Margaretha Persson

Novel and conventional biomarkers for prediction of incident cardiovascular events in the community.

CONTEXT Prior studies have demonstrated conflicting results regarding how much information novel biomarkers add to cardiovascular risk assessment. OBJECTIVE To evaluate the utility of contemporary biomarkers for predicting cardiovascular risk when added to conventional risk factors. DESIGN, SETTING, AND PARTICIPANTS Cohort study of 5067 participants (mean age, 58 years; 60% women) without cardiovascular disease from Malmö, Sweden, who attended a baseline examination between 1991 and 1994. Participants underwent measurement of C-reactive protein (CRP), cystatin C, lipoprotein-associated phospholipase 2, midregional proadrenomedullin (MR-proADM), midregional proatrial natriuretic peptide, and N-terminal pro-B-type natriuretic peptide (N-BNP) and underwent follow-up until 2006 using the Swedish national hospital discharge and cause-of-death registers and the Stroke in Malmö register for first cardiovascular events (myocardial infarction, stroke, coronary death). MAIN OUTCOME MEASURES Incident cardiovascular and coronary events. RESULTS During median follow-up of 12.8 years, there were 418 cardiovascular and 230 coronary events. Models with conventional risk factors had C statistics of 0.758 (95% confidence interval [CI], 0.734 to 0.781) and 0.760 (0.730 to 0.789) for cardiovascular and coronary events, respectively. Biomarkers retained in backward-elimination models were CRP and N-BNP for cardiovascular events and MR-proADM and N-BNP for coronary events, which increased the C statistic by 0.007 (P = .04) and 0.009 (P = .08), respectively. The proportion of participants reclassified was modest (8% for cardiovascular risk, 5% for coronary risk). Net reclassification improvement was nonsignificant for cardiovascular events (0.0%; 95% CI, -4.3% to 4.3%) and coronary events (4.7%; 95% CI, -0.76% to 10.1%). Greater improvements were observed in analyses restricted to intermediate-risk individuals (cardiovascular events: 7.4%; 95% CI, 0.7% to 14.1%; P = .03; coronary events: 14.6%; 95% CI, 5.0% to 24.2%; P = .003). However, correct reclassification was almost entirely confined to down-classification of individuals without events rather than up-classification of those with events. CONCLUSIONS Selected biomarkers may be used to predict future cardiovascular events, but the gains over conventional risk factors are minimal. Risk classification improved in intermediate-risk individuals, mainly through the identification of those unlikely to develop events.

Vildagliptin Enhances Islet Responsiveness to Both Hyper- and Hypoglycemia in Patients with Type 2 Diabetes

CONTEXT Dipeptidyl peptidase-4 inhibitors act by increasing plasma levels of glucagon-like peptide-1 and suppressing excessive glucagon secretion in patients with type 2 diabetes. However, their effects on the glucagon response to hypoglycemia are not established. OBJECTIVE The aim of the study was to assess effects of the dipeptidyl peptidase-4 inhibitor vildagliptin on alpha-cell response to hyper- and hypoglycemia. DESIGN We conducted a single-center, randomized, double-blind, placebo-controlled, two-period crossover study of 28-d treatment, with a 4-wk between-period washout. PATIENTS We studied drug-naive patients with type 2 diabetes and baseline glycosylated hemoglobin of 7.5% or less. INTERVENTION Participants received vildagliptin (100 mg/d) or placebo as outpatients. PRIMARY OUTCOME MEASURE(S): We measured the following: 1) change in plasma glucagon levels during hypoglycemic (2.5 mm glucose) clamp; and 2) incremental (Delta) glucagon area under the concentration-time curve from time 0 to 60 min (AUC(0-60 min)) during standard meal test. Before the study, it was hypothesized that vildagliptin would suppress glucagon secretion during meal tests and enhance the glucagon response to hypoglycemia. RESULTS The mean change in glucagon during hypoglycemic clamp was 46.7 +/- 6.9 ng/liter with vildagliptin treatment and 33.9 +/- 6.7 ng/liter with placebo; the between-treatment difference was 12.8 +/- 7.0 ng/liter (P = 0.039), representing a 38% increase with vildagliptin. In contrast, the mean glucagon DeltaAUC(0-60 min) during meal test with vildagliptin was 512 +/- 163 ng/liter x min vs. 861 +/- 130 ng/liter x min with placebo; the between-treatment difference was -349 +/- 158 ng/liter x min (P = 0.019), representing a 41% decrease with vildagliptin. CONCLUSIONS Vildagliptin enhances alpha-cell responsiveness to both the suppressive effects of hyperglycemia and the stimulatory effects of hypoglycemia. These effects likely contribute to the efficacy of vildagliptin to improve glycemic control as well as to its low hypoglycemic potential.

