Hossein Bahrami

Differences in the Incidence of Congestive Heart Failure by Ethnicity : The Multi-Ethnic Study of Atherosclerosis

BACKGROUND The relationship between incident congestive heart failure (CHF) and ethnicity as well as racial/ethnic differences in the mechanisms leading to CHF have not been demonstrated in a multiracial, population-based study. Our objective was to evaluate the relationship between race/ethnicity and incident CHF. METHODS The Multi-Ethnic Study of Atherosclerosis (MESA) is a cohort study of 6814 participants of 4 ethnicities: white (38.5%), African American (27.8%), Hispanic (21.9%), and Chinese American (11.8%). Participants with a history of cardiovascular disease at baseline were excluded. Cox proportional hazards models were used for data analysis. RESULTS During a median follow-up of 4.0 years, 79 participants developed CHF (incidence rate: 3.1 per 1000 person-years). African Americans had the highest incidence rate of CHF, followed by Hispanic, white, and Chinese American participants (incidence rates: 4.6, 3.5, 2.4, and 1.0 per 1000 person-years, respectively). Although risk of developing CHF was higher among African American compared with white participants (hazard ratio, 1.8; 95% confidence interval, 1.1-3.1), adding hypertension and/or diabetes mellitus to models including ethnicity eliminated statistical ethnic differences in incident CHF. Moreover, African Americans had the highest proportion of incident CHF not preceded by clinical myocardial infarction (75%) compared with other ethnic groups (P = .06). CONCLUSIONS The higher risk of incident CHF among African Americans was related to differences in the prevalence of hypertension and diabetes mellitus as well as socioeconomic status. The mechanisms of CHF also differed by ethnicity; interim myocardial infarction had the least influence among African Americans, and left ventricular mass increase had the greatest effect among Hispanic and white participants.

Novel metabolic risk factors for incident heart failure and their relationship with obesity: the MESA (Multi-Ethnic Study of Atherosclerosis) study.

OBJECTIVES The objectives of this study were to determine the associations of the metabolic syndrome, inflammatory markers, and insulin resistance with incident congestive heart failure (CHF), beyond established risk factors, and to examine whether these risk factors may provide the link between obesity and CHF. BACKGROUND Recently, increasing interest has emerged on the potential role of novel risk factors such as systemic inflammation, insulin resistance, and albuminuria in the pathophysiology of CHF and their relationship with obesity. METHODS The MESA (Multi-Ethnic Study of Atherosclerosis) study is a community-based multicenter cohort study of 6,814 participants (age 45 to 84 years, 3,601 women) of 4 ethnicities: Caucasians, African Americans, Hispanics, and Chinese Americans. Participants were recruited between 2000 and 2002 from 6 U.S. communities. Median follow-up time was 4 years. Participants with history of symptomatic cardiovascular disease were excluded. Cox proportional hazards models were used to analyze the associations of the metabolic syndrome, inflammatory markers, insulin resistance, and albuminuria with incident CHF, independent of established risk factors (age, gender, hypertension, diabetes mellitus, left ventricular hypertrophy, obesity, serum total cholesterol, and smoking), an interim myocardial infarction, and baseline magnetic resonance imaging parameters of left ventricular structure and function. RESULTS A total of 79 participants developed CHF during follow-up, and 26 participants (32.9%) had a myocardial infarction prior to CHF and 65% of the cases had CHF with preserved function (left ventricular ejection fraction >or=40%). In multivariable analyses, serum interleukin-6 (hazard ratio [HR] for 1 standard deviation 1.50, 95% confidence interval [CI] 1.10 to 2.03) or C-reactive protein (HR for 1 standard deviation 1.38; 95% CI 1.01 to 1.86) and macroalbuminuria (HR 4.31, 95% CI 1.58 to 11.76) were predictors of CHF, independent of obesity and the other established risk factors. Although obesity was significantly associated with incident CHF, this association was no longer significant after adding inflammatory markers (interleukin-6 or C-reactive protein) to the model. CONCLUSIONS Inflammatory markers and albuminuria are independent predictors of CHF. The association of obesity and CHF may be related to pathophysiologic pathways associated with inflammation.

