Cardiovascular risk factors and impaired glucose tolerance: the San Luis Valley Diabetes Study

Impact of Race on Outcomes in the Endovascular and Microsurgical Treatment in Patients With Intracranial Aneurysms

BACKGROUND AND OBJECTIVES

The impact of race on outcomes in the treatment of intracranial aneurysm (IA) remains unclear. We aimed to investigate the relationship between race classified into White, Black, Hispanic, and other and treatment outcomes in patients with ruptured and unruptured IAs.

METHODS

The study population consisted of 2836 patients with IA with endovascular treatment or microsurgical treatment (MST) from 16 centers in the United States and Asia, all participating in the observational "STAR" registry. The primary outcome was a 90-day modified Rankin Scale of 0 to 2. Secondary outcomes included periprocedural cerebral infarction and intracranial hemorrhage, perioperative symptomatic cerebral vasospasm in ruptured IA and mortality, and all causes of mortality within 90 days.

RESULTS

One thousand fifty-three patients were White (37.1%), 350 were Black (12.3%), 264 were Hispanic (9.3%), and 1169 were other (41.2%). Compared with White patients, Hispanic patients had a significantly lower proportion of primary outcome (adjusted odds ratio [aOR] 0.36, 95% CI, 0.23-0.56) and higher proportion of the periprocedural cerebral infarction, perioperative mortality, and all causes of mortality (aOR 2.53, 95% CI, 1.40-4.58, aOR 1.84, 95% CI, 1.00-3.38, aOR 1.83, 95% CI, 1.06-3.17, respectively). Outcomes were not significantly different in Black and other patients. The subgroup analysis showed that Hispanic patients with age ≥65 years (aOR 0.19, 95% CI, 0.10-0.38, interaction P = .048), Hunt-Hess grades 0 to 3 (aOR 0.29, 95% CI, 0.19-0.46, interaction P = .03), and MST (aOR 0.24, 95% CI, 0.13-0.44, interaction P = .04) had a significantly low proportion of primary outcome.

CONCLUSION

This study demonstrates that Hispanic patients with IA are more likely to have a poor outcome at 90 days after endovascular treatment or MST than White patients. Physicians have to pay attention to the selection of treatment modalities, especially for Hispanic patients with specific factors to reduce racial discrepancies.

Psychosocial Correlates and Outcomes of Physical Activity Among Latinos: A Review

Despite the many physical and psychological benefits of physical activity, it is well documented that the general population does not engage in sufficient leisure time physical activity to accrue such benefits. In the Latino population the situation is even more dire. This review focuses on studies of the relationship between physical activity and psychosocial correlates and outcomes in Latino men and women. It was demonstrated that the majority of studies with Latino participants examined constructs similar to those studied in the general population, namely, self-efficacy, social support, and perceived barriers. The existing literature is discussed in terms of (a) the lack of information on the psychological/psychosocial constructs of physical activity for Latinos, (b) the lack of intervention research, (c) reporting results of studies as “minority correlates,” (d) the importance of Latino subcultures and the heterogeneity of Latinos, and (e) the measurement of physical activity.

Camine Con Nosotros: Connecting Theory and Practice for Promoting Physical Activity among Hispanic Women

Despite the popularity and widespread use of theory in health education, practitioners still find it difficult to design and implement theory-based interventions. This is especially true when working with ethnic/racial minority groups, including Hispanic groups. Practitioners working with Hispanic communities face additional barriers that may often discourage them from using theories when planning interventions. These barriers include the diversity that exists within the Hispanic population, lack of reliable data, and issues related to cross-cultural applicability of current behavior theories. However, the use of theory constitutes a valuable tool for developing more effective programs, and theorist researchers should be more sensitive to practitioners’ needs. By explaining the processes for selecting and applying theory in the same detail as outcome results, researchers will contribute to increasing practitioners’ interest in theory. This article describes Camine con Nosotros, a theory-based physical activity program for Hispanic women, and explains the process of selecting the theoretical framework of the program and connecting theory and practice.

In vivo triglyceride synthesis in subcutaneous adipose tissue of humans correlates with plasma HDL parameters

BACKGROUNDS AND AIMS

Low concentrations of plasma HDL-C are associated with the development of atherosclerotic cardiovascular diseases and type 2 diabetes. Here we aimed to explore the relationship between the in vivo fractional synthesis of triglycerides (fTG) in subcutaneous (s.q.) abdominal adipose tissue (AT), HDL-C concentrations and HDL particle size composition in non-diabetic humans.

METHODS

The fTG in s.q. abdominal AT was measured in 16 non-diabetic volunteers (7 women, 9 men; Age: 49 ± 20 years; BMI: 31 ± 5 kg/m; Fasting Plasma Glucose: 90 ± 10 mg/dl) after (2)H2O labeling. HDL-C concentration and subclasses, large (L-HDL), intermediate (I-HDL) and small (S-HDL) were measured.

RESULTS

Linear regression analyses demonstrated significant associations of fTG with plasma concentration of HDL-C (r = 0.625,p = 0.009) and percent contribution of L-HDL (r = 0.798,p < 0.001), I-HDL (r = -0.765,p < 0.001) and S-HDL (r = -0.629, p = 0.009). When analyses were performed by gender, the associations remained significant in women (HDL-C: r = 0.822,p = 0.023; L-HDL: r = 0.892,p = 0.007; I-HDL: r = -0.927,p = 0.003) but not men.

CONCLUSIONS

Our study demonstrated an in vivo association between subcutaneous abdominal adipose tissue lipid dynamics and HDL parameters in humans, but this was true for women not men. Positive association with L-HDL and negative with I-HDL suggest that subcutaneous abdominal adipose tissue lipid dynamics may play an important role in production of mature functional HDL particles. Further studies evaluating the mechanism responsible for these associations and the observed gender differences are important and warranted to identify potential novel targets of intervention to increase the production of atheroprotective subclasses of HDL-Cs and thus decreasing the risks of development of atherosclerotic conditions.

HDL cholesterol and stroke risk: The Multi-Ethnic Study of Atherosclerosis

BACKGROUND AND PURPOSE

Accurate identification of risk factors for stroke is important for public health promotion and disease prevention. HDL cholesterol is a potential risk factor, yet its role in stroke risk is unclear, as is whether HDL cholesterol content or particle number might be a better indicator of stroke risk. Furthermore, the degree to which ethnicity moderates the risk is unknown. As such, the current study examines the associations between incident stroke and both HDL cholesterol concentration and particle number, and assesses the moderating role of race and ethnicity.

METHODS

The sample is a racially diverse cohort of US adults between the ages of 45-84 years enrolled in the Multi-Ethnic Study of Atherosclerosis between 2000 and 2002 and followed until December 2011. The associations among cholesterol content and stroke risk, particle number and stroke risk, and the interaction with race were explored.

RESULTS

The incidence of stroke was 2.6%. HDL cholesterol concentration (mmol/L) (Hazard Ratio (HR) = .56; 95% Confidence Interval (CI): .312-.988) and number of large HDL particles (μmol/L) (HR = .52, CI: .278-.956) were associated with lower stroke risk. When interactions with race were evaluated, the relationship between both HDL variables and stroke were significant in Blacks, but not other races.

CONCLUSIONS

Higher HDL cholesterol and a higher concentration of large particles are associated with lower risk of stroke in Blacks. Further research is needed to elucidate the mechanisms by which HDL subfractions may differentially affect stroke outcome in different races/ethnicities.

Do all components of the metabolic syndrome cluster together in U.S. Hispanics/Latinos? Results from the Hispanic Community Health study/Study of Latinos

PURPOSE

Metabolic syndrome (MetS), the clustering of several risk factors for cardiovascular disease, is highly prevalent in Hispanics/Latinos. We tested whether all components significantly loaded on the syndrome in Hispanics/Latinos and whether their contribution differed by sex and Hispanic ancestry. We also examined associations of MetS with prevalent diabetes and coronary heart disease in Hispanics/Latinos.

METHODS

Data were obtained from a population-based cohort of n = 15,823 participants in the HCHS/SOL study who self-identified as being of Central American, Cuban, Dominican, Mexican American, Puerto Rican, or South American ancestry and were aged 18 to 74 years at screening.

RESULTS

A latent variable model of waist circumference, systolic and diastolic blood pressure, triglycerides, high-density lipoprotein cholesterol (HDL-C), and fasting glucose fit the data in men and women, but the contribution of HDL-C was weak. No difference in the latent model of MetS was detected across Hispanic/Latino ancestry groups. MetS was significantly associated with diabetes and coronary heart disease.

CONCLUSIONS

Our results indicate that similar criteria for MetS may be applied across Hispanic/Latino ancestry groups but call into question the role of HDL-C in classifying the MetS in Hispanics/Latinos.

