Sex differences in body fat distribution and carotid intima media thickness: cross sectional survey using data from the British regional heart study

Association Between Risk Factors in Childhood and Sex Differences in Prevalence of Carotid Artery Plaques and Intima-Media Thickness in Mid-Adulthood in the Childhood Determinants of Adult Health Study

Background The origins of sex differences in cardiovascular diseases are not well understood. We examined the contribution of childhood risk factors to sex differences in adult carotid artery plaques and intima-media thickness (carotid IMT). Methods and Results Children in the 1985 Australian Schools Health and Fitness Survey were followed up when they were aged 36 to 49 years (2014-19, n=1085-1281). Log binomial and linear regression examined sex differences in adult carotid plaques (n=1089) or carotid IMT (n=1283). Childhood sociodemographic, psychosocial, and biomedical risk factors that might contribute to sex differences in carotid IMT/plaques were examined using purposeful model building with additional adjustment for equivalent adult risk factors in sensitivity analyses. Women less often had carotid plaques (10%) than men (17%). The sex difference in the prevalence of plaques (relative risk [RR] unadjusted 0.59 [95% CI, 0.43 to 0.80]) was reduced by adjustment for childhood school achievement and systolic blood pressure (RR adjusted 0.65 [95% CI, 0.47 to 0.90]). Additional adjustment for adult education and systolic blood pressure further reduced sex difference (RR adjusted 0.72 [95% CI, 0.49 to 1.06]). Women (mean±SD 0.61±0.07) had thinner carotid IMT than men (mean±SD 0.66±0.09). The sex difference in carotid IMT (β unadjusted -0.051 [95% CI, -0.061 to -0.042]) reduced with adjustment for childhood waist circumference and systolic blood pressure (β adjusted -0.047 [95% CI, -0.057 to -0.037]) and further reduced with adjustment for adult waist circumference and systolic blood pressure (β adjusted -0.034 [95% CI, -0.048 to -0.019]). Conclusions Some childhood factors contributed to adult sex differences in plaques and carotid IMT. Prevention strategies across the life course are important to reduce adult sex differences in cardiovascular diseases.

Sex Differences in Cardiac Troponin I and T and the Prediction of Cardiovascular Events in the General Population

BACKGROUND

Cardiac troponin concentrations differ in women and men, but how this influences risk prediction and whether a sex-specific approach is required is unclear. We evaluated whether sex influences the predictive ability of cardiac troponin I and T for cardiovascular events in the general population.

METHODS

High-sensitivity cardiac troponin (hs-cTn) I and T were measured in the Generation Scotland Scottish Family Health Study of randomly selected volunteers drawn from the general population between 2006 and 2011. Cox-regression models evaluated associations between hs-cTnI and hs-cTnT and the primary outcome of cardiovascular death, myocardial infarction, or stroke.

RESULTS

In 19 501 (58% women, mean age 47 years) participants, the primary outcome occurred in 2.7% (306/11 375) of women and 5.1% (411/8126) of men during the median follow-up period of 7.9 (IQR, 7.1-9.2) years. Cardiac troponin I and T concentrations were lower in women than men (P < 0.001 for both), and both were more strongly associated with cardiovascular events in women than men. For example, at a hs-cTnI concentration of 10 ng/L, the hazard ratio relative to the limit of blank was 9.7 (95% CI 7.6-12.4) and 5.6 (95% CI 4.7-6.6) for women and men, respectively. The hazard ratio for hs-cTnT at a concentration of 10 ng/L relative to the limit of blank was 3.7 (95% CI 3.1-4.3) and 2.2 (95% CI 2.0-2.5) for women and men, respectively.

CONCLUSIONS

Cardiac troponin concentrations differ in women and men and are stronger predictors of cardiovascular events in women. Sex-specific approaches are required to provide equivalent risk prediction.

