The impact of ethnicity and sex on subclinical cardiovascular disease: the Diabetes Heart Study

Carotid atherosclerosis in people of European, South Asian and African Caribbean ethnicity in the Southall and Brent revisited study (SABRE)

Background

Atherosclerotic cardiovascular disease (ASCVD) risk differs by ethnicity. In comparison with Europeans (EA) South Asian (SA) people in UK experience higher risk of coronary heart disease (CHD) and stroke, while African Caribbean people have a lower risk of CHD but a higher risk of stroke.

Aim

To compare carotid atherosclerosis in EA, SA, and AC participants in the Southall and Brent Revisited (SABRE) study and establish if any differences were explained by ASCVD risk factors.

Methods

Cardiovascular risk factors were measured, and carotid ultrasound was performed in 985 individuals (438 EA, 325 SA, 228 AC). Carotid artery plaques and intima-media thickness (cIMT) were measured. Associations of carotid atherosclerosis with ethnicity were investigated using generalised linear models (GLMs), with and without adjustment for non-modifiable (age, sex) and modifiable risk factors (education, diabetes, hypertension, total cholesterol, HDL-C, alcohol consumption, current smoking).

Results

Prevalence of any plaque was similar in EA and SA, but lower in AC (16, 16, and 6%, respectively; p < 0.001). In those with plaque, total plaque area, numbers of plaques, plaque class, or greyscale median did not differ by ethnicity; adjustment for risk factors had minimal effects. cIMT was higher in AC than the other ethnic groups after adjustment for age and sex, adjustment for risk factors attenuated this difference.

Conclusion

Prevalence of carotid artery atherosclerotic plaques varies by ethnicity, independent of risk factors. Lower plaque prevalence in in AC is consistent with their lower risk of CHD but not their higher risk of stroke. Higher cIMT in AC may be explained by risk factors. The similarity of plaque burden in SA and EA despite established differences in ASCVD risk casts some doubt on the utility of carotid ultrasound as a means of assessing risk across these ethnic groups.

Young men of color lower on adult attachment anxiety have higher carotid-intima media thickness compared to white young men: The exploration of an unexpected finding

Cardiovascular disease (CVD) remains the number one cause of death among men in the United States. Emerging research demonstrates that socioemotional mechanisms such as adult attachment, or the ways in which individuals are able to form and maintain socioemotional bonds, may impact physical health via alterations in physiological stress functioning. However, there may be key differences in the relation between attachment and physical health by race and sexual orientation. Thus, this study sought to examine the potential moderating effect of race and sexual orientation on the association between adult attachment and carotid-intima media thickness (cIMT), a measure of subclinical cardiovascular disease, among young men. The sample consisted of 72 young men (mean [SD] age = 22.92 [3.23]: 30.6 % identified as White, 30.6 % as Black, and 38.8 % as Other), each of which were surveyed and underwent an ultrasound to measure cIMT. Ordinary Least Squares (OLS) regression was used in order to examine our study hypotheses. We first ran a main effects model to examine adult attachment's (i.e., anxiety and avoidance) association with mean cIMT. We then ran two interaction models with an interaction between race/ethnicity and adult-related attachment and sexual orientation and adult attachment. We found that race significantly moderated the association between attachment-related anxiety and mean cIMT in our study sample. However, we did not find evidence to suggest that race moderated the association between attachment-related avoidance and mean cIMT in our study sample. In comparison to White individuals, Black individuals and those who identified as "Other" race with lower scores on attachment-related anxiety had higher mean cIMT. Additionally, higher scores on attachment-related anxiety were associated with lower mean cIMT among Black and "Other" respondents, but not among White respondents. We did not find evidence to suggest that sexual orientation moderated the association between adult attachment and mean cIMT in our study sample. Our findings suggest that adult attachment anxiety may be protective for young men of color but not for White young men. Future research should utilize longitudinal study designs in order to better understand how adult attachment influences CVD risk among racially/ethnically diverse young men.

Accelerated vascular aging: Ethnic differences in basilar artery length and diameter, and its association with cardiovascular risk factors and cerebral small vessel disease

Background and aims

Risk of stroke and dementia is markedly higher in people of South Asian and African Caribbean descent than white Europeans in the UK. This is unexplained by cardiovascular risk factors (CVRF). We hypothesized this might indicate accelerated early vascular aging (EVA) and that EVA might account for stronger associations between cerebral large artery characteristics and markers of small vessel disease.

Methods

360 participants in a tri-ethnic population-based study (120 per ethnic group) underwent cerebral and vertebral MRI. Length and median diameter of the basilar artery (BA) were derived from Time of Flight images, while white matter hyperintensities (WMH) volumes were obtained from T1 and FLAIR images. Associations between BA characteristics and CVRF were assessed using multivariable linear regression. Partial correlation coefficients between WMH load and BA characteristics were calculated after adjustment for CVRF and other potential confounders.

Results

BA diameter was strongly associated with age in South Asians (+11.3 μm/year 95% CI = [3.05; 19.62]; p = 0.008), with unconvincing relationships in African Caribbeans (3.4 μm/year [-5.26, 12.12]; p = 0.436) or Europeans (2.6 μm/year [-5.75, 10.87]; p = 0.543). BA length was associated with age in South Asians (+0.34 mm/year [0.02; 0.65]; p = 0.037) and African Caribbeans (+0.39 mm/year [0.12; 0.65]; p = 0.005) but not Europeans (+0.08 mm/year [-0.26; 0.41]; p = 0.653). BA diameter (rho = 0.210; p = 0.022) and length (rho = 0.261; p = 0.004) were associated with frontal WMH load in South Asians (persisting after multivariable adjustment for CVRF).

Conclusions

Compared with Europeans, the basilar artery undergoes more accelerated EVA in South Asians and in African Caribbeans, albeit to a lesser extent. Such EVA may contribute to the higher burden of CSVD observed in South Asians and excess risk of stroke, vascular cognitive impairment and dementia observed in these ethnic groups.

Albuminuria but not low eGFR is closely associated with atherosclerosis in patients with type 2 diabetes: an observational study

BACKGROUND

There is still controversy regarding the associations of urinary albumin excretion (UAE) and estimated glomerular filtration rate (eGFR) with atherosclerosis in patients with type 2 diabetes mellitus (T2DM). Therefore, it is necessary to explore the correlation between them in T2DM patients.

METHODS

We conducted a survey involving 2565 T2DM patients from a single center. The study cohort was classified into three groups based on the levels of albuminuria: normal UAE (UAE < 30 mg/24 h), moderate UAE (UAE between 30 and 299 mg/24 h) and high UAE (UAE ≥ 300 mg/24 h). Additionally, the patients were divided into three separate groups according to eGFR levels, including low eGFR (eGFR < 60 ml/min/1.73 m²), intermediate eGFR (eGFR 60-89 ml/min/1.73 m²) and normal eGFR (eGFR ≥ 90 ml/min/1.73 m²) groups. Atherosclerotic lesions were compared among the three UAE and eGFR groups. Regression analyses were used to assess the associations of atherosclerotic lesions with UAE and eGFR in T2DM.

RESULTS

After controlling for age, sex and diabetes duration, the prevalence of atherosclerotic plaque and stenosis were significantly increased from the normal to high UAE groups (plaque: 72.2%, 78.6% and 87.3%, respectively, p = 0.016 for trend; stenosis: 14.0%, 25.5% and 37.3%, respectively, p < 0.001 for trend). Likewise, the values of carotid intima-media thickness (CIMT) and femoral intima-media thickness (FIMT) were also obviously increased from the normal to high UAE groups (CIMT: p < 0.001 for trend; FIMT: p = 0.001 for trend). Conversely, only the FIMT value was clearly increased from the low to normal eGFR groups (p = 0.001 for trend). Fully adjusted regression analyses revealed that UAE was closely associated with the presence of atherosclerotic plaque (OR 1.20, 95% CI 1.03-1.40, p = 0.020) and stenosis (OR 1.17, 95% CI 1.01-1.35, p = 0.036), and with the values of CIMT (β 0.05, 95% CI 0.01-0.10, p = 0.029) and FIMT (β 0.07, 95% CI 0.03-0.11, p = 0.001) in T2DM patients. However, there was no significant association between eGFR levels and atherosclerotic lesions in T2DM after adjustment for multiple confounding factors.

CONCLUSIONS

Overall, albuminuria rather than low eGFR is closely associated with atherosclerotic lesions in T2DM patients. Albuminuria is an independent risk factor for carotid and femoral atherosclerotic lesions in T2DM. Therefore, albuminuria may be a potential early marker to predict the development of atherosclerosis in patients with T2DM.

Plasma metabolomic profiling in subclinical atherosclerosis: the Diabetes Heart Study

BACKGROUND

Incidence rates of cardiovascular disease (CVD) are increasing, partly driven by the diabetes epidemic. Novel prediction tools and modifiable treatment targets are needed to enhance risk assessment and management. Plasma metabolite associations with subclinical atherosclerosis were investigated in the Diabetes Heart Study (DHS), a cohort enriched for type 2 diabetes (T2D).

METHODS

The analysis included 700 DHS participants, 438 African Americans (AAs), and 262 European Americans (EAs), in whom coronary artery calcium (CAC) was assessed using ECG-gated computed tomography. Plasma metabolomics using liquid chromatography-mass spectrometry identified 853 known metabolites. An ancestry-specific marginal model incorporating generalized estimating equations examined associations between metabolites and CAC (log-transformed (CAC + 1) as outcome measure). Models were adjusted for age, sex, BMI, diabetes duration, date of plasma collection, time between plasma collection and CT exam, low-density lipoprotein cholesterol (LDL-C), and statin use.

RESULTS

At an FDR-corrected p-value < 0.05, 33 metabolites were associated with CAC in AAs and 36 in EAs. The androgenic steroids, fatty acid, phosphatidylcholine, and bile acid metabolism subpathways were associated with CAC in AAs, whereas fatty acid, lysoplasmalogen, and branched-chain amino acid (BCAA) subpathways were associated with CAC in EAs.