Elevated Lp-PLA2 Levels Add Prognostic Information to the Metabolic Syndrome on Incidence of Cardiovascular Events Among Middle-Aged Nondiabetic Subjects

Background—To explore potential interrelationships between lipoprotein-associated phosholipase A2 (Lp-PLA2), the metabolic syndrome (MetS), and incident cardiovascular disease (CVD). Methods and Results—MetS was defined by the National Cholesterol Education Program Adult treatment Panel III criteria in 4480 nondiabetic Malmö Diet and Cancer Study subjects without history of CVD. Incidence of first CVD event (stroke [130 cases] or myocardial infarction [131]) was monitored over 10 years of follow-up. Lp-PLA2 activity and mass were significantly higher in subjects with MetS. Lp-PLA2 activity compared with Lp-PLA2 mass was more strongly correlated to individual components and increased more linearly with number of MetS components. Elevated Lp-PLA2 activity (top compared with bottom tertile), but not elevated Lp-PLA2 mass, increased risk for incident CVD (relative risk, RR: 1.54, 95% CI 1.07 to 2.24), as did MetS (1.42, 1.06 to 1.90) after taking possible confounders into account. Relative to those without either elevated Lp-PLA2 activity or MetS, combination of MetS and elevated Lp-PLA2 activity increased risk for CVD (1.97, 1.34 to 2.90). Elevated Lp-PLA2 activity without MetS increased risk for CVD (1.40, 1.03 to 1.92) but not MetS without elevated Lp-PLA2 activity (1.46, 0.94 to 2.27). Conclusion—Lp-PLA2 is associated to the MetS. Higher plasma levels of Lp-PLA2 increased risk for incident CVD regardless of MetS. The simultaneous presence of elevated Lp-PLA2 activity and MetS may identify an especially high risk individual.

Scoring models of a diet quality index and the predictive capability of mortality in a population-based cohort of Swedish men and women.

OBJECTIVE To examine how different scoring models for a diet quality index influence associations with mortality outcomes. DESIGN A study within the Malmö Diet and Cancer cohort. Food and nutrient intakes were estimated using a diet history method. The index included six components: SFA, PUFA, fish and shellfish, fibre, fruit and vegetables, and sucrose. Component scores were assigned using predefined (based on dietary recommendations) and population-based cut-offs (based on median or quintile intakes). Multivariate Cox regression was used to model associations between index scores (low, medium, high) and all-cause and cause-specific mortality by sex. SETTING Malmö, the third largest city in Sweden. SUBJECTS Men (n 6940) and women (n 10,186) aged 44-73 years. During a mean follow-up of 14.2 years, 2450 deaths occurred, 1221 from cancer and 709 from CVD. RESULTS The predictive capability of the index for mortality outcomes varied with type of scoring model and by sex. Stronger associations were seen among men using predefined cut-offs. In contrast, the quintile-based scoring model showed greater predictability for mortality outcomes among women. The scoring model using median-based cut-offs showed low predictability for mortality among both men and women. CONCLUSIONS The scoring model used for dietary indices may have a significant impact on observed associations with disease outcomes. The rationale for selection of scoring model should be included in studies investigating the association between dietary indices and disease. Adherence to the current dietary recommendations was in the present study associated with decreased risk of all-cause and cause-specific mortality, particularly among men.

