Body composition and common carotid artery remodeling in a healthy population

Association between Low-Density Lipoprotein Cholesterol and Vascular Biomarkers in Primary Prevention

Several noninvasive vascular biomarkers have been proposed to improve risk stratification for atherothrombotic events. To identify biomarkers suitable for detecting intermediate-risk individuals who might benefit from lipid-lowering treatment in primary prevention, the present study tested the association of plasma LDL-cholesterol with coronary artery calcification (CAC) Agatston score, high carotid and femoral intima-media thickness (IMT), low carotid distensibility and high carotid-femoral pulse-wave velocity in 260 asymptomatic individuals at intermediate cardiovascular risk and without diabetes and lipid-lowering treatment. High or low vascular biomarkers were considered when their value was above the 95th or below the 5th percentile, respectively, of the distribution in the healthy or in the study population. LDL-cholesterol was independently associated with the CAC score = 0 (OR 0.67; 95%CI 0.48-0.92, p = 0.01), CAC score > 100 (1.59; 1.08-2.39, p = 0.01) and high common femoral artery (CFA) IMT (1.89; 1.19-3.06, p < 0.01), but not with other biomarkers. Our data confirm that in individuals at intermediate risk, lipid-lowering treatment can be avoided in the presence of a CAC score = 0, while it should be used with a CAC score > 100. CFA IMT could represent a useful biomarker for decisions regarding lipid-lowering treatment. However, sex- and age-specific reference values should be established in a large healthy population.

Associations between the Combined Fat Mass Index and Fat-Free Mass Index with Carotid Intima-Media Thickness in a Japanese Population: The Tohoku Medical Megabank Community-Based Cohort Study

AIM

Although many epidemiological studies have shown that obesity assessed by body mass index is associated with carotid intima-media thickness (cIMT), few studies have evaluated fat-free mass, which is a component of body composition. We investigated the associations between the combined fat mass index (FMI) and fat-free mass index (FFMI) with cIMT.

METHODS

We conducted a cross-sectional study of 3,873 men and 9,112 women aged 20 years or older who lived in Miyagi prefecture, Japan. The FMI and FFMI were calculated as fat mass and fat-free mass divided by height squared, respectively. The indices were classified into sex-specific quartiles and were combined into 16 groups. The maximum common carotid artery was measured using high-resolution B-mode ultrasound. An analysis of covariance was used to assess associations between the combined FMI and FFMI with cIMT adjusted for age and smoking status. The linear trend test was conducted by stratifying the FMI and FFMI, scoring the categories from 1 (lowest) to 4 (highest), and entering the number as a continuous term in the regression model.

RESULTS

In multivariable models, a higher FMI was not related to higher cIMT in men and women in most FFMI subgroups. Conversely, a higher FFMI was related to higher cIMT in all FMI subgroups (p＜0.001 for linear trend).

CONCLUSIONS

FMI was not associated with cIMT in most FFMI subgroups. Conversely, FFMI was positively associated with cIMT independently of FMI.

Gamma-glutamyltransferase, arterial remodeling and prehypertension in a healthy population at low cardiometabolic risk

Plasma gamma-glutamyltransferase (GGT) was suggested to reflect the level of systemic oxidative stress. Oxidative stress induces changes in arterial structure and function and contributes to the development of hypertension. Therefore, GGT may be associated with arterial remodeling and blood pressure (BP) increment, even in absence of disease. To test this hypothesis, we evaluated, in 825 healthy subjects at low cardiometabolic risk, the associations of plasma GGT with carotid artery intima-media thickness (IMT), luminal diameter and prehypertension; in 154 subjects was evaluated also the association with aortic stiffness (cfPWV). Associations were controlled for insulin sensitivity, C-reactive protein, and life-style habits. In the main population, BP was remeasured after 3 years. Carotid diameter and cfPWV, but not IMT, were directly and independently related to plasma GGT. Subjects with prehypertension (N = 330) had higher GGT as compared with subjects with normal BP (22 [14] vs 17 [11] IU/L; adjusted P = 0.001), and within prehypertensive subjects, those who developed hypertension during 3 years had higher GGT than those without incident hypertension (27 [16] vs 21 [14] IU/L; adjusted P < 0.05). Within subjects with arterial stiffness measurement, those with prehypertension (N = 79) had higher both GGT and arterial stiffness (25 [14] vs 16 [20] IU/L and 9.11 ± 1.24 vs 7.90 ± 0.94 m/s; adjusted P < 0.01 and <0.05). In the view of previous evidence linking plasma GGT concentration to the level of systemic oxidative stress, our findings suggest a role of oxidative stress in subclinical arterial damage and in prehypertension, even in healthy subjects free of cardiometabolic risk. Arterial organ damage may represent the link between GGT and hypertension.

Determinants of Intima-Media Thickness in the Young: The ALSPAC Study

OBJECTIVES

This study characterized the determinants of carotid intima-media thickness (cIMT) in a large (n > 4,000) longitudinal cohort of healthy young people age 9 to 21 years.

BACKGROUND

Greater cIMT is commonly used in the young as a marker of subclinical atherosclerosis, but its evolution at this age is still poorly understood.

METHODS

Associations between cardiovascular risk factors and cIMT were investigated in both longitudinal (ages 9 to 17 years) and cross-sectional (ages 17 and 21 years) analyses, with the latter also related to other measures of carotid structure and stress. Additional use of ultra-high frequency ultrasound in the radial artery at age 21 years allowed investigation of the distinct layers (i.e., intima or media) that may underlie observed differences.

RESULTS

Fat-free mass (FFM) and systolic blood pressure were the only modifiable risk factors positively associated with cIMT (e.g., mean difference in cIMT per 1-SD increase in FFM at age 17: 0.007 mm: 95% confidence interval [CI]: 0.004 to 0.010; p < 0.001), whereas fat mass was negatively associated with cIMT (difference: -0.0032; 95% CI: 0.004 to -0.001; p = 0.001). Similar results were obtained when investigating cumulative exposure to these factors throughout adolescence. An increase in cIMT maintained circumferential wall stress in the face of increased mean arterial pressure when increases in body mass were attributable to increased FFM, but not fat mass. Risk factor-associated differences in the radial artery occurred in the media alone, and there was little evidence of a relationship between intimal thickness and any risk factor.

