Impact of Lipids and Vascular Damage on Early Atherosclerosis in Adolescents with Parental Premature Coronary Artery Disease

AIM

To assess the relationship of cardiovascular risk factors (CRFs) with carotid intima media thickness (IMT) in adolescents with a parental history of premature coronary artery disease (PCAD).

METHODS

This cross-sectional study included 50 healthy adolescents, aged 14-18 years, both sexes, with a parental history of PCAD, that were compared to 50 controls without this history. Questionnaires regarding information of CRFs were applied. Blood chemistry analyses, included lipid profile, lipoprotein (a), low density lipoprotein (LDL) susceptibility to oxidation, and inflammatory cytokine levels. The IMT was evaluated by ultrasound.

RESULTS

The mean age of all participants was 15.9 years. Anthropometric measurements, blood pressure, and lipid profile were similar in both groups. However, the parental history of PCAD group exhibited lower high density lipoprotein cholesterol concentrations, shorter LDL particle oxidation time, and higher lipoprotein (a) levels compared to the control group. IMT was significantly higher in adolescents with a parental history of PCAD compared to controls, (0.53 ± 0.04 mm vs 0.47 ± 0.02 mm, p = 0.001). Among adolescents with a parental history of PCAD, those with ≥ 3 CRFs had significantly higher IMT values (0.56 mm) than those with < 3 CRFs (0.52 mm) and controls (0.48 mm). Multivariable analyses identified that systolic blood pressure and parental history of PCAD explained 26.8% and 16.1% of the variation in IMT. Furthermore, body mass index, LDL-C, ApoB-100, triglycerides and lipoprotein (a) interact with blood pressure levels to explain the IMT values.

CONCLUSION

Adolescents with a parental history of PCAD had higher IMT values than the control group, primary explained by systolic blood pressure and the parental inheritance. Adolescents with parental history of PCAD and ≥ 3 CRFs exhibited the highest IMT values. Notably, lipids and systolic blood pressure jointly contribute to explain IMT in these adolescents.

Metabolic syndrome, lipoprotein(a) and subclinical atherosclerosis in Mexican population

Objective

To assess the relationship of metabolic syndrome (MetS) and Lp(a) with subclinical atherosclerosis (CAC) in Mexican adults.

Method

Clinical, biochemical and tomographic data of visceral, subcutaneous, hepatic abdominal fat and CAC were evaluated in 953 women and men. Lp(a) was determined by nephelometry and MetS was diagnosed according to ATP III criteria. Multivariate logistic regression analysis was performed to determine the independent association of these variables with CAC.

Results

Age, weight, body mass index, systolic and diastolic blood pressure, volumes of visceral, subcutaneous and hepatic abdominal fat, lipids, glucose, insulin and HOMA-RI were significantly higher in subjects with MetS. The median Lp(a) was lower in subjects with MetS compared to subjects without MetS (3.7 [IR: 2.3-9.2 vs. 5.9 [IR: 2.5-13.1) mg/dL; p < 0.01). The number of components and the MetS were inversely associated with the elevated Lp(a) (> 30 mg / dL). The presence of MetS was associated with a CAC risk >0 (OR: 2.19, [95% CI (1.64-2.94)]; p < 0.001), independently of elevated Lp(a). The components of MetS that were independently associated with the presence of CAC > 0 UA were glycaemia > 100 mg/dL (OR 2.42, [95% CI (1.7-3.4)]; p < 0.0001) and high blood pressure (OR 2.14 [95% CI (1.5-3.1)]; p < 0.0001).

Conclusions

In Mexican population there is an inverse association between Lp(a) levels and MetS. The MetS and its components were associated with subclinical atherosclerosis. The high prevalence of obesity, diabetes, high blood pressure high triglycerides and low HDL-C, characteristics of Mexican population could explain the differences with other populations.

CORONARY ARTERY CALCIUM IS ASSOCIATED WITH LPA GENE VARIANT RS7765803-C IN MEXICAN MESTIZO POPULATION. THE GEA PROJECT

BACKGROUND

Lipoprotein(a) [Lp(a)] levels are genetically determined; high levels are a risk factor for coronary disease, although their association with coronary artery calcium (CAC) is controversial. Objective: The objective of the study was to assess the association of LPA gene polymorphisms with CAC in a Mexican Mestizo population.

