Jianwen Cai

Prevalence of Major Cardiovascular Risk Factors and Cardiovascular Diseases Among Hispanic/Latino Individuals of Diverse Backgrounds in the United States

CONTEXTnMajor cardiovascular diseases (CVDs) are leading causes of mortality among US Hispanic and Latino individuals. Comprehensive data are limited regarding the prevalence of CVD risk factors in this population and relations of these traits to socioeconomic status (SES) and acculturation.nnnOBJECTIVESnTo describe prevalence of major CVD risk factors and CVD (coronary heart disease [CHD] and stroke) among US Hispanic/Latino individuals of different backgrounds, examine relationships of SES and acculturation with CVD risk profiles and CVD, and assess cross-sectional associations of CVD risk factors with CVD.nnnDESIGN, SETTING, AND PARTICIPANTSnMulticenter, prospective, population-based Hispanic Community Health Study/Study of Latinos including individuals of Cuban (n = 2201), Dominican (n = 1400), Mexican (n = 6232), Puerto Rican (n = 2590), Central American (n = 1634), and South American backgrounds (n = 1022) aged 18 to 74 years. Analyses involved 15,079 participants with complete data enrolled between March 2008 and June 2011.nnnMAIN OUTCOME MEASURESnAdverse CVD risk factors defined using national guidelines for hypercholesterolemia, hypertension, obesity, diabetes, and smoking. Prevalence of CHD and stroke were ascertained from self-reported data.nnnRESULTSnAge-standardized prevalence of CVD risk factors varied by Hispanic/Latino background; obesity and current smoking rates were highest among Puerto Rican participants (for men, 40.9% and 34.7%; for women, 51.4% and 31.7%, respectively); hypercholesterolemia prevalence was highest among Central American men (54.9%) and Puerto Rican women (41.0%). Large proportions of participants (80% of men, 71% of women) had at least 1 risk factor. Age- and sex-adjusted prevalence of 3 or more risk factors was highest in Puerto Rican participants (25.0%) and significantly higher (P < .001) among participants with less education (16.1%), those who were US-born (18.5%), those who had lived in the United States 10 years or longer (15.7%), and those who preferred English (17.9%). Overall, self-reported CHD and stroke prevalence were low (4.2% and 2.0% in men; 2.4% and 1.2% in women, respectively). In multivariate-adjusted models, hypertension and smoking were directly associated with CHD in both sexes as were hypercholesterolemia and obesity in women and diabetes in men (odds ratios [ORs], 1.5-2.2). For stroke, associations were positive with hypertension in both sexes, diabetes in men, and smoking in women (ORs, 1.7-2.6).nnnCONCLUSIONnAmong US Hispanic/Latino adults of diverse backgrounds, a sizeable proportion of men and women had adverse major risk factors; prevalence of adverse CVD risk profiles was higher among participants with Puerto Rican background, lower SES, and higher levels of acculturation.

Multiple Metabolic Syndrome Is Associated With Lower Heart Rate Variability: The Atherosclerosis Risk in Communities Study

OBJECTIVE To test at the population level whether people with multiple metabolic syndrome (MMS) disorders have reduced cardiac autonomic activity (CAA). RESEARCH DESIGN AND METHODS We examined the association between the level of CAA and MMS disorders, at the degree of clustering and the segregate combination levels, using a random sample of 2,359 men and women aged 45–64 years from the biracial, population-based Atherosclerosis Risk in Communities (AR1C) Study. Supine resting 2-min beat-to-beat heart rate data were collected. High-frequency (HF) (0.15–0.35 Hz) and low-frequency (LF) (0.025–0.15 Hz) spectral powers, the ratio of LF to HF, and the SD of all normal R-R intervals (SDNN) were used as the conventional indices of heart rate variability (HRV) to measure CAA. The MMS disorders included hypertension, type 2 diabetes, and dyslipidemia. RESULTS HRV indices were significantly lower in individuals with MMS disorders. The multivariable adjusted mean HF was 0.85 (beat/min)2 in subjects with all three MMS disorders, in contrast to 1.31 beat/min)2 in subjects without any MMS disorder. At the segregated combination level, the multivariable adjusted means ± SEM of HF were 1.34 ± 0.05, 1.16 ± 0.05, 1.01 ± 0.17, and 1.34 ± 0.05 (beat/min)2, respectively, for subjects without any MMS disorder, with hypertension only, with diabetes only, and with dyslipidemia only, and the means ± SEM of HF were 0.93 ± 0.04,0.70 ± 0.15, and 1.20 ± 0.05 eat/min)2, respectively, for subjects with diabetes and hypertension, diabetes and dyslipidemia, and hypertension and dyslipidemia. An increase in fasting insulin of 1 SD was associated with 88% higher odds of having a lower HF The pattern of associations was similar for LF and SDNN. CONCLUSIONS These findings suggest that MMS disorders adversely affect cardiac autonomic control and a reduced cardiac autonomic control may contribute to the increased risk of subsequent cardiovascular events in individuals who exhibit MMS disorders.