Clinical ResearchHeart FailureNovel Metabolic Risk Factors for Incident Heart Failure and Their Relationship With Obesity: The MESA (Multi-Ethnic Study of Atherosclerosis) Study

OBJECTIVES The objectives of this study were to determine the associations of the metabolic syndrome, inflammatory markers, and insulin resistance with incident congestive heart failure (CHF), beyond established risk factors, and to examine whether these risk factors may provide the link between obesity and CHF. BACKGROUND Recently, increasing interest has emerged on the potential role of novel risk factors such as systemic inflammation, insulin resistance, and albuminuria in the pathophysiology of CHF and their relationship with obesity. METHODS The MESA (Multi-Ethnic Study of Atherosclerosis) study is a community-based multicenter cohort study of 6,814 participants (age 45 to 84 years, 3,601 women) of 4 ethnicities: Caucasians, African Americans, Hispanics, and Chinese Americans. Participants were recruited between 2000 and 2002 from 6 U.S. communities. Median follow-up time was 4 years. Participants with history of symptomatic cardiovascular disease were excluded. Cox proportional hazards models were used to analyze the associations of the metabolic syndrome, inflammatory markers, insulin resistance, and albuminuria with incident CHF, independent of established risk factors (age, gender, hypertension, diabetes mellitus, left ventricular hypertrophy, obesity, serum total cholesterol, and smoking), an interim myocardial infarction, and baseline magnetic resonance imaging parameters of left ventricular structure and function. RESULTS A total of 79 participants developed CHF during follow-up, and 26 participants (32.9%) had a myocardial infarction prior to CHF and 65% of the cases had CHF with preserved function (left ventricular ejection fraction >or=40%). In multivariable analyses, serum interleukin-6 (hazard ratio [HR] for 1 standard deviation 1.50, 95% confidence interval [CI] 1.10 to 2.03) or C-reactive protein (HR for 1 standard deviation 1.38; 95% CI 1.01 to 1.86) and macroalbuminuria (HR 4.31, 95% CI 1.58 to 11.76) were predictors of CHF, independent of obesity and the other established risk factors. Although obesity was significantly associated with incident CHF, this association was no longer significant after adding inflammatory markers (interleukin-6 or C-reactive protein) to the model. CONCLUSIONS Inflammatory markers and albuminuria are independent predictors of CHF. The association of obesity and CHF may be related to pathophysiologic pathways associated with inflammation.

Obesity and hypertension in an Iranian cohort study; Iranian women experience higher rates of obesity and hypertension than American women

BackgroundOnce considered as the main public health problem in developed countries, obesity has become a major problem throughout the world and developing countries, like Iran, are joining the global obesity pandemic. We determined the prevalence of overweight, obesity, and hypertension in a large cohort of Iranians and compared age-adjusted rates with the rates in the US.MethodsGolestan Cohort Study is a population-based study of 8,998 men and women, aged 35-81 years, from urban and rural areas. Anthropometric parameters were measured by interviewers. Prevalence rates were directly adjusted to the 2000 United States standard population.ResultsThe age-adjusted prevalence rates of overweight (BMI ≥ 25 kg/m2) and obesity (BMI ≥ 30 kg/m2) in this Iranian population were 62.2% and 28.0%, respectively. Both overweight and obesity were more common in women than men. Age-adjusted prevalence of overweight was significantly higher in Iranian women compared to the American women (68.6% vs. 61.6%), while the age-adjusted prevalence of obesity is closer in these two populations (34.9% vs. 33.2%). Iranian men—compared to American men—had significantly lower age-adjusted prevalence of overweight (53.7% vs. 68.8%) and obesity (16.2% vs. 27.5%). Age-adjusted prevalence of hypertension was higher in Iranian women than American women (35.7% vs. 30.5%). Diabetes mellitus was reported in 6.2% of participants. Mean waist-to-hip ratio (WHR) among women was 0.96. Smoking rates in men and women were 33.2% and 2.2%, respectively.ConclusionThe prevalence of obesity, overweight, and hypertension in Iran is as high as the US. However, Iranian women are more obese than American women and Iranian men are less obese than their American counterparts. This discrepancy might be due to the low rate of smoking among Iranian women. Iranian women have higher mean WHR than what WHO has defined in 19 other populations.

Relation of aortic wall thickness and distensibility to cardiovascular risk factors (from the Multi-Ethnic Study of Atherosclerosis [MESA]).

To determine the relation between aortic wall thickness (WT) and aortic distensibility (AD) with traditional cardiovascular risk factors in the Multi-Ethnic Study of Atherosclerosis (MESA) cohort, 1,053 participants in MESA who underwent cardiac magnetic resonance imaging were consecutively selected for the measurement of aortic WT and AD. Double inversion-recovery fast spin-echo images of the thoracic aorta were obtained to measure average and maximum WT. AD was measured at the same level using a gradient-echo cine sequence. Average and maximum WT were positively correlated with increasing age, and AD was inversely related to age (p <0.01). Compared with normotensive participants, those with hypertension had significantly greater mean average WT (2.45 vs 2.23 mm, p <0.01) and maximum WT (3.61 vs 3.41 mm, p <0.01) and lower AD (0.15 vs 0.2 mm Hg(-1), p <0.01). In multiple regression analysis, older age and hypertension were significantly associated with higher mean average WT, while older age, male gender, and higher blood pressure were associated with higher mean maximum WT. AD was inversely related to older age, hypertension, current smoking, African American ethnicity, and lower high-density lipoprotein cholesterol level. In conclusion, in the MESA cohort, older age and higher blood pressure were associated with higher aortic WT and lower AD. Decreased AD was further associated with current smoking, African American ethnicity, and higher high-density lipoprotein cholesterol level.

