Noninvasive methods for assessing early markers of atherosclerosis: the role of body composition and nutrition

PURPOSE OF REVIEW

To present the methodology used to assess early atherosclerosis and its application in assessing the impact of body composition and nutrition on the cardiovascular system.

RECENT FINDINGS

Accumulating evidence supports the use of noninvasive markers of subclinical atherosclerosis, namely carotid intima-media thickness, flow-mediated dilatation of the brachial artery and augmentation index or pulse wave velocity, in the prediction of cardiovascular risk, especially in primary prevention settings. These markers reflect early initiation of the atherogenetic process, as well as the impact of the treatment currently used. Factors like smoking cessation, exercise and a balanced nutrition have a remarkable effect on these markers and consequently on vascular function. It is interesting to note that individual nutrients such as lipids, vitamins, antioxidants, ethanol, caffeine and isoflavones are capable of manipulating vascular function, which is depicted in these markers of atherosclerosis.

SUMMARY

A number of noninvasive markers of early atherosclerosis are currently used in order to detect possible initiation of atherosclerotic procedure. Vascular function is greatly affected by nutrition, which might prove to be an alternative to drug therapy for reversing dysfunction of the vessels.

Free thyroxine is an independent predictor of subcutaneous fat in euthyroid individuals

OBJECTIVE

Thyroid function parameters have been associated with obesity, but associations with the type of adiposity have not been examined. We used ultrasound (US) to assess regional adiposity and investigated associations of thyroid function with parameters of central obesity.

DESIGN

Cross-sectional study.

METHODS

A total of 303 apparently healthy individuals (age 42.9+/-8.8, body mass index (BMI) 19.0-43.3, median 26.2 kg/m(2), 181 women) were examined for indices of the metabolic syndrome. BMI, waist and hip circumference, abdominal subcutaneous fat (SF), and preperitoneal fat (PF) layer was estimated. TSH, free thyroxine (fT(4)), triiodothyronine (T(3)), thyroid autoantibodies, insulin, glucose, and lipid levels were measured. Subjects receiving T(4) (9.2%) were excluded.

RESULTS

SF and SF/PF ratio were inversely correlated with fT(4) levels (r=-0.169, P=0.023, r=-0.193, P=0.009 respectively). In multivariate analysis, fT(4) was a predictor of SF and SF/PF, independently of age, sex, and smoking. SF correlated with TSH levels (r=0.149, P=0.037). PF and SF were positively associated with T(3) levels (r=0.245, P=0.004 and r=0.189, P=0.019 respectively). T(3) levels were positively associated with BMI (r=0.257, P=0.0004), waist perimeter (r=0.324, P<0.0001), and waist-to-hip ratio (WHR; r=0.363, P<0.0001). The T(3)/fT(4) ratio was positively correlated with SF (r=0.182, P=0.028), WHR (r=0.267, P=0.0003), and BMI (r=0.146, P=0.043).

CONCLUSIONS

Increasing SF accumulation as assessed by US is associated with lower fT(4) and higher TSH levels among euthyroid slightly overweight individuals. These associations indicate that subtle variation in thyroid function may participate in regional adiposity.

Impact of Prehypertension on Common Carotid Artery Intima-Media Thickness and Left Ventricular Mass

Background and Purpose— Prehypertension has been recently introduced by JNC 7 as a new blood pressure (BP) category, associated with increased target-organ damage. Subclinical atherosclerosis by means of common artery intima-media thickness (CCA-IMT) has been incompletely investigated in prehypertensive patients. The aim of our study was to assess the extent of CCA-IMT and left ventricular mass (LVM) in prehypertensive adults in comparison to normotensive and untreated hypertensive subjects.

Methods— From a total of 5221 consecutive patients screened to our Hypertension Unit we selected 896 consecutive individuals according to prespecified inclusion criteria, who underwent 24-hour ambulatory BP monitoring, carotid artery ultrasonographic, and echocardiographic measurements. Patients who received antihypertensive treatment during the BP monitoring were excluded. According to the office BP levels, patients were divided into 3 subgroups: normotensives (office BP <120/80 mm Hg), prehypertensives (120/80 mm Hg≤office BP<140/90 mm Hg), and hypertensives (office BP ≥140/90 mm Hg). Statistical analyses were performed by means of 1-way ANOVA, χ 2 test, and ANCOVA.