Association of cardiac autonomic function and the development of hypertension : The ARIC study

To relate cardiac autonomic function measured by heart rate variability (HRV) with prevalent and incident hypertension at the population level, the authors examined a stratified random sample of 2,061 examinees from the biracial Atherosclerosis Risk in Communities (ARIC) cohort. Baseline, supine, resting beat-to-beat heart rate data were collected. High frequency (HF, 0.15 to 0.35 Hz), low frequency (LF, 0.025 to 0.15 Hz) spectral powers, and LF/HF ratio, estimated from spectral analysis, and standard deviation of all normal RR intervals (SDNN), calculated from time domain analysis, were used as the conventional indices of cardiac autonomic function. From this sample, 650 prevalent hypertensives were identified. Of those normotensive at baseline (n = 1,338), 64 participants developed hypertension during 3 years of follow-up. In the cross-sectional analysis, the adjusted geometric means of HF were 1.26, 1.20, and 1.00 (beat/min)2 for normotensives, untreated hypertensives, and treated hypertensives, respectively; means of LF were 3.24, 3.26, and 2.58; means of LF/HF ratio were 2.57, 2.70, and 2.56; and means of SDNN were 39, 34, and 35 (ms) respectively. In the prospective analysis, a statistically significant, graded inverse association between baseline HF and the risk of incident hypertension was observed: the adjusted incident odds ratios (95% CI) were 1.00, 1.46 (0.61, 3.46), 1.50 (0.65, 3.50) and 2.44 (1.15, 5.20) from the highest to the lowest quartile of HF. No clear pattern of association was observed for LF. Significant trends of association for LF/HF and SDNN and incident hypertension were also found. These results suggest that cardiac autonomic function is associated with prevalent hypertension, and that reduced vagal function and the imbalance of sympatho-vagal function are associated with the risk of developing hypertension.

Association of vagal tone with serum insulin, glucose, and diabetes mellitus — The ARIC Study

Reduced vagal activity assessed by heart rate variability (HRV) has been observed in studies of diabetics, but this association has not been reported at the population level. To investigate the association of HRV with diabetes mellitus, as well as fasting serum insulin, and glucose, we examined a stratified random sample of 1933 individuals (154 diabetics and 1779 non-diabetics), aged 45-65 years from the Atherosclerosis Risk in Communities (ARIC) study cohort. Two-minute, resting, supine beat-to-beat heart rate records were collected. Power spectral density estimation was used to derive HRV high frequency power (HF, 0.15-0.35 Hz) as the conventional marker of vagal function. Age, race, and gender-adjusted geometric means of HF were 0.78 and 1.27 (beat/min)(2) for diabetics and non-diabetics respectively (P for mean difference <0.01), reflecting a reduced vagal activity in diabetics. In individuals not diagnosed as diabetics, a graded, inverse association was observed between fasting serum insulin and HF (P for trend <0.01): the age, race, and gender-adjusted geometric mean values of HF in the lowest and highest quartiles of serum insulin were 1.34 and 1.14 (beat/minute)(2), respectively. A similar association was observed between glucose and HF in a univariate model, but not in the adjusted model. This first population-based study on this subject confirmed that diabetics have significantly lower vagal activity than non-diabetics. In individuals not diagnosed as diabetics, serum insulin, and, to a lesser degree, serum glucose were inversely associated with vagal function, suggesting a role in the pathogenesis of diabetic neuropathy.