Copeptin, a marker of vasopressin, in abdominal obesity, diabetes and microalbuminuria: the prospective Malmö Diet and Cancer Study cardiovascular cohort

Background:High plasma copeptin (copeptin), the C-terminal fragment of arginine vasopressin pro-hormone, has been associated with the metabolic syndrome (MetS), diabetes mellitus (DM) development and nephropathy. Here we tested whether elevated copeptin level is associated with later development of the MetS, its individual components and microalbuminuria.Methods:We analysed copeptin at baseline (1991–1994) in the population-based Malmö Diet and Cancer Study cardiovasular cohort and re-examined 2064 subjects 15.8 years later (mean age 72.8 years, 59% women) with oral glucose tolerance test and measurement of MetS and its individual components.Results:After age and sex adjustment, increasing quartiles of copeptin at baseline (the lowest quartile as reference) were associated with MetS (P for trend=0.008), incident abdominal obesity (P for trend=0.002), DM (P for trend=0.001) and microalbuminuria (P for trend=0.002). After additional adjustment for all the MetS components at baseline, increasing copeptin quartiles predicted incident abdominal obesity (odds ratios 1.55, 1.30 and 1.59; P for trend=0.04), DM (odds ratios 1.18, 1.32 and 1.46; P for trend=0.04) and microalbuminuria (odds ratios 1.05, 1.08 and 1.65; P for trend=0.02) but not MetS (P for trend=0.19) at the reexamination. Further, the relationship between copeptin and microalbuminuria was independent of baseline C-reactive protein, incident DM and incident hypertension.Conclusion:Copeptin independently predicts DM and abdominal obesity but not the cluster of MetS. Apart from predicting DM and abdominal obesity, elevated copeptin signals increased risk of microalbuminuria. Interestingly, the association between copeptin and later microalbuminuria was independent of both prevalent and incident DM and hypertension. Our findings suggest a relationship between a dysregulated vasopressin system and cardiometabolic risk, which could have implications for risk assessment and novel preventive treatments.

Low Plasma Level of Atrial Natriuretic Peptide Predicts Development of Diabetes: The Prospective Malmo Diet and Cancer Study.

CONTEXT The cardiac natriuretic peptides are involved in blood pressure regulation, and large cross-sectional studies have shown lower plasma levels of N-terminal pro-natriuretic peptide levels [N-terminal atrial natriuretic peptide (N-ANP) and N-terminal brain natriuretic peptide (N-BNP)] in patients with insulin resistance, obesity, and diabetes. OBJECTIVE In this study, we prospectively tested whether plasma levels of mid-regional ANP (MR-ANP) and N-BNP predict new-onset diabetes and long-term glucose progression. DESIGN, SETTING, AND PATIENTS MR-ANP and N-BNP were measured in 1828 nondiabetic individuals of the Malmö Diet and Cancer cohort (mean age 60 yr; 61% women) who subsequently underwent a follow-up exam including an oral glucose tolerance test after a median follow-up time of 16 yr. Logistic regression was used to adjust for covariates. RESULTS During follow-up, 301 subjects developed new-onset diabetes. After full multivariate adjustment, MR-ANP was significantly inversely associated with incident diabetes (OR = 0.85; 95% CI = 0.73-0.99; P = 0.034) but not N-BNP (OR = 0.92; 95% CI = 0.80-1.06; P = 0.262). In fully adjusted linear regression models, the progression of fasting glucose during follow-up was significantly inversely related to baseline levels of MR-ANP (P = 0.004) but not N-BNP (P = 0.129). Quartile analyses revealed that the overall association was mainly accounted for by excess risk of incident diabetes in subjects belonging to the lowest quartile of MR-ANP. After full adjustment, the odds ratio for incident diabetes in the bottom compared with the top quartile of MR-ANP was 1.65 (OR = 1.08-2.51, P = 0.019) and 1.43 (OR = 1.04-1.96, P = 0.027) compared with all other subjects. CONCLUSION Low plasma levels of MR-ANP predict development of future diabetes and glucose progression over time, suggesting a causal role of ANP deficiency in diabetes development.

