased renal prostacyclin synthesis appears to be characteristic of patients with functional renal failure.

Association of plasma acylated ghrelin with blood pressure and left ventricular mass in patients with metabolic syndrome.

Objective The gut-derived hormone, ghrelin, improves cardiac function in healthy individuals and patients with chronic heart failure. The aim of this study was to investigate whether the major isoforms of the hormone, acylated and desacyl ghrelin, are related to inappropriate left ventricular mass in patients with the metabolic syndrome (MetS). Methods and results Plasma concentrations of ghrelin forms were measured in 180 white participants (65 normal weight, 60 obese without MetS and 55 obese with MetS; 56% men). MetS was defined according to Adult Treatment Panel III criteria. The presence of left ventricular hypertrophy (LVH) was diagnosed by sex-specific left ventricular mass/height2.7 cut-off values (>49.2 g/m2.7 for men and >46.7 g/m2.7 for women). Circulating concentrations of acylated ghrelin were increased in obesity and MetS, whereas desacyl ghrelin levels were decreased. Compared with participants in the lowest tertiles, the age-adjusted and sex-adjusted odds of having MetS were lower in the highest category of desacyl ghrelin (odds ratio 0.1, 95% confidence interval 0.1–0.4, P < 0.001). The prevalence of LVH was increased in the highest tertile of acylated ghrelin (odds ratio 3.4, 95% confidence interval 1.7–5.6, P < 0.05). Plasma acylated ghrelin was increased (P < 0.05) in patients with MetS exhibiting LVH compared with those with appropriate left ventricular mass, whereas plasma desacyl ghrelin was not changed (P = 0.490). Conclusion Acylated ghrelin was positively associated with SBP and left ventricular mass indices, even after correction for BMI. These results suggest that the increased acylated ghrelin concentrations may represent a compensatory mechanism to overcome the development of hypertension and LVH in patients with MetS.

The Proinflammatory Mediator CD40 Ligand Is Increased in the Metabolic Syndrome and Modulated by Adiponectin

OBJECTIVES We hypothesized that the CD40/CD40 ligand (CD40L) system is up-regulated in the metabolic syndrome (MS) and modulated by adiponectin (AN). The objectives were: 1) to compare plasma and monocyte CD40L in patients with MS and controls and its association with clinical and biochemical parameters, 2) to investigate platelets as a source of soluble CD40L (sCD40L), and 3) to analyze the effects of AN on CD40/CD40L. METHODS Plasma sCD40L and AN were measured in 246 controls and 128 patients with MS by ELISA. Monocyte CD40/CD40L expression and platelet CD40L content and release were compared in patients with MS and controls. Monocytes and endothelial cells were cultured with AN and CD40/CD40L expression determined by real-time RT-PCR and Western blotting. RESULTS Patients with MS had higher sCD40L and lower AN levels than controls (0.89 +/- 0.1 vs. 0.76 +/- 0.07 ng/ml and 10.10 +/- 0.65 vs. 12.99 +/- 0.80 microg /ml, P < 0.05). Monocyte CD40/CD40L expression was higher (P < 0.05) in patients than controls (CD40: 1.31 +/- 0.31 vs. 0.80 +/- 0.14 arbitrary units; CD40L: 1.24 +/- 0.85 vs. 0.43 +/- 0.14 pg/microg protein). No differences were observed on CD40L content between resting platelets from patients with MS and controls (7.7 +/- 3.5 vs. 7.2 +/- 2.2 pg/microg protein). Stimulated platelets from patients with the MS released more (P < 0.05) sCD40L than controls (582 +/- 141 vs. 334 +/- 60% change vs. nonstimulated platelets). AN reduced CD40L mRNA and protein expression in monocytes from MS patients and endothelial cells. CONCLUSIONS The enhanced sCD40L and cellular CD40L expression in the MS suggests that CD40L is of pathophysiological relevance in MS. Also, a new antiinflammatory effect of AN is described through the modulation of the CD40/CD40L system.

