Early adult risk factor levels and subsequent coronary artery calcification: the CARDIA Study

Coronary artery calcium and cardiovascular risk in diabetes

Measurement of coronary artery calcium score (CACS) by electron beam tomography has been shown to a powerful predictor of coronary heart disease events in asymptomatic non-diabetic subjects. In type 2 diabetes, measurement of CACS was found to be a powerful predictor of cardiovascular events which could enhance prediction provided by established risk models. 23% of type 2 diabetic subjects with low CACS were found to be at low risk for cardiovascular events. Moreover mortality was similar for type 2 diabetic and non-diabetic subjects with undetectable coronary artery calcification. Conversely type 2 diabetic subjects with high CACS were identified who were at high cardiovascular risk. Thus not all those with type 2 diabetes are at similar cardiovascular risk. Measurement of CACS enables cardiovascular risk in type 2 diabetes to be stratified so that the level of preventive therapy could be reduced in some and intensified in others. Although prospective data for the power of CACS to predict CHD events in type 1 diabetes are lacking, measurement of CACS could help in deciding on preventive therapy in type 1 diabetes.

Incidence and progression of coronary calcification in chronic kidney disease: the Multi-Ethnic Study of Atherosclerosis

We studied the incidence and progression of coronary artery calcification in people with early chronic kidney disease. We used a cohort of 562 adult patients with chronic kidney disease who had an estimated glomerular filtration rate of <60 ml/min/1.73 m(2), in a community-based study of people without clinical cardiovascular disease, the Multi-Ethnic Study of Atherosclerosis. The majority had stage 3 disease. Coronary artery calcification was measured at baseline and again approximately 1.6 or 3.2 years later. The prevalence of coronary artery calcification at baseline was 66%, and its adjusted prevalence was 24% lower in African Americans as compared to Caucasians. The incidence of coronary artery calcification was 6.1% per year in women and 14.8% in men. Coronary artery calcification progressed in approximately 17% of subjects per year across all subgroups, and diabetes was associated with a 65% greater adjusted risk of progression. Male gender and diabetes were the only factors associated with adjusted coronary artery calcification incidence and progression, respectively. Our study shows that coronary artery calcification is common in people with stage 3 disease, progresses rapidly, and may contribute to cardiovascular risk.

Heart disease risk factors in midlife predict subclinical coronary atherosclerosis more than 25 years later in survivors without clinical heart disease: the Rancho Bernardo Study

OBJECTIVES

To determine which of the classic modifiable coronary heart disease (CHD) risk factors, measured in midlife, are associated with subclinical coronary atherosclerosis in older age.

DESIGN

Prospective study.

SETTING

Community based.

PARTICIPANTS

Participants were 400 community-dwelling middle-aged adults who had no history of CHD at baseline (1972-1974), when CHD risk factors were measured, and who were still free of known CHD in 2000 to 2002.

MEASUREMENTS

Coronary artery plaque burden was assessed according to coronary artery calcium (CAC) score using computed tomography in 2000 to 2002.

RESULTS

Ordinal logistic regression analysis was used to compare baseline risk factors with severity of CAC. Mean age was 42 at baseline and 69 at the time of CAC assessment; 46.5% were male. In analyses adjusted for age, sex, and all other risk factors, one standard deviation increase in body mass index (odds ratio (OR)=1.24, 95%confidence interval (CI)=1.02-1.51; P=.03), cholesterol (OR=1.28, 95% CI=1.03-1.58; P=.020, pulse pressure (OR=1.24, 95% CI=1.03-1.50; P=.03), and log triglycerides (OR=1.22, 95% CI=0.99-1.50; P=.06) each independently predicted the presence and severity of coronary artery atherosclerosis.

CONCLUSION

Modifiable risk factors measured more than 25 years earlier influence plaque burden in elderly survivors without clinical heart disease.

Longitudinal association of PCSK9 sequence variations with low-density lipoprotein cholesterol levels: the Coronary Artery Risk Development in Young Adults Study

BACKGROUND

Mutations of PCSK9 are associated cross-sectionally with plasma low-density lipoprotein cholesterol (LDL-C) levels, but little is known about their longitudinal association with LDL-C levels from young adulthood to middle age.