Results— According to the office BP levels, the distribution of the study population was: normotensives (14.4%), prehypertensives (23.7%), and hypertensives (61.9%). Prehypertensive patients had higher CCA-IMT ( P =0.038) and LVM ( P =0.030) values than normotensive subjects, even after adjustment for baseline characteristics. Greater CCA-IMT values were observed in hypertensive patients in comparison to prehypertensives ( P =0.002).

Conclusions— Prehypertensive patients had higher CCA-IMT and LVM than their normotensive counterparts. Prehypertension status is cross-sectionally associated with subclinical atherosclerosis and target-organ damage.

Additive prognostic value of interleukin-6 at peak phase of dobutamine stress echocardiography in patients with coronary artery disease. A 6-year follow-up study

BACKGROUND

Interleukin-6 (IL-6) and tissue factor (TF) are elevated after myocardial ischemia during dobutamine stress echo (DSE). We examined the incremental prognostic value of IL-6 or TF measured during DSE over echocardiographic and clinical factors in patients with chronic coronary artery disease (CAD).

METHODS

We studied 106 patients with angiographically documented CAD. IL-6 and TF were measured at rest, peak, and during recovery. A wall motion score index was calculated.

RESULTS

Fifty-seven (54%) patients had ischemia at DSE. During follow-up (63.7 +/- 20 months), 36 patients (33%) had an adverse event (12 cardiac deaths, 24 acute coronary events). Patients with events had a higher peak IL-6 (P = .02) but similar rest and recovery IL-6 than those without. Patients with peak IL-6 > or =3.14 pg/mL (upper tertile) had a hazard ratio of 2.7 (95% CI 1.44-5.37) (P < .01 for an adverse event). The addition of peak wall motion score index in a multivariable model including risk factors, ejection fraction, revascularization, and multivessel disease increased the model's c statistic from 0.66 to 0.70 (P = .04). The addition of peak IL-6 further increased the model's c statistic to 0.75 (P = .04). Tissue factor was not related with cardiac events.

CONCLUSIONS

Interleuikin-6 levels measured during the peak phase of DSE incrementally contribute to risk stratification in patients with chronic CAD.

Inflammatory and non-invasive vascular markers: the multimarker approach for risk stratification in coronary artery disease

Current thinking supports the notion that several inflammatory proteins intervene with endothelium and haemostatic factors leading to plaque formation and rupture. Of these, C-reactive protein (CRP), monocyte/macrophage colony-stimulating factor (MCSF) and interleukin-6 (IL-6) promote atherogenesis by inducing monocyte-macrophage activation, foam cell formation, platelet activation, tissue factor expression, release of other procoagulant cytokines or downregulation of atheroprotective cytokines such as interleukin 10 and transforming growth factor b-1 (TGFb-1). CRP, MSCF and IL-6 are interrelated and have been found in increased blood concentrations in CAD. Increased levels of CRP and IL-6 predict a higher cardiovascular event rate in the general population and in addition to high MCSF or low TGFb-1 predict adverse outcome in CAD patients independently of traditional risk factors. Moreover, in CAD patients, the predictive value of MCSF is additive and beyond that of CRP suggesting the need of a "multimarker approach" in assessing cardiovascular risk. Accumulating evidence supports the utility of non-invasive markers of subclinical atherosclerosis, namely carotid intimal media thickness, flow mediated dilatation of the brachial artery, augmentation index or pulse wave velocity, in the prediction of cardiovascular risk particularly in primary prevention settings. The combination of these non-invasive tests has been shown to improve their prognostic accuracy compared to each other alone. Although several therapeutic strategies like vaccination against antigens promoting atherogenesis, cyclooxygenase inhibitors, statins, and ACE inhibitors may reduce the levels of these inflammatory markers and improve the non-invasive markers of subclinical atherosclerosis, the impact on cardiovascular risk resulting from these changes is unknown. The combination of an established inflammatory marker such as CRP or a vascular marker such as IMT with novel biochemical and vascular markers of cardiovascular disease may offer additive prognostic information for adverse outcome.