Association between Sports Participation in Early Life and Arterial Intima-Media Thickness among Adults

Background: Early sports practice is associated with several health benefits during childhood and adolescence, moreover, recent evidence also suggests that sports during childhood and adolescence can produce some benefits during adulthood. However, the association between early sports practice and arterial thickness is not clear. Thus, our aim was analyze the association between sports participation in childhood and adolescence, carotid/femoral intima–media thickness, and blood flow index in adulthood. Material and Methods: Sample was composed of 107 adults (64 males) between 30 years and 50 years, which were recruited from different gyms and university staff from São Paulo State University. Participants were divided according to sports participation in early life (engaged in sports during childhood and adolescence (n = 52) and no engagement in sports during childhood and adolescence (n = 55)). Carotid and femoral intima–media thickness were measured through Doppler ultrasonography method. Carotid and femoral index were estimated from ultrasonography measures. As covariates, the following were adopted: chronological age, sex, body fat (through dual-energy x-ray absorptiometry), c-reactive protein, HOMA, alcohol consumption, tobacco smoking, mean arterial pressure and current physical activity (pedometer). General estimating equations were used, adopting p < 0.05. Results: In the adjusted analyses, early sports participation was associated with lower carotid intima–media index (early sports participation: 0.64 mm ± 0.14 mm vs. no early sports participation: 0.71 mm ± 0.21 mm; p = 0.011), but not associated with femoral intima–media thickness, carotid resistive index and femoral resistive index after the adjustment by potential confounders. Conclusions: Sports participation in childhood and adolescence was associated with a reduced carotid intima–media thickness, independently of relevant confounders.

Consideration of Sex Differences in Design and Reporting of Experimental Arterial Pathology Studies-Statement From ATVB Council

There are many differences in arterial diseases between men and women, including prevalence, clinical manifestations, treatments, and prognosis. The new policy of the National Institutes of Health, which requires the inclusion of sex as a biological variable for preclinical studies, aims to foster new mechanistic insights and to enhance our understanding of sex differences in human diseases. The purpose of this statement is to suggest guidelines for designing and reporting sex as a biological variable in animal models of atherosclerosis, thoracic and abdominal aortic aneurysms, and peripheral arterial disease. We briefly review sex differences of these human diseases and their animal models, followed by suggestions on experimental design and reporting of animal studies for these vascular pathologies.

Gender-based differences in the relationship between fatty liver disease and atherosclerosis

Background

Carotid intima–media thickness (CIMT) is a surrogate of subclinical atherosclerosis. Fatty liver disease is also linked to increased risk of cardiovascular events. The aim of this study was to evaluate the association between fatty liver disease and CIMT according to gender.

Methods

Patients who had undergone carotid and abdominal ultrasound between June 2011 and December 2013 were retrospectively evaluated. The differences between the CIMT values measured in the common carotid artery and the prevalence of carotid plaque in patients with fatty liver disease and those with normal livers were investigated.

Results

Out of a total of 1 121 patients, the men had more fatty liver disease than the women. The mean CIMT of the men was significantly higher than that of the women, and the men had more plaque than the women. The women with fatty liver disease had a significantly higher mean CIMT value and more plaque than the women with normal livers. The differences between the men with fatty liver and those with normal livers in mean CIMT values and in the prevalence of plaque were not significant. In the women, multivariate analysis showed that fatty liver disease was independently associated with subclinical atherosclerosis [adjusted hazards ratio (HR) 1.65, 95% confidence interval (CI) 1.007–2.697, p = 0.047].

Conclusions

The men had more fatty liver disease, carotid plaque and higher CIMT values than the women. Fatty liver disease was a useful predictor of atherosclerosis, especially for the female study patients.

Cognitive Avoidant Coping Is Associated with Higher Carotid Intima Media Thickness Among Middle-Aged Adults

BACKGROUND

Cognitive avoidant coping (CAV) has been associated with elevated autonomic stress reactivity, thus presumably elevating risk for cardiovascular diseases. However, more direct evidence for this hypothesis is lacking.

PURPOSE

The purpose of this study was to relate carotid intima media thickness (IMT) to CAV in nonclinical participants.

METHODS

A total of 124 participants (61 women) with a mean age of 37.52 years (SD = 7.93, MIN = 30, MAX = 60) participated in the study. IMT was assessed by ultrasonic imaging and CAV via questionnaire (Mainz Coping Inventory; MCI).

RESULTS

Regression analysis revealed that although CAV was not significantly associated with IMT, there was a significant interaction of CAV and age. Whereas for younger adults, there was no significant relation for older individuals, CAV and IMT were significantly positively associated.

