Frequency of Subclinical Atherosclerosis in Brazilian HIV-Infected Patients

<div><p>Abstract Background: AIDS as well as atherosclerosis are important public health problems. The longer survival among HIV-infected is associated with increased number of cardiovascular events in this population, and this association is not fully understood. Objectives: To identify the frequency of subclinical atherosclerosis in HIV-infected patients compared to control subjects; to analyze associations between atherosclerosis and clinical and laboratory variables, cardiovascular risk factors, and the Framingham coronary heart disease risk score (FCRS). Methods: Prospective cross-sectional case-control study assessing the presence of subclinical atherosclerosis in 264 HIV-infected patients and 279 controls. Clinical evaluation included ultrasound examination of the carotid arteries, arterial stiffness by pulse wave velocity (PWV) and augmentation index (AIx), laboratory analysis of peripheral blood, and cardiovascular risk according to FCRS criteria. The significance level adopted in the statistical analysis was p < 0.05. Results: Plaques were found in 37% of the HIV group and 4% of controls (p < 0.001). Furthermore, carotid intima-media thickness was higher in the HIV group than in controls (p < 0.001). Patients with carotid plaque had higher fasting glucose, total cholesterol, low-density lipoprotein cholesterol, and triglycerides than those without plaques. The presence of HIV, adjusted for age, overweight/obesity, and smoking increased by almost fivefold the risk of atherosclerotic carotid plaque (OR: 4.9; 95%CI: 2.5-9.9; p < 0.001). Exposure to protease inhibitors did not influence carotid intima-media thickness, was not associated with carotid plaque frequency, and did not alter the mechanical characteristics of the arterial system (PWV and AIx). Conclusions: HIV-infected patients are at increased risk of atherosclerosis in association with classical cardiovascular risk factors. Treatment with protease inhibitors does not promote functional changes in the arteries, and shows no association with increased frequency of atherosclerotic plaques in carotid arteries. The FCRS may be inappropriate for this population.</p></div

Protein levels of angiotensin and MAPK isoforms in myocardial tissue; values presented as mean ± standard deviation.

<p>Protein levels were normalized to GAPDH levels. (A) Angiotensin levels; (B) ERK levels; (C) JNK levels; C (n = 6): control group; CL (n = 6): control group treated with losartan; OB (n = 6): obese group; OBL (n = 6): obese group treated with losartan; <b>*</b> p<0.05 vs. C group; #p<0.05 vs. OB group; ANOVA and Tukey's test.</p

Nutritional and endocrine evaluation.

<p>Values expressed as mean ± SD; NEFA: non-esterified fatty acid; AUC: area under curve from glucose tolerance test response; HOMA-IR: homeostatic model assessment index; * p<0.05, ** p<0.01 vs. Control (C) group; #p<0.05, ##p<0.01 vs. OB; † p<0.05, †† p<0.01 vs. CL; ANOVA and Tukey test.</p

Morphometric analysis of the myocardial tissue; values presented as mean ± standard deviation.

<p>(A) Cardiomyocite cross-sectional area (µm²); (B) cardiomyocyte nuclear volume (µm³); (C) collagen interstitial fraction (%). C: control group; CL: control group treated with losartan; OB: obese group; OBL: obese group treated with losartan; <b>*</b> p<0.05 vs. C group; #p<0.05 vs. OB group; † p<0.05 vs. CL group; ANOVA and Tukey's test.</p

Blood pressure and echocardiography study.

<p>Values expressed as mean ± standard deviation; SBP: systolic blood pressure; LA: left atrium diameter; LVEDd: left ventricular end-diastolic diameter; LVESd: left ventricular end-systolic diameter; PWT: posterior wall diastolic thickness of the left ventricle; IVST: interventricular septum diastolic thickness; LV relative thickness: relation between LV posterior wall systolic thickness and LVEDd; EFS: endocardium fraction shortening; PWSV: posterior wall shortening velocity; E/A: ratio between E and A waves evaluated in transmitral flow; DTE: E wave deceleration time; IVRT: LV isovolumetric relaxation time; IVRT/R-R0.5: ratio between IVRT and R-R heart rate interval; * p<0.05, ** p<0.01 vs. Control (C) group; #p<0.05, ##p<0.01 vs. OB; † p<0.05, †† p<0.01 vs. CL; ANOVA and Tukey test.</p

Protein levels of p85α subunit of PI 3-kinase (PI3K) in total and phosphorylated tyrosine forms in myocardial tissue; values presented as mean ± standard deviation.