Prevalence of Hypertension, Awareness, Treatment, and Control in the Hispanic Community Health Study/Study of Latinos

BACKGROUNDnThe prevention and control of hypertension is an essential component for reducing the burden of cardiovascular diseases. Here we describe the prevalence of hypertension in diverse Hispanic/Latino background groups and describe the proportion who are aware of their diagnosis, receiving treatment, and having their hypertension under control.nnnMETHODSnThe Hispanic Community Health Study/Study of Latinos is a longitudinal cohort study of 16,415 Hispanics/Latinos, aged 18-74 years from 4 US communities (Bronx, NY; Chicago, IL; Miami, FL; and San Diego, CA). At baseline (2008-2011) the study collected extensive measurements and completed questionnaires related to research on cardiovascular diseases. Hypertension was defined as measured blood pressure ≥140/90mm Hg or use of antihypertensive medication.nnnRESULTSnThe total age-adjusted prevalence of hypertension in this study was 25.5% as compared with 27.4% in non-Hispanic whites in the National Health and Nutrition Examination Survey. Prevalence of hypertension increased with increasing age groups and was highest in Cuban, Puerto Rican, and Dominican background groups. The percent with hypertension who were aware, being treated with medication, or had their hypertension controlled was lower compared with US non-Hispanic whites with hypertension and it was lowest in those without health insurance.nnnCONCLUSIONSnThese findings indicate a significant deficit in treatment and control of hypertension among Hispanics/Latinos residing in the United States, particularly those without health insurance. Given the relative ease of identification of hypertension and the availability of low-cost medications, enabling better access to diagnostic and treatment services should reduce the burden of hypertension in Hispanic populations.

Can Postmenopausal Hormone Replacement Improve Plasma Lipids in Women With Diabetes

OBJECTIVE To evaluate the association of postmenopausal hormone replacement with plasma lipids in diabetic women. RESEARCH DESIGN AND METHODS Cross-sectional data from a multiracial population study were used to evaluate the relationship of hormone replacement status with plasma lipids in diabetic (n = 694) versus nondiabetic (n = 5,321) postmenopausal women. RESULTS Although diabetic women who currently used hormone replacement had higher adjusted mean HDL cholesterol levels than those who did not (56.9 vs. 53.6 mg/dl), they had proportionately lower hormone-related increases in HDL, HDL2, and HDL3 cholesterol than did nondiabetic women (HDL cholesterol 64.9 [current users] vs. 55.7 mg/dl [those who never used hormones]). There was a trend toward greater triglyceride values with hormone replacement in diabetic women (156.6 [current users] vs. 125.4 mg/dl [those who never used hormones]) than in nondiabetic women (143.3 [current users] vs. 123.7 mg/dl [those who never used hormones]). LDL cholesterol and apolipoprotein B levels were lower and apolipoprotein A-I levels were higher with hormone replacement, to a similar degree in diabetic and nondiabetic women. CONCLUSIONS Diabetic women appear to have a blunted response to the HDL-raising effects of estrogen and an exaggerated hypertriglyceridemic response. This may result in attenuated cardioprotection from postmenopausal hormone replacement therapy and potentially an increased risk of acute pancreatitis from hypertriglyceridemia. The risks and benefits of postmenopausal hormone replacement need to be carefully weighed in diabetic women.

Reproducibility of extracranial carotid atherosclerotic lesions assessed by B-mode ultrasound: The atherosclerosis risk in communities study

The reproducibility in the identification of carotid artery lesions using B-mode ultrasound was studied in a large random sample selected from the Atherosclerosis Risk in Communities (ARIC) Study. Carotid lesions were defined as plaque with or without acoustic shadowing (indicative of mineralization). A weighted kappa (kappa w) statistic was used as a chance-adjusted measure of repeatability. In the ARIC baseline survey, the kappa w values for the assessment of lesions on repeat reading were 0.47, 0.60 and 0.69 in the left common carotid artery, the carotid bifurcation and the internal carotid artery, respectively. In a repeat scanning, the kappa w values ranged from 0.59 to 0.79 in the left carotid segments. The results were similar in the left and right carotid arteries. Covariates (age, race, gender, body mass index, study center) did not influence the reproducibility. Similar results were also found in both the baseline survey and the first follow-up examination. In conclusion, reproducibility in the assessment of carotid lesions by B-mode ultrasound can be achieved in multicenter studies at fair to good levels of agreement.

Body Mass Index, Sex, and Cardiovascular Disease Risk Factors Among Hispanic/Latino Adults: Hispanic Community Health Study/Study of Latinos

Background All major Hispanic/Latino groups in the United States have a high prevalence of obesity, which is often severe. Little is known about cardiovascular disease (CVD) risk factors among those at very high levels of body mass index (BMI). Methods and Results Among US Hispanic men (N=6547) and women (N=9797), we described gradients across the range of BMI and age in CVD risk factors including hypertension, serum lipids, diabetes, and C‐reactive protein. Sex differences in CVD risk factor prevalences were determined at each level of BMI, after adjustment for age and other demographic and socioeconomic variables. Among those with class II or III obesity (BMI ≥35 kg/m2, 18% women and 12% men), prevalences of hypertension, diabetes, low high‐density lipoprotein cholesterol level, and high C‐reactive protein level approached or exceeded 40% during the fourth decade of life. While women had a higher prevalence of class III obesity (BMI ≥40 kg/m2) than did men (7% and 4%, respectively), within this highest BMI category there was a >50% greater relative prevalence of diabetes, hypertension, and hyperlipidemia in men versus women, while sex differences in prevalence of these CVD risk factors were ≈20% or less at other BMI levels. Conclusions Elevated BMI is common in Hispanic/Latino adults and is associated with a considerable excess of CVD risk factors. At the highest BMI levels, CVD risk factors often emerge in the earliest decades of adulthood and they affect men more often than women.