CONCLUSIONS

Subtle changes in cIMT in the young may predominantly involve the media and represent physiological adaptations as opposed to subclinical atherosclerosis. Other vascular measures may be more appropriate for the identification of arterial disease before adulthood.

Predictors for progressions of brachial-ankle pulse wave velocity and carotid intima-media thickness over a 12-year follow-up: Hanzhong Adolescent Hypertension Study

Objective:

Atherosclerotic diseases are the leading cause of death worldwide. This study aimed to investigate the predictors of brachial–ankle pulse wave velocity (baPWV) and carotid intima–media thickness (CIMT) progression in a Chinese cohort over a 12-year follow-up period and to determine whether these predictors differ by follow-up time.

Methods:

A total of 202 participants were recruited from a previously established cohort in Shaanxi Province, China. Both baPWV and CIMT were measured in 2013 and 2017. Multivariable regression was used to determine the predictors of CIMT and baPWV progression.

Results:

Men had higher CIMT and baPWV and a higher rate of CIMT progression during two follow-ups than women. A 4-year change in SBP was associated with baPWV progression, whereas a 12-year change in DBP was associated with baPWV progression. The increased progression of baPWV presented a linear trend when subgrouping all the participants according to SBP and DBP changes over 4 and 12 years, respectively. In addition, heart rate (HR) change over 4 and 12 years was consistently associated with CIMT progression, and a linear trend was also seen when subgrouping the population.

Conclusion:

Our study demonstrated that SBP and DBP contributed differently in different stages to the progression of arterial stiffness in this Chinese cohort. Moreover, HR was consistently involved in the increased progression of CIMT in all periods. These findings underline the importance of early detection and control of blood pressure and resting HR for the prevention of arterial stiffness progression.

Correlating Carotid Intima-Media Thickness With Lipid Profile: Does It Improve Sonographic Diagnosis of Subclinical Atherosclerosis?

Objective. The purpose of this prospective study was to ascertain if lipid profile parameters could serve as predictors of carotid intima-media thickness (CIMT), which, when combined, may improve the sensitivity of sonographic CIMT measurement in the diagnosis of subclinical atherosclerotic changes. Methods. The lipid profiles and CIMT of 181 subjects without cardiovascular risk factors were measured at the internal, external, common, and bulbar segments. Results. The mean CIMT values obtained were 0.620 ± 0.055 cm for men and 0.575 ± 0.051 cm for women, and the η2 values (η2 < 0.04) were used as a measure of association. Across all segments of both carotid arteries, lipid profiles were significantly and moderately associated with but not predictive of CIMT (fasting blood sugar, total cholesterol, and low-density lipoprotein: η2 = 0.99–0.24). Conclusions. Although lipid profiles were moderately associated with CIMT, they are not significant predictors; hence, combining them with CIMT does not improve the diagnostic sensitivity of sonography in atherosclerosis screening.

A manifesto for cardiovascular imaging: addressing the human factor

Our use of modern cardiovascular imaging tools has not kept pace with their technological development. Diagnostic errors are common but seldom investigated systematically. Rather than more impressive pictures, our main goal should be more precise tests of function which we select because their appropriate use has therapeutic implications which in turn have a beneficial impact on morbidity or mortality. We should practise analytical thinking, use checklists to avoid diagnostic pitfalls, and apply strategies that will reduce biases and avoid overdiagnosis. We should develop normative databases, so that we can apply diagnostic algorithms that take account of variations with age and risk factors and that allow us to calculate pre-test probability and report the post-test probability of disease. We should report the imprecision of a test, or its confidence limits, so that reference change values can be considered in daily clinical practice. We should develop decision support tools to improve the quality and interpretation of diagnostic imaging, so that we choose the single best test irrespective of modality. New imaging tools should be evaluated rigorously, so that their diagnostic performance is established before they are widely disseminated; this should be a shared responsibility of manufacturers with clinicians, leading to cost-effective implementation. Trials should evaluate diagnostic strategies against independent reference criteria. We should exploit advances in machine learning to analyse digital data sets and identify those features that best predict prognosis or responses to treatment. Addressing these human factors will reap benefit for patients, while technological advances continue unpredictably.

Relation between age and carotid artery intima-medial thickness: a systematic review

Carotid artery intima-medial thickness (cIMT) represents a popular measure of atherosclerosis and is predictive of future cardiovascular and cerebrovascular events. Although older age is associated with a higher cIMT, little is known about whether this increase in cIMT follows a linear relationship with age or it is affected under influence of cardiovascular diseases (CVD) or CVD risk factors. We hypothesize that the relationship between cIMT and age is nonlinear and is affected by CVD or risk factors. A systematic review of studies that examined cIMT in the general population and human populations free from CVD/risk factors was undertaken. The literature search was conducted in PubMed, Scopus, and Web of Science. Seventeen studies with 32 unique study populations, involving 10,124 healthy individuals free from CVD risk factors, were included. Furthermore, 58 studies with 115 unique study populations were included, involving 65,774 individuals from the general population (with and without CVD risk factors). A strong positive association was evident between age and cIMT in the healthy population, demonstrating a gradual, linear increase in cIMT that did not differ between age decades (r = 0.91, P < 0.001). Although populations with individuals with CVD demonstrated a higher cIMT compared to populations free of CVD, a linear relation between age and cIMT was also present in this population. Our data suggest that cIMT is strongly and linearly related to age. This linear relationship was not affected by CVD or risk factors.

Diabetes Mellitus, Arterial Wall, and Cardiovascular Risk Assessment

Diabetes mellitus is an independent risk factor for atherothrombotic cardiovascular disease. Adults with diabetes are two to four times more likely to develop heart disease or stroke than adults without diabetes. The two major features of diabetes, i.e., hyperglycemia and insulin-resistance, trigger arterial stiffening and increase the susceptibility of the arterial wall to atherosclerosis at any given age. These pathological changes in the arterial wall may provide a functional and structural background for cardiovascular events. The present paper provides a critical overview of the clinical evidence linking diabetes-related metabolic abnormalities to cardiovascular risk, debates the pathophysiologic mechanisms through which insulin resistance and hyperglycemia may affect the arterial wall, and discusses the associations between vascular biomarkers, metabolic abnormalities and cardiovascular events.