METHODS AND RESULTS

We investigated the associations of 6 PCSK9 variants with LDL-C over 20 years in 1750 blacks and 1828 whites from the Coronary Artery Risk Development In Young Adults study. Generalized estimating equations were used to assess longitudinal differences in LDL-C levels between genotype categories. For blacks, LDL-C levels at age 18 were significantly lower (P<0.001) among those with 3 genetic variants (L253F, C679X, and Y142X; 81.5 mg/dL) and A443T (95.5 mg/dL) compared with noncarriers (109.6 mg/dL). The difference in LDL-C levels from noncarriers tended to widen for those with the 3 variants only, by 0.24 mg/dL per year of age (P=0.14). For whites with the R46L variant, compared with noncarriers, LDL-C levels at age 18 were significantly lower (84.4 mg/dL versus 100.9 mg/dL; P<0.001), and the increase in LDL-C with age was similar to noncarriers. The 3 genetic variants and the A443T variant in black men were associated with lower carotid intima-media thickness and lower prevalence of coronary calcification measured at ages 38 to 50.

CONCLUSIONS

Our results suggest that participants with several genetic variants of PCSK9 have persistently lower serum LDL-C levels than noncarriers from ages 18 to 50. Such long-term reduction in LDL-C levels is associated with reduced subclinical atherosclerosis burden in black men.

Lipid management in children

Atherosclerosis begins in childhood, and early initiation of prevention through behavioral means may lower the risk of future cardiovascular disease. The obesity epidemic threatens the cardiovascular health of today's children. Genetic dyslipidemias such as familial hypercholesterolemia and the presence of multiple risk factors in the same child or adolescent may require pharmacologic therapy.

The initiatives and outcomes for cardiovascular risks that can be achieved through paediatric counselling

PURPOSE OF REVIEW

Atherosclerosis is a result of a lifelong process. Obesity is associated with increased serum levels of inflammatory markers in children and adolescents like in adults, promoting coronary heart disease risk in an increasing proportion of young adults. Dietary patterns have a central role in the development of coronary heart disease through effects on serum lipids and development of body fatness. It is the purpose of this review to describe progress in this field.

RECENT FINDINGS

The supervised counselling aiming at low saturated fat intake by children decreases serum total and low-density lipoprotein (LDL) cholesterol values significantly and keeps them at lower level through childhood. It is not associated with abnormal growth or defects in cognitive or pubertal development. Coronary heart disease risk factor levels measured in childhood markedly influence vascular function and structure.

SUMMARY

To diminish the risk of premature atherosclerosis, the prime target in counselling of young children and their parents should be a change in fat quality rather than fat quantity. However, to prevent obesity, excessive consumption of total fat and sucrose needs to be avoided. Early commencement of statin therapy in children and adolescents suffering from familial hypercholesterolemia is beneficial in prevention of vascular atherosclerosis.

Prevalence and progression of subclinical atherosclerosis in younger adults with low short-term but high lifetime estimated risk for cardiovascular disease: the coronary artery risk development in young adults study and multi-ethnic study of atherosclerosis

BACKGROUND

We hypothesized that individuals with low 10-year but high lifetime cardiovascular disease risk would have a greater burden of subclinical atherosclerosis than those with low 10-year but low lifetime risk.

METHODS AND RESULTS

We included 2988 individuals < or = 50 years of age at examination year 15 from the Coronary Artery Risk Development in Young Adults (CARDIA) study and 1076 individuals < or = 50 of age at study entry from the Multi-Ethnic Study of Atherosclerosis (MESA). The 10-year risk and lifetime risk for cardiovascular disease were estimated for each participant, permitting stratification into 3 groups: low 10-year (<10%)/low lifetime (<39%) risk, low 10-year (<10%)/high lifetime risk (> or = 39%), and high 10-year risk (> or = 10%) or diagnosed diabetes mellitus. Baseline levels and change in levels of subclinical atherosclerosis (coronary artery calcium or carotid intima-media thickness) were compared across risk strata. Among participants with low 10-year risk (91% of all participants) in CARDIA, those with a high lifetime risk compared with low lifetime risk had significantly greater common (0.83 versus 0.80 mm in men; 0.79 versus 0.75 mm in women) and internal (0.85 versus 0.80 mm in men; 0.80 versus 0.76 mm in women) carotid intima-media thickness, higher coronary artery calcium prevalence (16.6% versus 9.8% in men; 7.1% versus 2.3% in women), and significantly greater incidence of coronary artery calcium progression (22.3% versus 15.4% in men; 8.7% versus 5.3% in women). Similar results were observed in MESA.

CONCLUSIONS

Individuals with low 10-year but high lifetime risk have a greater subclinical disease burden and greater incidence of atherosclerotic progression compared with individuals with low 10-year and low lifetime risk, even at younger ages.

