Cardiovascular disease risk and secondary prevention of cardiovascular disease among patients with low health literacy

OBJECTIVE

To explore the association between health literacy and the risk of cardiovascular disease (CVD), and to assess the differential effects by health literacy level of a nurse-coordinated secondary prevention program (NCPP) in patients with coronary artery disease (CAD).

METHODS

Data were collected in two medical centres participating in the RESPONSE trial (Randomised Evaluation of Secondary Prevention by Outpatient Nurse SpEcialists). CVD risk profiles were assessed at baseline and 12-month follow-up using the Systematic Coronary Risk Evaluation (SCORE). Health literacy was assessed by the short Rapid Estimate of Adult Literacy in Medicine (REALM-D) and the Newest Vital Sign (NVS-D); self-reported health literacy was evaluated by the Set of Brief Screening Questions (SBSQ-D).

RESULTS

Among 201 CAD patients, 18% exhibited reading difficulties, 52% had difficulty understanding and applying written information, and 5% scored low on self-reported health literacy. Patients with low NVS-D scores had a higher CVD risk [mean SCORE 5.2 (SD 4.8) versus 3.3 (SD 4.1), p < 0.01]. Nurse-coordinated care seemed to reduce CVD risk irrespective of health literacy levels without significant differences.

CONCLUSION

Inadequate health literacy is prevalent in CAD patients in the Netherlands, and is associated with less favourable CVD risk profiles. Where many other forms of CVD prevention fail, nurse-coordinated care seems to be effective among patients with inadequate health literacy.

Applicability of internationally available health literacy measures in the Netherlands

Health literacy measures for use in clinical-epidemiological research have all been developed outside Europe. In the absence of validated Dutch measures, we evaluated the cross-cultural applicability of the Rapid Estimate of Adult Literacy in Medicine (REALM), the Newest Vital Sign (NVS), the Set of Brief Screening Questions (SBSQ), and the measure of Functional Communicative and Critical Health Literacy (FCCHL). Each measure was translated into Dutch following standardized procedures. We assessed feasibility, internal consistency, and construct validity among patients with coronary artery disease (n = 201) and patients with diabetes type 2 (n = 88). Patients expressed most problems in responding to the NVS-D. They were not familiar with the type of food label and had difficulties calculating in portions instead of grams. The FCCHL-D items seemed too theoretical for many patients. Cronbach's alpha was acceptable for all measures. Correlation patterns between the measures were moderately coherent with a priori hypotheses. All translated measures were able to distinguish between high- and low-educated groups of patients, with the NVS-D performing best. Despite reasonable psychometric properties as demonstrated so far, these measures need to be further developed in order to increase applicability for assessing health literacy in clinical-epidemiological research in the Netherlands.

[Multidisciplinary guideline 'Heart failure 2010']

In the multidisciplinary practice guideline 'Heart failure 2010', the diagnosis of heart failure relies on a combination of signs and symptoms and on supplementary investigation with natriuretic peptides and echocardiography. Once diagnosed, it is important to detect the potentially treatable cause of the heart failure. The non-medical treatment consists of lifestyle advice, of which regular body exercise is the most important component. The medical treatment of patients with systolic heart failure consists of a diuretic, ACE inhibitor, and beta-blocker, optionally extended by an aldosterone antagonist, an angiotensin receptor blocker and/or digoxin. A restricted group of patients may require an internal cardiac defibrillator (ICD) and/or cardiac resynchronisation therapy. There is limited scientific evidence concerning treatment of patients with diastolic heart failure. It is important to coordinate the care of the patient with heart failure within a multidisciplinary team to provide optimal treatment and information for the patient.

[The growth hormone/insulin-like growth factor axis. What is its role in the atherosclerotic process?]

GROWTH HORMONE AND ATHEROSCLEROSIS: Adult-onset growth hormone (GH) deficiency is associated with an increase in cardiovascular morbidity and mortality.

MECHANISMS

Other than classical risk factors, such as dyslipidemia, a direct interaction between the activity of the GH/IGF-1 axis and the endothelium also plays a part. It is possible that the modulating effect of IGF-1 on nitric oxide (NO) synthesis is also important, together with the anabolic effect on the myocardiocytes. Substitution of recombinant GH induces rapid reduction in the atherosclerotic plaques, suggesting a direct effect of the GH/IGF axis on the atherosclerotic process. In addition to the acquired GH deficiency, as in non-substituted patients following hypophysectomy, attention has recently been focused on the relative GH deficiency as is seen in obesity and in the course of ageing. PERSPECTIVES FOR CARDIOVASCULAR ENDOCRINOLOGY: Therapeutic intervention in the GH/IGF axis might influence the atherosclerotic process. Study of the GH/IGF axis activity and of its correlation with atherosclerosis opens new perspectives in the understanding of the role of this axis in cardiovascular diseases.