Hemodynamic overload and intra-abdominal adiposity in obese children: Relationships with cardiovascular structure and function

BACKGROUND AND AIMS

Childhood obesity promotes adverse changes in cardiovascular structure and function. This study evaluated whether these changes are related to intra-abdominal adiposity and associated cardiometabolic risk or to body-size induced hemodynamic overload.

METHODS AND RESULTS

55 obese children/adolescents and 35 healthy-weight controls underwent carotid, cardiac and abdominal ultrasound to assess carotid artery intima-media thickness (IMT), diameter, distension and stiffness, left ventricular (LV) dimension, mass and function and extent of intra-abdominal adiposity. As compared to controls with healthy BMI, obese children had higher systolic blood pressure (BP), stroke volume and lower total peripheral resistance (P < 0.001-0.0001), higher plasma triglycerides, glycated hemoglobin, insulin and HOMA-IR index (P = 0.01-<0.0001), higher carotid IMT, diameter and distension (P < 0.005-0.0005), higher LV diameter, wall thickness and mass (P < 0.001-0.0001), and impaired LV diastolic function assessed by myocardial longitudinal performance (P < 0.005). In entire population, independent determinants of carotid diameter, LV diameter, wall thickness and mass were fat-free mass (or stroke volume, respectively) and BP. Carotid distension was determined by carotid diameter and BP, and carotid IMT by carotid diameter, BP, HDL-cholesterol and glycated hemoglobin. LV diastolic performance was inversely related to preperitoneal fat thickness and plasma insulin levels.

CONCLUSIONS

Obese youths present signs of impaired lipid and glucose metabolism, hyperdynamic circulation and cardiovascular changes. Increase in LV dimensions and mass and in carotid diameter and distension seems to reflect adaptation to body-size induced increase in hemodynamic load, changes in LV diastolic performance a negative impact of intra-abdominal adiposity and associated metabolic risk, and increase in IMT both adaptive remodeling and metabolic risk.

Arterial stiffness, atherosclerosis and cardiovascular risk: Pathophysiologic mechanisms and emerging clinical indications

Arterial stiffness results from a degenerative process affecting mainly the extracellular matrix of elastic arteries under the effect of aging and risk factors. Changes in extracellular matrix proteins and in the mechanical properties of the vessel wall related to arterial stiffening may activate number of mechanisms involved also in the process of atherosclerosis. Several noninvasive methods are now available to estimate large artery stiffness in the clinical setting, including carotid-femoral pulse wave velocity, the reference for aortic stiffness estimate, and local distensibility measures of superficial arteries, namely carotid and femoral. An independent predictive value of arterial stiffness for cardiovascular events has been demonstrated in general as well as in selected populations, and reference values adjusted for age and blood pressure have been established. Thus, arterial stiffness is emerging as an interesting tissue biomarker for cardiovascular risk stratification and estimation of the individual "biological age". This paper overviews the mechanisms accounting for development and progression of arterial stiffness and for associations between arterial stiffness, atherosclerotic burden and incident cardiovascular events, summarizes the evidence and caveat for clinical use of stiffness as surrogate marker of cardiovascular risk, and briefly outlines some emerging methods for large artery stiffness characterization.

Lean mass, and not fat mass, is an independent determinant of carotid intima media thickness in obese subjects

BACKGROUND AND AIMS

Obesity is an important determinant of increased cardiovascular risk. Increased fat mass has been assumed to constitute the main prominent contributor to changes in carotid intima-media thickness (c-IMT).

METHODS

In 421 consecutive subjects (301 women), c-IMT was evaluated ultrasonographically in 6 independent territories and body composition was assessed by dual-energy X-ray absorptiometry.

RESULTS

c-IMT was positively associated with lean body mass in both men (r = 0.328, p = <0.0001) and women (r = 0.268 p = <0.0001) and increased across lean mass quartiles (p = <0.0001 for linear-trend ANOVA). Stepwise linear regression analysis showed that age and lean mass (but not fat mass or traditional cardiovascular risk factors) contributed to 46.2% of c-IMT variance in men (p = <0.0001). Even within obese men, lean mass was an independent contributor to c-IMT variance. Among women, age, lean mass and ultrasensitive CRP levels contributed independently to 47.7% of c-IMT variance (p < 0.0001).

CONCLUSIONS

Lean mass, and not fat mass, might contribute to increase c-IMT in obese patients independently of classical atherosclerotic risk factors. These data reinforce the concept that the increase in metabolically fat-free mass that accompanies the body weight enlargement is closely related to the raise in blood pressure.

Adiposity and Cardiometabolic Risk in Children With and Without Antipsychotic Drug Treatment

CONTEXT

Pediatric obesity is common, particularly in children treated with antipsychotic medications. Antipsychotic exposure can increase cardiometabolic risk by increasing adiposity, and possibly via other adiposity-independent pathways.

OBJECTIVE

The objectives were to characterize relationships of adiposity with intrahepatic triglyceride (IHTG) content and carotid intima media thickness (CIMT) in children with and without antipsychotic drug treatment, and to explore whether vitamin D alters any effects in these relationships.

DESIGN

This was a cross-sectional case-control study.

SETTING

The setting was an academic medical center.

PATIENTS OR OTHER PARTICIPANTS

Participants were 44 children (ages, 6-19 y): 25 cases treated with antipsychotic and other psychotropic drug therapies and 19 untreated controls, frequency-matched on age, gender, and body mass index.

MAIN OUTCOME MEASURES

Main outcome measures were dual-energy x-ray absorptiometry percentage body fat (DEXA %fat), IHTG measured by magnetic resonance spectroscopy, and CIMT measured by ultrasonography. Fasting blood glucose, insulin, lipids, C-reactive protein, and liver enzymes were also evaluated.

RESULTS

There were no significant differences between cases and controls on measures of IHTG, CIMT, or DEXA %fat. In combined crude and adjusted analyses, DEXA %fat predicted IHTG (R(2) = 0.30) but not CIMT. Low levels of vitamin D were associated with larger effects of DEXA %fat on IHTG.

CONCLUSION

In treated and untreated children alike, adiposity is a significant predictor of liver fat content. This relationship was altered by low vitamin D level. These results suggest a modifiable pathway to hepatic steatosis. Further research is needed to test the hypothesis that children with high adiposity and low vitamin D have particularly increased risks for the development of fatty liver.