Plasma Adiponectin Levels in Relation to Carotid Intima Media Thickness and Markers of Insulin Resistance

Background—Circulating adiponectin is a marker for insulin sensitivity, derived from fat cells. It is largely unknown if adiponectin is also an independent marker for early atherosclerosis. Methods and Results—Plasma adiponectin levels were measured in 373 men and 514 women of middle-age by a time-resolved immunofluorometric assay. The subjects were sampled stratified for degree of insulin sensitivity (HOMA-IR). An ultrasound measurement of the right common carotid artery intima media thickness (IMT) was made. When the distribution of adiponectin was stratified into sex-specific quartiles (Q1 to Q4), men in Q4 differed from Q1 in higher mean age and high-density lipoprotein (HDL) cholesterol, but lower blood pressure, HbA1c, HOMA-index, and body mass index. Women showed similar associations. Mean IMT for men was significantly lower (P=0.03) in adiponectin Q4 as compared with Q1 when adjusted for age, waist, smoking, HDL cholesterol, and diastolic blood pressure. When adding HbA1c and HOMA to the model, the association was no longer significant (P=0.15). In women no difference in IMT was noticed across adiponectin quartiles. Conclusion—Plasma adiponectin is a marker of glucose metabolism and obesity and shows an inverse age-adjusted association with carotid ultrasound IMT in men, but not in women. This association is attenuated after adjustments for other risk factors.

Low Levels of Circulating CD4+FoxP3+ T Cells Are Associated With an Increased Risk for Development of Myocardial Infarction But Not for Stroke.

Objective—Regulatory T cells (Tregs) protect against atherosclerosis in experimental models, but their association with cardiovascular disease in humans remains to be elucidated. The aim of the present study was to determine whether circulating Tregs predict the development of acute cardiovascular events in humans. Methods and Results—The study cohort consisted of a random sample of participants (n=700), aged 68 to 73 years, from the Malmö Diet and Cancer Study. Mononuclear leukocytes, stored at −140○C at the baseline investigation in 1991–1994, were thawed and Tregs, defined by the expression of FoxP3 in CD4+ T cells, were analyzed by flow cytometry. There was no detectable loss of cells during storage, and the viability of thawed leukocytes was 95%. A low fraction of both CD4+FoxP3+ and CD4+CD25+FoxP3+ T cells was associated with a higher release of proinflammatory cytokines from activated mononuclear leukocytes, and this association was strongest for CD4+FoxP3+ cells. Eighty-four coronary events and 66 strokes were registered during follow-up until December 31, 2008. In a Cox proportional hazard regression model adjusting for major risk factors, low levels of baseline CD4+FoxP3+ T cells were associated with an increased risk for the development of acute coronary events but not stroke. There were no associations between CD4+CD25+FoxP3+ T cells and development of an acute coronary event or stroke. Conclusion—This study provides prospective evidence for the role of Tregs in the development of myocardial infarction. The findings are in accordance with previous experimental studies and provide clinical support for a protective role of Tregs in atherosclerosis. The lack of association between Tregs and stroke may reflect the more heterogeneous cause of this disease.