Treatment with granulocyte colony stimulating factor is associated with improvement in endothelial function

PRIMARY OBJECTIVE

Granulocyte-colony stimulating factor (G-CSF) is used for the mobilization of bone marrow and endothelial progenitor cells, though G-CSF-induced inflammation may cause endothelial dysfunction. We examined the effects of G-CSF on endothelium, C-reactive protein (CRP), tumour necrosis factor-alpha (TNF-alpha) and anti-inflammatory cytokines namely interleukin 10 (IL-10).

RESEARCH DESIGN

We studied 60 women with breast cancer, who were randomized to either subcutaneous G-CSF (5 microg/kg), o.d. for 5 days after adjuvant chemotherapy (n = 40) or placebo (n = 20).

EXPERIMENTAL INTERVENTIONS

We measured flow-mediated dilatation (FMD%) of the brachial artery by ultrasonography, CRP, TNF-alpha, IL-10 and the ratio TNF-alpha/ IL-10 blood levels before, 2-h and 5-days after the G-CSF or placebo treatment.

MAIN OUTCOMES AND RESULTS

There was a greater increase of FMD, IL-10 and reduction of TNF-alpha/ IL-10, 2 h and 5 days after the G-CSF treatment compared to placebo. Although, CRP and TNF-alpha were higher, TNF-alpha/IL-10 was lower at the end of G-CSF treatment compared to placebo. Improvement of FMD was related to changes of IL-10 and TNF-alpha/IL-10.

CONCLUSIONS

Treatment with G-CSF improves endothelial function in vivo, possibly by shifting the balance between the pro- and anti-inflammatory cytokines.

Correlations of Sialic Acid with Markers of Inflammation, Atherosclerosis and Cardiovascular Events in Hemodialysis Patients

<i>Background:</i> Serum total sialic acid (S-TSA) is associated with atherosclerotic process in general population. The aim of our study was to evaluate possible correlations of S-TSA with markers of inflammation and atherosclerosis in hemodialysis (HD) patients. <i>Methods:</i> We involved 53 asymptomatic, nondiabetic HD patients and 28 healthy controls. Atherosclerosis was evaluated by carotid ultrasonography, estimating intima media wall thickness and wall to lumen ratio bilaterally. To confirm our findings, we performed a 32-month cohort study, during which cardiovascular (CV) events were analyzed in relation to S-TSA concentration. <i>Results:</i> HD patients had higher S-TSA compared to controls (adjusted OR: 1.04, p = 0.026). In HD patients, S-TSA independently correlated with hs-CRP (p < 0.0001), lipoprotein(a) (p = 0.02), intima media wall thickness (p = 0.023) and wall to lumen ratio (p = 0.028). Increased S-TSA concentration was associated with more CV events (p = 0.03). <i>Conclusions:</i> Serum TSA seems to correlate with inflammation, accelerated atherosclerosis and CV events in nondiabetic HD patients, but more studies need to confirm our findings.

Acute smoke-induced endothelial dysfunction is more prolonged in smokers than in non-smokers

BACKGROUND

The aim of the study was to compare acute endothelial dysfunction caused by smoking one cigarette between smokers and non-smokers.

METHODS

Thirty volunteers, 15 smokers and 15 non-smokers, were asked to smoke the same type of cigarette and endothelial function was assessed by FMD (flow mediated dilatation) at fast, 30, 60 and 90 min post-smoking.

RESULTS

Overall response of FMD after smoking was significantly different between smokers and non-smokers (p=0.011). Endothelial dysfunction after smoking remained significant for 1-h in smokers (p=0.002), but only for 30 min in non-smokers (p=<0.001). FMD 1-h after smoking was significantly higher in non-smokers than in smokers (p=0.002).

CONCLUSIONS

Smokers seem to have sustained and more intensive unfavourable effects in endothelial function than non-smokers after smoking one cigarette. It is possible that long-term smoking diminishes the capacity of endothelium to counterbalance external factors that cause endothelial dysfunction.