CONCLUSIONS

Strikingly different metabolic signatures were associated with subclinical coronary atherosclerosis in AA and EA DHS participants.

Do ethnic inequalities in multimorbidity reflect ethnic differences in socioeconomic status? The HELIUS study

BACKGROUND

The burden of multimorbidity is likely higher in ethnic minority populations, as most individual diseases are more prevalent in minority groups. However, information is scarce. We examined ethnic inequalities in multimorbidity, and investigated to what extent they reflect differences in socioeconomic status (SES).

METHODS

We included Healthy Life in an Urban Setting study participants of Dutch (N = 4582), South-Asian Surinamese (N = 3258), African Surinamese (N = 4267), Ghanaian (N = 2282), Turkish (N = 3879) and Moroccan (N = 4094) origin (aged 18-70 years). Educational level, employment status, income situation and multimorbidity were defined based on questionnaires. We described the prevalence and examined age-adjusted ethnic inequalities in multimorbidity with logistic regression analyses. To assess the contribution of SES, we added SES indicators to the age-adjusted model.

RESULTS

The prevalence of multimorbidity ranged from 27.1 to 53.4% in men and from 38.5 to 69.6% in women. The prevalence of multimorbidity in most ethnic minority groups was comparable to the prevalence among Dutch participants who were 1-3 decades older. After adjustment for SES, the odds of multimorbidity remained significantly higher in ethnic minority groups. For instance, age-adjusted OR for multimorbidity for the Turkish compared to the Dutch changed from 4.43 (3.84-5.13) to 2.34 (1.99-2.75) in men and from 5.35 (4.69-6.10) to 2.94 (2.54-3.41) in women after simultaneous adjustment for all SES indicators.

CONCLUSIONS

We found a significantly higher prevalence of multimorbidity in ethnic minority men and women compared to Dutch, and results pointed to an earlier onset of multimorbidity in ethnic minority groups. These inequalities in multimorbidity were not fully accounted for by differences in SES.

Association between renal damage markers and carotid atherosclerosis in Afro-descendants with hypertension belonging to a minority ethnic group from Brazil

Ethnicity appears to play an important role in the prevalence and severity of hypertension, renal disease, and atherosclerosis. A cross-sectional study was conducted, including 206 Afro-descendants with hypertension, living in the remaining quilombo communities. These subjects underwent a carotid intima-media thickness (CIMT) assessment. The presence of renal injury was assessed by: (1) The glomerular filtration rate (GFR) estimated by the formula CKD-EPI using creatinine and cystatin C and (2) Albuminuria (ACR ≥30 mg/g). The Poisson distribution model was set with robust variance to identify factors associated with carotid atherosclerosis. The statistical analysis was performed using the Stata 12.0 software, adopting a significance level of 5%. Most subjects were women (61.65%); the average age was 61.32 (±12.44) years. Subjects (12.62%) were identified with GFR <60 mL/min/1.73 m2 and 22.8% with albuminuria. Patients (59.22%) presented with a high CIMT. In the adjusted regression model, age ≥60 years (PR: 1.232 [CI 95%:1.091-1.390], p value = .001), ACR ≥30 mg/g (PR: 1.176 [CI 95%: 1.007-1.373], p = .040), and GFR/CKD-EPI using cystatin C (PR: 1.250 [CI 95%: 1.004-1.557], p = .045) were independently associated with carotid atherosclerosis. The occurrence of atherosclerotic lesions was high in the studied group. Age, albuminuria, and GFR (estimated by the formula CKD-EPI using cystatin C) influenced the prevalence of carotid atherosclerosis.

Relationships between cerebral structure and cognitive function in African Americans with type 2 diabetes

BACKGROUND

Relationships between cognitive function and brain structure remain poorly defined in African Americans with type 2 diabetes.

METHODS

Cognitive testing and cerebral magnetic resonance imaging in African Americans from the Diabetes Heart Study Memory IN Diabetes (n = 480) and Action to Control Cardiovascular Risk in Diabetes MIND (n = 104) studies were examined for associations. Cerebral gray matter volume (GMV), white matter volume (WMV) and white matter lesion volume (WMLV) and cognitive performance (Mini-mental State Exam [MMSE and 3MSE], Digit Symbol Coding (DSC), Stroop test, and Rey Auditory Verbal Learning Test) were recorded. Multivariable models adjusted for age, sex, BMI, scanner, intracranial volume, education, diabetes duration, HbA1c, LDL-cholesterol, smoking, hypertension and cardiovascular disease assessed associations between cognitive tests and brain volumes by study and meta-analysis.

RESULTS

Mean(SD) participant age was 60.1(7.9) years, diabetes duration 12.1(7.7) years, and HbA1c 8.3(1.7)%. In the fully-adjusted meta-analysis, lower GMV associated with poorer global performance on MMSE/3MSE (β̂ = 7.1 × 10-3, SE 2.4 × 10-3, p = 3.6 × 10-3), higher WMLV associated with poorer performance on DSC (β̂ = -3 × 10-2, SE 6.4 × 10-3, p = 5.2 × 10-5) and higher WMV associated with poorer MMSE/3MSE performance (β̂ = -7.1 × 10-3, SE = 2.4 × 10-3, p = 3.6 × 10-3).

CONCLUSIONS

In African Americans with diabetes, smaller GMV and increased WMLV associated with poorer performance on tests of global cognitive and executive function. These data suggest that WML burden and gray matter atrophy associate with cognitive performance independent of diabetes-related factors in this population.

Associations of coronary artery calcified plaque density with mortality in type 2 diabetes: the Diabetes Heart Study

BACKGROUND

Coronary artery calcified plaque (CAC) is strongly predictive of cardiovascular disease (CVD) events and mortality, both in general populations and individuals with type 2 diabetes at high risk for CVD. CAC is typically reported as an Agatston score, which is weighted for increased plaque density. However, the role of CAC density in CVD risk prediction, independently and with CAC volume, remains unclear.

METHODS

We examined the role of CAC density in individuals with type 2 diabetes from the family-based Diabetes Heart Study and the African American-Diabetes Heart Study. CAC density was calculated as mass divided by volume, and associations with incident all-cause and CVD mortality [median follow-up 10.2 years European Americans (n = 902, n = 286 deceased), 5.2 years African Americans (n = 552, n = 93 deceased)] were examined using Cox proportional hazards models, independently and in models adjusted for CAC volume.

RESULTS

In European Americans, CAC density, like Agatston score and volume, was consistently associated with increased risk of all-cause and CVD mortality (p ≤ 0.002) in models adjusted for age, sex, statin use, total cholesterol, HDL, systolic blood pressure, high blood pressure medication use, and current smoking. However, these associations were no longer significant when models were additionally adjusted for CAC volume. CAC density was not significantly associated with mortality, either alone or adjusted for CAC volume, in African Americans.

CONCLUSIONS

CAC density is not associated with mortality independent from CAC volume in European Americans and African Americans with type 2 diabetes.

FGF23 Concentration and APOL1 Genotype Are Novel Predictors of Mortality in African Americans With Type 2 Diabetes

OBJECTIVE

Cardiovascular and renal complications contribute to higher mortality in patients with diabetes. We assessed novel and conventional predictors of mortality in African American-Diabetes Heart Study (AA-DHS) participants.

RESEARCH DESIGN AND METHODS

Associations between mortality and subclinical atherosclerosis, urine albumin-to-creatinine ratio (UACR), estimated glomerular filtration rate (eGFR), plasma fibroblast growth factor 23 (FGF23) concentration, African ancestry proportion, and apolipoprotein L1 genotypes (APOL1) were assessed in 513 African Americans with type 2 diabetes; analyses were performed using Cox proportional hazards models.

RESULTS

At baseline, participants were 55.6% female with median (25th, 75th percentile) age 55 years (49.0, 62.0), diabetes duration 8 years (5.0, 13.0), glycosylated hemoglobin 60.7 mmol/mol (48.6, 76.0), eGFR 91.3 mL/min/1.73 m² (76.4, 111.3), UACR 12.5 mg/mmol (4.2, 51.2), and coronary artery calcium 28.5 mg Ca²⁺ (1.0, 348.6); 11.5% had two APOL1 renal-risk variants. After 6.6-year follow-up (5.8, 7.5), 54 deaths were recorded. Higher levels of coronary artery calcified plaque, carotid artery calcified plaque, albuminuria, and FGF23 were associated with higher mortality after adjustment for age, sex, and African ancestry proportion. A penalized Cox regression that included all covariates and predictors associated with mortality identified male sex (hazard ratio [HR] 4.17 [95% CI 1.96-9.09]), higher FGF23 (HR 2.10 [95% CI 1.59-2.78]), and absence of APOL1 renal-risk genotypes (HR 0.07 [95% CI 0.01-0.69]) as the strongest predictors of mortality.

CONCLUSIONS

Accounting for conventional risk factors, higher FGF23 concentrations and APOL1 non-renal-risk genotypes associated with higher mortality in African Americans with diabetes. These data add to growing evidence supporting FGF23 association with mortality; mechanisms whereby these novel predictors impact survival remain to be determined.

Genome-wide association study of coronary artery calcified atherosclerotic plaque in African Americans with type 2 diabetes

Background

Coronary artery calcified atherosclerotic plaque (CAC) predicts cardiovascular disease (CVD). Despite exposure to more severe conventional CVD risk factors, African Americans (AAs) are less likely to develop CAC, and when they do, have markedly lower levels than European Americans. Genetic factors likely contribute to the observed ethnic differences. To identify genes associated with CAC in AAs with type 2 diabetes (T2D), a genome-wide association study (GWAS) was performed using the Illumina 5 M chip in 691 African American-Diabetes Heart Study participants (AA-DHS), with replication in 205 Jackson Heart Study (JHS) participants with T2D. Genetic association tests were performed on the genotyped and 1000 Genomes-imputed markers separately for each study, and combined in a meta-analysis.