The Hispanic paradox in cardiovascular disease and total mortality

Health statistics and epidemiologic studies have shown that Hispanics live longer than Non Hispanic Whites, despite a high prevalence of cardiovascular disease (CVD) risk factors and an average low socioeconomic status, both strong predictors of CVD and mortality. This phenomenon has been dubbed "The Hispanic paradox" and has been demonstrated in old and contemporary cohorts. To date, no factor has been identified that could explain this phenomenon, but socio demographic factors, dietary intake and genetic predisposition have been proposed as possible explanations for the Hispanic paradox. As with the French paradox, where French were found to have a lower rate of coronary heart disease (CHD), helped to identify the role of the Mediterranean diet and wine consumption in the prevention of CHD, the Hispanic paradox could help identify protective factors against CHD. This article describes the current evidence supporting the existence of the Hispanic paradox and provides a brief review on the possible explanations.

Characterization of vascular disease risk in postmenopausal women and its association with cognitive performance

OBJECTIVES

While global measures of cardiovascular (CV) risk are used to guide prevention and treatment decisions, these estimates fail to account for the considerable interindividual variability in pre-clinical risk status. This study investigated heterogeneity in CV risk factor profiles and its association with demographic, genetic, and cognitive variables.

METHODS

A latent profile analysis was applied to data from 727 recently postmenopausal women enrolled in the Kronos Early Estrogen Prevention Study (KEEPS). Women were cognitively healthy, within three years of their last menstrual period, and free of current or past CV disease. Education level, apolipoprotein E ε4 allele (APOE4), ethnicity, and age were modeled as predictors of latent class membership. The association between class membership, characterizing CV risk profiles, and performance on five cognitive factors was examined. A supervised random forest algorithm with a 10-fold cross-validation estimator was used to test accuracy of CV risk classification.

RESULTS

The best-fitting model generated two distinct phenotypic classes of CV risk 62% of women were "low-risk" and 38% "high-risk". Women classified as low-risk outperformed high-risk women on language and mental flexibility tasks (p = 0.008) and a global measure of cognition (p = 0.029). Women with a college degree or above were more likely to be in the low-risk class (OR = 1.595, p = 0.044). Older age and a Hispanic ethnicity increased the probability of being at high-risk (OR = 1.140, p = 0.002; OR = 2.622, p = 0.012; respectively). The prevalence rate of APOE-ε4 was higher in the high-risk class compared with rates in the low-risk class.

CONCLUSION

Among recently menopausal women, significant heterogeneity in CV risk is associated with education level, age, ethnicity, and genetic indicators. The model-based latent classes were also associated with cognitive function. These differences may point to phenotypes for CV disease risk. Evaluating the evolution of phenotypes could in turn clarify preclinical disease, and screening and preventive strategies. ClinicalTrials.gov NCT00154180.

Genetic and structure-function studies of missense mutations in human endothelial lipase

Endothelial lipase (EL) plays a pivotal role in HDL metabolism. We sought to characterize EL and its interaction with HDL as well as its natural variants genetically, functionally and structurally. We screened our biethnic population sample (n = 802) for selected missense mutations (n = 5) and identified T111I as the only common variant. Multiple linear regression analyses in Hispanic subjects revealed an unexpected association between T111I and elevated LDL-C (p-value = 0.012) and total cholesterol (p-value = 0.004). We examined lipase activity of selected missense mutants (n = 10) and found different impacts on EL function, ranging from normal to complete loss of activity. EL-HDL lipidomic analyses indicated that EL has a defined remodeling of HDL without exhaustion of the substrate and a distinct and preference for several fatty acids that are lipid mediators and known for their potent pro- and anti-inflammatory properties. Structural studies using homology modeling revealed a novel α/β motif in the C-domain, unique to EL. The EL dimer was found to have the flexibility to expand and to bind various sizes of HDL particles. The likely impact of the all known missense mutations (n = 18) on the structure of EL was examined using molecular modeling and the impact they may have on EL lipase activity using a novel structure-function slope based on their structural free energy differences. The results of this multidisciplinary approach delineated the impact of EL and its variants on HDL. Moreover, the results suggested EL to have the capacity to modulate vascular health through its role in fatty acid-based signaling pathways.

Cognitive decline and cardiometabolic risk among Hispanic and non-Hispanic white adults in the San Luis Valley Health and Aging Study

Cardiometabolic risk factors, including hypertension, dyslipidemia, central obesity, insulin resistance and diabetes are linked to cognitive impairment. The Hispanic population appears to be differentially affected by both cardiometabolic risk factors and cognitive impairment. We sought to determine whether ethnic differences in cognitive impairment in long-resident southwestern US elders was explained by the presence of cardiometabolic risk factors, and to explore patterns of cognitive decline over time. We performed a secondary analysis of data collected on 378 Hispanic and 409 non-Hispanic white adult participants in a longitudinal study of community-dwelling elderly in southern Colorado. Measures of cardiometabolic risk included waist circumference, blood pressure, diagnosis of diabetes, and random blood glucose. Cognitive measures included the Mini-Mental State Exam (MMSE) and the behavioral dyscontrol scale (a measure of executive cognitive function), at baseline and after an average of 22 months. Subjects were also administered the Center for Epidemiologic Studies Depression Scale, and the Coronary Artery Risk Development in Young Adults 1-Year Activity Recall. At baseline, Hispanic elders had a greater number of cardiometabolic risk factors and lower MMSE and behavioral dyscontrol scale scores than non-Hispanic whites. Hispanic ethnicity was associated with a greater likelihood of decline in general cognitive function, but not executive cognitive function, after adjusting for age and education. This differential decline was not explained by either individual or total number of baseline cardiometabolic risk factors, depression, or physical activity. A borderline increased risk of decline in general cognitive function was seen in sedentary individuals (P = 0.05).

Population-Based Resequencing of LIPG and ZNF202 Genes in Subjects with Extreme HDL Levels

Endothelial lipase (LIPG) and zinc finger protein 202 (ZNF202) are two pivotal genes in high density lipoprotein (HDL metabolism). We sought to determine their genetic contribution to variation in HDL-cholesterol levels by comprehensive resequencing of both genes in 235 individuals with high or low HDL-C levels. The selected subjects were 141 Whites (High HDL Group: n = 68, x¯=76.90mg/dl; Low HDL Group: n = 73, x¯=32.55mg/dl) and 94 Hispanics (High HDL Group: n = 46, x¯=74.85mg/dl; Low HDL Group: n = 48, x¯=29.95mg/dl). We identified a total of 185 and 122 sequence variants in LIPG and ZNF202, respectively. We found only two missense variants in LIPG (T111I and N396S) and two in ZNF202 (A154V and K259E). In both genes, there were several variants unique to either the low or high HDL group. For LIPG, the proportion of unique variants differed between the high and low HDL groups in both Whites (p = 0.022) and Hispanics (p = 0.017), but for ZNF202 this difference was observed only in Hispanics (p = 0.021). We also identified a common haplotype in ZNF202 among Whites that was significantly associated with the high HDL group (p = 0.013). These findings provide insights into the genetics of LIPG and ZNF202, and suggest that sequence variants occurring with high frequency in non-exonic regions may play a prominent role in modulating HDL-C levels in the general population.

Determinants of fasting plasma glucose and glycosylated hemoglobin among low income Latinos with poorly controlled type 2 diabetes

The objective of this study was to identify demographic, socio-economic, acculturation, lifestyle, sleeping pattern, and biomedical determinants of fasting plasma glucose (FPG) and glycosylated hemoglobin (HbA1c), among Latinos with type 2 diabetes (T2D). Latino adults (N = 211) with T2D enrolled in the DIALBEST trial were interviewed in their homes. Fasting blood samples were also collected in the participants' homes. Because all participants had poor glucose control, above-median values for FPG (173 mg/dl) and HbA1c (9.2%) were considered to be indicative of poorer glycemic control. Multivariate analyses showed that receiving heating assistance (OR: 2.20; 95% CI: 0.96-4.96), and having a radio (3.11, 1.16-8.35), were risk factors for higher FPG levels, and lower income (10.4, 1.54-69.30) was a risk factor for higher HbA1c levels. Lower carbohydrate intake during the previous day (0.04; 0.005-0.37), as well as regular physical activity (0.30; 0.13-0.69), breakfast (2.78; 1.10-6.99) and dinner skipping (3.9; 1.03-14.9) during previous week were significantly associated with FPG concentrations. Being middle aged (2.24, 1.12-4.47), 30-60 min of sleep during the day time (0.07, 0.01-0.74) and having medical insurance (0.31, 0.10-0.96) were predictors of HbA1c. Results suggest that contemporaneous lifestyle behaviors were associated with FPG and contextual biomedical factors such as health care access with HbA1c. Lower socio-economic status indicators were associated with poorer FPG and HbA1c glycemic control.