Atherosclerotic risk factors and carotid stiffness in elderly asymptomatic HD patients

Several studies showed that carotid atherosclerosis and stiffness are independent prognostic factors of cardiovascular morbidity and mortality in the general population and in end-stage renal disease patients. However, the impact of established risk factors on carotid structural and elastic properties in non-diabetic elderly hemodialysis patients with negative history for cardiovascular disease has not been fully elucidated. In this paper, we investigated the effect of established and potential risk factors on carotid atherosclerosis and stiffness. Thirty stable, non-symptomatic, non-diabetic patients, aged 65-years and older (mean age 71.4+/-4.15, range 65-79) on hemodialysis for more than 6 months, were included. All patients underwent B-mode ultrasonography of common carotid artery estimating intima-media wall thickness and wall-to-lumen ratio bilaterally and checking for the presence of plaques. Carotid elasticity was evaluated by compliance, distensibility, and the incremental elastic modulus (Einc), whereas systemic arterial stiffening was evaluated by the augmentation index provided by tonometry of radial artery. Our results showed that presence of carotid plaques and wall thickening were frequent findings in this population (76% and 73.3%, respectively) and they were positively associated with fibrinogen (P<0.005), diastolic blood pressure (P<0.004), visceral obesity (P<0.001) and bio-intact PTH (i-PTH) (P=0.03). Overall, systemic and carotid stiffness were strongly correlated with hs-CRP (P=0.018), serum ferritin (P=0.02) with age (P=0.03), lipids (P=0.03) and i-PTH (P=0.05). In conclusion, our findings show that stiffening and atherosclerosis in non-symptomatic elderly HD patients are very common and they are related not only to hemodynamic changes (diastolic blood pressure), inflammation (hs-CRP, fibrinogen, ferritin) or metabolic dysfunction (increased i-PTH, abnormal lipid profile), but also to abnormal fat deposition (increased waist to hip ratio and waist circumference). Considering the high morbidity and mortality of elderly patients, close monitoring of these parameters could be useful to prevent cardiovascular events.

Arterial Wave Reflections Are Associated With Left Ventricular Diastolic Dysfunction in Adamantiades-Behçet's Disease

BACKGROUND

Adamantiades-Behçet's disease (ABD) is characterized by systemic vasculitis. We investigated whether aortic distensibility and arterial wave reflections are linked to left ventricular (LV) diastolic dysfunction in ABD.

METHODS AND RESULTS

Eighty-two patients and 40 controls with similar atherosclerotic risk factors were examined by applanation tonometry of the radial artery (SphygmoCor) and echocardiography. Augmentation index (AI%) and arrival time (Deltat, ms) of reflected arterial waves as well as aortic distensibility (AoD) assessed by echocardiography were estimated. Doppler diastolic abnormalities were defined as proposed by the European Study Group on Diastolic Heart Failure by measurement of E/A ratio, isovolumic relaxation time, deceleration time, and flow propagation velocity. Patients had impaired central augmentation index (CAI), Deltat, and AoD compared with controls (P > .05). After adjusting for age, atherosclerotic risk factors, left ventricular mass, and medication the odds-ratio of AoD and CAI for left ventricular diastolic dysfunction was 0.664 (95%CI 0.449-0.982), P = .04, and 1.073 (95% CI 1.014-1.140), P = .001, respectively. The addition of CAI to the multivariable model including AoD significantly increased the power of the model for prediction of left ventricular diastolic dysfunction (-2 Log likelihood change = 18.8, P for change > .01).

CONCLUSION

Augmentation index has a complementary value to aortic distensibility in the assessment of left ventricular diastolic dysfunction in ABD.

Pressure wave reflections, central blood pressure, and aortic stiffness in patients with Adamantiades-Behcet's disease: a cross-sectional case-control study underlining the role of chronic corticosteroid treatment

BACKGROUND

Adamantiades-Behcet's disease (ABD) is a multisystemic inflammatory/autoimmune disease involving both microcirculation and macrocirculation. Aortic stiffness index and aortic augmentation index (AI) are indices for the estimation of arterial stiffness and pressure wave reflections, respectively. The effect of anti-inflammatory and immunosuppressive drugs used in ABD on these indices is unknown.