Results

Single nucleotide polymorphisms (SNPs), rs11353135 (2q22.1), rs16879003 (6p22.3), rs5014012, rs58071836 and rs10244825 (all on chromosome 7), rs10918777 (9q31.2), rs13331874 (16p13.3) and rs4459623 (18q12.1) were associated with presence and/or quantity of CAC in the AA-DHS and JHS, with meta-analysis p-values ≤8.0 × 10⁻⁷. The strongest result in AA-DHS alone was rs6491315 in the 13q32.1 region (parameter estimate (SE) = −1.14 (0.20); p-value = 9.1 × 10⁻⁹). This GWAS peak replicated a previously reported AA-DHS CAC admixture signal (rs7492028, LOD score 2.8).

Conclusions

Genetic association between SNPs on chromosomes 2, 6, 7, 9, 16 and 18 and CAC were detected in AAs with T2D from AA-DHS and replicated in the JHS. These data support a role for genetic variation on these chromosomes as contributors to CAC in AAs with T2D, as well as to variation in CAC between populations of African and European ancestry.

Electronic supplementary material

The online version of this article (10.1186/s12863-017-0572-9) contains supplementary material, which is available to authorized users.

APOL1 Gene Kidney Risk Variants and Cardiovascular Disease: Getting to the Heart of the Matter

Apolipoprotein L1 gene (APOL1) renal risk variants exhibit strong genetic associations with a spectrum of nondiabetic kidney diseases in individuals with recent African ancestry. Relationships between APOL1 kidney risk variants and cardiovascular disease (CVD) susceptibility and CVD-related death remain controversial. Some studies detected an increased risk for CVD, whereas others support protection from death and subclinical CVD and cerebrovascular disease. Because treatments for nondiabetic kidney disease may target this gene and its protein products, it remains critical to clarify the potential extrarenal effects of APOL1 kidney risk variants. This review addresses the current literature on APOL1 associations with CVD, cerebrovascular disease, and death. Potential causes of disparate results between studies are discussed.

The Apolipoprotein L1 Gene and Cardiovascular Disease

Relative to those with European ancestry, African Americans have an excess incidence of nondiabetic chronic kidney disease predominantly due to two coding renal-risk variants in the apolipoprotein L1 gene (APOL1). This APOL1-kidney disease association is independent of systemic hypertension or blood pressure. Recent reports describe extra-renal effects of the APOL1 G1 and G2 renal-risk variants on cardiovascular disease (CVD), subclinical atherosclerosis, lipoprotein particle concentrations, and survival. However, results have been less consistent than those seen in kidney disease, and the observed APOL1 associations with CVD vary from risk to protective. This manuscript reviews the relationships between APOL1 renal-risk variants and CVD, with an emphasis on study-specific factors that may have contributed to disparate observations. It is possible that APOL1 renal-risk variants impact the systemic vasculature, not only the kidneys. As novel therapies for APOL1-associated nephropathy are developed, APOL1 variant protein effects on large blood vessels and risk of CVD will need to be considered.

Relationships between measures of adiposity with subclinical atherosclerosis in patients with type 2 diabetes

OBJECTIVE

Assess cross-sectional relationships between body mass index (BMI), waist circumference (WC), pericardial (PAT), visceral (VAT), and subcutaneous adipose tissue (SAT) volumes with calcified plaque (CP) in African Americans (AAs) and European Americans (EAs) with type 2 diabetes.

METHODS

Computed tomography measured PAT, VAT, SAT, and CP in coronary arteries (CAC), carotid arteries, and aorta. Generalized estimating equations models were fitted to test for associations between adiposity and CP, stratified by ethnicity while accounting for familial correlations.

RESULTS

AAs (N = 753) vs. EAs (N = 562) had significantly lower PAT and VAT, despite equal or higher BMI. In multivariable models adjusting for age, gender, education, HbA1c, statins, smoking, cardiovascular disease, hypertension, nephropathy, and C-reactive protein, PAT positively associated with presence of CAC in AAs (P < 0.001), not EAs (P = 0.68; ethnicity interaction P < 0.01). Inverse associations were detected between SAT and severity of aorta CP (P < 0.01) in AAs and between BMI, WC, and SAT with severity of aorta CP in all participants.

CONCLUSIONS

Ethnic- and gender-specific differences in BMI, WC, PAT, SAT, and VAT were present in AAs and EAs with diabetes. Only PAT was positively associated with CAC in AAs; paradoxical inverse associations were seen between several other adiposity measures and subclinical cardiovascular disease.

APOL1 renal-risk genotypes associate with longer hemodialysis survival in prevalent nondiabetic African American patients with end-stage renal disease

Relative to European Americans, evidence supports that African Americans with end-stage renal disease (ESRD) survive longer on dialysis. Renal-risk variants in the apolipoprotein L1 gene (APOL1), associated with nondiabetic nephropathy and less subclinical atherosclerosis, may contribute to dialysis outcomes. Here, APOL1 renal-risk variants were assessed for association with dialytic survival in 450 diabetic and 275 nondiabetic African American hemodialysis patients from Wake Forest and Emory School of Medicine outpatient facilities. Outcomes were provided by the ESRD Network 6-Southeastern Kidney Council Standardized Information Management System. Dates of death, receipt of a kidney transplant, and loss to follow-up were recorded. Outcomes were censored at the date of transplantation or through 1 July 2015. Multivariable Cox proportional hazards models were computed separately in patients with nondiabetic and diabetic ESRD, adjusting for the covariates age, gender, comorbidities, ancestry, and presence of an arteriovenous fistula or graft at dialysis initiation. In nondiabetic ESRD, patients with 2 (vs. 0/1) APOL1 renal-risk variants had significantly longer dialysis survival (hazard ratio 0.57), a pattern not observed in patients with diabetes-associated ESRD (hazard ratio 1.29). Thus, 2 APOL1 renal-risk variants are associated with longer dialysis survival in African Americans without diabetes, potentially relating to presence of renal-limited disease or less atherosclerosis.

Admixture mapping of serum vitamin D and parathyroid hormone concentrations in the African American-Diabetes Heart Study

Vitamin D and intact parathyroid hormone (iPTH) concentrations differ between individuals of African and European descent and may play a role in observed racial differences in bone mineral density (BMD). These findings suggest that mapping by admixture linkage disequilibrium (MALD) may be informative for identifying genetic variants contributing to these ethnic disparities. Admixture mapping was performed for serum 25-hydroxyvitamin D, 1,25-dihydroxyvitamin D, vitamin D-binding protein (VDBP), bioavailable vitamin D, and iPTH concentrations and computed tomography measured thoracic and lumbar vertebral volumetric BMD in 552 unrelated African Americans with type 2 diabetes from the African American-Diabetes Heart Study. Genotyping was performed using a custom Illumina ancestry informative marker (AIM) panel. For each AIM, the probability of inheriting 0, 1, or 2 copies of a European-derived allele was determined. Non-parametric linkage analysis was performed by testing for association between each AIM using these probabilities among phenotypes, accounting for global ancestry, age, and gender. Fine-mapping of MALD peaks was facilitated by genome-wide association study (GWAS) data. VDBP levels were significantly linked in proximity to the protein coding locus (rs7689609, LOD=11.05). Two loci exhibited significant linkage signals for 1,25-dihydroxyvitamin D on 13q21.2 (rs1622710, LOD=3.20) and 12q13.2 (rs11171526, LOD=3.10). iPTH was significantly linked on 9q31.3 (rs7854368, LOD=3.14). Fine-mapping with GWAS data revealed significant known (rs7041 with VDBP, P=1.38×10(-82)) and novel (rs12741813 and rs10863774 with VDBP, P<6.43×10(-5)) loci with plausible biological roles. Admixture mapping in combination with fine-mapping has focused efforts to identify loci contributing to ethnic differences in vitamin D-related traits.

Ambient air pollution and racial/ethnic differences in carotid intima-media thickness in the Multi-Ethnic Study of Atherosclerosis (MESA)

BACKGROUND

In the USA, ethnic disparities in atherosclerosis persist after accounting for known risk factors. Ambient air pollution is associated with increased levels of atherosclerosis and differs in the USA by race/ethnicity. We estimated the influence of ambient air pollution exposure to ethnic differences in common carotid intima-media thickness (IMT).

METHODS

We cross-sectionally studied 6347 Caucasian-American, African-American, Hispanic and Chinese adults across 6 US cities in 2000-2002. Annual ambient air pollution concentrations (fine particulate matter [PM2.5] and oxides of nitrogen [NOX]) were estimated at each participant's residence. IMT was assessed by ultrasound.

RESULTS

The mean IMT was 19.4 and 37.6 μm smaller for Hispanic women and men, 53.6 and 7.1 μm smaller for Chinese women and men, and 23.4 and 38.7 μm higher for African-American women and men compared with Caucasian-American women and men. After adjustment for PM2.5, the differences in IMT remained similar for Hispanic and African-American participants but was even more negative for Chinese participants (mean IMT difference of -58.4 μm for women and -15.7 μm for men) compared with Caucasian-American participants. The IMT difference in Chinese participants compared with Caucasian-American participants related to their higher PM2.5 exposures was 4.8 μm (95% CI 0.2 to 10.8) for women and 8.6 μm (95% CI 3.4 to 15.3) for men. NOX was not related to ethnic differences in IMT.

CONCLUSIONS

The smaller carotid IMT levels in Chinese participants were even smaller after accounting for higher PM2.5 concentrations in Chinese participants compared with Caucasian-American participants. Air pollution was not related to IMT differences in African-American and Hispanic participants compared with Caucasian-American participants.

Subclinical Atherosclerosis Is Inversely Associated With Gray Matter Volume in African Americans With Type 2 Diabetes

OBJECTIVE

Relative to European Americans, African Americans manifest lower levels of computed tomography-based calcified atherosclerotic plaque (CP), a measure of subclinical cardiovascular disease (CVD). Potential relationships between CP and cerebral structure are poorly defined in the African American population. We assessed associations among glycemic control, inflammation, and CP with cerebral structure on MRI and with cognitive performance in 268 high-risk African Americans with type 2 diabetes.