Induction of postprandial inflammatory response in adult onset growth hormone deficiency is related to plasma remnant-like particle-cholesterol concentration

Increased cardiovascular mortality due to premature atherosclerosis is a clinical feature in the adult-onset GH deficiency (AGHD) syndrome. Inflammation is a key feature in atherogenesis and may be triggered by postprandial lipoprotein remnants. We hypothesized that increased postprandial lipoprotein remnant levels in AGHD may be associated with an inflammatory response. In this case-control study, 10 AGHD patients [6 males and 4 females; age, 48 +/- 9 yr; body mass index (BMI), 26.9 +/- 2.6 kg/m(2)] and 10 healthy control subjects (matched for age, BMI, gender, baseline lipid levels, and apolipoprotein E genotype) were included. They all ingested an oral fat load. Fasting and postprandial levels of plasma remnant-like particle-cholesterol (RLP-C; 0.31 +/- 0.13 mmol/liter and 4.14 +/- 1.37 mmol/liter.h in GHD; 0.18 +/- 0.06 mmol/liter and 2.56 +/- 1.02 mmol/liter.h in controls, respectively) were significantly increased in AGHD patients compared with control subjects. The median inflammatory cytokines, IL-6 and TNF-alpha, were higher in the fasting [3.9 (range, 3.1-11.9) pg/ml and 6.8 (range, 2.5-27.6) pg/ml, respectively] and postprandial [151.7 (range, 87.0-294.3) pg/ml.24 h and 289.9 (range, 87.5-617.6) pg/ml.24 h, respectively] states in AGHD than in controls [fasting, 0.9 (range, 0.2-5.2) pg/ml and 2.8 (range, 2.5-5.7) pg/ml; and postprandial, 54.5 (range, 11.50-126.5) pg/ml.24 h and 118.3 (range, 81.2-243.1) pg/ml.24 h, respectively]. In addition, postprandial profile of RLP-C and IL-6 in AGHD and in the total group were significantly associated (r(2) = 0.44, P < 0.05; and r(2) = 0.38, P < 0.01, respectively). In conclusion, the increased postprandial RLP-C level in GHD is associated with an inflammatory response that may result in increased susceptibility for premature atherosclerosis.

The atherogenic plasma remnant-like particle cholesterol concentration is increased in the fasting and postprandial state in active acromegalic patients

BACKGROUND

Premature atherosclerosis is a clinical feature in untreated acromegaly. Increased postprandial lipoprotein remnant levels are associated with premature atherosclerosis. In most studies, remnants have been measured indirectly using retinyl esters (RE) as a chylomicron core label. Remnants can also be directly quantified by immunoseparation using monoclonal antibodies to apolipoprotein (apo) AI and apo B100 to remove nonremnant lipoproteins. Cholesterol is quantified in the remaining apo E-rich remnant fraction (RLP-C).

OBJECTIVE

The aim of the present study was to investigate the role of postprandial lipaemia in patients with acromegaly to further define abnormalities leading to increased susceptibility for atherosclerosis.

PATIENTS

In a case-control study, the plasma postprandial lipoprotein remnant fraction (RLP-C and RE) were analysed in six patients with active acromegaly [two females, four males; aged 53 +/- 9 years; body mass index (BMI), 29 +/- 4 kg/m2] and in six normolipidaemic control subjects (matched for age, gender, BMI and apo E genotype). They underwent an oral vitamin A fat loading test.

RESULTS

Baseline plasma triglycerides (TG) were not significantly different in patients (1.75 +/- 0.71 mM) and controls (1.15 +/- 0.46 mM). Lipoprotein lipase activity was significantly lower in patients than in controls (108 +/- 21 vs. 141 +/- 19 U/l, respectively; P < 0.05). Baseline plasma apo E levels were higher in patients (60.8 +/- 7.9 mg/l) than in controls (48.3 +/- 5.9 mg/l; P < 0.05). No differences were found in the area under the postprandial TG curve (AUC-TG), the incremental AUC-TG (DeltaAUC-TG) and AUC-RE in the Sf < 1000 remnant fraction. However, fasting plasma RLP-C concentrations, isolated by immunoseparation, were increased in patients with active acromegaly (0.41 +/- 0.13 mM) compared to control subjects (0.20 +/- 0.07 mM; P < 0.05). Incremental postprandial RLP-C response (corrected for fasting values) was also significantly elevated in patients (2.14 +/- 1.19 mM/h/l) compared to controls (0.86 +/- 0.34 mM/h/l; P < 0.05). In both groups, the maximal RLP-C concentration was reached between 2 and 4 h.