Association of central adiposity with prediabetes and decreased insulin sensitivity in rural Chinese normal-weight and overweight women

This study investigated whether high central adiposity was associated with prediabetes and decreased insulin sensitivity (IS) in both normal-weight (body mass index [BMI] <23 kg/m(2)) and overweight (BMI >or=23 kg/m(2)) rural Chinese women. Adipose variables measured by dual-energy x-ray absorptiometry (percentage body fat, percentage lower-body fat [%LF], and percentage trunk fat [%TF]) and general adipose variables (BMI and waist circumference) were used for examining the association of adiposity with prediabetes among 4071 rural Chinese women aged 20 to 60 years. Furthermore, the association of adiposity with IS was tested in both normal- and overweight women with normal glucose tolerance. BMI was highly correlated with percentage body fat and waist circumference, but was weakly correlated with %LF and %TF. Both high %TF (top quartile of %TF) and low %LF (lower 3 quartiles of %LF) were associated with higher prevalence of prediabetes in both normal- and overweight women. Compared with normal-weight women in low %TF, the odds of prediabetes were similarly increased for women with high %TF regardless of whether they were overweight (odds ratio [95% confidence interval] = 1.6 [1.3-2.0]) or not (odds ratio [95% confidence interval] = 1.5 [1.2-2.0]). Similarly, among 3280 women with normal glucose tolerance, high %TF was associated with increased fasting insulin, 2-hour oral glucose tolerance test insulin, and homeostasis model assessment of insulin resistance regardless of weight status (normal or overweight). Among relatively lean, rural Chinese women, high %TF was associated with increased odds of prediabetes and lower IS regardless of weight status (normal or overweight).

B-type Natriuretic Peptide (BNP) Is Useful in Detecting Asymptomatic Left Ventricular Dysfunction in Low-Income, Uninsured Patients

Low-income, uninsured individuals with multiple cardiovascular risk factors (CRFs) are at risk of heart failure (HF). B-type natriuretic peptide (BNP) screening for asymptomatic left ventricular dysfunction (ALVD) has not been tested specifically in this group. The purposes of this study were to describe BNP levels in asymptomatic low-income, uninsured individuals with multiple CRFs and determine the correlation between BNP levels and echocardiography for identifying ALVD. Methods: This correlational study included 53 patients (age 55 ± 10 years, 83% non-White, 64% female). BNP testing and echocardiogram (ECHO) were performed. Results: Of the 30 patients (57%) diagnosed with ALVD by ECHO, 21 (40%) had diastolic and 9 (17%) systolic dysfunction. BNP levels were lower among those with normal left ventricular (LV) function (29.6 ± 24 pg/mL) than those with diastolic (80.2 ± 69 pg/mL, p = .01) and systolic dysfunction (337.1 ± 374 pg/mL, p = .009). sParticipants with BNP ≥50 pg/ mL were 5.75 times more likely to exhibit diastolic dysfunction (odds ratio [OR] = 5.75, 95% confidence interval [CI] 1.29— 25.51; p < .01) and those with BNP ≥100 pg/mL were 7.80 times more likely to have systolic dysfunction (OR = 7.8, 95% CI 1.60—37.14; p < .005) than those with lower levels. With BNP cut point of 50 pg/mL, area under the curve (AUC) was 0.82 (95% CI 0.63—1.00) with sensitivity of 88% and specificity of 67%. Conclusion: BNP is a low-cost method to detect ALVD in high-risk, uninsured, low-income individuals. Elevated BNP levels should prompt initiation of further diagnostic testing and early treatment.

Lipid, lipoproteins, C-reactive protein, and hemostatic factors at baseline in the diabetes prevention program

OBJECTIVE

Individuals with impaired glucose tolerance (IGT) appear to be at increased risk for cardiovascular disease (CVD) due at least in part to an increased prevalence of risk factors. We evaluated lipid, lipoprotein, C-reactive protein (CRP), fibrinogen, and tissue plasminogen activator (tPA) levels at study entry in the largest multiethnic cohort of participants with IGT described, namely in the Diabetes Prevention Program (DPP).

RESEARCH DESIGN AND METHODS

Measurements were performed at the baseline visit of 3,819 randomized participants of the DPP. Among 3,622 participants who were not taking lipid-lowering medicines, cardiovascular risk factors were analyzed in relation to demographic, anthropometric, and metabolic measures. Major determinants of risk factors were assessed in multivariate analysis.

RESULTS

Over 40% of participants had elevated triglyceride, LDL cholesterol, and CRP levels and reduced HDL cholesterol levels. Men had higher triglyceride and tPA and lower HDL cholesterol concentrations and smaller LDL particle size than women, whereas women had higher CRP and fibrinogen levels. African Americans had less dyslipidemia but higher fibrinogen levels, and Asian Americans had lower CRP and fibrinogen levels than Caucasians and Hispanics. The surrogate measure of insulin resistance (homeostasis model assessment of insulin resistance [HOMA-IR]) had the strongest association with HDL cholesterol, triglyceride, and tPA levels and LDL particle size. BMI had the greatest influence on CRP and fibrinogen levels. Using median splits of indexes of insulin resistance and insulin secretion (insulin-to-glucose ratio), participants with greater insulin resistance had a more adverse CVD risk-factor profile, whereas insulin secretion had little influence on risk factors.

CONCLUSIONS

The pattern of CVD risk factors in participants with IGT in the DPP exhibits substantial heterogeneity and is significantly influenced by race, sex, and age, as well as by obesity, glucose, and insulin measures. The degree of insulin resistance, as reflected by HOMA-IR, showed the greatest association with the cardiovascular risk factors.

Metabolic syndrome at follow-up in women with and without gestational diabetes mellitus in index pregnancy

We prospectively studied 262 women with prior gestational diabetes mellitus (GDM) and 66 control women to compare their prevalence of metabolic syndrome and its relationship with insulin secretion and sensitivity. A 75-g oral glucose tolerance test was scheduled 5 years after delivery along with lipid profile, anthropometrics, and blood pressure measurement. Metabolic syndrome was defined according to the National Cholesterol Education Program 2001, and insulin sensitivity and secretion were estimated with the homeostasis model assessment. Women with prior GDM had similar insulin sensitivity and lower insulin secretion than control women. In comparison with control women, women with prior GDM had higher blood pressure, waist circumference, very low-density lipoprotein cholesterol, and oral glucose tolerance test blood glucose values but, with the exception of fasting hyperglycemia, did not have an increased prevalence of metabolic syndrome or its components. The multivariate prediction of metabolic syndrome and its components was similar with age and current homeostasis model assessment-insulin secretion and resistance indexes or with age, obesity, and GDM. The main predictor was current insulin resistance in the first case and obesity in the second, obesity being the best predictor overall. We conclude that in our population and at midterm follow-up, women with prior GDM have a decreased insulin secretion and display a higher prevalence of fasting hyperglycemia but not the full-blown picture of metabolic syndrome. Obesity, a surrogate index of insulin resistance, is the best predictor of metabolic syndrome at follow-up.

Issues in achieving compliance with antihypertensive treatment in the Latino population

Latino Americans are the largest growing ethnic minority group in the United States. The level of awareness and control of hypertension among Latino Americans has remained virtually unchanged in the past 20 years. Untreated hypertension often progresses and is a major risk factor for cardiovascular disease. Hypertension control can be achieved with simple and well-tolerated medication regimens that are cost-effective and reduce morbidity and mortality in all populations studied. Clinicians can work to increase compliance by developing a basic understanding of the social, demographic, and historical conditions that affect Latino Americans. Language proficiency, cultural scripts, and health beliefs and attitudes influence patient-clinician communication in specific ways among Latino patients. Health care systems and plans should work on creating culturally competent health care programs to serve the needs of this diverse population.

Prevalence of non-traditional cardiovascular disease risk factors among persons with impaired fasting glucose, impaired glucose tolerance, diabetes, and the metabolic syndrome: analysis of the Third National Health and Nutrition Examination Survey (NHANES III)

PURPOSE

To calculate the prevalence of non-traditional cardiovascular disease (CVD) risk factors across diabetes status and for persons with and without the metabolic syndrome.

METHODS

Data were analyzed from the Third National Health and Nutrition Examination Survey for normal plasma glucose [<100 mg/dl, n=4589]; impaired fasting glucose [IFG, 100-125 mg/dl, n=2008], diabetes [fasting glucose #10878; 126 mg/dl or diabetes medication, n=750]; and participants with and without the metabolic syndrome, n=1938 and n=5409, respectively.