RESEARCH DESIGN AND METHODS

Associations among hemoglobin A1c (HbA1c), C-reactive protein (CRP), and CP in coronary arteries, carotid arteries, and the aorta with MRI volumetric analysis (white matter volume, gray matter volume [GMV], cerebrospinal fluid volume, and white matter lesion volume) were assessed using generalized linear models adjusted for age, sex, African ancestry proportion, smoking, BMI, use of statins, HbA1c, hypertension, and prior CVD.

RESULTS

Participants were 63.4% female with mean (SD) age of 59.8 years (9.2), diabetes duration of 14.5 years (7.6), HbA1c of 7.95% (1.9), estimated glomerular filtration rate of 86.6 mL/min/1.73 m(2) (24.6), and coronary artery CP mass score of 215 mg (502). In fully adjusted models, GMV was inversely associated with coronary artery CP (parameter estimate [β] -0.47 [SE 0.15], P = 0.002; carotid artery CP (β -1.92 [SE 0.62], P = 0.002; and aorta CP [β -0.10 [SE 0.03] P = 0.002), whereas HbA1c and CRP did not associate with cerebral volumes. Coronary artery CP also associated with poorer global cognitive function on the Montreal Cognitive Assessment.

CONCLUSIONS

Subclinical atherosclerosis was associated with smaller GMV and poorer cognitive performance in African Americans with diabetes. Cardioprotective strategies could preserve GMV and cognitive function in high-risk African Americans with diabetes.

Vitamin D Associations With Renal, Bone, and Cardiovascular Phenotypes: African American-Diabetes Heart Study

CONTEXT

Vitamin D binding protein (DBP) is an important determinant of bioavailable vitamin D (BAVD) and may provide clues to racial variation in osteoporosis and atherosclerosis.

OBJECTIVE

The objective was to assess relationships between DBP, BAVD, 25-hydroxyvitamin D (25OHD), and 1,25 di-hydroxyvitamin D (1,25OH2D) with kidney, bone, adipose, and atherosclerosis phenotypes in African Americans with type 2 diabetes.

DESIGN

Cross-sectional (N = 545) and longitudinal (N = 288; mean 5.1 ± 0.9-year follow-up) relationships between vitamin D concentrations with renal phenotypes, vertebral bone mineral density, aorto-iliac, coronary artery, and carotid artery calcified plaque (CP), and adipose tissue volumes were studied.

SETTING

African American-Diabetes Heart Study.

PATIENTS

Participants were 56.7% female with mean ± standard deviation (sd) age 55.6 ± 9.6 years, diabetes duration 10.3 ± 8.2 years, and eGFR 90.9 ± 22.1 ml/min/1.73 m(2).

INTERVENTIONS

None.

MAIN OUTCOMES AND MEASURES

Associations tested between vitamin D and the previously mentioned phenotypes adjusting for age, sex, African ancestry proportion, diabetes duration, statins, smoking, changes in estimated glomerular filtration rate, body mass index, hemoglobin A1c, and blood pressure.

RESULTS

1,25OH2D was inversely associated with change in coronary artery CP (parameter estimate [β] -0.005, standard error [SE] 0.002; P = .037), with a trend for change in carotid artery CP (β -0.007, SE 0.004; P = .074). Further adjustment for renin-aldosterone-system blockade revealed inverse association between 1,25OH2D and change in albuminuria (β -0.004, SE 0.002; P = .037). DBP, BAVD, and 25OHD did not associate significantly with changes in albuminuria, CP, or bone mineral density. BAVD was inversely associated with visceral, subcutaneous, intermuscular, and pericardial adipose volumes.

CONCLUSIONS

In contrast to BAVD and 25OHD, only 1,25OH2D levels were significantly and inversely associated with changes in subclinical atherosclerosis and albuminuria in African Americans, suggesting potential beneficial effects.

Electrochemical Skin Conductance in Diabetic Kidney Disease

BACKGROUND

There is a need to identify patients with diabetic kidney disease (DKD) using noninvasive, cost-effective screening tests. Sudoscan®, a device using electrochemical skin conductance (ESC) to measure sweat gland dysfunction, is valuable for detecting peripheral neuropathy. ESC was tested for association with DKD (estimated glomerular filtration rate (eGFR) <60 ml/min/1.73 m(2)) in 383 type 2 diabetes mellitus (T2D)-affected patients; diagnostic thresholds were determined in 540 patients.

METHODS

Relationships between ESC with eGFR and urine albumin:creatinine ratio (UACR) were assessed in 202 European Americans and 181 African Americans with T2D.

RESULTS

In 92 European American DKD cases and 110 T2D non-nephropathy controls, respectively, mean (SD) ages were 69 (9.7) and 61 (10.8) years, hemoglobin A1c (HbA1c) 7.4 (1.2) and 7.4 (1.3)%, eGFR 29.6 (12.2) and 87.8 (14.2) ml/min/1.73 m(2), and UACR 1,214 (1,705) and 7.5 (5.8) mg/g. In 57 African American cases and 124 controls, respectively, mean (SD) ages were 64.0 (11.9) and 59.5 (9.7) years, HbA1c 7.4 (1.3) and 7.5 (1.7)%, eGFR 29.6 (13.3) and 90.2 (16.2) ml/min/1.73 m(2), and UACR 1,172 (1,564) and 7.8 (7.1) mg/g. Mean (SD) ESC (μS) was lower in cases than controls (European Americans: case/control hands 49.5 (18.5)/62.3 (16.2); feet 62.1 (17.9)/73.6 (13.8), both p < 1.3 × 10(-6); African Americans: case/control hands 39.8 (19.0)/48.5 (17.1); feet 53.2 (21.3)/63.5 (19.4), both p ≤ 0.01). Adjusting for age, sex, body mass index and HbA1c, hands and feet ESC associated with eGFR <60 ml/min/1.73 m(2) (p ≤ 7.2 × 10(-3)), UACR >30 mg/g (p ≤ 7.0 × 10(-3)), UACR >300 mg/g (p ≤ 8.1 × 10(-3)), and continuous traits eGFR and UACR (both p ≤ 5.0 × 10(-9)). HbA1c values were not useful for risk stratification.

CONCLUSIONS

ESC measured using Sudoscan® is strongly associated with DKD in African Americans and European Americans. ESC is a useful screening test to identify DKD in patients with T2D.

Nulliparity is associated with less healthy markers of subclinical cardiovascular disease in young women with overweight and obesity

OBJECTIVE

Higher parity is associated with increased subclinical cardiovascular disease (CVD) in mid-life and older women and with increased CVD risk overall. The relationship between parity, subclinical CVD, and infertility in young women with overweight and obesity has been infrequently evaluated.

METHODS

Reproductive histories were obtained in 191 (66%) young women with overweight and obesity (BMI 25-39.9 kg/m(2) ) participating in a weight loss trial. Baseline carotid intima-media thickness (IMT) and inter-adventitial diameter (IAD) were assessed via B-mode ultrasound. Linear regression was used to estimate the relationship between parity and carotid measures, adjusted for demographic, cardiovascular, and reproductive risk factors.

RESULTS

Nulliparous women (n = 70, age 34.9 ± 7.1) had increased common carotid IAD (0.230 mm, SE 0.08, P = 0.003) and mean common carotid artery (CCA) IMT (0.031 mm, SE 0.01, P = 0.007) compared with parous women (n = 102, age 39.5 ± 4.9), persisting after adjustment for age, race, and CVD risk factors. No other reproductive factors were statistically significantly associated.

CONCLUSIONS

Nulliparity is associated with markers of less healthy carotid arteries in a sample of disease-free 25- to 45-year-old women with overweight or obesity. This may represent a beneficial effect of pregnancy or indicate overall better health in women with overweight/obesity who are capable of childbearing.

APOL1 associations with nephropathy, atherosclerosis, and all-cause mortality in African Americans with type 2 diabetes

Albuminuria and reduced estimated glomerular filtration rate (eGFR) associate with two apolipoprotein L1 gene (APOL1) variants in nondiabetic African Americans (AAs). Whether APOL1 associates with subclinical atherosclerosis and survival remains unclear. To determine this, 717 African American-Diabetes Heart Study participants underwent computed tomography to determine coronary artery-, carotid artery-, and aorta-calcified atherosclerotic plaque mass scores in addition to the urine albumin:creatinine ratio (UACR), eGFR, and C-reactive protein (CRP). Associations between mass scores and APOL1 were assessed adjusting for age, gender, African ancestry, body mass index (BMI), hemoglobin A1c, smoking, hypertension, use of statins and angiotensin-converting enzyme inhibitors, albuminuria, and eGFR. Participants were 58.9% female with mean age 56.5 years, eGFR 89.5 ml/min per 1.73 m(2), UACR 169.6 mg/g, and coronary artery-, carotid artery-, and aorta-calcified plaque mass scores of 610, 171, and 5378, respectively. In fully adjusted models, APOL1 risk variants were significantly associated with lower levels of carotid artery-calcified plaque (β=-0.42, s.e. 0.18; dominant model) and marginally lower coronary artery plaque (β=-0.36, s.e. 0.21; dominant model), but not with aorta-calcified plaque, CRP, UACR, or eGFR. By the end of a mean follow-up of 5.0 years, 89 participants had died. APOL1 nephropathy risk variants were significantly associated with improved survival (hazard ratio 0.67 for one copy; 0.44 for two copies). Thus, APOL1 nephropathy variants associate with lower levels of subclinical atherosclerosis and reduced risk of death in AAs with type 2 diabetes mellitus.