<p>Total protein levels were normalized to GAPDH levels. (A) protein bands for PI3K, phosphor-Tyr-PI3K, and GAPDH; (B) PI3K expression values; (C) phospho-Tyr-PI3K expression values; C (n = 6): control group; CL (n = 6): control group treated with losartan; OB (n = 6): obese group; OBL (n = 6): obese group treated with losartan; * p<0.05 vs. C group; #p<0.05 vs. OB group; † p<0.05 vs. CL group; ANOVA and Tukey's test.</p

Serum glycemic levels following intraperitoneal glucose loads in (A) glucose tolerance test (GTT) and (B) insulin tolerance test; Data are expressed as means±SE; C: control group; CL: control group treated with losartan; OB: obese group; OBL: obese group treated with losartan; * p<0.05, OB vs. C group; #p<0.05, OB vs. OBL group; Repeated measures ANOVA and Bonferroni's test.

<p>Serum glycemic levels following intraperitoneal glucose loads in (A) glucose tolerance test (GTT) and (B) insulin tolerance test; Data are expressed as means±SE; C: control group; CL: control group treated with losartan; OB: obese group; OBL: obese group treated with losartan; * p<0.05, OB vs. C group; #p<0.05, OB vs. OBL group; Repeated measures ANOVA and Bonferroni's test.</p

Protein levels of β-subunit of insulin receptor (βIR) in total and tyrosine phosphorylated forms in myocardial tissue; values presented as mean ± standard deviation.

<p>Total protein levels were normalized to GAPDH levels. (A) proteins bands for βIR, phosphor-Tyr-βIR and GAPDH; (B) βIR expression values; (C) phospho-Tyr-βIR expression values; C (n = 6): control group; CL (n = 6): control group treated with losartan; OB (n = 6): obese group; OBL (n = 6): obese group treated with losartan; * p<0.05 vs. C group; #p<0.05 vs. OB group; ANOVA and Tukey's test.</p

Pathological hypertrophy and cardiac dysfunction are linked to aberrant endogenous unsaturated fatty acid metabolism

<div><p>Pathological cardiac hypertrophy leads to derangements in lipid metabolism that may contribute to the development of cardiac dysfunction. Since previous studies, using high saturated fat diets, have yielded inconclusive results, we investigated whether provision of a high-unsaturated fatty acid (HUFA) diet was sufficient to restore impaired lipid metabolism and normalize diastolic dysfunction in the pathologically hypertrophied heart. Male, Wistar rats were subjected to supra-valvar aortic stenosis (SVAS) or sham surgery. After 6 weeks, diastolic dysfunction and pathological hypertrophy was confirmed and both sham and SVAS rats were treated with either normolipidic or HUFA diet. At 18 weeks post-surgery, the HUFA diet failed to normalize decreased E/A ratios or attenuate measures of cardiac hypertrophy in SVAS animals. Enzymatic activity assays and gene expression analysis showed that both normolipidic and HUFA-fed hypertrophied hearts had similar increases in glycolytic <u>enzyme</u> activity and down-regulation of fatty acid oxidation <u>genes</u>. Mass spectrometry analysis revealed depletion of unsaturated fatty acids, primarily linoleate and oleate, within the endogenous lipid pools of normolipidic SVAS hearts. The HUFA diet did not restore linoleate or oleate in the cardiac lipid pools, but did <u>maintain</u> body weight and adipose mass in SVAS animals. Overall, these results suggest that, in addition to decreased fatty acid oxidation, aberrant unsaturated fatty acid metabolism may be a maladaptive signature of the pathologically hypertrophied heart. The HUFA diet is insufficient to reverse metabolic remodeling, diastolic dysfunction, or pathologically hypertrophy, <u>possibly</u> do to preferentially partitioning of unsaturated fatty acids to adipose tissue.</p></div

Echocardiographic data 6 weeks post SVAS surgery.

<p>Echocardiographic data 6 weeks post SVAS surgery.</p