CONCLUSIONS

Findings suggest that CAV could constitute a risk factor for cardiovascular diseases with increasing age.

Serum adiponectin is associated with homocysteine in elderly men and women, and with 5,10-methylenetetrahydrofolate reductase (MTHFR) in a sex-dependent manner

Plasma homocysteine associates positively with cardiovascular disease. C-to-T substitution at base 677 of the 5,10-methylenetetrahydrofolate reductase (MTHFR) gene associates with increased plasma homocysteine. The association of adiponectin with cardiovascular disease is unclear. This study of survivors of a 30-year cohort of the Jewish Israeli population, 310 men and 273 women (mean age, 70.5 ± 7.0 years for both), investigated the relationship between adiponectin and homocysteine, and between adiponectin and the MTHFR C677T genotype. Serum adiponectin associated positively with total homocysteine in both men (r = 0.27, P < .001) and women (r = 0.22, P < .001). In women, the TT MTHFR genotype associated with lower median adiponectin levels, 8.98 mg/L, compared with 9.88 and 10.57 mg/L for TC and CC, respectively (P = .05; CC vs TT, P = .01). In men, the trend was opposite, but not statistically significant: 7.90, 7.03, and 6.88 mg/L for TT, TC, and CC genotypes, respectively (P = .5). This study demonstrated a positive association between homocysteine and adiponectin in both elderly men and women and a statistically significant association between adiponectin and MTHFR C677T genotypes in women only.

Advanced practice nurses facilitating clinical translational research

BACKGROUND

In 2006, the Clinical and Translational Science Award (CTSA), initiated by the National Center for Research Resources, was launched, with the overall goal to improve human health through clinical translational research. The purpose of this study was to examine the association between the total visit length for standardized study visits requiring the services of either a physician colleague or a designated advanced practice nurse (APN) for a protocol conducted in a clinical research center (CRC) supported with CTSA funds.

METHODS

Data collected for administrative purposes between June 2008 and September 2009 were used. This retrospective study compared the total visit length for the standardized study visits of a single study protocol requiring a gluteal fat biopsy procedure performed by either a physician colleague (an MD in this case) or a CRC-based APN employed by the CRC.

RESULTS

During the observed time period, 67 gluteal fat biopsy procedures were performed by one physician colleague, and 33 procedures were performed by one CRC-based APN. The mean total visit length of standardized study visits for research subjects treated by the physician colleague was 192.9 ± 65.8 minutes, whereas the mean total visit length of standardized study visits for research subjects treated by the APN was 154.8 ± 40.9 minutes (P = .003). Generalized least squares random effects regression model further evaluated the association between provider and visit length while controlling for age, gender, percent body fat and physical activity. The type of provider (P < .001) and gender (P < .05) were associated with length of visit.

CONCLUSIONS

The introduction of a CRC-based APN to perform advanced procedures demonstrates an efficient use of resources to meet the advanced clinical needs of specific research protocols. In this retrospective study, the ready availability of an APN (employed by the CRC) to perform gluteal fat biopsies during standardized study visits led to a decrease in total visit length, and thus a more rapid "turnover" of clinical research space compared to the use of a physician colleague. To best meet the needs of clinical researchers, CRCs should consider the employment of other clinicians to complement the research facilitation services provided by registered nurses. The addition of an APN to the CRC research facilitation team is novel and lends itself to the spirit of the clinical translational research initiative; additional studies evaluating the contribution of other licensed practitioners to improve research facilitation efficiency are needed.

Differences in atherosclerosis according to area level socioeconomic deprivation: cross sectional, population based study

OBJECTIVES

To examine the relation between area level social deprivation and ultrasound markers of atherosclerosis (common carotid intima-media thickness and plaque score), and to determine whether any differences can be explained by "classic" (currently recognised) or "emerging" (novel) cardiovascular risk factors.

DESIGN

Cross sectional, population based study.

SETTING

NHS Greater Glasgow Health Board area.

PARTICIPANTS

666 participants were selected on the basis of how their area ranked in the Scottish Index of Multiple Deprivation 2004. Approximately equal numbers of participants from the most deprived areas and the least deprived areas were included, as well as equal numbers of men and women and equal numbers of participants from each age group studied (35-44, 45-54, and 55-64 years).