Tumour-necrosis factor-A polymorphisms and gastric cancer risk: a meta-analysis

Inflammation is one of the early phases in the development of gastric cancer. Therefore, several studies have examined the association of polymorphisms in tumour-necrosis factor-A gene (TNF-A) with gastric cancer risk. This meta-analysis reviews and summarises published evidence for these associations. Searching several databases yielded 24 independent studies that reported on the associations between TNF-A polymorphisms and gastric cancer risk. We analysed available data for the most commonly investigated polymorphisms: TNF-A –308G>A (23 studies), TNF-A –238G>A (9 studies), and TNF-A –857C>T (5 studies). Summary odds ratios (ORs) and 95% confidence intervals (95% CIs) were calculated in the random-effects model using the DerSimonian–Laird method. Q-statistic and I2-statistic were calculated to examine heterogeneity, and funnel plots were plotted to examine small study effects. The overall ORs (95% CIs) for AG and AA genotypes vs GG genotype for TNF-A –308 were 1.09 (0.94–1.27) and 1.49 (1.11–1.99), respectively. For TNF-A –238, the corresponding ORs (95% CIs) were 1.05 (0.84–1.33) and 1.25 (0.30–5.26), respectively. The overall ORs (95% CIs) for CT and TT genotypes (vs CC) for TNF-A –857 were 1.06 (0.89–1.27) and 1.57 (0.91–2.70), respectively. The statistically significant association between TNF-A –308GG and gastric cancer was limited to western populations. This association showed little heterogeneity (I2=0) and remained consistently strong when analyses were limited to anatomic and histologic subtypes of gastric cancer, or limited to studies in which genotype frequencies were in Hardy–Weinberg equilibrium, or limited to larger studies. These same subgroup analyses did not change results associated with other polymorphisms. In conclusion, TNF-A –308AA genotype was associated with a statistically significant increased risk of gastric cancer, whereas other studied polymorphisms were not. The association between TNF-A –857TT genotype and gastric cancer was near significant, and may become significant if more studies are published.

Cardiovascular Effects of Exposure to Cigarette Smoke and Electronic Cigarettes : Clinical Perspectives From the Prevention of Cardiovascular Disease Section Leadership Council and Early Career Councils of the American College of Cardiology

Cardiovascular morbidity and mortality as a result of inhaled tobacco products continues to be a global healthcare crisis, particularly in low- and middle-income nations lacking the infrastructure to develop and implement effective public health policies limiting tobacco use. Following initiation of public awareness campaigns 50 years ago in the United States, considerable success has been achieved in reducing the prevalence of cigarette smoking and exposure to secondhand smoke. However, there has been a slowing of cessation rates in the United States during recent years, possibly caused by high residual addiction or fatigue from cessation messaging. Furthermore, tobacco products have continued to evolve faster than the scientific understanding of their biological effects. This review considers selected updates on the genetics and epigenetics of smoking behavior and associated cardiovascular risk, mechanisms of atherogenesis and thrombosis, clinical effects of smoking and benefits of cessation, and potential impact of electronic cigarettes on cardiovascular health.

N-terminal pro-B-type natriuretic peptide as a predictor of incident atrial fibrillation in the Multi-Ethnic Study of Atherosclerosis: the effects of age, sex and ethnicity