METHODS

We included 1594 subjects 35-70 years old. Six polymorphisms of the LPA gene were analyzed. CAC score was determined by tomography and Lp(a) serum levels by immunonephelometry. The association of LPA polymorphism with CAC and Lp(a) was evaluated by logistic regression.

RESULTS

The prevalence of Lp(a) ≥30 mg/dL was 10%, and of CAC >0 was 26.9%. Three polymorphisms were associated with high Lp(a) levels: rs10455872-G (p = 0.013), rs6907156-T (p = 0.021), and rs7765803-C (p = 0.001). Homozygotes (CC) for the rs7765803 variant compared with the G allele (CG + GG) carriers had higher Lp(a) levels (8.9 [3.3-23.9] vs. 4.9 [2.3-11.2] mg/dL; p = 0.015) and higher prevalence of CAC >0 (36.5% vs. 26.3%, p = 0.045) and were associated with CAC > 0 (odds ratio = 1.7, 95% confidence interval: 1.06-2.7; p < 0.026). The other polymorphisms were not associated with CAC.

CONCLUSIONS

This is the first study to demonstrate in a Mexican Mestizo population that carriers of the rs7765803-C allele of LPA gene have 2.6 times greater risk for high Lp(a) values and 1.7 times higher risk for coronary artery disease.

[Prevalence and extent of coronary artery calcification in an asymptomatic cardiovascular Mexican population: Genetics of Atherosclerotic Disease study]

OBJECTIVE

The prevalence of coronary artery calcification (CAC), a specific marker of atherosclerosis, is unknown in Mexico. Our aim was to investigate the prevalence and quantity of CAC and their association with cardiovascular risk factors in a Mexican population.

METHODS

CAC was measured by multidetector computed tomography in asymptomatic subjects who participated in the Genetics of Atherosclerotic Disease study. Cardiovascular risk factors and medication were recorded.

RESULTS

The sample included 1,423 individuals (49.5% men), aged 53.7±8.4 years. Those with CAC showed a higher prevalence of dyslipidaemia, diabetes, hypertension, and other risk factors. The prevalence of CAC>0 Agatston units was significantly higher among men (40%) than among women (13%). Mean values of CAC score increased consistently with increasing age and were higher in men than women in each age group. Age and high low density lipoprotein cholesterol were independently associated with prevalence of CAC>0 in men and women, while increasing systolic blood pressure in women and age in both genders showed an independent association with CAC extension.

CONCLUSIONS

In the Mexican population the prevalence and extent of CAC were much higher in men than in women, and strongly increased with age. Independent predictors of CAC prevalence were age and low density lipoprotein cholesterol (LDL-C).

Fatty liver and abdominal fat relationships with high C-reactive protein in adults without coronary heart disease

BACKGROUND AND RATIONALE

Fatty liver (FL) and abdominal visceral fat (AVF) are strongly associated with systemic inflammation, however, it has not been defined if each one is independently involved, and if the insulin resistance is associated. To investigate if FL, AVF and insulin resistance are independently or additively associated with the high-sensitivity C-reactive protein (hs-CRP) in subjects without coronary artery disease we included 491 men and 553 women.

MATERIAL AND METHODS

All had anthropometric and plasma biochemical measurements, FL and AVF assessments by computed tomography.

RESULTS

The FL prevalence was 35.6% in men and 28.0% in women, p < 0.01. The prevalence of obesity, metabolic syndrome and homeostasis model assessment of insulin resistance (HOMA-IR) was significantly higher in FL compared to non FL subjects. FL and AVF accounted for 21 and 17%, respectively, to hs-CRP plasma levels. FL, AVF ≥ P75 and HOMA-IR ≥ P75 were independently and additively associated with plasma hs-CRP. The risk of hs-CRP ≥ 3 mg/L increased progressively in men from 1.36 (0.5-3.86) through 3.58 (1.32-9.7) in those with 1 or 3 factors respectively. In women from 2.25 (1.2-4.2) to 4.67 (2.3-9.4), respectively. In conclusion, both the FL and hs-CRP ≥ 3 mg/L occur in 1 of every 3 non CAD subjects. In men, FL and AVF ≥ P75 were associated with 3.6 times the risk of hs-CRP ≥ 3 mg/L, while in women, these factors were independently and additively associated with a 4.7 times higher risk of systemic inflammation.