MAIN OUTCOME MEASURES

Carotid intima-media thickness and plaque score, as detected by ultrasound.

RESULTS

The mean age and sex adjusted intima-media thickness was significantly higher in participants from the most deprived areas than in those from the least deprived areas (0.70 mm (standard deviation (SD) 0.16 mm) v 0.68 mm (SD 0.12 mm); P=0.015). On subgroup analysis, however, this difference was only apparent in the highest age tertile in men (56.3-66.5 years). The difference in unadjusted mean plaque score between participants from the most deprived and those from the least deprived areas was more striking than the difference in intima-media thickness (least deprived 1.0 (SD 1.5) v most deprived 1.7 (SD 2.0); P<0.0001). In addition, a significant difference in plaque score was apparent in the two highest age tertiles in men (46.8-56.2 years and 56.3-66.5 years; P=0.0073 and P<0.001) and the highest age tertile in women (56.3-66.5 years; P<0.001). The difference in intima-media thickness between most deprived and least deprived males remained significant after adjustment for classic risk factors, emerging risk factors, and individual level markers of socioeconomic status (P=0.010). Adjustment for classic risk factors and emerging cardiovascular risk factors, either alone or in combination, did not abolish the deprivation based difference in plaque presence (as a binary measure; adjusted odds ratio of 1.73, 95% confidence interval 1.07 to 2.82). However, adjustment for classic risk factors and individual level markers of early life socioeconomic status abolished the difference in plaque presence between the most deprived and the least deprived individuals (adjusted odds ratio 0.94, 95% CI 0.54 to 1.65; P=0.84).

CONCLUSIONS

Deprivation is associated with increased carotid plaque score and intima-media thickness. The association of deprivation with atherosclerosis is multifactorial and not adequately explained by classic or emerging risk factors.

Association between impaired glucose tolerance and carotid atherosclerosis: a study in 64-year-old women and a meta-analysis

BACKGROUND AND AIMS

Impaired glucose tolerance (IGT) is regarded as a transient metabolic state leading to type-2 diabetes, and is known to predict future risk of cardiovascular disease. This study was designed to investigate if IGT is associated with subclinical atherosclerosis.

METHODS AND RESULTS

In a population-based cohort of 64-year-old women, a group with IGT determined by repeated oral glucose tolerance tests (n=205) was compared with healthy women with normal glucose tolerance (NGT, n=188). Intima-media thickness (IMT) and plaques in the common carotid arteries (CCA) and bulbs were measured by ultrasound. The 95% confidence interval (CI) of the difference between the IGT and NGT groups was -0.03 to 0.03mm. There was no difference in carotid bulb IMT or in the occurrence, size, and characteristics of plaques between the IGT and NGT groups. A meta-analysis was used to calculate summary measures of 12 reviewed studies showing a difference of 0.030 (95% CI 0.012-0.048) mm in carotid IMT between IGT and NGT groups. Heterogeneity in IMT differences between studies was shown.

CONCLUSIONS

In our population-based cohort of 64-year-old women, IGT was not associated with increased occurrence of subclinical atherosclerosis. However, a meta-analysis of 12 studies, including our current study, showed that IGT was associated with a small increase in the CCA IMT.

Psychological, social and biological determinants of ill health (pSoBid): study protocol of a population-based study

BACKGROUND

Disadvantaged communities suffer higher levels of physical and mental ill health than more advantaged communities. The purpose of the present study was to examine the psychosocial, behavioural and biological determinants of ill health within population groups in Glasgow that differed in socioeconomic status and in their propensity to develop chronic disease especially coronary heart disease and Type 2 diabetes mellitus.

METHODS

Participants were selected at random from areas known to be at the extremes of the socioeconomic continuum in Glasgow. Within the categories of least deprived and most deprived, recruitment was stratified by sex and age to achieve an overall sample containing approximately equal numbers of males and females and an even distribution across the age categories 35-44, 45-54 and 55-64 years. Individuals were invited by letter to attend for assessment of their medical history, risk factor status, cognitive function and psychological profile, morbidity, and carotid intima-media thickness and plaque count as indices of atherosclerosis. Anonymised data on study subjects were collected from the General Practice Administration System for Scotland to analyse characteristics of participants and non-participants.