Short sleep duration and incident coronary artery calcification

CONTEXT

Coronary artery calcification is a subclinical predictor of coronary heart disease. Recent studies have found that sleep duration is correlated with established risk factors for calcification including glucose regulation, blood pressure, sex, age, education, and body mass index.

OBJECTIVE

To determine whether objective and subjective measures of sleep duration and quality are associated with incidence of calcification over 5 years and whether calcification risk factors mediate the association.

DESIGN, SETTING, AND PARTICIPANTS

Observational cohort of home monitoring in a healthy middle-aged population of 495 participants from the Coronary Artery Risk Development in Young Adults (CARDIA) cohort Chicago site (black and white men and women aged 35-47 years at year 15 of the study in 2000-2001 with follow-up data at year 20 in 2005-2006). Potential confounders (age, sex, race, education, apnea risk, smoking status) and mediators (lipids, blood pressure, body mass index, diabetes, inflammatory markers, alcohol consumption, depression, hostility, self-reported medical conditions) were measured at both baseline and follow-up. Sleep metrics (wrist actigraphy measured duration and fragmentation, daytime sleepiness, overall quality, self-reported duration) were examined for association with incident calcification. Participants had no detectable calcification at baseline.

MAIN OUTCOME MEASURE

Coronary artery calcification was measured by computed tomography in 2000-2001 and 2005-2006 and incidence of new calcification over that time was the primary outcome.

RESULTS

Five-year calcification incidence was 12.3% (n = 61). Longer measured sleep duration was significantly associated with reduced calcification incidence (adjusted odds ratio, 0.67 per hour [95% confidence interval, 0.49-0.91 per hour]; P = .01). No potential mediators appreciably altered the magnitude or significance of sleep (adjusted odds ratio estimates ranged from 0.64 to 0.68 per sleep hour; maximum P = .02). Alternative sleep metrics were not significantly associated with calcification.

CONCLUSION

Longer measured sleep is associated with lower calcification incidence independent of examined potential mediators and confounders.

Computed tomography imaging, coronary calcium and atherosclerosis

Coronary calcium score measured by electron beam tomography provides an indication of current atherosclerotic burden in the coronary arteries. It correlates with conventional risk factors, but less so with Type 2 diabetes. Measurement of coronary calcium score has been shown to be a powerful predictor of coronary heart disease events in the general population, in different racial groups, and in Type 2 diabetes. It adds incremental value to conventional risk factors and risk scores. Its role in monitoring therapy remains to be proven.

Coronary artery calcification, arterial stiffness and renal insufficiency associate with serum levels of tumor necrosis factor-alpha in Japanese type 2 diabetic patients

Although the kidneys are the major source of proinflammatory cytokines, association of tumor necrosis factor-alpha (TNF-alpha) with severity of atherosclerosis or kidney function in diabetic patients is unclear. Two hundred type 2 diabetic patients and 30 age-matched nondiabetic subjects consecutively admitted to our hospital were enrolled. The Agatston coronary artery calcium score (CACS), a quantitative marker of coronary atherosclerosis, was obtained using multidetector-row computed tomography. Arterial stiffness was assessed by brachial-ankle pulse wave velocity (baPWV). Diabetic patients had higher log(CACS+1) (p=0.0089), baPWV (p=0.0293), frequency of elevated urinary albumin excretion (UAE) (p<0.0001) and TNF-alpha (p=0.0029) and similar estimated glomerular filtration rate (eGFR) compared to nondiabetic subjects. When diabetic patients were grouped into four subgroups with or without elevated UAE and renal insufficiency (UAE of >/=30 or <30mg/24h and eGFR of <60 or >/=60ml/min per 1.73m(2)), patients with micro- and macroalbuminuric renal insufficiency showed the highest log(CACS+1) (p<0.0001), baPWV (p=0.0068) and TNF-alpha (p<0.0001) of these groups. Log(CACS+1) (p=0.0008) and baPWV (p=0.0006) positively and eGFR (p<0.0001) negatively correlated with TNF-alpha in diabetic patients. We find that coronary artery calcification, arterial stiffness, and renal insufficiency associate with circulating levels of TNF-alpha in type 2 diabetic patients.