Relationship of Dickkopf1 (DKK1) with cardiovascular disease and bone metabolism in Caucasian type 2 diabetes mellitus

Objectives

Dickkopf-1 (DKK1) is a potent inhibitor of Wnt signalling, which exerts anabolic effects on bone and also takes part in the regulation of vascular cells. Our aims were to evaluate serum DKK1 in type 2 diabetes (T2DM) patients and to analyze its relationships with cardiovascular disease (CVD). We also evaluated the relationship between DKK1 and bone metabolism.

Design

We conducted a cross-sectional study in which we measured serum DKK1 (ELISA, Biomedica) in 126 subjects: 72 patients with T2DM and 54 non-diabetic subjects. We analysed its relationship with clinical CVD, preclinical CVD expressed as carotid intima media thickness (IMT), and bone metabolism.

Results

T2DM patients with CVD (P = 0,026) and abnormal carotid IMT (P = 0,038) had higher DKK1 concentrations. DKK1 was related to the presence of CVD in T2DM, independently of the presence of risk factors for atherosclerosis. Therefore, for each increase of 28 pg/ml of serum DKK1 there was a 6,2% increase in the risk of CVD in T2DM patients. The ROC curve analysis to evaluate the usefulness of DKK1 as a marker for high risk of CVD showed an area under the curve of 0,667 (95% CI: 0,538–0,795; P = 0,016). In addition, there was a positive correlation between serum DKK1 and spine bone mineral density in the total sample (r = 0,183; P = 0,048).

Conclusion

In summary, circulating DKK1 levels are higher in T2DM with CVD and are associated with an abnormal carotid IMT in this cross-sectional study. DKK1 may be involved in vascular disease of T2DM patients.

Prevalence and determinants of electrocardiographic abnormalities in African Americans with type 2 diabetes

Background: Electrocardiographic (ECG) abnormalities are independently associated with poor outcomes in the general population. Their prevalence and determinants were assessed in the understudied African American population with type 2 diabetes.

Methods: Standard 12-lead ECGs were digitally recorded in 635 unrelated African American-Diabetes Heart Study (AA-DHS) participants, automatically processed at a central lab, read, and coded using standard Minnesota ECG Classification. Age- and sex-specific prevalence rates of ECG abnormalities were calculated and logistic regression models were fitted to examine cross-sectional associations between participant characteristics and ECG abnormalities.

Results: Participants were 56% women with a mean age of 56 years; 60% had at least one minor or major ECG abnormality [23% ⩾1 major (or major plus minor), and 37% ⩾1 minor (with no major)]. Men had a higher prevalence of ⩾1 minor or major ECG abnormality (66.1% men vs. 55.6% women, p = 0.0089). In univariate analysis, age, past history of cardiovascular disease, diabetes duration, systolic blood pressure, sex and statin use were associated with the presence of any (major or minor) ECG abnormalities. In a multivariate model including variables, female sex (OR [95% CI] 0.79 [0.67, 0.93]), statin use (0.79 [0.67, 0.93]) and diabetes duration (1.03 [1.0, 1.05]) remained statistically significant.

Conclusions: Nearly three out of five African Americans with diabetes had at least one ECG abnormality. Female sex and statin use were significantly associated with lower odds of any ECG abnormality and diabetes duration was significantly associated with higher odds of any ECG abnormality in the multivariable model.

Sclerostin is positively associated with bone mineral density in men and women and negatively associated with carotid calcified atherosclerotic plaque in men from the African American-Diabetes Heart Study

CONTEXT

Bone mineral density (BMD) and calcified atherosclerotic plaque (CP) demonstrate inverse relationships. Sclerostin, an endogenous regulator of the Wnt pathway and bone formation, has been associated with impaired osteoblast activation and may play a role in vascular calcification.

OBJECTIVE

Our objective was to assess the relationships between sclerostin, BMD, and CP.

DESIGN

Generalized linear models were fitted to test for associations between sclerostin, volumetric BMD (vBMD), and CP.

PARTICIPANTS

A targeted population of 450 unrelated African Americans (AAs) with type 2 diabetes (T2D) was 56% female with mean/SD/median age of 55.4/9.5/55.0 years and a diabetes duration of 10.3/8.2/8.0 years.

MAIN OUTCOME MEASURES

Plasma sclerostin, computed tomography-derived thoracic and lumbar vertebrae trabecular vBMD, coronary artery, carotid artery, and aortoiliac CP were measured.

RESULTS

Plasma sclerostin was 1119/401/1040 pg/mL, thoracic vBMD was 206.3/52.4/204.8 mg/cm3, lumbar vBMD was 180.7/47.0/179.0 mg/cm3, coronary artery CP score was 284/648/13, carotid artery CP score was 46/132/0, and aortoiliac CP score was 1613/2910/282. Sclerostin levels were higher in men than women (P<.0001). Before and after adjusting for age, sex, body mass index, blood pressure, smoking, hemoglobin A1c, and low-density lipoprotein-cholesterol, plasma sclerostin levels were positively associated with thoracic and lumbar vertebrae vBMD (P<.0001). Sex-stratified analyses verified significant relationships in both men and women (both P<.001). Sclerostin was not associated with CP except for an inverse relationship with carotid CP in men (fully adjusted model, P=.03).

CONCLUSIONS

In this cross-sectional study of AA men and women with T2D, circulating sclerostin was positively associated with vBMD in the spine in both sexes and inversely associated with carotid artery CP in men. Sclerostin may play a role in skeletal mineral metabolism in AA but fails to explain inverse relationships between BMD and CP.

Population ancestry and genetic risk for diabetes and kidney, cardiovascular, and bone disease: modifiable environmental factors may produce the cures

Variable rates of disease observed between members of different continental population groups may be mediated by inherited factors, environmental exposures, or their combination. This article provides evidence in support of differential allele frequency distributions that underlie the higher rates of nondiabetic kidney disease in the focal segmental glomerulosclerosis spectrum of disease and lower rates of coronary artery calcified atherosclerotic plaque and osteoporosis in populations of African ancestry. With recognition that these and other common complex diseases are affected by biological factors comes the realization that targeted manipulation of environmental exposures and pharmacologic treatments will have different effects based on genotype. The present era of precision medicine will couple one's genetic makeup with specific therapies to reduce rates of disease based on the presence of disease-specific alleles.

Genetic analysis of adiponectin variation and its association with type 2 diabetes in African Americans

OBJECTIVE

Adiponectin is an adipocytokine that has been implicated in a variety of metabolic disorders, including T2D and cardiovascular disease. Studies evaluating genetic variants in ADIPOQ have been contradictory when testing association with T2D in different ethnic groups.

DESIGN AND METHODS

In this study, 18 SNPs in ADIPOQ were tested for association with plasma adiponectin levels and diabetes status. SNPs were examined in two independent African-American cohorts (nmax = 1,116) from the Insulin Resistance Atherosclerosis Family Study (IRASFS) and the African American-Diabetes Heart Study (AA-DHS).

RESULTS

Five polymorphisms were nominally associated with plasma adiponectin levels in the meta-analysis (P = 0.035-1.02 × 10(-6) ) including a low frequency arginine to cysteine mutation (R55C) which reduced plasma adiponectin levels to <15% of the mean. Variants were then tested for association with T2D in a meta-analysis of these and the Wake Forest T2D case-control study (n = 3,233 T2D, 2645 non-T2D). Association with T2D was not observed (P ≥ 0.08), suggesting limited influence of ADIPOQ variants on T2D risk.

CONCLUSIONS

Despite identification of variants associated with adiponectin levels, a detailed genetic analysis of ADIPOQ revealed no association with T2D risk. This puts into question the role of adiponectin in T2D pathogenesis: whether low adiponectin levels are truly causal for or rather a consequence.

Plasma Dickkopf1 (DKK1) concentrations negatively associate with atherosclerotic calcified plaque in African-Americans with type 2 diabetes

BACKGROUND

Bone mineral density (BMD) and atherosclerotic arterial calcified plaque (CP) demonstrate inverse relationships through unknown mechanisms. Dickkopf-1 (DKK1) is an endogenous inhibitor of bone formation, and serum DKK1 has been associated with impaired osteoblast activation and susceptibility to bone loss. Plasma DKK1, BMD in the spine, and CP in three arterial beds were assessed in African-Americans (AAs) to determine relationships of serum DKK1 with atherosclerotic vascular calcification.

METHODS

Plasma DKK1, computed tomography-derived trabecular volumetric BMD (vBMD) in thoracic and lumbar vertebrae, and coronary artery, carotid artery, and aortoiliac CP were measured in 450 unrelated AAs with type 2 diabetes. Generalized linear models were fitted to test for associations between DKK1, vBMD, and CP.

RESULTS

Participants were 56% female with mean/SD/median age of 55.4/9.5/55.0 yr, diabetes duration of 10.3/8.2/8.0 yr, plasma DKK1 of 481.6/271.8/417 pg/ml, coronary artery CP mass score of 284/648/13, carotid artery CP mass score of 46/132/0, and aortoiliac CP mass score of 1613/2910/282. Adjusting for age, sex, body mass index, mean arterial blood pressure, smoking, hemoglobin A(1c), and low-density lipoprotein-cholesterol, DKK1 was inversely associated with coronary artery and aortoiliac CP [parameter estimates -0.0011 (P = 0.0137) and -0.0010 (P = 0.0214), respectively], with a trend for carotid artery CP (P = 0.1404). No associations were observed between DKK1 and vBMD in the thoracic or lumbar vertebrae.

CONCLUSIONS

Plasma DKK1 levels were inversely associated with coronary artery and aortoiliac CP, but not vBMD, in this cross-sectional study of AAs with type 2 diabetes. DKK1 may play a role in vascular mineral metabolism in this clinical setting.

Admixture mapping of coronary artery calcified plaque in African Americans with type 2 diabetes mellitus

BACKGROUND

The presence and severity of coronary artery calcified plaque (CAC) differs markedly between individuals of African and European descent, suggesting that admixture mapping may be informative for identifying genetic variants associated with subclinical cardiovascular disease.