CONCLUSIONS

In conclusion, the atherogenic postprandial remnants, represented by RLP-C, were significantly elevated at baseline and in the postprandial period, whereas the larger-sized remnants, represented by retinyl esters (Sf < 1000), were not different from controls. The disturbances in the postprandial RLP-C response increased the susceptibility for premature atherosclerosis as observed in patients with acromegaly.

Isolation of remnant particles by immunoseparation: a new approach for investigation of postprandial lipoprotein metabolism in normolipidemic subjects

Abnormal postprandial lipoproteins are associated with an increased risk for cardiovascular disease. Postprandial remnant lipoproteins were usually analyzed indirectly using retinyl esters (RE) as a chylomicron core label during an oral fat loading test. Apo B-100 containing VLDL remnants in addition to apo B-48 containing chylomicron remnants can also be directly quantified using the RLP-Cholesterol Immunoseparation Assay. This recently available method uses monoclonal antibodies to apo A-I and apo B-100 to remove non-remnant lipoproteins and quantifies cholesterol in the remaining apo E-rich remnant fraction. In the present study we compared the analysis of retinyl ester with the immuno-based RLP-Cholesterol (RLP-C) analysis in measuring postprandial remnant lipoproteins in healthy normolipidemic subjects. Sixteen healthy normolipidemic subjects were selected for this study. Postprandial plasma retinyl esters peaked at 5.0+/-1.2 h, whereas plasma RLP-C showed a peak significantly earlier (P<0.001) at 3.5+/-0.6 h. In comparison, postprandial plasma TG and FFA peaked at 3.3+/-1.1 h (P<0.005 compared to retinyl esters). In conclusion, levels of RLP-C changed, during the postprandial phase, in parallel with plasma TG and FFA concentrations and peaked significantly earlier than retinyl esters. Postprandial measurements of RLP-C can be considered as a fast alternative method for the more laborious retinyl-ester analysis in clinical studies.

Growth hormone (GH) treatment decreases postprandial remnant-like particle cholesterol concentration and improves endothelial function in adult-onset GH deficiency

Premature atherosclerosis is a clinical feature in adult-onset GH deficiency. Evidence is accumulating that disturbances in triglyceride metabolism, reflected by abnormalities in circulating remnant lipoproteins, are associated with increased atherogenic potential. In a case-controlled intervention study, we investigated postprandial lipoprotein metabolism using a new remnant lipoprotein method based on immunoseparation principle [RLP-cholesterol (RLP-C)]. In addition, we analyzed retinyl ester (RE) analysis in plasma and in Sf < 1000 fraction. Endothelial function was assessed as flow-mediated dilatation (FMD). Eight patients diagnosed with acquired adult-onset GH deficiency and eight controls matched for gender, age, body mass index, and apolipoprotein (apo) E genotype were enrolled in the study. Oral vitamin A fat loading tests were performed at baseline in both groups and after 6 months of treatment with recombinant human GH (rh-GH) in the adult-onset GH-deficient patients. Adult-onset GH-deficient patients had significantly higher fasting RLP-C, postprandial RLP-C concentrations (plasma RLP-C, 0.29 +/- 0.14 mmol/L; and incremental area under the curve-RLP-C, 2.13 +/- 1.60 mmol*h/L, respectively) than controls (0.19 +/- 0.06 mmol/L and 1.05 +/- 0.72 mmol*h/L (P: < 0.05), respectively). They also had significantly higher postprandial RE in plasma and Sf < 1000 fraction. Treatment with rh-GH significantly reduced postprandial RLP-C concentrations (incremental area under the curve-RPL-C 0.73 +/- 0.34 mmol*h/L; P: < 0.05) but had no effects on the fasting RLP-C concentrations (0.317 +/- 0.09 mmol/L, P: < 0.05), or on the postprandial RE in plasma and in Sf < 1000 fraction. Endothelial function measured as FMD was improved from 5.9 +/- 3.3% to 10.2 +/- 4.0% (P: < 0.05) in patients treated with rh-GH. It is concluded that patients with adult-onset GH deficiency have increased levels of fasting and postprandial RLP-C and an impaired endothelial function as measured as FMD. Treatment with rh-GH resulted in a decrease of postprandial RLP-C concentration, thereby improving the postprandial atherogenic lipoprotein profile and improvement of endothelial function, however, the clearance of large chylomicron particles as reflected by RE remained disturbed.