Obesity and carotid artery remodeling

BACKGROUND/OBJECTIVE

The present study tested the hypothesis that obesity-related changes in carotid intima-media thickness (IMT) might represent not only preclinical atherosclerosis but an adaptive remodeling meant to preserve circumferential wall stress (CWS) in altered hemodynamic conditions characterized by body size-dependent increase in stroke volume (SV) and blood pressure (BP).

SUBJECTS/METHODS

Common carotid artery (CCA) luminal diameter (LD), IMT and CWS were measured in three different populations in order to study: (A) cross-sectional associations between SV, BP, anthropometric parameters and CCA LD (266 healthy subjects with wide range of body weight (24-159 kg)); (B) longitudinal associations between CCA LD and 3-year IMT progression rate (ΔIMT; 571 healthy non-obese subjects without increased cardiovascular (CV) risk); (C) the impact of obesity on CCA geometry and CWS (88 obese subjects without CV complications and 88 non-obese subjects matched for gender and age).

RESULTS

CCA LD was independently associated with SV that was determined by body size. In the longitudinal study, baseline LD was an independent determinant of ΔIMT, and ΔIMT of subjects in the highest LD quartile was significantly higher (28±3 μm) as compared with those in the lower quartiles (8±3, 16±4 and 16±3 μm, P=0.001, P<0.05 and P=0.01, respectively). In addition, CCA CWS decreased during the observational period in the highest LD quartile (from 54.2±8.6 to 51.6±7.4 kPa, P<0.0001). As compared with gender- and age-matched lean individuals, obese subjects had highly increased CCA LD and BP (P<0.0001 for both), but only slightly higher CWS (P=0.05) due to a significant increase in IMT (P=0.005 after adjustment for confounders).

CONCLUSIONS

Our findings suggest that in obese subjects, the CCA wall thickens to compensate the luminal enlargement caused by body size-induced increase in SV, and therefore, to normalize the wall stress. CCA diameter in obesity could represent an additional biomarker, depicting the impact of altered hemodynamics on arterial wall.

Carotid intima media thickness is associated with body fat abnormalities in HIV-infected patients

BACKGROUND

HIV-infected patients may be at increased risk of cardiovascular (CV) events, and lipodystrophy is generally associated with proatherogenic metabolic disturbances. Carotid intima-media thickness (cIMT) has been used as a surrogate marker for atherosclerosis and it has been shown to be an independent risk factor for CV disease. Our objective was to evaluate cIMT in HIV-infected patients on combined anti-retroviral therapy (cART) with and without lipodystrophy defined by fat mass ratio (L-FMR), and to determine the association of lipodystrophy and visceral obesity [(visceral (VAT), subcutaneous adipose tissue (SAT) volume and VAT/SAT ratio, objectively evaluated by CT scan] with cIMT.

METHODS

Cross-sectional study of 199 HIV-infected patients. Body composition by DXA and abdominal CT, lipids, blood pressure, inflammatory markers, and cIMT by ultrasonography were performed. L-FMR was defined as the ratio of the percentage of trunk fat mass to the percentage of lower limb fat mass by DXA. Categorical variables were compared using the chi-square or Fisher's exact test. Spearman correlation coefficients were estimated to study the association between cIMT and clinical and metabolic characteristics. Means of cIMT, adjusted for age, were calculated, using generalized linear models.

RESULTS

L-FMR was present in 41.2% of patients and cIMT was higher in these patients [0.81 (0.24) vs. 0.76 (0.25); p=0.037)]. Lipodystrophic patients had higher VAT and VAT/SAT ratio and lower SAT. cIMT was associated with lipodystrophy evaluated by FMR, trunk fat, total abdominal fat, VAT and VAT/SAT ratio. No association was observed between cIMT and leg fat mass. Using generalized linear models, cIMT means were adjusted for age and no significant differences remained after this adjustment. The adjusted mean of cIMT was 0.787 (95%CI: 0.751-0.823) in patients without lipodystrophy, and 0.775 (95%CI: 0.732-0.817) in those with lipodystrophy (p=0.671).

CONCLUSIONS

HIV-infected patients on cART with lipodystrophy defined by FMR, had a significantly higher cIMT. Carotid IMT was also associated with classical cardiovascular risk factors. In these patients, visceral adipose tissue had a significant impact on cIMT, although age was the strongest associated factor.

Lean body mass may explain apparent racial differences in carotid intima-media thickness in obese children

BACKGROUND

Racial differences in carotid intima-media thickness (cIMT) have been suggested to be associated with the disproportionally high prevalence of cardiovascular disease in black adults. The objective of this study was to evaluate the effects of cardiovascular risk factors on the racial differences seen in cIMT in obese children.

METHODS

Obese subjects aged 4 to 21 years were recruited prospectively. Height, weight, blood pressure, fasting insulin, glucose, lipid panel, high-sensitivity C-reactive protein, and body composition by dual-energy x-ray absorptiometry were obtained. B-mode carotid imaging was analyzed by a single blinded physician.

RESULTS

A total of 120 subjects (46 white, 74 black) were enrolled. Black subjects exhibited greater cIMT (0.45 ± 0.03 vs 0.43 ± 0.02 cm, P < .01) and higher lean body mass index (19.3 ± 3.4 vs 17.3 ± 3.2 kg/m², P = .02) than white subjects. Simple linear regression revealed modest associations between mean cIMT and race (R = 0.52, P < .01), systolic blood pressure (R = 0.47, P < .01), and lean body mass (R = 0.51, P < .01). On multivariate regression analysis, lean body mass remained the only measure to maintain a statistically significant relationship with mean cIMT (P < .01).

CONCLUSIONS

Black subjects demonstrated greater cIMT than white subjects. The relationship between race and cIMT disappeared when lean body mass was accounted for. Future studies assessing the association of cardiovascular disease risk factors to cIMT in obese children should include lean body mass in the analysis.

Carotid artery remodelling in relation to body fat distribution, inflammation and sustained weight loss in obesity

BACKGROUND

Obesity is known to be associated with carotid artery remodelling, but less is known about how body fat distribution, inflammation and weight loss may affect this relation.

METHODS

Ultrasonography, dual-energy X-ray absorptiometry and computed tomography were performed to evaluate carotid artery intima-media thickness (IMT), body composition and fat distribution, respectively. Participants were divided into three matched study groups (n = 44 per group): obese patients with sustained weight loss 10 years after bariatric surgery [surgery group, body mass index (BMI) 31.5 kg m(-2)]; obese patients who maintained stable weight during the same time period (obese group, BMI 42.5 kg m(-2)); and normal weight subjects (lean group, BMI 24.4 kg m(-2)).