Fatty liver largely explains associations of subclinical hypothyroidism with insulin resistance, metabolic syndrome, and subclinical coronary atherosclerosis

BACKGROUND

The association of subclinical hypothyroidism (SCH) with insulin resistance, metabolic syndrome (MS), and coronary atherosclerosis is uncertain.

OBJECTIVE

To investigate the role of increased intrahepatic fat in the association of SCH with insulin resistance, MS, and coronary atherosclerosis.

DESIGN, PATIENTS, AND METHODS

We conducted a cross-sectional study in a sample of 753 subjects (46% males) aged 35-70 years with no history of diabetes, renal, hepatic, thyroid, or coronary heart disease, and were participants of the Genetics of Atherosclerotic Disease study. SCH was defined as a high serum TSH level with normal free thyroxine concentration. Fatty liver (FL), coronary artery calcification (CAC), and abdominal visceral adipose tissue were assessed by computed tomography. Cross-sectional associations of SCH with and without FL, with MS, insulin resistance, and subclinical atherosclerosis defined as a CAC score >0, were examined in logistic regression models.

RESULTS

SCH was observed in 17.7% of the population studied. The prevalence of FL was similar in both euthyroid and SCH subjects (31.8 vs 27.8%, P=0.371). SCH plus FL subjects were heavier and had more metabolic abnormalities compared with SCH plus normal liver subjects. In multivariate-adjusted logistic regression analyses, SCH plus FL was associated with MS (odds ratio (OR): 2.73, 95% CI: 1.26-5.92), insulin resistance (OR: 4.91, 95% CI: 1.63-14.75), and CAC score >0 (OR: 3.05, 95% CI: 1.20-7.76). SCH without FL showed no associations.

CONCLUSION

SCH with FL is associated with increased odds of MS, insulin resistance, and CAC, independent of potential confounders.

Pioglitazone improves the cardiovascular profile in patients with uncomplicated systemic lupus erythematosus: a double-blind randomized clinical trial

OBJECTIVE

We studied the effect of pioglitazone on insulin levels, inflammation markers, high-density lipoprotein (HDL) composition and subclasses distribution, in young women with uncomplicated systemic lupus erythematosus (SLE).

METHODS

This double-blind trial included 30 premenopausal women (30 ±8 years old) with SLE, who were randomized to pioglitazone (30 mg/day) or placebo treatment for 3 months. Plasma and HDL lipids were determined by colorimetric enzymatic assays, insulin by radioimmunometric assay, inflammation by immunonephelometry and HDL size and subclasses distribution by a native 4-30% polyacrylamide gradient gel electrophoresis.

RESULTS

Compared with placebo, pioglitazone significantly increased HDL-cholesterol plasma levels (14.2%), reduced fasting insulin plasma levels (23.6%) and the homeostasis model assessment-insulin resistance (31.7%). C-reactive protein (70.9%) and serum amyloid A (34.9%) were also significantly reduced with the pioglitazone use, whereas the HDL particle size was increased (8.80 nm vs. 8.95 nm; p = 0.044) by changes in the distribution of HDL(2b), HDL(3b), and HDL(3c) subclasses. The change in HDL size correlated with a rise in free and cholesterol-ester content in the HDL particles.

CONCLUSION

Pioglitazone significantly enhanced insulin sensitivity, reduced inflammation, and modified HDL characteristics, suggesting a potential beneficial effect of this drug in patients with SLE with a risk to develop cardiovascular disease.

TRIAL REGISTRATION

This trial is registered at ClinicalTrials.gov Protocol Registration System, with the number NCT01322308.