RESULTS

After adjustment for age, race, sex, body mass index, physical inactivity, cigarette smoking and alcohol consumption, a higher odds (p-trend < 0.01) of the metabolic syndrome, an elevated HOMA-insulin resistance index, chronic kidney disease, elevated C-reactive protein, high fibrinogen, and high white blood cell count was observed across diabetes status. After similar adjustment, the metabolic syndrome was associated with (odds ratio; 95% confidence interval) low apolipoprotein A1 (2.27: 1.30,3.96), high apolipoprotein-B (2.97: 2.03,4.34), a higher HOMA insulin resistance index (5.25: 4.16, 6.63), chronic kidney disease (2.27: 1.42, 3.63), and elevated markers of inflammation [high white blood cell count (1.55: 1.14, 2.10), and elevated C-reactive protein (1.46: 1.06, 2.00)]. Among participants with IFG, the presence of impaired glucose tolerance (IGT) was associated with a higher prevalence of the HOMA insulin reistance index, 32.3%, high fibrinogen, 18.5%, and elevated C-reactive protein, 13.2%, compared to persons with IFG alone, 19.7%, 13.3% and 5.7%, respectively (each p <== 0.05).

CONCLUSIONS

In this representative of the US population, an increased prevalence of non-traditional CVD risk factors was present among persons with diabetes, IGT and IFG compared to IFG alone, and the metabolic syndrome.

Improvements in glucose tolerance in obese males with abnormal glucose tolerance following 10 days of aerobic exercise

BACKGROUND

Aerobic exercise training has been shown to produce beneficial changes in glucose tolerance and insulin sensitivity in obese individuals if performed at high enough intensities and/or durations. We examined the effects of a moderate intensity, short-term exercise training protocol on glucose tolerance in obese males with glucose intolerance.

METHODS

Fourteen abdominally obese, sedentary males with normal glucose tolerance (NGT; n = 7) and abnormal glucose tolerance (AGT; n = 7) completed 40 min of exercise bouts for 10 consecutive days at approximately 75% of age-predicted maximum heart rate. Fasting glucose and insulin levels, and glucose tolerance and insulin response to glucose were measured before and after the training period.

RESULTS

Participants did not experience significant mass loss during the 10-day investigation. Individuals in the AGT group experienced significant (P < 0.05) improvement in glucose tolerance [glucose area: 1,763.67 (255.98) mmol L(-1) x 120 min(-1) vs. 1,682.98 (266.91) mmol L(-1) x 120 min(-1)] and fasting insulin levels [44.57 (7.58) microU mL(-1) vs. 36.14 (3.97) microU mL(-1)] as a result of training. Significant (P < 0.05) reductions in fasting glucose concentrations [5.82 (0.19) mmol L(-1) vs. 5.42 (0.18) mmol L(-1)] and a decrease in fasting insulin concentrations [44.71 (9.39) microU mL(-1) vs. 35.0 (7.15) microU mL(-1); P = 0.064] were observed in the NGT group following the training period.

CONCLUSIONS

The data suggest that moderate, short-term exercise without concomitant mass loss is effective in improving glucose tolerance and insulin response to a glucose load in obese males with abnormal glucose tolerance.

Recent and temporal trends (1975 to 1999) in the treatment, hospital, and long-term outcomes of Hispanic and non-Hispanic white patients hospitalized with acute myocardial infarction: a population-based perspective

BACKGROUND

Extremely limited population-based data are available describing recent and temporal trends in the characteristics, treatment, and outcomes of Hispanic and non-Hispanic white patients hospitalized with acute myocardial infarction (AMI).

METHODS

This was a community-based, observational study of 9649 greater Worcester residents hospitalized in all hospitals serving the Worcester, Massachusetts, metropolitan area in 12 one-year periods between 1975 and 1999. In the total study sample, 171 (2%) patients were Hispanic. Hispanic patients were matched with 395 non-Hispanic white patients on the basis of age, sex, and year of hospitalization.

RESULTS

Hispanics were more likely to present to greater Worcester hospitals with a history of diabetes as compared with non-Hispanic whites. Hispanics were less likely to have an initial, Q-wave AMI during the index hospitalization. After controlling for a limited number of known potentially confounding factors, Hispanics were at lower risk for development of heart failure (OR, 0.63; 95% CI, 0.41, 0.96). Both Hispanics (13% vs 11%) and non-Hispanic whites (28% vs 9%), however, had declines in hospital case-fatality rates between 1975 and 1999. An overall similar treatment pattern and increasing trends in the use of effective cardiac medications over time were observed in both patient groups. However, Hispanics were significantly less likely to be treated with coronary angioplasty during the acute hospitalization. Trends of a worse long-term survival for discharged Hispanic patients were observed over a 10-year follow-up period.

CONCLUSIONS

The results of this community-wide study suggest encouraging hospital outcomes in Hispanic and non-Hispanic white patients hospitalized with AMI. Enhanced secondary prevention efforts remain needed to improve the hospital and long-term outcomes of patients with AMI, irrespective of race or ethnicity.

The Singapore impaired glucose tolerance follow-up study: does the ticking clock go backward as well as forward?

OBJECTIVE

To 1). document the change in glucose tolerance for subjects with normal glucose tolerance (NGT) and impaired glucose tolerance (IGT) over time, 2). identify baseline factors associated with worsening of glucose tolerance, and 3). determine whether cardiovascular disease (CVD) risk factors associated with IGT improved in tandem with glucose tolerance.

RESEARCH DESIGN

Subjects with IGT and NGT (matched for age, sex, and ethnic group) were identified from a cross-sectional survey conducted in 1992. Subjects with IGT (297) and NGT (298) (65.0%) were reexamined in 2000. Glucose tolerance (assessed by 75-g oral glucose tolerance test), anthropometric data, serum lipids, blood pressure, and insulin resistance were determined at baseline and at the follow-up examination.

RESULTS

For NGT subjects, 14.0% progressed to IGT and 4.3% to diabetes over 8 years. For IGT subjects, 41.4% reverted to NGT, 23.0% remained impaired glucose tolerant, and 35.1% developed diabetes. Obesity, hypertriglyceridemia, higher blood pressure, increased insulin resistance, and lower HDL cholesterol at baseline were associated with worsening of glucose tolerance in both IGT and NGT subjects. Those with IGT who reverted to NGT remained more obese and had higher blood pressure than those with NGT in both 1992 and 2000. However, serum triglyceride, HDL cholesterol, and insulin resistance values in 2000 became indistinguishable from those of subjects who maintained NGT throughout the study period.

CONCLUSIONS

Some, but not all, CVD risk factors associated with IGT and with the risk of future diabetes normalize when glucose tolerance normalizes. Continued surveillance and treatment in subjects with IGT, even after they revert to NGT, may be important in the prevention of CVD.

Dietary and plasma lipid, lipoprotein, and apolipoprotein profiles among elderly Hispanics and non-Hispanics and their association with diabetes

BACKGROUND

There are limited data about dietary intakes and plasma lipids of elderly US Hispanics.

OBJECTIVE

The disparity in prevalence of type 2 diabetes among population groups underscored our need to assess dietary and plasma risk factors for cardiovascular disease.

DESIGN

Plasma lipids and apolipoproteins and dietary intakes of macronutrients were measured in elderly subjects (60-98 y): 490 Hispanics of Caribbean origin (Puerto Ricans and Dominicans) and 163 non-Hispanic whites. Plasma values were related to ethnicity and to macronutrient intake. Differences in plasma lipids due to diabetes were assessed among the Hispanics.

RESULTS

Intakes of carbohydrate and polyunsaturated fatty acids were higher and intakes of cholesterol and saturated and monounsaturated fatty acids were lower in Hispanics than in non-Hispanic whites. Concentrations of total cholesterol, HDL cholesterol, and apolipoprotein A-I were significantly lower among Hispanic women than among non-Hispanic white women; a similar trend was seen in men. Dyslipidemia (high triacylglycerols and low HDL cholesterol) was more prevalent among Hispanics with than without diabetes.

CONCLUSIONS

Ethnic differences in serum lipids exist and appear to be associated with differences in dietary intakes. However, both Hispanics and non-Hispanic whites had lipid profiles indicating a high risk of cardiovascular disease. Hispanics with diabetes were at higher risk of dyslipidemia than were those without diabetes. Our data suggest that lifestyle changes, including diet modification and exercise, could be of significant benefit to both ethnic groups.

Socioeconomic, cultural, and behavioral factors affecting Hispanic health outcomes

Evidence suggests that social and economic factors are important determinants of health. Yet, despite higher porverty rates, less education, and worse access to health care, health outcomes of many Hispanics living in the United States today are equal to, or better than, those of non-Hispanic whites. This paradox is described in the literature as the epidemiological paradox or Hispanic health paradox. In this paper, the authors selectively review data and research supporting the existence of the epidemiological paradox. They find substantial support for the existence of the epidemiological paradox, particularly among Mexican Americans. Census undercounts of Hispanics, misclassification of Hispanic deaths, and emigration of Hispanics do not fully account for the epidemiological paradox. Identifying protective factors underlying the epidemiological paradox, while improving access to care and the economic conditions among Hispanics, are important research and policy implications of this review.