RESULTS

Patients in the surgery group, compared with those in the obese group, had slightly lower common carotid artery (CCA) IMT (0.75 ± 0.18 vs. 0.78 ± 0.17 mm) and common carotid bulb (CCB) IMT (0.92 ± 0.32 vs. 0.97 ± 0.32 mm); however, these differences were not statistically significant. Lean individuals, compared with those in the surgery group, had significantly lower CCA and CCB IMT values (P < 0.001). In forward stepwise multiple regression analyses including all subjects (n = 132), CCA IMT was predicted mainly by visceral adipose tissue, but was also related to blood pressure and levels of triglycerides and high-sensitivity C-reactive protein. Carotid lumen diameter was primarily influenced by lean body mass.

CONCLUSION

Visceral adiposity was the main determinant of premature carotid artery atherosclerosis, possibly through elevated blood pressure, dyslipidaemia and inflammation. Lean body mass predicted carotid artery lumen diameter. Obese patients with long-term sustained weight loss did not have thinner carotid artery walls compared with their weight-stable obese counterparts.

Carotid Intima Media Thickness Is Independently Associated with Male Gender, Middle Age, and IGF-1 in Metabolically Healthy Obese Individuals

Background/Aims. The effect of benign obesity on subclinical cardiovascular disease is still questionable. The purpose of this study was to assess carotid intima media thickness (CIMT), as a marker of subclinical atherosclerosis, and to evaluate its relation to age, sex, and IGF-1 in metabolically healthy obese (MHO) subjects. Methods. A total of 75 MHO subjects and 80 age, and sex matched healthy nonobese control subjects were included in the study. Body mass index (BMI), waist circumference (WC), blood pressure, fasting plasma glucose, fasting insulin, HOMA-IR, lipid profile, insulin like growth factor-1 (IGF-1), and CIMT were assessed in all subjects. Results. MHO subjects had significantly higher CIMT and lower IGF-1 than healthy nonobese controls. Mean CIMT was significantly higher in MHO men age subgroup range from 30 to 50 years than in their age range matched (premenopausal) MHO women subgroup. In MHO subjects, CIMT was positively correlated with age, BMI, WC, SBP, HOMA-IR, TG, and LDL-C, and negatively correlated with IGF-1. Regression analysis revealed that middle age, male sex and IGF-1 remained independently associated with CIMT in MHO subjects. Conclusion. CIMT is elevated and IGF-1 is reduced in MHO subjects, and CIMT is independently associated with male gender, middle age, and IGF-1. Definition of healthy obesity may be broadened to include IMT measurement.

Concomitant carotid plaque development and brachial artery diameter enlargement: a retrospective, recall-based study in postmenopausal women

BACKGROUND AND AIM

To verify if the carotid plaque development is concomitant to brachial artery diameter enlargement, in healthy postmenopausal women.

METHODS AND RESULTS

This is a retrospective, recall study. We enrolled 40 postmenopausal women, selected from a database for the period 2000-2008, not affected by subclinical carotid atherosclerosis and without risk factors for cardiovascular disease. At the recall visit, carotid and brachial duplex scan was again obtained. The incidence of plaque was 30% after a mean follow-up period of 60 months. There were no differences in baseline characteristics between subjects developing carotid atherosclerosis and subjects who did not, except for the brachial diameter change, follow-up and heart rate. The logistic-regression analysis confirmed that only brachial diameter change resulted to be correlated with the development of carotid atherosclerosis.

CONCLUSION

Brachial artery diameter increase is concomitant to carotid plaque development. Vascular enlargement could not be a focal change but a systemic process associated with atherosclerotic plaque development. Brachial diameter could be a tool with a predictive significance.

Oscillometric measurement of brachial artery cross-sectional area and its relationship with cardiovascular risk factors and arterial stiffness in a middle-aged male population

An enlarged arterial diameter is associated with an increased risk for cardiovascular disease. This study examined the relationship of noninvasively measured brachial artery cross-sectional area with cardiovascular risk factors and arterial stiffness in a middle-aged male population. Absolute volumetric changes of the brachial artery were measured with a newly developed oscillometric method during a general health examination in 387 men (mean age: 38±9 years) without known cardiovascular disease. Based on the measurement, the estimated area (eA) of the brachial artery at end-diastole was obtained. Brachial artery volume elastic modulus (VE) and brachial-ankle pulse wave velocity (baPWV) were simultaneously measured as indices of arterial stiffness by the same device. The relationships of eA with cardiovascular risk factors, including age, obesity, hypertension, dyslipidemia, impaired fasting glucose/diabetes mellitus (IFG/DM), hyperuricemia, smoking and their associated continuous variables, as well as VE and baPWV, were examined. Overall, the mean eA was 12.9 ± 2.9 mm². The eA was significantly higher in subjects with obesity, hypertension or IFG/DM than in those without each of these risk factors. In a multiple linear regression analysis, body mass index (β=0.31, P<0.001), age (β=0.25, P<0.001), systolic blood pressure (β=0.16, P=0.004) and pulse rate (β=-0.13, P=0.005) were independent determinants of eA. In contrast, neither VE nor baPWV were selected as independent determinants of eA. In conclusion, enlarged brachial artery cross-sectional area was significantly associated with cardiovascular risk factors such as age, body mass index and systolic blood pressure, but it was not associated with increased arterial stiffness.

Taking small steps towards targets - perspectives for clinical practice in diabetes, cardiometabolic disorders and beyond

Big changes are hard. When trying to achieve guideline targets in diabetes and cardiometabolic disorders, patients can lack commitment or suffer despondency. It is much easier to make small changes in lifestyle or treatment, which are less noticeable and easier to manage long-term. Obesity is central to the cardiometabolic disorders, and even small weight losses of 2-5% can improve the cardiometabolic risk profile and substantially reduce the risk of developing type 2 diabetes. Likewise, small increases in physical activity, such as 15-30 min of brisk walking per day, can cut the risk of heart disease by 10%. Lifestyle or treatment changes that lead to small improvements in metabolic parameters also impact patient outcome - for example, a 5 mmHg decrease in blood pressure can translate into significant reductions in the rates of myocardial infarction and cardiovascular mortality. Benefits of small changes can also be seen in health economic outcome models. Implementing change at an individual versus a population level has different implications for overall benefit and patient motivation. Even very small steps taken in trying to reach guideline targets should represent a positive achievement for patients. Patient engagement is essential - only when patients commit themselves to change can benefits be maintained, and physicians should recognise their influence. Small changes in individual parameters can result in significant beneficial effects; however, a major impact can occur when small changes are made together in multiple parameters. More research is required to elucidate the full impact of small changes on patient outcome.