Diurnal triglyceride profiles in healthy normolipidemic male subjects are associated to insulin sensitivity, body composition and diet

BACKGROUND

Elevated fasting and postprandial triglycerides (TG) are established risk factors for Coronary Heart Disease (CHD). Usually, fasting plasma TG are measured, although TG are mainly produced in a postprandial state. Our objective was to investigate diurnal TG profiles using serial capillary TG measurements, in normolipidemic healthy males.

MATERIALS AND METHODS

Forty-eight, non-obese, non-smoking males (range: 20-55 years, mean age: 32 +/- 12 years), measured diurnal capillary TG, at six fixed timepoints during the day on three different days and recorded their food intake. Insulin sensitivity was estimated by HOMA. Diurnal capillary TG profiles were calculated as integrated area under the mean capillary TG curve (TGc-AUC).

RESULTS

All subjects had normal fasting plasma TG and cholesterol. The average TGc-AUC was 23.6 +/- 6.7 mmol h L-1. Significant correlations with TGc-AUC were: fasting insulin (r = 0. 40, P < 0.005), HOMA (r = 0.32, P < 0.05), relative fat mass (r = 0. 31, P < 0.05), dietary protein-(r = 0.31, P < 0.05) and saturated fat intake (r = 0.30, P < 0.05). Age was not associated to diurnal triglyceridemia. After subdividing the group into quartiles on the base of TGc-AUC, differences were found between the highest (n = 12) and lowest quartile (n = 12) for: fasting capillary TG, fasting insulin, HOMA and systolic blood pressure. Fasting plasma TG and dietary intake were not different.

CONCLUSION

Diurnal TG profiles in healthy normolipidemic males are not age-dependent, but are associated to insulin sensitivity, fat mass and diet. Diurnal capillary TG profiles may be a valuable additional tool in estimating a risk profile for CHD since significant differences in diurnal TG are not always reflected by elevated fasting plasma TG.

High dose of simvastatin normalizes postprandial remnant-like particle response in patients with heterozygous familial hypercholesterolemia

Familial hypercholesterolemia (FH) and disturbances in postprandial lipoprotein metabolism are both associated with premature atherosclerosis. The effect of beta-hydroxy-beta-methylglutaryl coenzyme A reductase inhibitors on plasma cholesterol levels in patients with FH is well established; however, it is not known whether postprandial lipoproteins are also influenced. In this case-controlled intervention study, we investigated the effects of high-dose simvastatin on postprandial lipoproteins. We used a new method to analyze remnant lipoproteins based on the immunoseparation principle (remnant-like particle cholesterol [RLP-C] assay) and the well-established measurement of retinyl ester (RE) analysis in plasma and in the Svedberg flotation unit (Sf)<1000 fraction. Seven heterozygous FH patients and 7 control subjects matched for sex, age, body mass index, triglycerides, and apolipoprotein E genotype were enrolled in the study. An oral vitamin A (RE) fat-loading test was performed at baseline in both groups and after 3 months of high-dose simvastatin (80 mg/d) treatment in the FH patients. Before treatment, FH patients had significantly higher fasting and postprandial concentrations of lipoprotein remnants (plasma RLP-C 42+/-19 mg/dL and area under the RLP-C curve 415+/-82 mg. L(-1). h(-1), respectively) than did control subjects (7+/-3 mg/dL and 101+/-35 mg. L( -1). h(-1), respectively; P<0.05), suggesting a delayed clearance of chylomicron remnant particles in the FH patients. Treatment with simvastatin significantly reduced fasting and postprandial remnant lipoprotein cholesterol concentrations (13+/-3 mg/dL and 136+/-53 mg. L(-1). h(-1), respectively; P<0.05 for both). Postprandial RE in the Sf<1000 fraction, not total RE in plasma, was also significantly higher in FH patients than in control subjects (24+/-10 versus 6.3+/-5.9 mg. L( -1). h(-1), P<0.05), but treatment with simvastatin did not result in improvement of the postprandial RE response, either in the Sf<1000 fraction or in plasma. It is concluded that heterozygous FH patients have increased fasting and postprandial remnant lipoprotein concentrations. Treatment with simvastatin significantly reduced the fasting and postprandial RLP-C concentrations but did not result in improved postprandial RE response.