Independent association of von Willebrand factor with surrogate markers of atherosclerosis in middle-aged asymptomatic subjects

Summary.  Von Willebrand factor (VWF) is considered a reliable marker of endothelial damage. Plasma levels of VWF were measured in 857 middle‐aged subjects (80.4% men) free of clinically overt atherosclerotic disease, in relation to cardiovascular risk factors, carotid intima‐media thickness (IMT) and microalbuminuria, two established surrogate markers of atherosclerosis. There was linear trend for the increase of VWF, carotid IMT (p < 0.001) and microalbuminuria (p = 0.018). The association between VEF and both markers remained statistically significant after adjusting for cardiovascular risk factors and inflammatory markers (p < 0.01). In conclusion, VWF was independently associated with both structural and functional surrogates of atherosclerosis in asymptomatic subjects, thus representing a systemic biomarker of subclinical atherosclerosis.

Independent Association of Fibrinogen with Carotid Intima-Media Thickness in Asymptomatic Subjects

Background: Fibrinogen has been found to be an independent risk factor for cardiovascular disease. Both genetic and environmental factors contribute to its variability in plasma. However, whether the relation between fibrinogen and carotid intima-media thickness (IMT) is independent of those factors has not been established. Therefore, the aim of this study was to investigate the relations of plasma fibrinogens and the –455 G/A Bβ-fibrinogen polymorphism with the carotid IMT in a series of asymptomatic subjects. Methods: Markers of inflammation, C-reactive protein (CRP) and leukocytes, and endothelial perturbation (von Willebrand factor, vWF) were measured in 135 subjects. All individuals underwent a complete clinical examination and lipid measurements (cholesterol and its fractions HDL and LDL and triglycerides). The carotid IMT was measured by B-mode ultrasound in the common carotid artery. Results: Patients in the highest fibrinogen tertile had a significantly higher BMI (p < 0.01), LDL-cholesterol (p < 0.01), leukocyte count, CRP and vWF (p < 0.001). In the univariate model a strong positive relationship was found between plasma fibrinogen and carotid IMT (p < 0.01). Fibrinogen also correlated positively with age, BMI, arterial systolic pressure, cholesterol, cholesterol-LDL, smoking, CRP and vWF (p < 0.01). In the multivariate analysis, the association of fibrinogen with carotid IMT remained significant (p < 0.01) after adjustment for all the parameters analyzed. Conclusion: In a population sample of adults without clinically overt atherosclerotic disease, elevated fibrinogen was related to carotid IMT independent of a wide range of important confounding variables.

Circulating osteoprotegerin is increased in the metabolic syndrome and associates with subclinical atherosclerosis and coronary arterial calcification.

CONTEXT The relationship between osteoprotegerin (OPG) a glycoprotein related to bone metabolism and the metabolic syndrome (MS) has not been established. OBJECTIVE The aim of this study is to evaluate OPG concentration in patients with MS and its association with subclinical atherosclerosis and coronary arterial calcification (CAC). MATERIALS/METHODS The study included 238 asymptomatic patients. MS was diagnosed according to the NCEP/ATPIII guidelines. OPG was measured by ELISA. All subjects underwent ultrasonography of the common carotid arteries to measure intima-media thickness (IMT) and evaluate the presence of atheroma plaques. In a subgroup (n=39) CAC was quantified by ECG-triggered cardiac computed tomography. Adipose tissue was excised from 25 patients and OPG expression by RT-PCR and immunohistochemistry was studied. RESULTS Patients with the MS (n=60) had higher OPG than patients without (n=178) (p<0.05). OPG correlated with IMT (r=0.2, p=0.005) and patients with atheroma plaques had higher OPG (p=0.008) and also those with coronary artery calcification (p<0.05). OPG expression was confirmed in adipose tissue (n=12) and the expression was significantly higher in patients with MS than in those without (p=0.003). CONCLUSIONS This study shows that OPG may potentially be a biomarker for cardiovascular risk/damage in the MS and identifies adipose tissue as a potential source of OPG.

Relación entre las fases precoces de la enfermedad renal y el síndrome metabólico