Effects of an intensive behavioral weight loss intervention consisting of caloric restriction with or without physical activity on common carotid artery remodeling in severely obese adults

OBJECTIVE

Obesity increases cardiovascular disease risk and adversely affects vascular structure and function. Few studies have evaluated the vascular effects of non-surgical weight reduction in the severely obese. We hypothesized that weight loss and improvements in cardiometabolic factors would reduce common carotid artery intima-media thickness (CIMT) and inter-adventitial diameter (AD) in severely obese adults.

METHODS

We performed carotid ultrasound and measured cardiometabolic factors in 90 severely obese participants (body mass index (BMI)≥35 kg/m(2), age 30-55) at baseline and 6 months in a randomized clinical trial of dietary intervention with (n=45) or without (n=45) physical activity.

RESULTS

The achieved weight loss (mean=8%) did not differ significantly by intervention group (P=0.10) and resulted in a 0.07 mm mean decrease in AD (P=0.001). AD change was positively correlated with changes in BMI, waist circumference, abdominal visceral and subcutaneous fat, and body fat mass, and AD decreased more in men (P<0.05 for all). After multivariable adjustment, changes in BMI (P=0.03) and abdominal subcutaneous fat (P=0.04) were significant determinants of AD change. Although CIMT did not decrease significantly overall (-0.008 mm, P=0.16), individuals who lost at least 5% of their body weight experienced a significant mean reduction in CIMT of 0.02 mm (P=0.002). CIMT change was positively correlated with changes in BMI, waist circumference, fat-free mass, leptin, and insulin (P<0.05 for all). After multivariable adjustment, insulin reduction remained a significant determinant of CIMT decrease (P=0.03).

CONCLUSION

A 6 month intensive behavioral intervention can significantly reverse metabolic and vascular abnormalities in severely obese adults.

Carotid circumferential wall stress homeostasis in early remodeling: theoretical approach and clinical application

PURPOSE

To assess the influence of cardiovascular risk factors on arterial wall growth and the remodeling process.

METHODS

In a theoretical part, we used a well-established relationship linking the rate of thickening of the arterial wall to the circumferential wall stress (CWS) increase. In a clinical part, we measured the intima-media thickness (IMT) in 166 subjects with increased cardiovascular risk score but no treatment for hypertension or hypercholesterolemia, no diabetes, and no cardiovascular disease. Far wall IMT and lumen diameter were measured along the right carotid artery by high-resolution ultrasonography and computerized image analysis.

RESULTS

A decreasing linear relationship between IMT and CWS was deduced from the theoretical model, implying that an increase in CWS would result in an IMT increase, and that the higher the IMT-CWS slope, the higher the thickening response. Subjects with advanced age, renal insufficiency, high 10-year Framingham risk, carotid atherosclerosis, and advanced atherosclerosis at other sites had sharper IMT-CWS slope (p < 0.05), in agreement with the homeostasis of CWS hypothesis.

CONCLUSIONS

The IMT increase responding to a CWS increase was greater in high-risk patients.

Brachial artery diameter measurement: a tool to simplify non-invasive vascular assessment

AIM

The mechanisms of vascular remodeling have attracted great interest since it is a phenomenon related to cardiovascular diseases. We would like to examine studies that contributed to clarify the remodeling mechanisms, to explore the different faces of atherosclerosis process.

DATA SYNTHESIS

A number of invasive and non-invasive vascular assessment methods were developed, to detect the early sign of atherosclerosis. It became clear that the invasive tests were not applicable to large-scale studies. Consequently, a non-invasive test was developed. Studies showed that the endothelial function evaluation is a predictor of future cardiac events in individuals at cardiovascular risk and in those with established disease. However, analyzing several works, an interesting concept emerged, i.e., the inverse relation between endothelium-dependent dilation and vessel size, since large vessel tend not to dilate significantly. This notion emphasized the role of basal diameter on vascular response. In particular, as brachial artery diameter is the measure on which FMD is based, it could add more information in clinical evaluation, simplifying the assessment. Several studies showed that morphological change of brachial artery is a better indicator of the extent of coronary disease rather than FMD. Other studies showed that brachial diameter has predictive significance in the stratification of cardiovascular risk.

CONCLUSION

Brachial diameter is a useful and simple tool. It should be incorporated into the overall assessment of cardiovascular risk but further studies are warranted to determine the final place of brachial diameter assessment in routine clinical setting.

Factors influencing endothelial function in healthy pre- and post-menopausal women of the EU-RISC study

BACKGROUND

We studied the impact of lifestyle, body composition, different insulin sensitivity indices and the first insulin response in healthy pre- and post-menopausal women with a low cardiovascular risk profile (the EU-RISC study, 'Relationship between Insulin Sensitivity and Cardiovascular Disease' (n = 51, 47 ± 4 years, body mass index 23.6 ± 3.7 kg/m(2), waist girth 79.2 ± 10.3 cm) on endothelial function (flow mediated arterial dilatation (FMD)), an early marker for atherosclerosis.

RESULTS

Waist circumference (p = 0.06), tobacco consumption (p = 0.02) and leucocyte count (p = 0.09) were inversely related with FMD in both pre- and post-menopausal women. Neither insulin sensitivity nor first insulin response indices were correlated with FMD. In pre-menopausal women (n = 24), waist (p < 0.02), waist-to-hip ratio (p < 0.02), HDL cholesterol (p < 0.01) and smoking habits (p < 0.03) were significantly correlated with endothelial function. In postmenopausal women (n = 27) age (r = -0.17, p = 0.04) was related with FMD.

CONCLUSION

Smoking and waist circumference, a simple marker of visceral adiposity, were related with endothelial function in healthy pre- and post-menopausal women.