Effect of glucose tolerance status on PAI-1 plasma levels in overweight and obese subjects

OBJECTIVE

The aim of our study was to examine whether plasminogen activator inhibitor-1 (PAI-1) plasma levels varied as a function of differences in glucose tolerance status independently of body fatness, body-fat distribution, and insulin sensitivity.

RESEARCH METHODS AND PROCEDURES

Plasma PAI-1 antigen levels, along with insulin resistance [measured by homeostatic model assessment (HOMA(IR))], central fat accumulation, body composition, blood pressure, and fasting concentrations of glucose, insulin, and lipids, were measured in 229 overweight and obese [body mass index (BMI) > or =25 kg/m(2)) subjects with normal glucose tolerance (NGT) and in 44 age- and BMI-matched subjects with impaired glucose tolerance (IGT).

RESULTS

Plasma PAI-1 antigen levels were significantly higher in IGT than in NGT subjects. Log PAI-1 was positively correlated with BMI, HOMA(IR), and log insulin, and inversely associated with high-density lipoprotein-cholesterol both in IGT and in NGT individuals. On the other hand, log PAI-1 was positively correlated with waist circumference, fat mass (FM), fat-free mass, systolic and diastolic blood pressure, and log triglycerides only in the NGT group. After multivariate analyses, the strongest determinants of PAI-1 levels were BMI, FM, waist circumference, and high-density lipoprotein cholesterol in the NGT group and only HOMA(IR) in the IGT cohort.

DISCUSSION

This study demonstrates that PAI-1 concentrations are higher in IGT than in NGT subjects. Furthermore, we suggest that the influences of total adiposity, central fat, and insulin resistance, main determinants of PAI-1 concentrations, are different according to the degree of glucose tolerance.

Postchallenge hyperglycemia and mortality in a national sample of U.S. adults

OBJECTIVE

Although postchallenge hyperglycemia is a well-established feature of type 2 diabetes, its association with risk of mortality is uncertain. Therefore, the aim of this study was to assess the independent association of fasting and 2-h glucose levels with all-cause and cardiovascular disease (CVD) mortality.

RESEARCH DESIGN AND METHODS

We analyzed data from the Second National Health and Nutrition Examination Survey (NHANES II) Mortality Study, a prospective cohort study of U.S. adults examined in the NHANES II, and focused on the 3,092 adults aged 30-74 years who underwent an oral glucose tolerance test at baseline (1976-1980). Deaths were identified from U.S. national mortality files from 1976 to 1992. To account for the complex survey design, we used SUDAAN statistical software for weighted analysis.

RESULTS

Compared with their normoglycemic counterparts (fasting glucose [FG] < 7.0 and 2-h glucose < 7.8 mmol/l), adults with fasting and postchallenge hyperglycemia (FG > or =7.0 and 2-h glucose > or =11.1 mmol/l) had a twofold higher risk of death after 16 years of follow-up (age- and sex-adjusted relative hazard [RH] 2.1, 95% CI 1.4-3.2). However, adults with isolated postchallenge hyperglycemia (FG < 7.0 and 2-h glucose > or =11.1 mmol/l) were also at higher risk of death (1.6, 1.0-2.6). In proportional hazards analysis, FG (fully adjusted RH 1.10 per 1 SD; 95% CI 1.01, 1.22) and 2-h glucose (1.14, 1.00-1.29) showed nearly identical predictive value for mortality. Similar trends were observed for CVD mortality.

CONCLUSIONS

These results suggest that postchallenge hyperglycemia is associated with increased risk of all-cause and CVD mortality independently of other CVD risk factors.

A case-control study of physical activity and non-insulin dependent diabetes mellitus (NIDDM). the San Luis Valley Diabetes Study

PURPOSE

The purpose of this study was to examine the association between physical activity and non-insulin dependent diabetes mellitus (NIDDM).

METHODS

We conducted a population-based case-control study in Hispanic and non-Hispanic white men and women, ages 20-74. A total of 167 cases with NIDDM and 1100 controls with normal glucose tolerance were included. All subjects completed an oral glucose tolerance test.

RESULTS

Persons with recently diagnosed NIDDM reported significantly lower levels of physical activity than control subjects. For total metabolic units, the odds ratio for subjects in the highest tertile compared to those in the lowest tertile was 0.60 (95% confidence interval (CI) = 0.37-0.98) after adjusting for age, sex, ethnicity, and family history of diabetes. The adjusted odds ratio for persons reporting high levels of vigorous activity (at least three times per week for 20 minutes) was also less than 1, but was not statistically significant (odds ratio (OR) = 0.73, 95% CI = 0.47-1.14). Similar adjusted odds ratios were observed for high versus low levels of self-assessed work activity (OR = 0.50, 95% CI = 0.34-0.74) and leisure time physical activity (OR = 0.62, 95% CI = 0.44-0.90). Further adjustments for body mass index attenuated the strength of the association between physical activity and NIDDM. This is consistent with the hypothesis that obesity is one consequence of physical inactivity that puts individuals at increased risk for NIDDM. The association of physical activity and NIDDM was stronger in Hispanic than in non-Hispanic white subjects, although this difference was not statistically significant.

CONCLUSIONS

High levels of physical activity are associated with lower odds of NIDDM and this relationship may be stronger in Hispanic subjects.

Prevalence of diabetes and impaired glucose tolerance in adult hypopituitarism on low dose oral hydrocortisone replacement therapy

OBJECTIVE

The conventional dosage of hydrocortisone, used for many years in the management of hypopituitarism (30 mg per day), has now been shown to be more than is physiologically necessary. On this conventional corticosteroid therapy studies have demonstrated an increased prevalence of diabetes and impaired glucose tolerance, which may contribute to the increased vascular morbidity and mortality reported in the condition. In these studies no information is available on oral glucose tolerance test (OGTT) timing in relation to administration of oral steroid and variable hydrocortisone doses were employed.

PATIENTS

In order to assess glucose tolerance in patients treated with lower, more physiological doses, we performed a 75-g OGTT at least 1 month after hydrocortisone therapy was adjusted to 15 mg at 0800 h and 5 mg at 1700 h in 45 adult onset hypopituitary patients (30 M, 15 F). Mean (+/- SD) duration of hypopituitarism was 12 +/- 10 years, mean age 52 +/- 14 years and BMI 29.3 +/- 5.1 kg/m2. All were on hydrocortisone, 43 on thyroxine, 31 on sex steroids, 9 on desmopressin and 33 had documented growth hormone deficiency. Hydrocortisone 15 mg was taken at 0800 and the OGTT commenced at 0900.

RESULTS

Using standard WHO criteria 36 patients (80%) had normal glucose tolerance, 1 (2%) had newly diagnosed diabetes and 8 (18%) had impaired glucose tolerance. Using the recently announced American Diabetes Association criteria for diagnosis 96% had normal glucose tolerance, 2% had diabetes and 2% impaired fasting glucose.

CONCLUSION

The markedly reduced prevalence of diabetes and impaired glucose tolerance on lower hydrocortisone replacement doses in our series of patients with hypopituitarism, not previously known to be diabetic, is of great interest. This lower prevalence may eventually result in reduced vascular complication rates.

Gender and treatment differences in knowledge, health beliefs, and metabolic control in Mexican Americans with type 2 diabetes

PURPOSE

The purpose of this project was to describe metabolic control, knowledge, and health beliefs of Mexican Americans with type 2 diabetes.

METHODS

The study site was Starr County, Texas, a border community located on the Rio Grande River and bordering northern Mexico. Of the total sample of 360 persons, 252 agreed to participate in this intervention study and were randomized either to the treatment group or the control group that waited 1 year to begin the intervention.

RESULTS

The majority of individuals were Spanish-speaking females with a mean age of 54 years and a mean diabetes duration of 8 years. For those treated with diet only, males exhibited higher fasting blood glucose levels than females. Gender effects were seen for cholesterol level, with females exhibiting higher levels than males. Males expressed stronger perceptions of control and social support for diet. Bivariate relationships were found between acculturation and diabetes knowledge. The health belief subscales of control and impact on job together explained 16% of the variance in HbA1c values.

CONCLUSIONS

Males and females held differing beliefs about ability to control their diabetes and degree of social support for diet. The impact of gender differences on ability to integrate diabetes self-care and on effectiveness of diabetes programs has not been determined but should be considered in future research.

Outcome of Hispanic patients treated with thrombolytic therapy for acute myocardial infarction: results from the GUSTO-I and III trials. Global Utilization of Streptokinase and TPA for Occluded Coronary Arteries

OBJECTIVES

We sought to describe the differences in the process of care and clinical outcomes between Hispanics and non-Hispanics receiving thrombolytic therapy for myocardial infarction (MI).

BACKGROUND

Hispanics are the fastest growing and second largest minority in the U.S. but most cardiovascular disease data on Hispanics has been derived from retrospective studies and vital statistics. Despite their higher cardiovascular risk-factor profile, better outcomes after MI have been reported in Hispanics.

