Risk factors and determinants of carotid intima-media thickness in children: protocol for a systematic review and meta-analysis

The Association between Cardiovascular Risk Factors and Carotid Intima-Media Thickness in 42,726 Adults in UK Biobank: A Cross-Sectional Study

BACKGROUND

Traditional modifiable cardiovascular risk factors, such as high blood pressure, have long been positively correlated with high carotid intima-media thickness (cIMT). However, traditional cardiovascular risk factors made a minor contribution to cIMT variance, meaning that other markers may be regarded as independent markers for increasing cIMT.

AIMS

To investigate the simple demographic patterns of carotid intima-media thickness (cIMT) in the UK Biobank and to identify which upstream cardiovascular disease (CVD) risk factors are independently associated with cIMT.

METHODS AND RESULTS

A cross-sectional-based study of healthy middle-aged people recruited in the UK between 2006 and 2010 (n = 42,726).

RESULTS

This study showed that the cardiovascular risk profile generally worsened across the cIMT quantiles from lowest to highest. The lowest cIMT quartile was defined as having a mean cIMT < 588 µm, while the highest cIMT quartile was defined as having a mean cIMT > 748 µm. Specifically, the highest cIMT quantile group had a worse CVD risk factors profile compared to the lowest cIMT quantile group. It was found that, for every one SD increase in age and systolic blood pressure, the mean cIMT increased by 0.357 SD and 0.115 SD, respectively.

CONCLUSION

Systolic blood pressure and age were the strongest independent risk factors for a high cIMT value compared to other risk factors.

Increased circulating levels of MIP-1α and CD14 are associated with the presence of severe stenosis and hypoechoic plaques in patients with carotid atherosclerosis

OBJECTIVE

Carotid atherosclerosis, a major cause of ischemic cerebrovascular events, is characterized by a pro-inflammatory and pro-oxidant vascular microenvironment. The current risk score models based on traditional risk factors for cardiovascular risk assessment have some limitations. The identification of novel blood biomarkers could be useful to improve patient management. The aim of the study was to evaluate the association of selected inflammation- and oxidative stress-related markers with the presence of severe stenosis and/or vulnerable plaques.

METHODS

Circulating levels of soluble CD40 ligand, interleukin-10, macrophage inflammatory protein (MIP)-1α, endoglin, CD163, CD14, E-selectin, tumor necrosis factor-α, monocyte chemoattractant protein-1, C-Reactive protein, CD40 L + T lymphocytes, total antioxidant capacity, glutathione reductase activity, and protein carbonyl content were determined in patients with carotid atherosclerosis.

RESULTS

Multiparametric analysis showed significantly higher levels of MIP-1α in patients with stenosis ≥70% than in patients with stenosis <70%, and significantly higher levels of CD14 in patients with hypoechoic (vulnerable) lesions compared to those with hyperechoic (stable) ones. The area under the curve obtained by the receiver operating characteristic curve analysis was 0.7253 for MIP-1α and 0.6908 for CD14.

CONCLUSIONS

Our data suggest that circulating MIP-1α and CD14 levels are associated with the presence of advanced stenosis and of vulnerable carotid plaques.

The association between vitamin B12, folate, homocysteine levels, and carotid intima-media thickness in children with obesity: a cross-sectional study

OBJECTIVES

We aimed to evaluate the association between vitamin B12, folate, homocysteine levels, and carotid intima-media thickness (CIMT) among children with obesity in whom vitamin deficiencies are more frequent.

METHODS

Herein, 100 children with obesity (58 girls) were included (age, 5-18 years). Height, weight, body mass index (BMI), waist circumference (WC), puberty stage, blood pressure, and biochemical values were collected from medical records; standard deviations (SDS) and percentiles were calculated. Obesity was defined as BMI SDS of >+2SDS. Vitamin B12 and folate levels of <300 pg/mL and <4.8 ng/mL, respectively, were considered deficient. A radiologist quantified measurements from the carotid artery.

RESULTS

Mean patient age was 12.52 ± 3.63 years. The mean weight SDS, BMI SDS, and WC/height were +3.37 ± 0.93, +2.93 ± 0.55, and 0.65 ± 0.05, respectively. In pubertal cases, insulin (p<0.001), the homeostatic model assessment for insulin resistance (HOMA-IR) (p=0.001) and homocysteine (p=0.002) levels were higher; vitamin B12 (p<0.001) and folate (p<0.001) levels were lower than those in prepubertal ones. WC and HOMA-IR correlated with CIMT; however, homocysteine levels were not correlated with CIMT.

CONCLUSIONS

In our study, pubertal cases had lower vitamin B12 and folate levels as well as higher homocysteine levels. Although no correlation was identified between homocysteine levels and CIMT, this condition may be related to our study group comprising children, who had a shorter duration of obesity than those in adults. As CIMT was higher in children/adolescents with increased WC, it is proposed that they need central obesity more frequently and carefully follow-up.

Interventions to Decrease Carotid-Intima Media Thickness in Children and Adolescents With Type 1 Diabetes: A Systematic Review and Meta-Analysis

Introduction

Hyperglycemia is associated with a higher cardiovascular risk, as evidenced by increased carotid-intima media thickness (CIMT) in youth with diabetes. We conducted a systematic review and meta-analysis to assess the effect of pharmacological or non-pharmacological interventions on CIMT in children and adolescents with prediabetes or diabetes.