RESULTS

700 subjects were recruited. The response (active participants per 100 invitation letters) in the least deprived group was 35.1% and in the most deprived group was 20.3%. Lowest response was seen in young males (least deprived 22.4% and most deprived 14.1%).

CONCLUSION

This cross-sectional study recruited the planned sample of subjects from least deprived and most deprived areas within Glasgow. As evident in other studies response differed between the most and least deprived areas. This study brought together researchers/academics from diverse disciplines to build a more sophisticated understanding of the determinants of health inequalities than can be achieved through unidisciplinary approaches. Future analyses will enable an understanding of the relationships between the different types of measure, and of the pathways that link poverty, biology, behaviour and psychology and lead to health inequalities.

Adiponectin and the cardiovascular system: from risk to disease

Adiponectin is known to play a role in fatty acid and glucose metabolism through a change in insulin sensitivity and activation of fuel oxidation by AMP-activated protein kinase. Adiponectin can be considered an important factor able to modulate the adipovascular axis which, through genomic and environmental influences, affects the cardiovascular risk milieu, from the pre-metabolic syndrome-- through the metabolic syndrome--to the overt atherosclerotic process and its clinical manifestations. Hypoadiponectinaemia can be viewed as an early sign of a complex cardiovascular risk factor predisposing to the atherosclerosis process as well as a contributing factor accelerating the progress of the atherosclerotic plaque. In addition, adiponectin per se holds a protective role thanks to its anti-inflammatory and antiatherogenic properties. The early identification of patients "at cardiovascular risk" means in the current practice to search for indexes of metabolic derangements and pro-inflammatory status (adiponectin) from adolescence and childhood.

Heritability estimation of sex-specific effects on human quantitative traits

Recent studies have suggested that sex-specific genetic architecture could be because of the effects of autosomal genes that are differentially expressed in males and females. Yet, few studies have explored the effects of X-linked genes on sex-specific genetic architecture. In this study, we extended the variance component, maximum likelihood method to evaluate the relative contributions of sex-specific effects on both autosomes and the X chromosome to estimates of heritability of 20 quantitative human phenotypes in the Hutterites. Seventeen of these traits were previously analyzed in this population under a model that did not include X chromosomal effects; three traits are analyzed for the first time (age at menarche, percent fat and fat-free mass [FFM]). Seven traits (systolic blood pressure (SBP), adult height, fasting insulin, triglycerides, lipoprotein (a) [Lp(a)], serotonin, and age at menarche) showed significant X-linked effects; three of these (SBP, adult height, and triglycerides) showed X-linked effects only in males. Four traits (Lp(a), low-density lipoprotein cholesterol, ratio of percent predicted forced expiratory volume at 1 s/forced vital capacity, and FFM) showed significant sex-environment interactions, and two traits (high-density lipoprotein cholesterol and FFM) showed significant sex-specific autosomal effects. Our analyses demonstrate that sex-specific genetic effects may not only be common in human quantitative traits, but also that the X chromosome both plays a large role in these effects and has a variable influence between the sexes.

Decreased risk of death from coronary heart disease amongst men with higher 'femininity' scores: a general population cohort study

CONTEXT

At all ages men have higher rates of coronary heart disease (CHD) than women, although similar proportions of men and women eventually die of CHD. Gender differences in CHD incidence and mortality are often explained in relation to biological (hormonal) and behavioural risk factors (e.g. smoking), but psychological factors and broader social constructions of gender are rarely considered.

OBJECTIVE

To examine the relationship between measures of gender role orientation at baseline in 1988 and mortality from CHD over 17 years (to June 2005).

DESIGN

Prospective cohort study linked to national mortality reporting.

SETTING

Socially varied, mainly urban area centred on city of Glasgow in West Central Scotland, UK.

PARTICIPANTS

In total, 1551 participants (704 men and 847 women) aged 55 years took part in detailed interviews with nurses trained in survey methods in 1988. These included a wide range of measures of physical development and functioning, self reported health and health behaviour, personal and social circumstances and a measure of gender role orientation (yielding scores for 'masculinity' and 'femininity').

MAIN OUTCOME MEASURES

Mortality from CHD up to June 2005 (88 CHD deaths in men; 41 CHD deaths in women).