Leukocyte telomeres are longer in African Americans than in whites: the National Heart, Lung, and Blood Institute Family Heart Study and the Bogalusa Heart Study

Leukocyte telomere length (LTL) is ostensibly a bio-indicator of human aging. Here we report that African Americans have longer LTL than whites. We studied cross-sectionally 2453 individuals from the National Heart, Lung, and Blood Institute (NHLBI) Family Heart Study (age = 30-93 years) and the Bogalusa Heart Study (age = 19-37 years), comprising 1742 whites and 711 African Americans. We measured LTL by Southern blots of the terminal restriction fragments length. In 234 participants, telomere repeats were also measured by quantitative polymerase chain reaction (qPCR). Adjusted for age and body mass index (BMI), the respective leukocyte telomere lengths (mean +/- SEM) were considerably longer in African Americans than in whites both in the Family Heart Study (7.004 +/- 0.033 kb vs. 6.735 +/- 0.024 kb, p < 0.0001) and the Bogalusa Heart Study (7.923 +/- 0.063 kb vs. 7.296 +/- 0.039 kb, p < 0.0001). We confirmed the racial effect on LTL by qPCR (3.038 +/- 0.565 T/S units for African Americans vs. 2.714 +/- 0.487 T/S units for whites, p < 0.001). Cross-sectionally, sex- and BMI-adjusted LTL became shorter with age (range 19-93 years) at a steeper slope in African Americans than in whites (0.029 kb year(-1) vs. 0.020 kb year(-1), respectively, p = 0.0001). We suggest that racial difference in LTL arises from a host of interacting biological factors, including replication rates of hematopoietic stem cells.

Prehypertension during young adulthood and coronary calcium later in life

BACKGROUND

High blood pressure in middle age is a well-established risk factor for cardiovascular disease, but the consequences of low-level elevations during young adulthood are unknown.

OBJECTIVE

To measure the association between prehypertension exposure before age 35 years and coronary calcium later in life.

DESIGN

Prospective cohort study.

SETTING

Four communities in the United States.

PARTICIPANTS

Black and white men and women age 18 to 30 years recruited for the CARDIA (Coronary Artery Risk Development in Young Adults) Study in 1985 through 1986 who were without hypertension before age 35 years.

MEASUREMENTS

Blood pressure trajectories for each participant were estimated by using measurements from 7 examinations over the course of 20 years. Cumulative exposure to blood pressure in the prehypertension range (systolic blood pressure of 120 to 139 mm Hg, or diastolic blood pressure of 80 to 89 mm Hg) from age 20 to 35 years was calculated in units of mm Hg-years (similar to pack-years of tobacco exposure) and related to the presence of coronary calcium measured at each participant's last examination (mean age, 44 years [SD, 4]).

RESULTS

Among 3560 participants, the 635 (18%) who developed prehypertension before age 35 years were more often black, male, overweight, and of lower socioeconomic status. Exposure to prehypertension before age 35 years, especially systolic prehypertension, showed a graded association with coronary calcium later in life (coronary calcium prevalence of 15%, 24%, and 38% for 0, 1 to 30, and >30 mm Hg-years of exposure, respectively; P < 0.001). This association remained strong after adjustment for blood pressure elevation after age 35 years and other coronary risk factors and participant characteristics.

LIMITATION

Coronary calcium, although a strong predictor of future coronary heart disease, is not a clinical outcome.

CONCLUSION

Prehypertension during young adulthood is common and is associated with coronary atherosclerosis 20 years later. Keeping systolic pressure below 120 mm Hg before age 35 years may provide important health benefits later in life.

Subendothelial lipoprotein retention as the initiating process in atherosclerosis: update and therapeutic implications

The key initiating process in atherogenesis is the subendothelial retention of apolipoprotein B-containing lipoproteins. Local biological responses to these retained lipoproteins, including a chronic and maladaptive macrophage- and T-cell-dominated inflammatory response, promote subsequent lesion development. The most effective therapy against atherothrombotic cardiovascular disease to date--low density lipoprotein-lowering drugs--is based on the principle that decreasing circulating apolipoprotein B lipoproteins decreases the probability that they will enter and be retained in the subendothelium. Ongoing improvements in this area include more aggressive lowering of low-density lipoprotein and other atherogenic lipoproteins in the plasma and initiation of low-density lipoprotein-lowering therapy at an earlier age in at-risk individuals. Potential future therapeutic approaches include attempts to block the interaction of apolipoprotein B lipoproteins with the specific subendothelial matrix molecules that mediate retention and to interfere with accessory molecules within the arterial wall that promote retention such as lipoprotein lipase, secretory sphingomyelinase, and secretory phospholipase A2. Although not the primary focus of this review, therapeutic strategies that target the proatherogenic responses to retained lipoproteins and that promote the removal of atherogenic components of retained lipoproteins also hold promise. The finding that certain human populations of individuals who maintain lifelong low plasma levels of apolipoprotein B lipoproteins have an approximately 90% decreased risk of coronary artery disease gives hope that our further understanding of the pathogenesis of this leading killer could lead to its eradication.