Methods

We conducted systematic searches of MEDLINE, EMBASE, and CENTRAL, together with supplementary searches in trial registers and other sources for studies completed up to September 2019. Interventional studies assessing ultrasound CIMT in children and adolescents with prediabetes or diabetes were considered for inclusion. Where appropriate, data were pooled across studies using random-effect meta-analysis. Quality was assessed using The Cochrane Collaboration’s risk-of-bias tool and a CIMT reliability tool.

Results

Six studies involving 644 children with type 1 diabetes mellitus were included. No study involved children with prediabetes or type 2 diabetes. Three randomized controlled trials (RCTs) evaluated the effects of metformin, quinapril, and atorvastatin. Three non-randomized studies, with a before-and-after design, evaluated the effects of physical exercise and continuous subcutaneous insulin infusion (CSII). The mean CIMT at baseline ranged from 0.40 to 0.51 mm. The pooled difference in CIMT was -0.01 mm (95% CI: -0.04 to 0.01) for metformin compared to placebo (2 studies; 135 participants; I2: 0%). The difference in CIMT was -0.01 mm (95% CI: -0.03 to 0.01) for quinapril compared to placebo (1 study; 406 participants). The mean change from baseline in CIMT was -0.03 mm (95% CI: -0.14 to 0.08) after physical exercise (1 study; 7 participants). Inconsistent results were reported for CSII or for atorvastatin. CIMT measurement was rated at a higher quality on all reliability domains in 3 (50%) studies. The confidence in results is limited by the low number of RCTs and their small sample sizes, as well as the high risk of bias in before-and-after studies.

Conclusions

Some pharmacological interventions may decrease CIMT in children with type 1 diabetes. However, there is great uncertainty with respect to their effects and no strong conclusions can be drawn. Further evidence from larger RCTs is required.

Systematic Review Registration

PROSPERO, CRD42017075169

Risk factors during first 1,000 days of life for carotid intima-media thickness in infants, children, and adolescents: A systematic review with meta-analyses

BACKGROUND

The first 1,000 days of life, i.e., from conception to age 2 years, could be a critical period for cardiovascular health. Increased carotid intima-media thickness (CIMT) is a surrogate marker of atherosclerosis. We performed a systematic review with meta-analyses to assess (1) the relationship between exposures or interventions in the first 1,000 days of life and CIMT in infants, children, and adolescents; and (2) the CIMT measurement methods.

METHODS AND FINDINGS

Systematic searches of Medical Literature Analysis and Retrieval System Online (MEDLINE), Excerpta Medica database (EMBASE), and Cochrane Central Register of Controlled Trials (CENTRAL) were performed from inception to March 2019. Observational and interventional studies evaluating factors at the individual, familial, or environmental levels, for instance, size at birth, gestational age, breastfeeding, mode of conception, gestational diabetes, or smoking, were included. Quality was evaluated based on study methodological validity (adjusted Newcastle-Ottawa Scale if observational; Cochrane collaboration risk of bias tool if interventional) and CIMT measurement reliability. Estimates from bivariate or partial associations that were least adjusted for sex were used for pooling data across studies, when appropriate, using random-effects meta-analyses. The research protocol was published and registered on the International Prospective Register of Systematic Reviews (PROSPERO; CRD42017075169). Of 6,221 reports screened, 50 full-text articles from 36 studies (34 observational, 2 interventional) totaling 7,977 participants (0 to 18 years at CIMT assessment) were retained. Children born small for gestational age had increased CIMT (16 studies, 2,570 participants, pooled standardized mean difference (SMD): 0.40 (95% confidence interval (CI): 0.15 to 0.64, p: 0.001), I2: 83%). When restricted to studies of higher quality of CIMT measurement, this relationship was stronger (3 studies, 461 participants, pooled SMD: 0.64 (95% CI: 0.09 to 1.19, p: 0.024), I2: 86%). Only 1 study evaluating small size for gestational age was rated as high quality for all methodological domains. Children conceived through assisted reproductive technologies (ART) (3 studies, 323 participants, pooled SMD: 0.78 (95% CI: -0.20 to 1.75, p: 0.120), I2: 94%) or exposed to maternal smoking during pregnancy (3 studies, 909 participants, pooled SMD: 0.12 (95% CI: -0.06 to 0.30, p: 0.205), I2: 0%) had increased CIMT, but the imprecision around the estimates was high. None of the studies evaluating these 2 factors was rated as high quality for all methodological domains. Two studies evaluating the effect of nutritional interventions starting at birth did not show an effect on CIMT. Only 12 (33%) studies were at higher quality across all domains of CIMT reliability. The degree of confidence in results is limited by the low number of high-quality studies, the relatively small sample sizes, and the high between-study heterogeneity.

CONCLUSIONS

In our meta-analyses, we found several risk factors in the first 1,000 days of life that may be associated with increased CIMT during childhood. Small size for gestational age had the most consistent relationship with increased CIMT. The associations with conception through ART or with smoking during pregnancy were not statistically significant, with a high imprecision around the estimates. Due to the large uncertainty in effect sizes and the limited quality of CIMT measurements, further high-quality studies are needed to justify intervention for primordial prevention of cardiovascular disease (CVD).