Comparison between the Framingham and prospective cardiovascular of Münster scores for risk assessment of coronary heart disease in human immunodeficiency virus-positive patients in Pernambuco, Brazil

BACKGROUND

The Framingham score is used in most studies on human immunodeficiency virus (HIV)-positive patients to estimate the risk for coronary heart disease; however, it may have some limitations for detecting risk among these individuals.

OBJECTIVE

The aim of this study was to evaluate the agreement between the Framingham and Prospective Cardiovascular of Münster (PROCAM) scores among HIV-positive individuals and to investigate the factors associated with disagreement between the two scores.

METHOD

A cross-sectional study was conducted in a population of HIV/acquired immunodeficiency syndrome (AIDS) patients attending the outpatient's clinics of two reference centers for HIV/AIDS in Pernambuco, Brazil. Agreement between the Framingham and PROCAM scores was evaluated using the kappa index. From this analysis, a variable called "disagreement between scores" was created, and univariate and multivariate analysis were performed to investigate the factors associated with this variable.

RESULTS

The prevalence of low, moderate, and high risk were, respectively, 78.7%, 13.5%, and 7.8% by Framingham score and 88.5%, 4.3%, and 7.2% by PROCAM (kappa = 0.64, P ≤ 0.0001). Agreement in the subgroup with metabolic syndrome by the International Diabetes Federation (IDF) (kappa = 0.51, P ≤ 0.0001) and the National Cholesterol Education Program (NCEP) (kappa = 0.59, P ≤ 0.0001) criteria was moderate. The Framingham score identified greater proportion of women with moderate risk. Factors independently associated with disagreement were: smoking, sex, age, low-density lipoprotein cholesterol, diastolic blood pressure, and metabolic syndrome.

CONCLUSION

There was a good agreement between the Framingham and PROCAM scores in HIV-positive patients, but a higher proportion of moderate-high risk was identified by the Framingham score. This disagreement should be evaluated in cohort studies to observe clinical outcomes over the course of time.

Impact of waist circumference versus adiponectin level on subclinical atherosclerosis: a cross-sectional analysis in a sample from the general population

OBJECTIVE

Waist circumference is a clinical marker of obesity and an established risk factor for cardiovascular (CV) disease. Adiponectin, an adipocyte-derived hormone and new biomarker of obesity, was recently proposed as the missing link between obesity and increased cardiovascular risk. We evaluated waist and adiponectin in a middle-aged population-based cohort to compare the impact of both obesity-markers on subclinical atherosclerosis, in relation to other CV risk factors. DESIGN, SETTING & SUBJECTS: Seven noninvasive measurements of atherosclerosis (NIMA), as surrogate markers of (subclinical) atherosclerosis, were determined in 1517 participants of the Nijmegen Biomedical Study, aged 50-70 years, who were drawn from the Dutch community.

RESULTS

Both men and women with a high waist (M >104 cm; F >95 cm) showed increased pulse wave velocity (PWV) (M: +9.4%; F: +8.3%) and thicker intima-media thickness (IMT) (M: +7.3%; F: +4.3%) and women also showed increased plaque thickness (+16.6%). After adjustment for other CV risk factors both men and women showed increased IMT (M: +4.8%; F: +2.8%) and men also showed increased PWV (+9.6%). Both men and women with a low adiponectin level (M <2.2 mg L(-1); F <3.5 mg L(-1)) showed a decreased ankle-brachial index after exercise (M: -9.5%; F: -3.9%) and increased IMT (M: +3.7%; F: +3.6%) and women also showed increased PWV (+6.8%), but after adjustment for other CV risk factors low adiponectin level was no longer associated with deteriorated outcomes of NIMA.

CONCLUSIONS

Waist circumference showed independent associations with noninvasive measurements of subclinical atherosclerosis, whereas the association of adiponectin level with subclinical atherosclerosis was not independent of other CV risk factors. Prospective studies are needed to elucidate, if the atherogenic effect of a low adiponectin level is mediated by other CV risk factors and not by low adiponectin level intrinsically.

Effect of sedentary behaviour and vigorous physical activity on segment-specific carotid wall thickness and its progression in a healthy population

AIMS

This study investigated whether sedentary behaviour and different activity levels have an independent association with carotid intima-media thickness (IMT) and with the 3-year IMT progression in different carotid segments.

METHODS AND RESULTS

The study population included 614 healthy men and women (mean age = 44 +/- 8 years) without carotid atherosclerosis and without increased coronary heart disease risk, who underwent B-mode carotid ultrasound and objective physical activity assessment by accelerometer (mean monitoring time = 5.7 +/- 1.5 days). Time spent in sedentary (57.6 +/- 9.1%), light (41.0 +/- 9.2%), moderate and vigorous activities was determined. Sedentary behaviour was expressed as the ratio of time spent in sedentary and light activity (sedentary/light ratio) as these two activities occupied the majority of waking time. In 495 subjects, the carotid ultrasound was repeated 3 years after the baseline examination. After adjustment for age and the established risk factors that were independent determinants of carotid wall thickness in our population, sedentary/light ratio was independently associated only with the common carotid artery (CCA) IMT. The 3-year increase in CCA IMT was significantly lower in subjects with periods of vigorous activity (7 +/- 40 microm) when compared with those with light activity only or with periods of moderate activity (22 +/- 51 and 19 +/- 46 microm, respectively, P < 0.05).

CONCLUSION

The healthy, young-to-middle age population of this study spent more than half of their waking time in sedentary activities. The proportion of time spent in sedentary activities was directly associated with baseline CCA IMT, independently of age and established atherosclerotic risk factors. In the longitudinal analysis, period of vigorous activity influenced the 3-year IMT progression in CCA.

Fat distribution influences the cardio-metabolic profile in a clinically healthy European population

BACKGROUND AND AIMS

Waist and hip circumferences are largely influenced by Fat Mass and several other determinants. To evaluate the specific effects of a preferential fat distribution, we corrected the waist and hip circumferences for all their determinants. We then examined the association between fat distribution and several cardio-metabolic parameters in a clinically healthy population.

SUBJECTS AND METHODS

In a subgroup of 625 females (F) and 490 males (M) from the RISC (Relationship between Insulin Sensitivity and Cardiovascular Disease) study, we evaluated insulin sensitivity by hyperinsulinaemic euglycaemic clamp and intima-media thickness (IMT) of the common (CCA) and internal (ICA) carotid artery by ultrasound imaging. Waist and hip circumferences were adjusted for age, height, fat and fat-free mass; in males, waist was also adjusted by hip and vice versa.