METHODS AND RESULTS

Admixture mapping of CAC was performed in 1040 unrelated African Americans with type 2 diabetes mellitus from the African American-Diabetes Heart Study, Multi-Ethnic Study of Atherosclerosis and Family Heart Study using the Illumina custom ancestry informative marker panel. All cohorts obtained computed tomography scanning of the coronary arteries using identical protocols. For each ancestry informative marker, the probability of inheriting 0, 1, and 2 copies of a European-derived allele was determined. Linkage analysis was performed by testing for association between each ancestry informative marker using these probabilities and CAC, accounting for global ancestry, age, sex, and study. Markers on 1p32.3 in the GLIS1 gene (rs6663966, logarithm of odds [LOD]=3.7), 1q32.1 near CHIT1 (rs7530895, LOD=3.1), 4q21.2 near PRKG2 (rs1212373, LOD=3.0), and 11q25 in the OPCML gene (rs6590705, LOD=3.4) had statistically significant LOD scores, whereas markers on 8q22.2 (rs6994682, LOD=2.7), 9p21.2 (rs439314, LOD=2.7), and 13p32.1 (rs7492028, LOD=2.8) manifested suggestive evidence of linkage. These regions were uniformly characterized by higher levels of European ancestry associating with higher levels or odds of CAC. Findings were replicated in 1350 African Americans without diabetes mellitus and 2497 diabetic European Americans from Multi-Ethnic Study of Atherosclerosis and the Diabetes Heart Study.

CONCLUSIONS

Fine mapping these regions will likely identify novel genetic variants that contribute to CAC and clarify racial differences in susceptibility to subclinical cardiovascular disease.

Relationships between serum MCP-1 and subclinical kidney disease: African American-Diabetes Heart Study

Background

Monocyte chemoattractant protein-1 (MCP-1) plays important roles in kidney disease susceptibility and atherogenesis in experimental models. Relationships between serum MCP-1 concentration and early nephropathy and subclinical cardiovascular disease (CVD) were assessed in African Americans (AAs) with type 2 diabetes (T2D).

Methods

Serum MCP-1 concentration, urine albumin:creatinine ratio (ACR), estimated glomerular filtration rate (eGFR), and atherosclerotic calcified plaque (CP) in the coronary and carotid arteries and infrarenal aorta were measured in 479 unrelated AAs with T2D. Generalized linear models were fitted to test for associations between MCP-1 and urine ACR, eGFR, and CP.

Results

Participants were 57% female, with mean ± SD (median) age 55.6±9.5 (55.0) years, diabetes duration 10.3±8.2 (8.0) years, urine ACR 149.7±566.7 (14.0) mg/g, CKD-EPI eGFR 92.4±23.3 (92.0) ml/min/1.73m², MCP-1 262.9±239.1 (224.4) pg/ml, coronary artery CP 280.1±633.8 (13.5), carotid artery CP 47.1±132.9 (0), and aorta CP 1616.0±2864.0 (319.0). Adjusting for age, sex, smoking, HbA_1c, BMI, and LDL, serum MCP-1 was positively associated with albuminuria (parameter estimate 0.0021, P=0.04) and negatively associated with eGFR (parameter estimate −0.0003, P=0.001). MCP-1 remained associated with eGFR after adjustment for urine ACR. MCP-1 levels did not correlate with the extent of CP in any vascular bed, HbA_1c or diabetes duration, but were positively associated with BMI. No interaction between BMI and MCP-1 was detected on nephropathy outcomes.

Conclusions

Serum MCP-1 levels are associated with eGFR and albuminuria in AAs with T2D. MCP-1 was not associated with subclinical CVD in this population. Inflammation appears to play important roles in development and/or progression of kidney disease in AAs.

Effect of race and genetics on vitamin D metabolism, bone and vascular health

The pathophysiology of chronic kidney disease-mineral and bone disorder accounts for an inverse relationship between bone mineralization and vascular calcification in progressive nephropathy. Inverse associations between bone mineral density (BMD) and calcified atherosclerotic plaque are also observed in individuals of European and African ancestry without nephropathy, suggesting a mechanistic link between these processes that is independent of kidney disease. Despite lower dietary calcium intake and serum 25-hydroxyvitamin D (25(OH)D) concentrations, African Americans have higher BMD and develop osteoporosis less frequently than do European Americans. Moreover, despite having more risk factors for cardiovascular disease, African Americans have a lower incidence and severity of calcified atherosclerotic plaque formation than do European Americans. Strikingly, evidence is now revealing that serum 25(OH)D and/or 1,25 dihydroxyvitamin D levels associate positively with atherosclerosis but negatively with BMD in African Americans; by contrast, vitamin D levels associate negatively with atherosclerosis and positively with BMD in individuals of European ancestry. Biologic phenomena, therefore, seem to contribute to population-specific differences in vitamin D metabolism, bone and vascular health. Genetic and mechanistic approaches used to explore these differences should further our understanding of bone-blood vessel relationships and explain how African ancestry protects from osteoporosis and calcified atherosclerotic plaque, provided that access of African Americans to health care is equivalent to individuals of European ethnic origin. Ultimately, in our opinion, a new mechanistic understanding of the relationships between bone mineralization and vascular calcification will produce novel approaches for disease prevention in aging populations.

Cerebral white matter hyperintensity in African Americans and European Americans with type 2 diabetes

Previous studies involving inner city populations detected higher cerebral white matter hyperintensity (WMH) scores in African Americans (AAs) compared with European Americans (EAs). This finding might be attributable to the higher prevalence of cardiovascular disease (CVD) risk factors and poorer access to healthcare in AAs. Despite racial differences in CVD risk factor profiles, AAs have paradoxically lower levels of subclinical CVD. We hypothesized that AAs with diabetes and good access to healthcare would have comparable or lower levels of WMH as EAs. Racial differences in the distribution of WMH were analyzed in 46 AAs and 156 EAs with type 2 diabetes enrolled in the Diabetes Heart Study (DHS)-Mind, and replicated in a sample of 113 AAs and 61 EAs patients who had clinically indicated cerebral magnetic resonance imaging. Wilcoxon 2-sample tests and linear models were used to compare the distribution of WMH in AAs and EAs and to test for association between WMH and race. The unadjusted mean WMH score from the Diabetes Heart Study-Mind was 1.9 in AAs and 2.3 in EAs (P = .3244). Among those with clinically indicated magnetic resonance imaging, the mean WMH score was 2.9 in AAs and 3.9 in EAs (P = .0503). Adjustment for age and sex produced no statistically significant differences in WMH score between AAs and EAs. These independent datasets reveal comparable WMH scores in AAs and EAs, suggesting that disparities in access to healthcare and environmental exposures likely underlie the previously reported excess burden of WMH in AAs.

Relationships between calcified atherosclerotic plaque and bone mineral density in African Americans with type 2 diabetes

Inverse relationships have been reported between bone mineral density (BMD) and calcified atherosclerotic plaque (CP). This suggests these processes may be related. We examined relationships between BMD and CP in 753 African Americans with type 2 diabetes from 664 families, accounting for the effects of modifiable cardiovascular disease (CVD) risk factors. Association analyses were performed using generalized estimating equations (GEEs) to assess cross-sectional relationships between computed tomography-determined measures of thoracic and lumbar vertebral volumetric BMD (vBMD) and CP in the coronary and carotid arteries and infrarenal aorta. Significant inverse associations were seen between thoracic and lumbar vBMD and CP in all three vascular beds in unadjusted analyses. A fully adjusted model accounting for age, sex, body mass index, systolic blood pressure, low-density lipoprotein cholesterol, C-reactive protein, hemoglobin A(1c), smoking, and hormone-replacement therapy revealed significant inverse associations between thoracic vBMD and CP in coronary and carotid arteries and aorta, whereas lumbar vBMD was associated with CP in coronary artery and aorta. Inverse associations exist between vertebral BMD and calcified atherosclerotic plaque in African-American men and women with type 2 diabetes. This relationship was independent of conventional CVD risk factors and supports the hypothesis that bone metabolism and atherosclerotic plaque mineralization are related processes.

Effects of race on albuminuria and risk of cardiovascular and kidney disease

The literature describing the relationship between urinary protein excretion and risk of cardiovascular disease and renal disease is rapidly proliferating. Several studies have demonstrated racial differences in the relationship between albuminuria and associated disorders. The purpose of this article is to summarize the effects of race on the relationship between albuminuria and renal and cardiovascular disease risk, propose explanatory hypotheses, and suggest directions for future investigation.

Carotid artery intima-media thickness in college students: race/ethnicity matters

OBJECTIVE

Racial/ethnic differences in common carotid artery intima-media thickness (CIMT) and in risk factors associated with CIMT have been predominantly observed in middle-aged and older individuals. We aimed to characterize racial/ethnic differences CIMT and other cardiovascular risk factors in a healthy, young-adult population.

METHODS

College students were recruited as part of a study to characterize determinants of atherogenesis. Students were eligible if they were lifetime non-smokers, lived in the United States since six months of age, and attended high school in the United States. Blood pressure, heart rate, height, and weight were measured, B-mode carotid ultrasound was performed, questionnaires were administered and a 12-h fasting blood sample was collected. Associations between CIMT and other variables were assessed in 768 students aged 18-25 years using linear regression analysis.

RESULTS

In models adjusted for common cardiovascular risk factors, sex exhibited the strongest influence on CIMT, with men having 15.4 μm larger CIMT compared to women (95%CI 6.6, 24.2). Race/ethnicity was also strongly associated with CIMT. African Americans had 17.3 μm greater CIMT (95%CI -0.3, 34.8) compared to non Hispanic Whites, whereas Asians and Hispanic Whites had 14.3 (95%CI -24.3, -4.4) and 15.4 (95%CI -26.2, -4.7) μm smaller CIMT, respectively. BMI and systolic blood pressure were positively associated with CIMT.

CONCLUSION

The risk factors associated with atherogenesis later in life are already present and observable in college-aged young adults, so targeted campaigns to reduce life-long cardiovascular disease burden should be initiated earlier in life to improve public health.