METHODS

In this cross-sectional study we examined 74 subjects with ABD (aged 40.1 +/- 12.5 years, 24 men) and 24 control subjects by using the noninvasive technique of radial artery applanation tonometry and pulse wave analysis for assessment of aortic AI by application of transfer functions. Echocardiography was used for assessment of aortic stiffness index. Classic cardiovascular (CV) risk factors, left ventricular and endothelial function of the brachial artery, as well as intima-media thickness of carotid artery, were also assessed.

RESULTS

Corticosteroids were the only drug having a negative and independent effect on aortic AI, but not on aortic stiffness. Patients taking corticosteroids had lower aortic AI and central systolic blood pressure (BP), but not aortic stiffness and peripheral systolic BP, when compared to those without corticosteroids (21+/-14% v 12+/-14%, P < .050). Medication, traditional CV risk factors, and functional or structural CV parameters were all comparable among the two groups. The AI was similar between the control group and patients with ABD taking corticosteroids.

CONCLUSIONS

The AI, but not aortic stiffness, is lower in patients with ABD taking corticosteroids compared to patients not taking corticosteroids and similar to the control group. These results imply a role of inflammation or immunomodulatory mechanisms in the regulation of pressure wave reflections.

Common carotid artery intima-media thickness and the risk of stroke recurrence

BACKGROUND AND PURPOSE

Increased common carotid artery intima-media thickness (CCA-IMT) has been associated with an increased risk of myocardial infarction and stroke. We investigated the relationship between CCA-IMT and recurrent stroke in a cohort of ischemic stroke patients.

METHODS

High-resolution B-mode ultrasonographic measurements of the CCA-IMT were performed in a consecutive series of 238 patients hospitalized in our institution with first-ever ischemic stroke. Stroke risk factors and secondary prevention therapies were documented. Patients were followed-up prospectively and the outcome event of interest was recurrent stroke.

RESULTS

During a mean follow-up period of 28.9 months (range: 6 to 60 months), 27 recurrent strokes were documented. Patients who experienced recurrent cerebrovascular events had significantly (P=0.005) higher CCA-IMT values (1.01 mm, 95% CI:0.92 to 1.11 mm) than subjects who were free of stroke recurrence (0.88 mm, 95% CI:0.85 to 0.91 mm). After adjustment for baseline characteristics, risk factors and stroke subtypes and secondary prevention therapies increasing CCA-IMT was found to be an independent predictor of stroke recurrence. For each increment of 0.1 mm in CCA-IMT the probability of experiencing recurrent stroke increased by 18.0% (95% CI:2.0% to 36.0%, P=0.027).

CONCLUSIONS

Increased CCA-IMT values are associated with a higher risk of long-term stroke recurrence.

Myocardial Ischemia Induces Interleukin-6 and Tissue Factor Production in Patients With Coronary Artery Disease

BACKGROUND

Interleukin-6 (IL-6) and macrophage colony stimulating factor plasma levels are elevated in acute coronary syndromes. IL-6 has an inherent negative inotropic action and, with tissue factor (TF), mediates the ischemia-reperfusion myocardial injury. We hypothesized that inducible ischemia leads to cytokine production, TF expression, and consequently persistent left ventricular dysfunction after dobutamine stress echocardiography (DSE) in coronary artery disease patients.

METHODS AND RESULTS

DSE was performed in 103 patients with angiographically documented coronary artery disease. Blood samples were obtained at rest, at peak stress, and 30 minutes after cessation of dobutamine infusion for measurement of macrophage colony stimulating factor, IL-6, and TF. New or worsening wall motion abnormalities at peak stress and their duration into recovery were noted. Median IL-6 and TF levels were increased at peak stress and at 30 minutes into recovery compared with rest (2.7 and 2.4 versus 2.1 pg/mL for IL-6, 310 and 385 versus 266 pg/mL for TF [P<0.01] in patients with an ischemic response; n=55). Compared with rest, a greater release of IL-6 at peak stress and recovery was observed in patients with increasing number of ischemic segments at peak DSE (2 versus 3 to 4 versus 5 to 6 versus 7 to 8 segments; P=0.03). The time to recovery of wall motion abnormalities was also associated with IL-6 levels at peak stress and recovery (r=0.51 and r=0.39, P<0.05). Macrophage colony stimulating factor levels remained unchanged throughout DSE.

