Potential reductions in United States coronary heart disease mortality by treating more patients

Approximately one half of the recent decline observed in age-adjusted coronary heart disease (CHD) mortality rates can be attributed to the use of modern medical and surgical interventions. In 2000, however, only about 30% to 60% of eligible patients actually received the appropriate treatment. To examine the reduction in CHD mortality potentially achievable by increasing the provision of specific medical and surgical treatment to eligible patients with CHD in the United States, we integrated the data on CHD patient numbers, medical and surgical treatment uptake levels, and treatment effectiveness using a previously validated CHD policy model. We estimated the number of deaths prevented or postponed for 2000 (baseline) and for an alternative scenario (60% of eligible patients). In 2000, the treatment levels in the United States were generally poor; only 30% to 60% of eligible patients received the appropriate therapy. These treatments resulted in approximately 159,330 fewer deaths. By treating 60% of eligible patients, 297,470 fewer deaths would have been obtained (minimum 118,360; maximum 628,120), representing 134,635 less than in 2000, with approximately 32% from heart failure therapy, 30% from secondary prevention therapy, 19% from acute coronary syndrome treatment, 15% from primary prevention with statins, 0.5% from hypertension treatment, and 1% from coronary bypass surgery for chronic angina. These findings remained stable in the sensitivity analysis. In conclusion, increasing the proportion of eligible patients with CHD who received the appropriate treatment could have achieved approximately 135,000 fewer deaths in 2000, almost doubling the benefit actually achieved. Future strategies should maximize the delivery of appropriate therapies to all eligible patients with CHD and prioritize medical therapies for secondary prevention and heart failure.

Multivitamin use in pregnant and nonpregnant women: results from the Behavioral Risk Factor Surveillance System

OBJECTIVE

Relatively few studies have investigated characteristics associated with multivitamin use in pregnant women in the U.S. We examined multivitamin use among pregnant and nonpregnant women of childbearing age, in relation to socioeconomic factors, demographic data, health behaviors, and health status.

METHODS

This investigation used 2004 data from the Behavioral Risk Factor Surveillance System (BRFSS), a cross-sectional study of noninstitutionalized adults aged 18 years or older. Analyses were limited to women 18 to 44 years of age in states and territories where questions about multivitamin use were asked.

RESULTS

Overall, 78% of pregnant women reported multivitamin use, compared with 47% of women who were not pregnant. Using logistic regression, two factors were found to be significantly associated with multivitamin use in pregnant women: income and marital status. Among nonpregnant women, the significant predictors were age, income, physical activity, education level, desire for a child in the near future, race/ethnicity, body mass index, and cigarette smoking status.

CONCLUSION

We found differences in the reported use of multivitamins between pregnant and nonpregnant women of childbearing age as well as predictors of use.

Hypertriglyceridemia and its pharmacologic treatment among US adults

BACKGROUND

Increasing evidence supports triglyceride (TG) concentration as a risk factor for cardiovascular disease. The prevalence of hypertriglyceridemia during a period of rising prevalence of obesity and its pharmacological treatment among US adults are poorly understood.

METHODS

We examined data for 5610 participants 20 years or older from the National Health and Nutrition Examination Surveys from 1999 to 2004.

RESULTS

The unadjusted prevalence (percentage [SE]) of a TG concentration of 150 mg/dL or higher (to convert triglycerides to millimoles per liter, multiply by 0.0113) was 33.1% (0.8%); a TG concentration of 200 mg/dL or higher, 17.9% (0.7%), a TG concentration of 500 mg/dL or higher, 1.7% (0.2%), and a TG concentration of 1000 mg/dL or higher, 0.4% (0.1%). Overall, 1.3% (0.2%) of participants used 1 of 3 prescription medications indicated to treat hypertriglyceridemia (ie, fenofibrate, gemfibrozil, or niacin); this percentage was 2.6% (0.4%) among participants with a TG concentration of 150 mg/dL or higher and 3.6% (0.7%) among participants with a TG concentration of 200 mg/dL or higher.