RESULTS

After adjusting for smoking, binge drinking, body mass index, systolic blood pressure, household income and psychological well-being, higher 'femininity' scores in men were associated with a lower risk of CHD death (hazards ratio per unit increase in 'femininity' score 0.65, 95% CIs 0.48-0.87, P = 0.004). No such relationship was observed amongst women. 'Masculinity' scores were unrelated to CHD mortality in either men or women.

CONCLUSIONS

These results suggest that social constructions of gender influence the risk of ill health, here death from CHD. Men who are less able to identify themselves with characteristics identified as 'feminine' or expressive (who have a more limited stereotypically masculine self-image) may be at increased risk of coronary disease. Further research on the link between social constructions of gender and health is needed.

Thicker carotid intima layer and thinner media layer in subjects with cardiovascular diseases. An investigation using noninvasive high-frequency ultrasound

BACKGROUND

The thickness of the arterial intima increases and that of the media decreases with increasing age and degree of atherosclerosis. Separate estimates of the individual intima and media layers might therefore be more appropriate than the commonly used method estimating the combined intima-media thickness (IMT).

METHODS AND RESULTS

One hundred consecutive 70-year-old subjects from the PIVUS study were investigated. Separate estimates of the thickness of the carotid artery intima and media wall layers were carried out noninvasively using 25MHz high-frequency ultrasound. Subjects with a diagnosis of cardiovascular disease (CVD), coronary heart disease (CHD), myocardial infarction (MI) or stroke had a significantly thicker intima layer (all P<0.0001) and a thinner media layer (all P<0.05) than healthy subjects. The intima/media thickness ratio also differed significantly between subjects with and without a diagnosis of CVD (0.43+/-0.20versus 0.75+/-0.48, P=0.0002). Subjects with hypertension or hyperlipidemia also had a thicker carotid intima than subjects without these diagnoses (P<0.0005 for both). None of the corresponding intima+media thickness values differed significantly. Similar results were obtained in women and men.

CONCLUSION

Separate assessment of carotid artery intima and media thickness using noninvasive high-frequency ultrasound appears to be of potential value, as a striking difference in intima thickness and the intima/media thickness ratio was found between subjects with and without CVD.

Gender differences in carotid intima-media thickness in patients with suspected coronary artery disease

Selecting patients who have suspected coronary artery disease (CAD) for coronary angiography remains difficult in some subgroups (e.g., women have often atypical symptoms and false-positive findings on noninvasive tests). This study evaluated gender differences and the clinical value of carotid intima-media thickness (IMT) in predicting CAD. We evaluated 558 patients who had symptoms and underwent coronary angiography: 91 women (61.2 +/- 9.5 years of age) had CAD (> or =1 lesion with a decrease >50% in luminal diameter of a coronary artery), 29 women (57.9 +/- 7.0 years of age) did not have CAD, 372 men (58.9 +/- 9.2 years of age) had CAD, and 66 men (54.6 +/- 8.7 years of age) did not have CAD. Maximal IMT was assessed bilaterally at the common carotid, bulb, and internal carotid arteries and expressed as mean IMT for each patient. Among patients who did not have CAD, women had lower mean IMT values than men (0.93 +/- 0.15 vs 1.05 +/- 0.19, p < 0.001). This gender difference was not seen in patients who had CAD (1.3 +/- 0.31 vs 1.31 +/- 0.31, p = 0.92). Among women and men, those with CAD had larger IMT values than those without CAD. Multivariable regression analysis showed that age, CAD, hypertension, smoking, and diabetes had the strongest effect on IMT values in women and men. Receiver-operator characteristic analysis showed that women had a significantly lower IMT threshold for likelihood of CAD (p < 0.001) and that a mean IMT of 1.069 mm was highly predictive of concomitant CAD (sensitivity 79%, specificity 90%, positive predictive value 96%); for men, the mean IMT threshold was 1.153 mm (sensitivity 66%, specificity 74%, positive predictive value 93%). In conclusion, carotid IMT assessment may be a valuable tool in selecting patients for coronary angiography to predict the likelihood of CAD. This particularly concerns women in whom sensitivity and specificity of mean IMT are high.