METHODS

We studied the baseline characteristics, resource use and outcomes of 734 Hispanics and 27,054 non-Hispanics treated for MI in the GUSTO-I and -III trials. The primary end point of both trials was 30-day mortality.

RESULTS

Hispanics were younger, shorter, lighter and more often diabetic and began thrombolysis 9 min later, compared with non-Hispanics. Measures of socioeconomic status (educational level, employment and health insurance) were lower among Hispanics. Fewer Hispanics than non-Hispanics underwent in-hospital angiography (70% vs. 74%, p = 0.013) or bypass surgery (11% vs. 13.5%, p = 0.04). Hispanics received more angiotensin-converting enzyme (ACE) inhibitors and less calcium-channel blockers, prophylactic lidocaine and inotropic agents. Mortality at 30 days and at one year did not differ significantly between Hispanics and non-Hispanics (6.4% vs. 6.7% and 9.0% vs. 9.7%, respectively). We noted no interactions between thrombolytic strategy and Hispanic status on major outcomes (30-day death, stroke and major bleeding).

CONCLUSIONS

The care of Hispanics with MI differed slightly from that of non-Hispanics. Nevertheless, these differences in care did not affect long-term outcomes.

Influence of hyperglycemia and hyperuricemia on long-term transplant survival in kidney transplant recipients

Long-term prognosis in kidney transplant recipients depends on multiple factors. The purpose of this study was to quantify the influence of hyperuricemia and hyperglycemia (elements of the so-called 'syndrome X', i.e., a combination of metabolic disorders like hyperuricemia, diabetes mellitus, hyperlipidemia, and hypertension) on organ function in 350 kidney transplant recipients who had received 375 kidney transplants up to 1990 and in whom sex, age of recipient and donor, nephrologic disease, duration of dialysis, human leukocyte antigen (HLA) classification, and duration of transplant ischemia had been well matched. We found the influence of hyperuricemia on graft survival to be statistically significant (p < or = 0.05), while a statistically significant correlation between hyperglycemia and graft survival could not be detected in the present study. The transplant survival rates 2, 4, and 5 yr post-kidney-transplantation were 96.7, 80.7, and 78.7 in normogylcemic patients vs. 96.9, 85, and 82.7% in hyperglycemic ( > 100 mg,dL) kidney transplant recipients (p > 0.05). Transplant survival in hyperuricemic patients (male, > 8 mg dL; female, > 6.2 mg/dL) 2, 4, and 5 yr post-transplantation was significantly reduced (92.2, 70.6, and 68.8% vs. 98.1, 85.6, and 83.3%), as compared to normouricemic recipients. A combined presence of both hyperuricemia and hyperglycemia probably influencing the prognosis post-kidney-transplantation failed to reach the level of statistical significance. We found a significant correlation between age of recipients and plasma glucose (p < or = 0.01) and between serum uric acid concentrations and diuretic therapy (p < or = 0.05) and gender (p < or = 0.(5). In conclusion, hyperuricemia after kidney transplantation seems to reduce graft survival, whereas an influence of the carbohydrate metabolism has to be denied.

LDL size in African Americans, Hispanics, and non-Hispanic whites : the insulin resistance atherosclerosis study

The prevalence of cardiovascular disease (CVD) and atherosclerosis varies among several minority ethnic groups in the United States. Recently, small, dense low density lipoprotein (LDL) particle size has been recognized as a risk factor for CVD. We examined LDL size as a possible explanation for differences in CVD rates in 1571 subjects from the Insulin Resistance Atherosclerosis Study (IRAS), a multiethnic study of insulin resistance and cardiovascular risk factors. LDL size (A) was significantly different by ethnic group (African Americans 262.1+/-0.6, Hispanics 257.6+/-0.6, and non-Hispanic whites 259.2+/-0.4, P<0.001). Ethnic differences in LDL size continued to be statistically significant after adjustment for upper body adiposity, insulin resistance, and glucose tolerance status. However, after further adjustment for other cardiovascular risk factors, especially ethnic differences in triglyceride and high density lipoprotein (HDL) cholesterol levels, the ethnic differences in LDL size were markedly attenuated and in general no longer statistically significant. The relation of triglyceride, HDL cholesterol, insulin resistance, and adiposity to LDL size in each ethnic group was similar. LDL size differs by ethnic group, which is independent of obesity or insulin resistance. These ethnic differences appear to be due to ethnic variations in dyslipidemia (especially differences in triglyceride levels); ethnic differences in LDL size are not consistent with previously reported ethnic dissimilarities in CVD or atherosclerosis.

Effect of exercise on postprandial insulin responses in Mexican American and non-Hispanic women

Postprandial insulin responses (integrated area under the curve) to an oral glucose load after a period of aerobic exercise and no exercise (control) were compared in sedentary normoglycemic Mexican American and non-Hispanic women pair-matched (n = 9) on total body fat mass (21.8 +/- 3.5 kg). The age (27.4 +/- 3.0 years), body mass index (BMI) (23.6 +/- 1.4 kg/m2), waist to hip ratio (WHR) (0.85 +/- .02), waist circumference (83.5 +/- 4.5 cm), lean mass (36.2 +/- 1.5 kg), and maximal O2 consumption ([VO2 max] 32.9 +/- 1.6 mL x kg(-1) x min(-1)) were similar, although the centrality index (subscapular/triceps skinfolds) was significantly greater in Mexican Americans (0.88 +/- 0.06 v 0.70 +/- 0.05, P < .01). Exercise (treadmill walking for 50 minutes at 70% VO2 max) and control trials were performed 4 weeks apart and 5 to 12 days after the onset of menstruation. A 75-g oral glucose load was administered 15 hours after the completion of each trial, with the subjects 12 hours postprandial. Blood samples were drawn prior to glucose ingestion (fasting, 0 minutes) and at minutes 15, 30, 60, 90, 120, and 150 postingestion. The postprandial insulin response was calculated using a trapezoidal method. In Mexican Americans, significant (P < .02) reductions in the postprandial insulin response (exercise v control, 6.5 +/- 1.0 v 8.5 +/- 1.4 pmol/L x min x 10(4)) and fasting insulin (exercise v control, 77.4 +/- 7.0 v 88.5 +/- 10.3 pmol/L) occurred after exercise compared with the control condition. In non-Hispanics, neither the postprandial insulin response (exercise v control, 7.2 +/- 1.0 v 6.2 +/- 0.9 pmol/L x min x 10(4)) nor fasting insulin (exercise v control, 77.0 +/- 8.2 v 82.9 +/- 8.9 pmol/L) were significantly different between trials. The postprandial insulin response in the control trial was significantly correlated with the change in the insulin response (control minus exercise) in the 18 women (r = .56, P = .01). No trial or group differences were found for postprandial glucose and C-peptide responses. Mexican American women have a high risk of developing type 2 diabetes, and aerobic exercise may be valuable in the prevention or delay of onset of diabetes by reducing peripheral insulin resistance.

Insulin resistance and lipid metabolism

The 3 major components of the dyslipidemia of insulin resistance are increased triglyceride levels, decreased high-density lipoprotein (HDL) cholesterol, and changes in the composition of low-density lipoprotein (LDL) cholesterol. Hyperinsulinemia and the central obesity that typically accompanies insulin resistance are thought to lead to overproduction of very low-density lipoprotein (VLDL) cholesterol. The result is more triglyceride-rich particles, fewer HDL particles, and more small, dense LDL. Postprandial triglyceride levels and measures of postprandial remnants also may contribute to increased coronary artery disease (CAD) risk in individuals with insulin resistance. Deficiency of lipoprotein lipase, an insulin-sensitive enzyme, might explain the abnormal levels of remnant particles in insulin resistance. The potential benefits of successful treatment of dyslipidemia are illustrated by clinical trials in patients with the dyslipidemia characteristic of insulin resistance (i.e., normal or only moderately elevated LDL, elevated VLDL, and low HDL). Both weight loss and exercise can improve insulin resistance and associated dyslipidemia. In patients with type 2 diabetes mellitus, certain antidiabetic therapies can also improve the lipid profile by improving insulin resistance.

Arterial hypertension and glycemia in non-diabetic subjects: is there an association independent of obesity?

BACKGROUND

A possible association of glycemia with arterial hypertension has been suggested by the frequent co-occurrence of impaired glucose tolerance or Type 2 diabetes mellitus with arterial hypertension. The objective was to examine the relationship of glycated hemoglobin (HbA1c) concentration with arterial hypertension status in non-diabetic subjects.

METHODS

A cross-sectional analysis of baseline data from the EPIC-Potsdam Cohort Study, Germany, was performed. The study population comprised 1846 non-diabetic subjects, 772 men and 1074 women, age 35-65. Blood pressure was measured three times consecutively. Level of HbA1c was determined by an assay based on monoclonal antibodies. Body height, weight and circumferences were obtained. Arterial hypertension status was either determined through blood pressure measurement (blood pressure > or = 160/95 mmHg) or based on antihypertensive drug use. HbA1c was divided into sex-specific quintiles and logistic regression was used to estimate the odds of being hypertensive and the corresponding confidence intervals.