CONCLUSIONS

Reversible ischemia induced during DSE increases IL-6 and TF plasma levels. IL-6 is related to the extent of left ventricular dysfunction at peak stress and to persistent LV dysfunction during recovery.

Acute effects of caffeine on blood pressure and wave reflections in healthy subjects: should we consider monitoring central blood pressure?

BACKGROUND

Data concerning blood pressure changes, acutely induced by caffeine consumption, are conflicting. Furthermore, limited data exist regarding central hemodynamic response to caffeine ingestion by healthy young subjects. We investigated the acute effect of coffee (80 mg of caffeine) and decaffeinated coffee on peripheral and central hemodynamics, as well as on wave reflections.

SUBJECTS

For this purpose, 16 healthy volunteers (eight females and eight males, mean age 29+/-3.2 years) were investigated.

METHODS

Repeated measurements were performed at baseline and 30, 60, 90 and 120 min after oral administration of each beverage in a double-blind crossover design. Aortic blood pressures, augmentation index (AI) and pressure (AP) and timing of reflected waves were evaluated by using applanation tonometry and pulse wave analysis.

RESULTS

Regular coffee increased central systolic (SBP) and diastolic pressure (DBP) from 96.2+/-9.9 to 101.1+/-10.1 mmHg, p=0.011 and from 72.6+/-9.4 to 76.5+/-9.0 mmHg, p=0.027, respectively, but no change was observed following consumption of decaffeinated coffee. Peripheral systolic blood pressure did not change significantly after the administration of either coffee. Augmentation index increased significantly following regular coffee consumption. The change in AI was significantly higher following regular compared to decaffeinated coffee consumption as shown by analysis of variance (ANOVA) for repeated measures (p=0.001).

CONCLUSIONS

These caffeine effects reveal an unfavourable effect on wave reflections and therefore on left ventricular (LV) pulsatile afterload. It also revealed a significant acute effect of caffeine consumption on central hemodynamics which is not observed at peripheral pressures.

Aortic elastic properties and left ventricular diastolic function in patients with Adamantiades-Behcet's disease

OBJECTIVES

We investigated whether Adamantiades-Behcet's disease (ABD) is related to impaired aortic (Ao) elastic properties and left ventricular (LV) function.

BACKGROUND

Adamantiades-Behcet's disease is an inflammatory disorder characterized by vasculitis leading to vascular complications and, rarely, myocarditis.

METHODS

We studied 82 patients with ABD (age: 40 +/- 12 years) and 24 normal control subjects by echocardiography. Abdominal Ao diameter (mm/m(2)) and Ao elastic indexes--namely, Ao strain (%), distensibility (cm(2) x dyn(-1)x 10(-6)), stiffness index, and pressure strain modulus (Ep) (cm(2) x dyn(-1) x 10(-6))--were calculated from the echocardiographically derived thoracic Ao diameters (mm/m(2)), and the measurement of pulse pressure obtained by cuff sphygmomanometry. Isovolumic relaxation time (IVRT) (ms), deceleration time (DT) (ms), and flow propagation velocity (FPV) (cm/s) were measured by Doppler echocardiography to assess diastolic LV function. The duration of disease and presence of vascular complications were noted.

RESULTS

Patients versus control subjects had increased Ao diameters (p < 0.01), lower mean Ao strain and distensibility (4 vs. 9 and 1.4 vs. 3.4, respectively, p < 0.01), higher mean aortic stiffness index and Ep (15.6 vs. 6 and 1.17 vs. 0.44, respectively, p < 0.01), and impaired IVRT and FPV (p < 0.01). Aortic function indexes were related to the duration of disease (p < 0.01) and increased DT (p < 0.01). Deceleration time >190 ms predicted vascular complications with 80% sensitivity and 71% specificity (odds ratio 6.52 [confidence interval: 2.23 to 19.03]).