In vivo evidence of defective postprandial and postabsorptive free fatty acid metabolism in familial combined hyperlipidemia

Overproduction of very low density lipoprotein (VLDL) is the major characteristic of subjects with familial combined hyperlipidemia (FCHL). As enhanced free fatty acid (FFA) flux to the liver may be one of the determinants of VLDL overproduction, we studied FFA changes and products of hepatic FFA metabolism in response to a 24-h oral fat loading test (50 g/m(2)) in 7 FCHL subjects and 7 matched control subjects. The response to the meal was subdivided into a postprandial (up to 8 h after ingestion of the meal) and postabsorptive period (from 8 to 24 h). Although postheparin plasma lipolytic activities were not different between both groups, the postprandial FFA area under the curve (FFA-AUC) and FFA incremental area under the curve (FFA-dAUC) were higher in FCHL subjects than in control subjects (6.05 +/- 0.45 vs. 3.43 +/- 0.46 and 2.60 +/- 0.49 vs. 0.96 +/- 0.31 mmol. h/L, respectively; P < 0.01 for each). The postprandial increase in ketone bodies was almost four times higher in FCHL patients. As ketogenesis occurs predominantly in hepatocytes, these findings suggest that during the postprandial period in FCHL an increased flux of FFA to the liver occurs, possibly because of inadequate incorporation of FFA into triglycerides (TGs) in adipocytes. In the postabsorptive period, FFA and ketone bodies significantly decreased in FCHL subjects, in contrast to control subjects, in whom both increased. These results may represent a diminished release of FFA from adipocytes by hormone-sensitive lipase (HSL) in FCHL patients. The decrease in postabsorptive FFA and ketone bodies in FCHL patients could not be explained by insulin-mediated inhibition of HSL, as both FCHL subjects and control subjects had similar postabsorptive insulin concentrations, which were below fasting concentrations. This study provides in vivo evidence of impaired metabolism of postprandial FFA in FCHL, which may explain in part the hepatic VLDL overproduction characteristic of FCHL subjects.

[Diurnal triglyceride profiles in 30 young healthy men as a function of diet, fasting triglyceride levels, body composition and insulin sensitivity]

OBJECTIVE

To study predictors of diurnal capillary triglyceride (TG-c) profiles in healthy males.

DESIGN

Observational, cross-sectional.

SETTING

University Hospital Utrecht, Department of Internal Medicine, the Netherlands.

METHOD

In 30 healthy males (20-34 years) TG-c was measured during three days, six times a day. Fasting blood was collected at inclusion. Body composition and HOMA ratio as insulin sensitivity index were determined. TG-c profiles were calculated as integrated area under the mean TG-c curve (TG-AUC).

RESULTS

All subjects had normal fasting plasma and capillary TG and cholesterol concentrations. Diurnal TG-c values were higher than fasting values. The average TG-AUC was 24.6 +/- 6.7 mmol/l over 14 hrs. Variables associated with TG-AUC were: fasting TG-c, relative fat mass, total protein and saturated fat intake. After correction for fasting TG-c only diet and fat mass were correlated with TG-AUC. The relative fat mass was positively correlated with the HOMA ratio and fasting insulin concentrations, suggesting that decreased insulin sensitivity accompanied increased body fat.

CONCLUSION

Triglyceride profiles provide information about the total diurnal TG load. The best determinant of diurnal triglyceride changes was fasting triglycerides. However, diet, body composition and insulin sensitivity are also important. Future investigations should address the question whether triglyceride profiles may be used to estimate more accurately the individual risk profile for coronary heart disease.

Elective orthopedic surgery, a model for the study of cytokine activation and regulation

Induction and downregulation of cytokine production occurs after contact with various inflammatory stimuli. To elucidate the early events after a physical stressor, we studied these processes in 13 patients undergoing elective total hip replacement surgery. In these patients we followed the plasma concentrations of tumour necrosis factor alpha (TNF), interleukin 1beta (IL-1beta), IL-6 and IL-1 receptor antagonist (IL-1Ra), mRNA for these cytokines in peripheral blood cells (PBCs), and the lipopolysaccharide(LPS)-stimulated ex vivo production of these cytokines in whole blood cultures (WBCs). Plasma TNF and IL-1beta were not affected by the surgical procedure, although IL-1beta mRNA levels in PBCs increased significantly. Plasma IL-6 and IL-1Ra increased from 2 to 3 h post-incision onwards. The LPS-induced ex vivo production in WBCs of TNF, IL-1beta and IL-6 decreased from 2 h post-incision; that of IL-1Ra increased. Downregulation of TNF production was not associated with lower TNF-mRNA suggesting post-transcriptional regulatory processes. In contrast, downregulation of IL-1beta production was associated with significantly lower IL-1beta mRNA, suggesting both post-transcriptional and transcriptional mechanisms. Remarkably, the increase of plasma IL-6 occurred when the IL-6 production ex-vivo in WBCs was maximally downregulated. This suggests that other immunocompetent cells and not PBCs are the source for plasma IL-6 and that the IL-6 production in those other cells might be regulated differentially.