[Obesity or overweight and metabolic syndrome in Mexico City teenagers]

aim: To know the metabolic syndrome and its components prevalence in Mexico City adolescents sample.

DESIGN

A cross-sectional survey was conducted in 772 men and 1078 women, 12 to 16 years old, from 8 randomly selected public junior high schools in Mexico City.

METHODS

Anthropometric variables, lipids, lipoproteins, Apo AI and B, glucose and insulin were determined.

RESULTS

Prevalence of metabolic syndrome was 12.5%, 11.15% in men and 13.5% en women (p ns). The most frequently metabolic syndrome component found in México City adolescents was low HDL-C levels (38%), followed by hypertriglyceridemia (25.5%), hypertension (19.2%), central obesity (11.8%) and elevated fasting glucose (1.7). Except by the hypertriglyceridemia, higher in woman than in men, 28.2% vs. 21.6%, p < 0.001, the prevalence of metabolic syndrome components was similar between males and females.

CONCLUSIONS

The high prevalence of biochemical and physiological factors of metabolic syndrome, associated with overweight and obesity in Mexico City adolescents, increases the risk of premature development of coronary atherosclerosis and diabetes mellitus in this population.

Blood pressure and associated cardiovascular risk factors in adolescents of Mexico City

OBJECTIVE

To determine the prevalence of high blood pressure and associated cardiovascular risk factors in Mexican adolescents.

METHODS

A cross-sectional study was conducted in 770 male and 1076 female students (12 to 16 years old) from eight randomly selected high schools in Mexico City. Anthropometry, blood pressure and fasting lipids and lipoproteins were measured.

RESULTS

Blood pressure levels were adjusted for age, gender, and height. The prevalence rates of hypertension (systolic blood pressure (SBP) and/or diastolic (DBP) > or =95th percentile), and pre-hypertension (SBP or DBP > or =90th but <95th percentile) were 10.6 and 10%, respectively. Compared to normotensive subjects, those with high blood pressure showed a significantly higher prevalence of obesity, overweight, and dyslipidemia. A stepwise multiple regression analysis showed that waist (18.3%), Tanner stage (4.7%), age (2.1%), gender (0.6%), and body mass index (BMI, 0.3%) accounted for 26% of the variance in SBP; whereas BMI (8.7%), age (4.8%), Tanner stage (1.7%), waist (0.4%), and gender (0.4%) accounted for 15.9% of the variance in DBP.

CONCLUSIONS

These results reveal a high prevalence of high blood pressure in adolescents living in Mexico City. Prehypertensive and hypertensive subjects showed a higher prevalence of cardiovascular risk factors, suggesting that, as adults, these adolescents will be at a higher risk of developing cardiovascular disease.

Apolipoprotein E polymorphism is related to plasma lipids and apolipoproteins in Mexican adolescents

Previous studies in the Mexican population have failed to show an effect of apolipoprotein E (APOE) polymorphism on the lipid profile. The purpose of the present study was to determine the frequencies of APOE phenotypes, and their influence on lipid and apolipoprotein levels in a random sample of Mexican adolescents living in Mexico City. APOE polymorphism, fasting insulin levels, lipid levels, and apolipoprotein levels were determined in 420 adolescents. We found a high frequency of APOE*3 subjects (89.5%) and a low frequency of APOE*2 (3.0%) and APOE*4 (7.5%) subjects. The APOE*4 subjects (including APOE 4,3 and APOE 4,4) showed the highest concentrations of total cholesterol, low-density lipoprotein cholesterol, and apoB and the lowest high-density lipoprotein cholesterol levels, whereas carriers of the APOE*2 allele (APOE 3,2 and APOE 2,2) had the lowest values for total and low-density lipoprotein cholesterol and the highest concentrations of high-density lipoprotein cholesterol. No significant differences in triglyceride and insulin levels among subjects with different APOE polymorphisms were observed. Unlike previous studies in the Mexican population, our results show that lipid and lipoprotein levels are under the influence of APOE polymorphism. As in whites, APOE*4 may be a cardiovascular risk factor in the Mexican population.