Objective Atrial fibrillation (AF) is a common source of medical costs, morbidity and mortality. NT pro-brain natriuretic peptide (BNP) is a remarkably strong predictor of AF in older whites; we aimed to assess if this biomarker was as predictive in other racial groups. Design We used covariate-adjusted Cox model regressions to estimate the HRs of developing AF as a function of NT proBNP, and tested for interactions of NT proBNP with age, gender and race/ethnicity. Setting The Multi-Ethnic Study of Atherosclerosis (MESA). Patients 5518 subjects were followed over a median of 7.6 years. During this time, 267 developed AF. Results NT proBNP was statistically significantly associated with incident AF; for ln NT proBNP, the adjusted HR was 2.2 (95% CI 1.9 to 2.5). Assessed by quintiles, the relationship between NT proBNP was strong and graded; the unadjusted HR for the highest quintile of NT proBNP was 23.7 (95% CI 11.1 to 50.6) and adjusted was 11.4 (95% CI 5.1 to 25.3). NT proBNP was an excellent predictor of incident AF in the younger and older age groups, in men and women and in the different race/ethnicity groups: the HR for ln NT proBNP as a predictor of incident AF ranged from 2.0 to 3.9 in each subgroup. Conclusions NT proBNP is a robust predictor of incident AF; its prognostic value is more significant in younger patients and women compared with older patients and men. NT proBNP was also as strongly predictive in black patients, Hispanics and Asian/Chinese as in white patients despite a lower incidence of arrhythmia.

N-terminal Pro-B-Type Natriuretic Peptide, Left Ventricular Mass, and Incident Heart Failure: Multi-Ethnic Study of Atherosclerosis

Background—Elevated N-terminal pro-B-type natriuretic peptide (NT-proBNP) is associated with clinically overt heart failure (HF). However, whether it provides additive prognostic information for incident HF beyond traditional risk factors and left ventricular (LV) mass index among multi-ethnic asymptomatic individuals has not yet been determined. We studied the associations of plasma NT-proBNP and magnetic resonance imaging defined LV mass index with incident HF in an asymptomatic multi-ethnic population. Methods and Results—A total of 5597 multi-ethnic participants without clinically apparent cardiovascular disease underwent baseline measurement of NT-proBNP and were followed for 5.5±1.1 years. Among them, 4163 also underwent baseline cardiac magnetic resonance imaging. During follow-up, 111 participants experienced incident HF. Higher NT-proBNP was significantly associated with incident HF, independent of baseline age, sex, ethnicity, systolic blood pressure, diabetes mellitus, smoking, estimated glomerular filtration rate, medications (anti-hypertensive and statin), LV mass index, and interim myocardial infarction (hazard ratio: 1.95 per 1U log NT-proBNP increment, 95% CI 1.54–2.46, P<0.001). This relationship held among different ethnic groups, non-Hispanic whites, African-Americans, and Hispanics. Most importantly, NT-proBNP provided additive prognostic value beyond both traditional risk factors and LV mass index for predicting incident HF (integrated discrimination index=0.046, P<0.001; net reclassification index; 6-year risk probability categorized by <3%, 3–10%, >10% =0.175, P=0.019; category-less net reclassification index=0.561, P<0.001). Conclusions—Plasma NT-proBNP provides incremental prognostic information beyond traditional risk factors and the magnetic resonance imaging-determined LV mass index for incident symptomatic HF in an asymptomatic multi-ethnic population. Clinical Trial Registration—URL: http://www.clinicaltrials.gov. Unique identifier: NCT00005487.

Lutein supplementation in retinitis pigmentosa: PC-based vision assessment in a randomized double-masked placebo-controlled clinical trial [NCT00029289]

BackgroundThere is no generally accepted medical or surgical treatment to stop the progressive course of retinitis pigmentosa. Previous studies have suggested lutein as a potential treatment with positive effects on macular pigment density. The objective of this study was to examine the effect of lutein supplementation on preservation of visual function in patients with retinitis pigmentosa (RP)MethodsIn a double-masked randomized placebo-controlled phase I/II clinical trial with a cross-over design, 34 adult patients with RP were randomized to two groups. One group, consisted of 16 participants, received lutein supplementation (10 mg/d for 12 wks followed by 30 mg/d) for the first 24 weeks and then placebo for the following 24 weeks, while the other group included 18 participants for whom placebo (24 weeks) was administered prior to lutein. Visual acuity, contrast sensitivity, and central visual field were measured at different illumination levels at baseline and every week using a PC-based test at home.ResultsFor visual acuity (VA) at normal illumination level, treatment with lutein reduced logMAR, i.e. improved VA, but this effect was not statistically significant. The changes in normal (100%), low (4%), and very low (0.1%) illumination log CS were not statistically significant (p-values: 0.34, 0.23, and 0.32, respectively). Lutein had a statistically significant effect on visual field (p-value: 0.038) and this effect increased in the model assuming a 6-week delay in effect of lutein. Comparing the development of vision measures against the natural loss expected to occur over the course of 48 weeks, most measures showed reduced decline, and these reductions were significant for normal illumination VA and CS.ConclusionThese results suggest that lutein supplementation improves visual field and also might improve visual acuity slightly, although these results should be interpreted cautiously. As a combined phase I and II clinical trial, this study demonstrated the efficacy and safety of lutein supplementation.