Insulin resistance and circadian rhythm of cardiac autonomic modulation

BackgroundInsulin resistance (IR) has been associated with cardiovascular diseases (CVD). Heart rate variability (HRV), an index of cardiac autonomic modulation (CAM), is also associated with CVD mortality and CVD morbidity. Currently, there are limited data about the impairment of IR on the circadian pattern of CAM. Therefore, we conducted this investigation to exam the association between IR and the circadian oscillations of CAM in a community-dwelling middle-aged sample.MethodHomeostasis models of IR (HOMA-IR), insulin, and glucose were used to assess IR. CAM was measured by HRV analysis from a 24-hour electrocardiogram. Two stage modeling was used in the analysis. In stage one, for each individual we fit a cosine periodic model based on the 48 segments of HRV data. We obtained three individual-level cosine parameters that quantity the circadian pattern: mean (M), measures the overall average of a HRV index; amplitude (Â), measures the amplitude of the oscillation of a HRV index; and acrophase time (θ), measures the timing of the highest oscillation. At the second stage, we used a random-effects-meta-analysis to summarize the effects of IR variables on the three circadian parameters of HRV indices obtained in stage one of the analysis.ResultsIn persons without type diabetes, the multivariate adjusted β (SE) of log HOMA-IR and M variable for HRV were -0.251 (0.093), -0.245 (0.078), -0.19 (0.06), -4.89 (1.76), -3.35 (1.31), and 2.14 (0.995), for log HF, log LF, log VLF, SDNN, RMSSD and HR, respectively (all P < 0.05). None of the IR variables were significantly associated with  or θ of the HRV indices. However, in eight type 2 diabetics, the magnitude of effect due to higher HOMA-IR on M, Â, and θ are much larger.ConclusionElevated IR, among non-diabetics significantly impairs the overall mean levels of CAM. However, the  or θ of CAM were not significantly affected by IR, suggesting that the circadian mechanisms of CAM are not impaired. However, among persons with type 2 diabetes, a group clinically has more severe form of IR, the adverse effects of increased IR on all three HRV circadian parameters are much larger.

High Cholesterol Awareness, Treatment, and Control Among Hispanic/Latinos: Results From the Hispanic Community Health Study/Study of Latinos

Background We assessed high cholesterol (HC) awareness, treatment, and control rates among US Hispanic/Latino adults and describe factors associated with HC awareness and management. Methods and Results Baseline data (collected 2008–2011) from a multisite probability sample of Hispanic/Latino adults in the Hispanic Community Health Study/Study of Latinos (18 to 74 years old; N=16 207) were analyzed. HC was defined as low-density lipoprotein-cholesterol ≥130 mg/dL and/or total cholesterol ≥240 mg/dL or use of cholesterol-lowering medication. Among Hispanic/Latino adults with HC, almost half (49.3%) were not aware of their condition and only 29.5% were receiving treatment. Men had a higher HC prevalence than women (44.0% versus 40.5%) but a lower rate of treatment (28.1% versus 30.6%). Younger adults were significantly less likely to be HC aware compared to those who were older. Those with hypertension, diabetes, and high socioeconomic position were more likely to be HC aware. US-born Hispanic/Latino were more likely to be HC unaware than foreign-born Hispanics/Latinos, but longer US residency was significantly associated with being HC aware, treated, and controlled. Cholesterol control was achieved among 64.3% of those who were HC treated. However, younger adults, women, those with lower income, those uninsured, and more recent immigrants were less likely to be HC controlled. Individuals of Puerto Rican or Dominican background were most likely to be HC aware and treated, whereas those of Mexican or Central American background were least likely to be HC treated. Individuals of Cuban and South American background had the lowest rates of HC control, whereas Puerto Ricans had the highest. Conclusions Understanding gaps in HC awareness, treatment, and control among US Hispanic/Latino adults can help inform physicians and policymakers to improve disease management and patient education programs.