Correlates of coronary artery calcified plaque in blacks and whites with type 2 diabetes

PURPOSE

To examine whether the relationship between cardiovascular disease risk factors and coronary artery calcification (CAC) is modified by race among those with diabetes.

METHODS

Data were pooled data from three studies (Multi-Ethnic Study of Atherosclerosis, Family Heart Study, Diabetes Heart Study) for a total of 835 blacks and 1122 whites with diabetes. CAC was quantified by cardiac computed tomography and risk factors were obtained using standard methods. Regression models examined the relationship between risk factors and presence and quantity of CAC.

RESULTS

The average age of the cohort was 60 years; 57% were women. Presence of CAC was lower in blacks compared to whites (odds ratio = 0.22 for men, 0.57 for women, p <0.01). Hemoglobin A1c, duration of diabetes, low-density lipoprotein, smoking, and body mass index were independently associated with presence of CAC; high-density lipoprotein, triglycerides, and C-reactive protein were not. Race did not modify these associations. Adjustment for multiple risk factors did not explain the race disparity in CAC.

CONCLUSIONS

CAC was reduced in blacks compared to whites in persons with diabetes. This effect was most pronounced in men. The relationship between risk factors and CAC did not differ between races. Racial differences in CAC are likely due to unmeasured risk factors and/or genetic susceptibility.

Ethnic differences in the relationship between pericardial adipose tissue and coronary artery calcified plaque: African-American-diabetes heart study

BACKGROUND

Calcified atherosclerotic plaque (CP) is less prevalent and less severe in African-Americans (AA), relative to European Americans (EA). Because pericardial adipose tissue (PAT) is associated with CP in the neighboring coronary arteries, we explored ethnic-specific relationships between PAT and CP.

METHODS

PAT volume and coronary and aortic CP were measured in 561 EA and 575 AA subjects with type 2 diabetes using single and multidetector computed tomography. Generalized estimating equations with exchangeable correlation and the sandwich estimator of the variance were used to test for associations between PAT and CP.

RESULTS

Mean (sd) ages of AA and EA participants were 56.7 (9.5) and 62.0 (8.9) yr, respectively; diabetes duration was 10.5 (8.1) and 10.1 (7.3) yr; and PAT volume was 86.9 (38.6) and 131.7 (55.3) cm3/45 mm. In AA and EA participants, respectively, mean (sd) coronary CP mass scores were 803 (1,889) and 1,465 (2,847) mg calcium; and aortic CP, 5,407 (10,651) and 10,090 (15,087) mg calcium. Adjusting for age, gender, body mass index, blood pressure, height, smoking, lipid-lowering medications, C-reactive protein, albuminuria, high-density lipoprotein-cholesterol, and triglycerides, parameter estimates for the relationship between PAT and log(coronary CP+1) were 0.012 in AA (P<0.0001) and 0.003 (P=0.24) in EA, with a significant ethnic difference (P=0.019). No significant relationships or ethnic differences were observed between PAT and aortic CP (P=0.24, fully adjusted model).

CONCLUSIONS

Pericardial adiposity is strongly associated with coronary atherosclerosis in AA with type 2 diabetes. Novel cardiovascular disease risk factors such as PAT may contribute to ethnic disparities in susceptibility to development of coronary atherosclerosis.

Review of the Diabetes Heart Study (DHS) family of studies: a comprehensively examined sample for genetic and epidemiological studies of type 2 diabetes and its complications

The Diabetes Heart Study (DHS) is a genetic and epidemiological study of 1,443 European American and African American participants from 564 families with multiple cases of type 2 diabetes. Initially, participants were comprehensively examined for measures of subclinical cardiovascular disease (CVD) including computed tomography measurement of vascular calcified plaque, ultrasound imaging of carotid artery wall thickness, and electrocardiographic intervals. Subsequent studies have investigated the relationship between bone mineral density and vascular calcification, measures of adiposity, and biomarkers. Ongoing studies are carrying out an extensive evaluation of cerebrovascular disease using magnetic resonance imaging and cognitive assessment. A second, parallel study, the African American DHS, has expanded the sample of African Americans to investigate marked racial differences in subclinical CVD between European Americans and African Americans. Studies in development will evaluate the impact of social stress during the lifecourse on CVD risk, and the prevalence of gastroparesis in this diabetes enriched sample. In addition, the ongoing high mortality rate in DHS participants provides novel insights into the increased risks for type 2 diabetes affected individuals. A comprehensive genetic analysis of the sample is underway using the genome-wide association study (GWAS) approach. Data from this GWAS survey will complement prior family-based linkage data in the analysis of genetic contributors to the wide range of traits in the sample. To our knowledge the DHS family of studies has created the most comprehensively examined sample of individuals with type 2 diabetes yet available, and represents a unique resource for the study people with type 2 diabetes. The aim of this review is to provide a collective overview of the major results from the DHS family of studies, and relate them to the larger body of biomedical investigations of diabetes and its complications.

Regional adipose tissue associations with calcified atherosclerotic plaque: African American-diabetes heart study

Coronary artery calcified atherosclerotic plaque (CP) is strongly associated with nonsubcutaneous adipose tissue, particularly pericardial adipose tissue (PAT), in community-based studies. We tested for relationships between regional adipose tissue depots and CP in African Americans with longstanding type 2 diabetes. Infrarenal aorta, coronary, and carotid artery CP and pericardial, visceral, intermuscular, and subcutaneous organ-specific adipose tissue volumes were measured using single and multidetector computed tomography (CT) in 422 African Americans with type 2 diabetes. Generalized estimating equations using exchangeable correlation and the sandwich estimator of the variance were used to test for associations between CP and adipose tissue depots. Mean (s.d.) age was 56.5 (7.6) years, diabetes duration 10.3 (7.6) years, PAT 85.3 (36.1) cm(3)/45 mm and visceral adipose tissue (VAT) 174.9 (70.1) cm(3)/15 mm. Adjusting for age, gender, BMI, blood pressure, medications, proteinuria, smoking, lipids, and 25-hydroxyvitamin D, PAT was positively associated with the presence (P = 0.009) and quantity of coronary artery CP in African Americans (P = 0.004), as well as the quantity of infrarenal aorta CP (P = 0.004). As in European Americans, PAT is associated with CP in African Americans with type 2 diabetes. Ethnic differences in the relationships between organ-specific adipose tissue depots and atherosclerosis require further study.

Potential effects of MYH9-associated nephropathy on dialysis and kidney transplant outcomes

Several related disorders comprise the spectrum of nonmuscle myosin heavy chain 9-associated (MYH9) nephropathy. The contribution of variants in this single MYH9 gene to ethnic differences in the incidence rates of end-stage renal disease is now clearly established. The importance of recognizing the role of MYH9 in these inherited kidney disorders goes beyond simple disease association; there may well be effects on clinical outcomes in patients on dialysis and after kidney transplantation. MYH9 polymorphisms may affect treatment outcomes in severe kidney disease and such gene effects are rarely encountered in practice.

Vitamin d, adiposity, and calcified atherosclerotic plaque in african-americans

CONTEXT

Inverse associations are reported between circulating 25-hydroxyvitamin D and visceral adiposity. The effects of vitamin D levels on atherosclerosis are unknown.

OBJECTIVE

The objective of this study was to test for relationships between vitamin D, adiposity, bone density, and atherosclerosis in African-Americans.

DESIGN

Circulating 25-hydroxyvitamin D, 1,25 dihydroxyvitamin D, intact PTH, C-reactive protein and computed tomography-derived calcified atherosclerotic plaque (CP), bone density, and fat volumes were measured.

SETTING

Examinations were performed at a single outpatient general clinical research center visit.

SUBJECTS

Three hundred forty African-Americans with type 2 diabetes were evaluated. Mean +/- SD age was 55.6 +/- 9.6 yr, diabetes duration 10.6 +/- 8.3 yr, glomerular filtration rate 1.6 +/- 0.5 ml/sec, body mass index 35.6 +/- 8.7 kg/m(2), and 25-hydroxyvitamin D concentration 50.4 +/- 30.5 nmol/liter.

MAIN OUTCOME MEASURE

Biomarkers were tested for association with pericardial, visceral, im, and sc adipose tissues; thoracic and lumbar vertebral bone density; and aorta, coronary, and carotid artery CP.

RESULTS

Adjusting for age, gender, body mass index, glycosylated hemoglobin, and glomerular filtration rate, 25-hydroxyvitamin D was negatively associated with visceral adiposity (P = 0.009) and positively associated with carotid artery CP and aorta CP (P = 0.013 and 0.014, respectively) but not with coronary artery CP or bone density.

CONCLUSIONS

We confirmed an inverse association between vitamin D and visceral adiposity in African-Americans with diabetes. In addition, positive associations exist between 25-hydroxyvitamin D and aorta and carotid artery CP in African-Americans. The effects of supplementing vitamin D to raise the serum 25-hydroxyvitamin D level on atherosclerosis in African-Americans are unknown. Prospective trials are needed to determine the cardiovascular effects of supplemental vitamin D in this ethnic group.

Ethnic differences in the relationship between albuminuria and calcified atherosclerotic plaque: the African American-diabetes heart study

OBJECTIVE

Despite higher rates of nephropathy, calcified atherosclerotic plaque is less prevalent in African Americans with diabetes relative to European Americans. We explored ethnicity-specific relationships between albuminuria and calcified plaque involving the infrarenal aorta, coronary artery, and carotid artery in 835 European American and 393 African American subjects with type 2 diabetes.

RESEARCH DESIGN AND METHODS

Generalized estimating equations with exchangeable correlation and the sandwich estimator of the variance were used to test for association between the principal component of calcified plaque in the three vascular beds and urine albumin-to-creatinine ratio (ACR).