RESULTS

The highest compared to the lowest quintiles of HbA1c were in univariate analysis associated with being hypertensive. Adjustment for age and body mass index completely removed any significant association with arterial hypertension status. The odds ratio in men was 1.1 (95% CI 0.7-1.8), and in women it was 0.9 (95% CI 0.5-1.4). Repeating the analysis with systolic and diastolic blood pressure among untreated hypertensives yielded similar results.

CONCLUSION

Unlike previous studies, our data do not support an association of HbA1c with arterial hypertension that is statistically independent of age and body mass index. Whether these established arterial hypertension risk factors are truly confounders of the HbA1c-arterial hypertension association or rather potentially antecedent factors requires further study.

Relationships between insulin resistance and lipoproteins in nondiabetic African Americans, Hispanics, and non-Hispanic whites: the Insulin Resistance Atherosclerosis Study

The study purpose was to explore the association between dyslipidemia and insulin resistance in three ethnic groups. The Insulin Resistance Atherosclerosis Study (IRAS) is a multicenter epidemiologic study conducted at four clinical centers in California, Texas, and Colorado. The study population for this analysis consisted of 931 non-Hispanic white, African American, and Hispanic men and women (aged 45 to 64 years) without diabetes. The IRAS clinical examinations included lipoprotein measures, a 75-g glucose tolerance test, and the frequently sampled intravenous glucose tolerance (FSIGT) test. The results show a consistent relationship between insulin-mediated glucose disposal and dyslipidemia in African American, Hispanic, and non-Hispanic white men and women. Further, LDL size was inversely associated with insulin resistance in all three ethnic groups. These findings indicate that dyslipidemia is a fundamental part of the insulin resistance syndrome in all of the ethnic groups studied.

Mortality from coronary heart disease and cardiovascular disease among adult U.S. Hispanics: findings from the National Health Interview Survey (1986 to 1994)

OBJECTIVES

We sought to estimate the coronary heart disease (CHD) and cardiovascular disease (CVD) mortality experience of U.S. Hispanics.

BACKGROUND

Limited information is available concerning the mortality from CHD among U.S. Hispanics, the nation's second largest minority group.

METHODS

The study used data from the National Health Interview Survey (1986 to 1994), including representative national samples of 246,239 non-Hispanic whites, 38,042 blacks and 14,965 Hispanics who were > or = 45 years old at baseline. Mean follow-up of mortality was 5 years (range 1 to 10).

RESULTS

During the follow-up period, 27,702 whites (11%), 4,976 blacks (13%) and 1,061 Hispanics (7%) died. Among men, the age-adjusted total mortality per 100,000 person-years was 3,089 in whites and 2,466 in Hispanics, and among women, it was 1,897 and 1,581 in whites and Hispanics, respectively. The Hispanic/white mortality rate ratio for CHD was 0.77 (95% confidence interval [CI] 0.64 to 0.93) and 0.82 (95% CI 0.66 to 1.01) for men and women, respectively. The rate ratio was 0.79 (95% CI 0.68 to 0.91) and 0.80 (95% CI 0.69 to 0.94), respectively, for mortality from cardiovascular diseases. Given the lower all-cause mortality in Hispanics, the proportion of total deaths due to CHD and CVD was similar between the two populations for the same gender and were, respectively, 29.7% and 44.7% in white men, 28.1% and 44.3% in Hispanic men, 24.9% and 43.2% in white women and 24.1% and 41% in Hispanic women.

CONCLUSIONS

These data from a cohort of a large national sample are consistent with vital statistics that show that all-cause, CHD and CVD mortality is approximately 20% lower among adult Hispanics than among whites in the United States.

Greater incidence of hospitalized myocardial infarction among Mexican Americans than non-Hispanic whites. The Corpus Christi Heart Project, 1988-1992

BACKGROUND

Since Mexican Americans have adverse patterns of risk factors for myocardial infarction relative to non-Hispanic whites, the incidence of myocardial infarction should be greater among Mexican Americans than among non-Hispanic whites. This expectation conflicts with reports generated from death certificate registries.

METHODS AND RESULTS

Data regarding myocardial infarction attacks and incident events were collected for a 4-year period in the Corpus Christi Heart Project, a population-based surveillance project for hospitalized coronary heart disease events. For both women and men, Mexican Americans experienced greater hospitalization rates for both attacks and incident events than non-Hispanic whites. Age-adjusted attack rate ratios comparing Mexican Americans with non-Hispanic whites were 1.59 (95% CI, 1.05 to 2.41) and 1.31 (95% CI, 1.18 to 1.45) among women and men, respectively. Corresponding incidence ratios were 1.52 (95% CI, 1.28 to 1.80) and 1.25 (95% CI, 1.10 to 1.42).

CONCLUSIONS

This is the first report documenting greater incidence of hospitalized myocardial infarction among Mexican Americans than among non-Hispanic whites, a biologically plausible finding given the risk factor patterns observed in the Mexican-American population. Public health planners and clinicians should be aware of the importance of myocardial infarction as a health problem in the Mexican-American population. Culturally appropriate prevention strategies should be developed for and tested in Mexican-American populations.

Epidemiology of non-insulin-dependent diabetes mellitus and its macrovascular complications. A basis for the development of cost-effective programs

Non-insulin-dependent diabetes mellitus is a major health problem in developed countries. The descriptive epidemiology of this disease and its cardiovascular complications are reviewed, and insulin resistance is identified as a common risk factor for both of them. The requirements for cost-effective programs to modify insulin resistance to prevent this disorder and its cardiovascular complications are discussed.

Distribution and correlates of lipids and lipoproteins in elderly Japanese-American men. The Honolulu Heart Program

Adverse lipid and lipoprotein levels are clearly linked with increased risk of cardiovascular disease in middle age, but evidence in elderly and minority populations is less certain. In this study the distribution and correlates of lipids and lipoproteins were evaluated cross-sectionally in 3044 elderly (71 to 93 years) Japanese-American men from the Honolulu Heart Program who were recently reexamined (1991 to 1993). Mean +/- SD lipid concentrations were 189 +/- 33 mg/dL for total cholesterol, 51 +/- 13 mg/dL for HDL cholesterol, 109 +/- 31 mg/dL for LDL cholesterol, and 147 +/- 89 mg/dL for triglycerides. Prevalence of dyslipidemic patterns was relatively infrequent (total cholesterol > or = 240 mg/dL: 6.7%; HDL cholesterol < 35 mg/dL, 6.4%; LDL cholesterol > or = 160 mg/dL: 5.5%; triglycerides > or = 200 mg/dL. 18.7%), while prevalence of desirable total (< 200 mg/dL) and HDL cholesterol (> or = 60 mg/dL) concentrations was more common (62.7% and 23.7%, respectively). Mean levels of total cholesterol, LDL cholesterol, and triglyceride decreased significantly with increasing age (P < .001), while mean HDL cholesterol level increased slightly (P < .05). After univariate analyses of potential correlates, multiple linear regression models were used to identify variables independently associated with each of the lipids. After adjustment for other variables, levels of fibrinogen and hematocrit were positively associated and insulin, white blood cell count, and use of diabetic medication were negatively associated with total cholesterol. Correlates for LDL cholesterol were similar but also included vital capacity (positive relation) and alcohol (negative relation). Heart rate, physical activity, alcohol, and hematocrit were positively associated with HDL cholesterol; body mass index, subscapular skinfold thickness, glucose, fibrinogen, white blood cell count, and hypertension were negatively associated. Factors associated with triglycerides tended to be similar, yet the direction of relations was reversed. Age-adjusted total cholesterol levels were significantly lower in men who had coronary surgery, thromboembolic stroke, and hemorrhagic stroke but were higher in those with peripheral vascular disease. Lower HDL cholesterol levels were found in men with prevalent angina, angioplasty, definite myocardial infarction, thromboembolic stroke, and peripheral vascular disease. LDL cholesterol and triglycerides showed fewer significant relations with these conditions. Findings indicate that elderly Japanese-American men have a favorable lipid profile, except for elevated triglyceride levels, relative to levels in other populations of older Americans and that a number of cardiovascular risk factors and diseases are strongly associated with lipids in elderly men. These analyses also identify several modifiable factors that may favorably influence lipid and lipoprotein levels in the elderly.

Ethnic differences in carotid wall thickness. The Insulin Resistance Atherosclerosis Study

BACKGROUND AND PURPOSE

Ethnic differences in cardiovascular disease (CVD) morbidity and mortality have been observed in US adults. However, little data exist on differences in indices of preclinical atherosclerosis such as carotid wall intima-media thickness (IMT) for US non-Hispanic whites, Hispanics, and blacks. This study was undertaken to determine whether there were ethnic differences in carotid wall IMT.