INTRODUCTION AND OBJECTIVES Advanced kidney disease is a major health problem due to its association with high cardiovascular morbidity and mortality. Early recognition of advanced kidney disease is the mainstay to avoid its progression. Since metabolic syndrome and insulin resistance are risk factors for both cardiovascular and advanced kidney disease, we investigated the relationship of early kidney disease (EKD) with metabolic syndrome and insulin resistance, and their association with surrogate markers of arteriosclerosis. METHODS We studied 1498 subjects. Insulin resistance was defined as HOMA ≥3.7 mmol (μU)/L(2) and EKD as stages 1 and 2 of the NKF-KDOQI. Carotid intima-media thickness was used as a surrogate marker of arteriosclerosis. RESULTS The presence of one trait of metabolic syndrome was associated with an odds ratio (OR) for EKD of 2.3 (95% confidence interval [CI], 1.18-4.48) that increased to 6.72 (95% CI, 3.56-13.69) in subjects with the syndrome. All the traits of the syndrome except low level of high-density lipoproteins showed an increased OR for EKD. Increasing HOMA was also directly correlated with higher OR for EKD, being as high as 3.89 (95% CI, 1.99-7.59) for subjects in the fourth quartile. Subjects with the syndrome plus EKD showed an increased intima-media thickness compared with those without kidney disease. CONCLUSIONS Insulin resistance and all metabolic syndrome traits except low level of high-density lipoproteins were significantly associated with an increased OR for EKD. Both metabolic syndrome and EKD were independently and additively related to the presence of surrogate markers of arteriosclerosis.

Traditional and Novel Bone Remodeling Markers in Premenopausal and Postmenopausal Women

CONTEXT Bone turnover markers (BTMs) may identify changes in bone remodeling within a relatively short time interval before changes in bone mineral density can be detected. New markers such as osteoprotegerin, receptor activator of nuclear factor-κB ligand, and sclerostin have emerged, but there is little information about their potential use in clinical practice. OBJECTIVES The aim of this study was to analyze the ability of several BTMs to predict bone loss in pre- and postmenopausal women and to monitor the efficacy of treatment in osteoporotic women. DESIGN, PATIENTS, AND SETTING We performed an observational prospective study in pre- and postmenopausal ambulatory women (n = 72 and n = 152, respectively). INTERVENTION Postmenopausal women with osteoporosis (n = 18) were treated with risedronate and calcium. Women filled out a questionnaire and underwent bone mineral density measurement using dual-energy x-ray absorptiometry at the time of enrollment and after 1 year of follow-up. BTMs were measured at baseline, at 6 months, and after 1 year. RESULTS Increased levels of N-terminal propeptide of type 1 procollagen (P1NP) and β-type I collagen telopeptides (CTXs) were associated with low bone mineral density in the premenopausal (P = .02 and P = .04, respectively) and postmenopausal (P = .03 and P = .02) groups. The best analytical performance to diagnose osteoporosis was for β-CTX, osteocalcin, and P1NP, with areas under the curve of 0.70 (P = .005), 0.64 (P = .048), and 0.71 (P = .003). A significant decrease was found in P1NP, osteocalcin, tartrate-resistant acid phosphatase-5b, β-CTX, and bone alkaline phosphatase after 1 year of treatment (all P < .05). CONCLUSIONS Our data suggest that measurement of β-CTX and P1NP shows adequate analytical performance and could potentially be included in algorithms for the screening of osteoporosis. Furthermore, these two markers, along with osteocalcin and tartrate-resistant acid phosphatase-5b, are useful to monitor the response to risedronate.

Involvement of the leptin-adiponectin axis in inflammation and oxidative stress in the metabolic syndrome

The aim of the present work was to study whether the leptin-adiponectin axis may have a pathophysiological role in the increased systemic inflammation and oxidative stress observed in patients with the metabolic syndrome (MS). Leptin, adiponectin, and markers of inflammation and oxidative stress were measured in a sample of 140 Caucasian subjects (74 males/66 females), aged 28–82 years, 60 with and 80 without the MS. Total concentrations of adiponectin as well as its multimeric forms HMW, MMW and LMW were significantly lower in individuals with the MS. The ratio adiponectin/leptin, a marker of dysfunctional adipose tissue, was dramatically decreased in the MS group. Systemic oxidative stress, as evidenced by levels of thiobarbituric acid reactive substances (TBARS), as well as markers of inflammation such as serum amyloid A (SAA), C-reactive protein (CRP) and osteopontin were significantly increased in subjects with the MS. Total adiponectin concentrations were negatively correlated with levels of TBARS and CRP levels. Furthermore, the ratio adiponectin/leptin was negatively correlated with SAA concentrations as well as with CRP levels. We concluded that a dysfunctional adipose tissue as suggested by a low adiponectin/leptin ratio may contribute to the increased oxidative stress and inflammation, hallmarks of the MS.