Vildagliptin Reduces Glucagon during Hyperglycemia and Sustains Glucagon Counterregulation during Hypoglycemia in Type 1 Diabetes

CONTEXT The dipeptidyl peptidase-4 inhibitor, vildagliptin, inhibits glucagon secretion at hyperglycemia but appears to enhance glucagon counterregulation during hypoglycemia in type 2 diabetes. OBJECTIVE The objective of the investigation was to study whether vildagliptin also improves α-cell function in type 1 diabetes (T1D). PATIENTS AND METHODS The study was a single-center, double-blind, randomized, placebo-controlled crossover study involving 28 patients with C-peptide negative and antibody positive T1D [21 males, seven females, glycosylated hemoglobin 57.9 mmol/mol (7.5%)]. Patients received vildagliptin (50 mg twice a day) or placebo as an add-on to their insulin therapy for 4 wk each. On d 28 of the respective treatment period, patients were served a standard meal (500 kcal) to raise the circulating incretin hormone levels followed by a hyperinsulinemic hypoglycemic clamp at 2.5 mmol/liter. MAIN OUTCOME MEASURE The increase in plasma glucagon levels during the 30-min hypoglycemic clamp (min 165-195 of the test) was measured. RESULTS During the meal, glucagon levels were lower with vildagliptin than with placebo (120 min area under the curve(glucagon) 2.4±0.2 vs. 2.6±0.2 nmol/liter×minutes, P=0.022 for between group difference). In contrast, during hypoglycemia, the glucagon counterregulation was not reduced by vildagliptin (increase in glucagon 1.5±1.0 pmol/liter with vildagliptin vs. 1.7±0.8 pmol/liter with placebo, P=NS). In addition, the counterregulatory responses in epinephrine, norepinephrine, cortisol, and pancreatic polypeptide were not different between the treatments. During the 4-wk treatment period, vildagliptin reduced the mean glycosylated hemoglobin, whereas there was no change with placebo [between group difference was -3.4±1.0 mmol/mol (-0.32±0.09%; P=0.002)] from baseline of 57.9 mmol/mol (7.5%). CONCLUSIONS Vildagliptin, although inhibiting glucagon secretion during hyperglycemia, does not compromise the glucagon counterregulatory response during hypoglycemia in T1D.

Soluble urokinase plasminogen activator receptor in plasma is associated with incidence of CVD. Results from the Malmö Diet and Cancer Study

BACKGROUND Soluble urokinase plasminogen activator receptor (suPAR) is a highly sensitive marker that reflects increased inflammation and is positively correlated with pro-inflammatory biomarkers. The aim of this study was to explore the relationship between suPAR, cardiovascular disease (CVD) risk factors and incidence of CVD. METHODS suPAR was assessed in a random sample of participants (N=569), aged 63-68 years (mean age 65.5), from the Malmö Diet and Cancer Study (MDCS) cardiovascular cohort. Baseline examination was conducted between 1991 and 1994. suPAR in blood was analysed using a commercially available assay (suPARnostic). Cox regression analysis was used to investigate the incidence of CVD (coronary events or ischemic stroke), in relation to sex-specific tertiles of suPAR. RESULTS Significantly higher plasma levels of suPAR was found in women, smokers, diabetics and older subjects. suPAR was significantly positively correlated with markers of systemic inflammation (i.e., high sensitive C-reactive protein (hsCRP) and white blood cells (WBC), but not to lipoprotein-associated phospholipase A2 (Lp-PLA(2)), a specific vascular inflammatory biomarker.87 subjects had a CVD event during follow-up (mean 14.1 years). In an age/sex-adjusted model, the hazard ratio (HR) for incident CVD was 2.53 (95%CI: 1.44-4.46) for the top compared to the bottom tertile of suPAR. This association remained significant after further adjustment for smoking, low density lipoprotein (LDL), systolic blood pressure, use of anti-hypertensive medication, diabetes, hsCRP, WBC and Lp-PLA(2) (HR: 2.25; 1.07-4.72). CONCLUSION Elevated levels of suPAR are, independently of established cardiovascular risk factors, associated with an increased incidence of CVD in elderly subjects.