METHODS

Internal carotid artery (ICA) IMT and common carotid artery (CCA) IMT, indices of atherosclerosis, were assessed with the use of B-mode ultrasound in 1020 nondiabetic participants in the Insulin Resistance Atherosclerosis Study, a multicenter study designed to examine the association between insulin resistance and carotid atherosclerosis. The study included 281 blacks, 329 Hispanics, and 410 non-Hispanic whites aged 40 to 69 years.

RESULTS

Blacks had significantly greater CCA IMT than non-Hispanic whites (865 versus 808 microns); this remained significant after adjustment for major CVD risk factors and insulin sensitivity (864 versus 823 microns). There were no significant differences in ICA IMT between blacks and non-Hispanic whites. Hispanics had significantly lesser CCA IMT than non-Hispanic whites (749 versus 776 microns), and these differences remained significant after adjustment for traditional cardiovascular risk factors and insulin sensitivity (750 versus 778 microns). There were no significant differences in ICA IMT between non-Hispanic whites and Hispanics.

CONCLUSIONS

We conclude that ethnic differences exist in CCA but not in ICA IMT in nondiabetic subjects. These differences in IMT, which are indicators of atherosclerosis, are a non-invasive measure that is consistent with some of the data on clinical end points. These differences may be associated with the observed differences in CVD morbidity and mortality among major ethnic groups in the United States.

Distribution and correlates of insulin in elderly men. The Honolulu Heart Program

The role of insulin in cardiovascular disease is uncertain, and studies in elderly or minority populations are infrequent. Fasting and 2-hour insulin concentrations and their cross-sectional associations with cardiovascular risk factors were examined in 3562 elderly (aged 71 to 93 years) Japanese American men from the Honolulu Heart Program who were reexamined between 1991 and 1993. Insulin distributions were skewed (mean and median: 16.8 and 12 microU/mL for fasting; 117.2 and 93 microU/mL for 2-hour); fasting but not 2-hour insulin levels declined significantly with age (P < .0001 and P = .54, respectively). Factors most strongly correlated with insulin included measures of obesity, fat distribution, and levels of triglyceride, glucose (r = .38 to r = .50 fasting, r = .21 to r = .27 2-hour), and HDL cholesterol (r = -.41 and r = -.22, respectively). Other correlates included fibrinogen, hematocrit, heart rate, blood pressure, cigarettes per day (all positive), alcohol, physical activity, and forced vital capacity (negative). Associations were also evident across risk factor quintiles. Insulin levels were significantly elevated in men with hypertension and diabetes. In multiple linear regression analyses, log10 fasting insulin was positively and independently associated with body mass index, triglycerides, glucose, fibrinogen, hematocrit, heart rate, diabetes, and hypertension and negatively associated with HDL cholesterol, physical activity, and forced vital capacity. In general, results were similar for log10 2-hour insulin and when subjects who fasted < 12 hours or had diabetes were excluded. Substitution of medication use and blood pressure for hypertension indicated independent associations of medication use but not blood pressure with insulin.(ABSTRACT TRUNCATED AT 250 WORDS)

Phytoestrogens, body composition, and breast cancer

To the extent that diet is involved in the etiology of breast cancer, its effect may be mediated, in part, through hormonal mechanisms. It has been suggested that the consumption of phytoestrogens is related inversely to breast cancer risk. Phytoestrogens are weak estrogens of plant derivation that may have antiestrogenic effects through competitively binding to estrogen receptors, thus diminishing the binding of stronger endogenous estrogens. This paper advances the hypothesis that, through this mechanism, dietary phytoestrogens may attenuate the adverse consequences of obesity on the development of postmenopausal breast cancer. Such an association might partly explain the low breast cancer rates observed among postmenopausal Hispanic women despite their greater adiposity, an important breast cancer risk factor. This hypothesis would lead us to expect that obesity increases the risk of postmenopausal breast cancer in women consuming small quantities of phytoestrogens but does not increase risk in women consuming larger quantities. If the hypothesis is confirmed, such as association could have important implications for reducing breast cancer risk through diet, using naturally occurring substances, particularly in women for whom postmenopausal obesity is an important health concern.

A community-based, culturally sensitive education and group-support intervention for Mexican Americans with NIDDM: a pilot study of efficacy

The purpose of this study was to determine the feasibility of providing a diabetes patient education and group-support intervention that was directed by a Mexican-American clinical nurse specialist (CNS), dietitian, and community worker; consistent with national standards; and designed for the Mexican-American culture. In a rural Texas-Mexico border community, subjects with diabetes were randomly selected to participate in the intervention, and a family member of each subject participated as a support person. The intervention involved 8 weeks of educational sessions with instruction on nutrition, blood glucose self-monitoring, exercise, and other diabetes self-management topics, and provided group support. Group discussion was facilitated using a series of Spanish-language videotapes that had been developed and previously tested in the target Mexican-American community. Results suggested statistically significant improvements in diabetes knowledge, fasting blood sugar levels, and glycosylated hemoglobin levels. The study documented the feasibility and potential benefits of the intervention.

Incidence and predictors of diabetes in Japanese-American men. The Honolulu Heart Program

Reports on the incidence and predictors of diabetes in minority populations are infrequent. The 6-year cumulative incidence of diabetes between 1965 and 1974 was estimated among 7210 Japanese-American men aged 45 to 68 years who were enrolled in the Honolulu Heart Program and were free of clinically recognized diabetes at baseline. The incidence of "possible" diabetes (based on history, medication, or hospital diagnosis) was 12.8% and the incidence of "probable" diabetes (based on diabetic medication) was 5.7%. Estimates of incidence in subjects with a nonfasting glucose concentration less than 225 mg/dL 1 hour after a 50-g load were 9.7 and 4.0%, respectively. Multivariate adjusted odds ratios (ORs) for probable diabetes in all subjects comparing the upper quintile with the lower four quintiles combined for continuous variables indicated statistically significant direct associations with body mass index (OR, 1.69; 95% confidence interval (CI), 1.31 to 2.18), 1-hour postchallenge glucose level (OR, 5.79; 95% CI, 4.58 to 7.33), triglyceride levels (OR, 1.47; 95% CI, 1.14 to 1.91), systolic blood pressure (OR, 1.36; 95% CI, 1.05 to 1.76), and parental history of diabetes (OR, 1.73; 95% CI, 1.29 to 2.33), and an inverse association with physical activity (OR, 0.49; 95% CI, 0.34 to 0.72), using logistic regression models including these variables as well as age, subscapular/triceps skinfold ratio, and hematocrit simultaneously. Associations were similar but slightly weaker in men with glucose levels less than 225 mg/dL and in those who remained free of cardiovascular disease. When older men (55 to 68 years old) were compared with younger (45 to 54 years old) men, associations among the older group were stronger for body mass index, physical activity, and systolic blood pressure and they were weaker for glucose levels, triglyceride values, and parental diabetes. Results suggest that body mass index, physical inactivity, glucose level, and parental diabetes appear to be independent risk factors for diabetes, while triglyceride and systolic blood pressure levels may be markers for an adverse cardiovascular risk factor profile associated with diabetes and may reflect an insulin resistance syndrome.

Hyperinsulinemia, risk factors, and coronary heart disease. The Zutphen Elderly Study

We investigated the association between fasting insulin concentration--an indicator of insulin resistance in nondiabetic individuals--cardiovascular risk factors, and coronary heart disease in a study of 390 men in the town of Zutphen. In 1990, an extensive examination was carried out on the participating men (aged 70 to 89 years). Fasting insulin levels were determined and a number of other risk factors measured. Known and newly diagnosed diabetics were excluded from the data analyses. Fasting insulin concentration was significantly associated with levels of glucose, triglycerides, uric acid, serum albumin, creatinine, and fibrinogen as well as resting heart rate. Inverse associations with high-density lipoprotein cholesterol and factor VII activity were observed. These results were independent of confounding factors such as age, body mass index, ratio of subscapular to triceps skinfold thicknesses, cigarette smoking, physical activity, and alcohol consumption. Men with a fasting insulin level higher than 80 pmol/L (highest quartile of the distribution) had a significantly higher prevalence of coronary heart disease and especially of myocardial infarction. This result was independent of potential confounding variables as well as of possible intermediates (total and high-density lipoprotein cholesterol, hypertension, serum triglycerides, fasting glucose, and other risk factors related to fasting insulin) (odds ratio, 2.2; 95% confidence interval, 1.2-4.0). No association between fasting insulin level and hypertension or blood pressure was observed. These results show that fasting insulin is an important indicator of coronary heart disease in elderly men. Clotting factors, resting heart rate, uric acid, serum albumin, and creatinine may also play a role in this metabolic syndrome.