RESULTS

Mean +/- SD ages of African American and European American participants were 56.7 +/- 9.6 and 61.7 +/- 9.1 years, respectively, with diabetes duration of 10.4 +/- 7.4 and 10.0 +/- 7.3 years and median urine ACR of 17.5 and 13.4 mg/g. In African American and European American participants, respectively, median calcified plaque mass scores were 53.5 and 291 for coronary artery, 3 and 35.5 for carotid artery, and 761 and 3,237 for aorta. With adjustment for age, sex, glomerular filtration rate, and BMI, albuminuria was significantly associated with calcified plaque in European Americans (P = 3.4 x 10(-8)) but not in African Americans (P = 0.33), with significant ethnic interaction (P = 0.01). Ethnic differences in this relationship persisted after adjustment for blood pressure, smoking, lipids, and use of ACE inhibitors or angiotensin receptor blockers.

CONCLUSIONS

Albuminuria is strongly associated with severity of calcified plaque in European Americans with diabetes but not in African Americans. Disparities in this relationship may contribute to ethnic differences in the rates of cardiovascular disease that are observed in subjects with type 2 diabetes.

Bone morphogenetic protein 7 (BMP7) gene polymorphisms are associated with inverse relationships between vascular calcification and BMD: the Diabetes Heart Study

Inverse relationships have been observed between BMD and vascular calcification (VC), suggesting an underlying metabolic pathway linking these processes. Bone morphogenetic proteins (BMPs) are potential candidate genes that may mediate this relationship. Four single nucleotide polymorphisms (SNPs) in the BMP2 gene, 2 SNPs in BMP4, and 16 SNPs in BMP7 were tested for association with measures of VC using CT (coronary and carotid arteries, abdominal aorta), and BMD was measured using DXA (lumbar spine, hip, and distal radius) and quantitative CT (QCT; thoracic and lumbar spine) in 920 European Americans from 374 Diabetes Heart Study families: 762 with type 2 diabetes. Variance components quantitative trait locus association analysis was computed using SOLAR software, and a bivariate principal component analysis (PCA) assessed for genetic relationships between BMD and VC. Association was observed between several measures of BMD and BMP7 rs17404303 (thoracic spine QCT p = 0.03; lumbar spine QCT p = 0.02; hip DXA p = 0.06, dominant models). In addition, 6 of 16 BMP7 SNPs showed significant and opposing effects on the bivariate PCA for VC and BMD (two-sided exact test, p = 0.0143). Polymorphisms in BMP7 are associated with inverse relationships between bone mineralization and VC in the coronary, carotid, and abdominal aorta in a diabetes-enriched cohort of European Americans.

Cardiovascular disease in chronic kidney disease

The presence of kidney disease, manifested by low glomerular filtration rates (GFR) and/or large amounts of protein in the urine, is independently associated with increased rates of cardiovascular disease (CVD). The severity of kidney disease is associated with graded increases in risk for CVD and death. Chronic kidney disease (CKD) should be recognized and treatment initiated early to maximize the chances for slowing nephropathy progression and reducing proteinuria. We recommend screening for CKD in all patients with CVD, including computing an estimated GFR and evaluating for proteinuria using a spot urine albumin:creatinine ratio. Aggressive management of traditional cardiovascular risk factors should be employed in this high-risk population, specifically rigorous hypertension control (including the use of angiotensin-converting enzyme inhibitors (ACEI)/angiotensin receptor blocking agents (ARB)), management of hyperglycemia, hyperlipidemia and smoking cessation. Further studies are needed to identify the unique renal failure-related (non-traditional) risk factors that contribute to accelerated atherosclerosis in this population and performance of randomized trials to assess the effects of cardiovascular interventions in individuals with CKD.

Ethnic variation in the correlation between random serum glucose concentration and glycated haemoglobin

AIMS

To determine if the relationship between serum glucose concentration and glycated haemoglobin is different between African-Americans and whites.

METHODS

Retrospective cross-sectional study comparing the association between glycated haemoglobin and serum glucose levels, based upon ethnicity. Two databases were evaluated: (i) 4215 African-American and 6359 white outpatients who had simultaneous glycated haemoglobin, random serum glucose and creatinine concentration measurements between 2000 and 2007 at the North Carolina Baptist Hospital and (ii) 1021 white and 312 African-American Diabetes Heart Study (DHS) participants.

RESULTS

In North Carolina Baptist Hospital clinic attendees, a given glycated haemoglobin was associated with higher serum glucose concentrations in African-Americans compared with whites. In a multivariate model with glycated haemoglobin as the outcome variable, racial differences remained significant after adjustment for serum glucose, age, gender and kidney function. For individuals with a serum glucose between 5.6 and 8.3 mmol/l, the glucose : glycated haemoglobin ratio was 1.03 +/- 0.16 mmol/l/% in white individuals and 0.99 +/- 0.17 mmol/l/% in African-Americans (P < 0.0001). For a glycated haemoglobin value of 7.0%, there was a 0.98-mmol/l difference in predicted serum glucose concentration in 50-year-old African-American men, relative to white. Results were replicated in the DHS, where in a best-fit linear model, after adjustment for glucose, African-American race was a significant predictor of glycated haemoglobin (P < 0.0001).

CONCLUSIONS

African-Americans have higher glycated haemoglobin values at given serum glucose concentrations relative to whites. This finding may contribute to the observed difference in glycated haemoglobin values reported between these race groups.

Insulin sensitivity in African-American and white women: association with inflammation

Whether the contribution of inflammation to risk for chronic metabolic disease differs with ethnicity is not known. The objective of this study was to determine: (i) whether ethnic differences exist in markers of inflammation and (ii) whether lower insulin sensitivity among African Americans vs. whites is due to greater inflammatory status. Subjects were African-American (n = 108) and white (n = 105) women, BMI 27-30 kg/m(2). Insulin sensitivity was assessed with intravenous glucose tolerance test and minimal modeling; fat distribution with computed tomography; body composition with dual-energy X-ray absorptiometry; markers of inflammation (tumor necrosis factor (TNF)-alpha, soluble tumor necrosis factor receptor (sTNFR)-1, sTNFR-2, C-reactive protein (CRP), and interleukin (IL)-6) with enzyme-linked immunosorbent assay (ELISA). Whites had greater intra-abdominal adipose tissue (IAAT), insulin sensitivity, and concentrations of TNF-alpha, sTNFR-1, and sTNFR-2 than African Americans. Greater TNF-alpha in whites vs. African Americans was attributed to greater IAAT in whites. Among whites, but not African Americans, CRP was independently and inversely associated with insulin sensitivity, after adjusting for IAAT (r = -0.29 P < 0.05, and r = -0.13 P = 0.53, respectively). Insulin sensitivity remained lower in African Americans after adjusting for CRP (P < 0.001). In conclusion, greater IAAT among whites may be associated with greater inflammation. Insulin sensitivity was lower among African Americans, independent of obesity, fat distribution, and inflammation.

Differences in subclinical cardiovascular disease between African American and Caucasian women with systemic lupus erythematosus

Racial differences exist in disease rates and mortality in both cardiovascular disease (CVD) and systemic lupus erythematosus (SLE). The objective of this cross-sectional study was to compare the frequency and risk factors for subclinical CVD in African American (AA) and Caucasian women with SLE and no prior CVD events. Traditional CVD risk factors and SLE-related factors were assessed in 309 SLE women. Subclinical CVD was assessed by carotid ultrasound to measure intimamedial thickness (IMT) and plaque, and electron beam computed tomography (EBCT) was used to measure coronary artery calcium (CAC). AA women had less education and higher levels of body mass index, blood pressure, lipoprotein(a), C-reactive protein (CRP), fibrinogen, and erythrocyte sedimentation rate (ESR). However, AA women had lower albumin, more and longer duration of corticosteroid use, higher SLE disease activity and damage, and more dsDNA antibodies compared with Caucasian women after adjustment for age and study site. More AA women had carotid plaque (adjusted odds ratio [OR], 1.94; 95% confidence interval [CI], 1.03-3.65) and higher carotid IMT (0.620 vs 0.605 mm, P = 0.07) but similar CAC compared with Caucasians. A multivariate analysis revealed that the following risk factor variables were significantly different between the racial groups and associated with plaque: blood pressure, current corticosteroid use, SLE disease activity, and SLE damage. All factors contributed to the result, but no individual risk factor fully accounted for the association between race and plaque. In conclusion, the presence of carotid plaque was higher in AA compared with Caucasian women with SLE, in contrast to studies of non-SLE subjects, in which AA have similar or less plaque than Caucasians. A combination of SLE-related and traditional CVD risk factors explained the racial difference in plaque burden.

Comparison of common carotid artery intima-media thickness between Brazilian Euro-descendants and Afro-descendants with atherosclerosis risk factors

OBJECTIVE

To compare common carotid intima-media thickness (IMT) between the two major Brazilian ethnic groups (those of African descent and those of European descent) among individuals with one or more risk factors for atherosclerotic disease.

METHOD

Two hundred and six patients with one or more risk factors for atherosclerotic disease were evaluated in a cross-sectional study in which their clinical, ethnic and Demographic characteristics were collected. All patients underwent duplex ultrasound examination of their carotid vessels to obtain IMT measurements.

RESULTS

One hundred and fifty-three patients (74.3%) had a carotid IMT greater than 1.0 mm at one or more point of measurement in at least one common carotid artery. There was a significant correlation between older age and mean carotid wall thickness (R=0.479 / P<0.01). Multivariate analysis identified male sex, arterial hypertension and older age as variables associated with increased IMT (P<0.05 for all variables). When IMT was compared between the two ethnic groups in this study, no significant differences were noted. Euro-descendants and Afro-descendants had similar IMT values, even when the groups were stratified by degree of IMT (normal vs. increased) and presence of stroke and/or transient ischemic attack (yes vs. no).

CONCLUSIONS

The risk factors associated with increased common carotid artery IMT in Brazilian individuals are similar to those in previously described populations. No differences were observed between the two main Brazilian ethnic groups. Longitudinal studies are required for a better evaluation of the incidence, etiologic factors and evolution of carotid intimomedial thickening in this population.