CONCLUSION

Aortic elastic properties and diastolic LV function are impaired in patients with ABD and are interrelated. The link between diastolic LV dysfunction and vascular complications suggests the presence of a common pathophysiologic pathway and provides a possible marker of risk for vascular disease.

A video lesson series is effective in changing the dietary intakes and food-related behaviors of low-income homemakers

OBJECTIVE

To examine the relative cost-effectiveness of a self-administered video series in delivering nutrition education to low-income homemakers.

DESIGN

A quasi-experimental design was used, with subjects randomly assigned to traditional lessons (Traditional Group) or video lessons (Video Group).

SUBJECTS/SETTING

108 subjects were recruited, with 93 nonpregnant, low-income, female homemakers completing the study (response rate = 86%). Subjects had recently enrolled in the Expanded Food and Nutrition Education Program, or the Food Stamp Nutrition Education Program, and had a videocassette recorder and telephone.

INTERVENTION

Both groups received 12 lessons from the Eating Right Is Basic Series, 3rd edition, with the Traditional Group being taught in face-to-face sessions and the Video Group receiving self-administered, video-lesson packets.

OUTCOME MEASURES

Dietary intake and food behaviors were assessed at pre and post intervention with 24-hour recalls and a 14-item checklist.

STATISTICAL ANALYSES

Chi(2) and t tests were used to compare the groups on demographics and pre-intervention dietary factors. Multiple analysis of variance was used for comparisons of change from pre to post intervention.

RESULTS

Significant improvements were observed in both groups for fruits, calcium, and vitamins A and C. The Video Group improved on fiber intake (P<or=.005). The groups did not differ on dietary or behavior change (P=.2357). Duplication and implementation costs of the video series totaled 4,820 dollars, or 36% of the traditional lesson cost of 13,463 dollars.

APPLICATIONS

Both methods achieved similar improvements in diet and behaviors, but the video method was less expensive. The video series seems to be a cost-effective method for delivering nutrition education to low-income homemakers.

Oral L-arginine improves endothelial dysfunction in patients with essential hypertension

BACKGROUND

L-Arginine is a nitric oxide precursor, which augments endothelium-dependent vasodilatation in hypercholesterolemic humans and animals. Endothelium-dependent vasodilation is attenuated in patients with hypertension; however the effects of oral L-arginine on endothelial function of the conduit arteries in patients with essential hypertension have not previously been investigated.

METHODS

In a prospective randomized double blind trial, 35 patients with essential hypertension received either 6 g L-arginine (18 subjects) or placebo (17 subjects). Patients were examined for flow-mediated endothelium-dependent dilatation of the brachial artery before and 1.5 h after administration of L-arginine or placebo. At the end of the protocol the nitrate-induced, endothelium-independent vasodilatation was evaluated.

RESULTS

Two groups of L-arginine and placebo were similar regarding age, sex, blood lipids, smoking, diabetes, coronary artery disease, body mass index, intima-media thickness of the common carotid artery, clinics blood pressure and baseline brachial artery parameters. Administration of L-arginine or placebo did not change significantly heart rate, blood pressure, baseline diameter, blood flow or reactive hyperemia. L-Arginine resulted in a significant improvement of flow-mediated dilatation (1.7+/-3.4 vs. 5.9+/-5.4%, P=0.008) while placebo did not significantly change this parameter (3.0+/-2.7 vs. 3.1+/-2.2%, P=ns). The effect of L-arginine on flow-mediated dilatation was significantly different from the effect of placebo (P=0.05). L-Arginine did not significantly influence nitrate-induced dilatation (16+/-6.9 vs. 17.7+/-6.7%, P=ns).

CONCLUSIONS

Oral administration of L-arginine acutely improves endothelium-dependent, flow-mediated dilatation of the brachial artery in patients with essential hypertension. The long-term effects of L-arginine in these patients require further investigation.