RESULTS

Both F and M with enlarged waist showed significantly increased plasma insulin, C-peptide, total cholesterol, non-high density lipoprotein-cholesterol, low density lipoprotein cholesterol and triglycerides, when compared with subjects with a smaller waist circumference. Males also showed lower glucose uptake and higher heart rate and ICA-IMT. A larger hip in both females and males was linked to a significantly greater inhibition of free fatty acids during the clamp test.

CONCLUSION

Adjustment of waist circumference for its determinants permits the detection of early impairment of cardiovascular function and of glucose and lipid metabolism in a clinically healthy population, in particular in normal body weight subjects. Enlarged hip adjusted values are associated with greater insulin sensitivity.

Beta cell (dys)function in non-diabetic offspring of diabetic patients

AIMS/HYPOTHESIS

The first-degree offspring of patients with type 2 diabetes are prone to develop type 2 diabetes, and have both insulin resistance and beta cell impairment. However, it is still unclear whether both pathophysiological features are inseparably combined and which is the outstanding determinant in the offspring.

METHODS

Glucose metabolism, insulin sensitivity (calculated as M value divided by insulin [M/I]) and beta cell function were studied in the offspring of individuals with type 2 diabetes (n = 187; 57% females; age 43.8 +/- 8.1 years; BMI 26.8 +/- 4.5 kg/m(2)) and in individuals without a family history of type 2 diabetes (controls, n = 519, 55% females; age 43.4 +/- 8.2 years; BMI 26.4 +/- 3.7 kg/m(2), no significant differences between the groups for any characteristic) by performance of 75 g OGTT and 2 h hyperinsulinaemic (40 mU min(-1) m(-2))-isoglycaemic clamp tests. Beta cell function was evaluated by calculating insulinogenic index (IGI) from C-peptide AUC:glucose AUC ratios from the first hour of OGTT (IGI[60 min]) and from the total OGTT (IGI[120 min]).

RESULTS

During the OGTT, the offspring of individuals with type 2 diabetes showed 4-14% higher plasma glucose from 30 to 120 min (p < 0.05) and 20-29% higher serum insulin from 90 to 120 min, but decreased IGI(60 min) and IGI(120 min) (p < 0.05). M/I was 11% lower in the offspring of affected individuals than in controls (p < 0.01). To study the offspring of patients with type 2 diabetes with insulin sensitivity similar to that of the control group, the offspring of affected patients were divided into M/I quartiles. Those in the third M/I quartile showed M/I values and major anthropometric characteristics similar to those of the controls, but insulin AUC and C-peptide AUC values were lower in the first hour and the total OGTT (p < 0.05). The third M/I quartile had lower IGI values at 60 min and 120 min: 11% and 14% lower, respectively (p < 0.02).

CONCLUSIONS/INTERPRETATION

The first-degree offspring of type 2 diabetic patients show insulin resistance and beta cell dysfunction in response to oral glucose challenge. Beta cell impairment exists in insulin-sensitive offspring of patients with type 2 diabetes, suggesting beta cell dysfunction to be a major defect determining diabetes development in diabetic offspring.

TRIB3 functional Q84R polymorphism is a risk factor for metabolic syndrome and carotid atherosclerosis

OBJECTIVE

To determine the association of TRIB3 Q84R polymorphism with metabolic syndrome (MetS) and carotid atherosclerosis.

RESEARCH DESIGN AND METHODS

A case-control study enrolled 513 Chinese subjects in three groups: control, MetS, and obese. The functional TRIB3 Q84R polymorphism was genotyped among subjects undergoing carotid ultrasonography. The clinical and biochemical characteristics were determined.

RESULTS

For individuals with the TRIB3 R84 allele, the odds ratio for developing MetS was 2.349 (P = 0.018), abdominal obesity 2.351 (P = 0.012), hypertriglyceridemia 2.314 (P = 0.00003), and insulin resistance 1.697 (P = 0.023). Likewise, the odds ratio for individuals with the TRIB3 R84 allele to develop thickened intima-media thickness was 2.208 (P = 0.040).

CONCLUSIONS

Individuals with the functional TRIB3 Q84R polymorphism are at risk for MetS. The TRIB3 R84 allele especially predisposes to carotid atherosclerosis in part through the effects of abdominal obesity, hypertriglyceridemia, and insulin resistance.

The effect of menopause on carotid artery remodeling, insulin sensitivity, and plasma adiponectin in healthy women

BACKGROUND

The mechanisms by which menopause may influence the systemic subclinical atherosclerosis are unexplained. The aim of this cross-sectional study was to evaluate the associations between early menopause, established cardiovascular (c-v) risk factors, metabolic parameters (insulin secretion and sensitivity, plasma adiponectin), and carotid intima-media thickness (IMT) in healthy women.

METHODS

In 74 menopausal women (mean age = 51 +/- 3 years, mean duration of menopause = 2.9 +/- 1.2 years) and in 74 nonmenopausal women comparable for age and body mass index (BMI), common carotid artery (CCA) luminal diameter, and IMT in different carotid segments were measured in digitized ultrasound images. Insulin sensitivity and secretion were assessed using the euglycemic hyperinsulinemic clamp technique and oral glucose tolerance test (OGTT). Insulin secretion was reconstructed by mathematical modeling.

RESULTS

CCA diameter (5.55 +/- 0.46 vs. 5.21+/- 0.51 mm, P < 0.001), CCA IMT (608 +/- 78 vs. 576 +/- 74 microm, P < 0.01) and systolic blood pressure (BP) (117 +/- 12 vs. 113 +/- 11 mm Hg, P < 0.05) were higher in menopausal women, whereas CCA IMT/diameter ratio and IMT in other carotid segments did not differ between the groups. By multivariate models, independent predictors of CCA diameter were menopause and body weight (cumulative R2 = 0.37) and independent correlates of CCA IMT were luminal diameter, systolic BP and low-density lipoprotein (LDL) cholesterol (cumulative R2 = 0.48). Fasting insulin, insulin secretion, and sensitivity and plasma adiponectin were similar in the two groups and were not related to carotid IMT.

CONCLUSIONS

Early menopause is associated with CCA remodeling, characterized by a proportional increase in luminal diameter and wall thickness, independent of atherosclerotic risk factors and metabolic variables.