CONCLUSIONS

Among US adults, hypertriglyceridemia is common. Until the benefits of treating hypertriglyceridemia that is not characterized by extreme elevations of TG concentration with medications are incontrovertible, therapeutic lifestyle change remains the preferred treatment.

Weight control behaviors in overweight/obese U.S. adults with diagnosed hypertension and diabetes

Background

Obesity is a major risk factor for development and progression of hypertension and diabetes, which often coexist in obese patients. Losing weight by means of energy restriction and physical activity has been effective in preventing and managing these diseases. However, weight control behaviors among overweight/obese adults with these conditions are poorly understood.

Methods

Using self-reported data from 143,386 overweight/obese participants (aged ≥ 18 years) in the 2003 Behavioral Risk Factor Surveillance System, we examined the proportion of overweight/obese adults who tried to lose weight and their weight control strategies by hypertension and/or diabetes status.

Results

Among all participants, 58% of those with hypertension, 60% of those with diabetes, and 72% of those with both diseases tried to lose weight, significantly higher than the 50% of those with neither condition (Bonferroni corrected P < 0.017 for all comparisons). The multivariate-adjusted odds ratio (AOR) for trying to lose weight was 1.11 (95% confidence interval [CI]: 1.05–1.17) in participants with hypertension, 1.02 (95% CI: 0.90–1.15) in participants with diabetes, and 1.18 (95% CI: 1.07–1.29) in participants with both diseases (participants with neither condition as the referent). Among 78,446 participants who tried to lose weight, 23% of those with hypertension only and 28% of those with both hypertension and diabetes reported adopting a low fat/low calorie (LF/LC) diet in controlling their weight, significantly higher than 19% of those with neither disease (Bonferroni corrected P < 0.017 for all comparisons). Participants with both diseases had a significantly lower percentage of adopting physical activity in controlling their weight than those with neither condition (6% versus 12%, P < 0.01). After multivariate adjustment, the AOR for adopting a LF/LC diet plus physical activity to lose weight was 1.46 (95% CI: 1.15–1.84) in participants with both diseases. The AOR for adopting a LF/LC diet only to lose weight was 1.72 (95% CI: 1.35–2.20) in participants with both diseases and was 1.21 (95% CI: 1.03–1.40) in participants with hypertension only.

Conclusion

The proportion of overweight/obese patients with diagnosed hypertension and/or diabetes who attempted to lose weight remains suboptimal and the weight control strategies varied significantly among these patients.

Prevalence of pre-diabetes and its association with clustering of cardiometabolic risk factors and hyperinsulinemia among U.S. adolescents: National Health and Nutrition Examination Survey 2005-2006

OBJECTIVE

Impaired fasting glucose (IFG) and/or impaired glucose tolerance (IGT) are considered to constitute "pre-diabetes." We estimated the prevalence of IFG, IGT, and pre-diabetes among U.S. adolescents using data from a nationally representative sample.

RESEARCH DESIGN AND METHODS

We analyzed data from participants aged 12-19 years in the National Health and Nutrition Examination Survey 2005-2006. We used fasting plasma glucose and 2-h glucose during an oral glucose tolerance test to assess the prevalence of IFG, IGT, and pre-diabetes and used the log-binomial model to estimate the prevalence ratios (PRs) and 95% CIs.

RESULTS

The unadjusted prevalences of IFG, IGT, and pre-diabetes were 13.1, 3.4, and 16.1%, respectively. Boys had a 2.4-fold higher prevalence of pre-diabetes than girls (95% CI 1.3-4.3). Non-Hispanic blacks had a lower rate than non-Hispanic whites (PR 0.6, 95% CI 0.4-0.9). Adolescents aged 16-19 years had a lower rate than those aged 12-15 years (0.6, 0.4-0.9). Overweight adolescents had a 2.6-fold higher rate than those with normal weight (1.3-5.1). Adolescents with two or more cardiometabolic risk factors had a 2.7-fold higher rate than those with none (1.5-4.8). Adolescents with hyperinsulinemia had a fourfold higher prevalence (2.2-7.4) than those without. Neither overweight nor number of cardiometabolic risk factors was significantly associated with pre-diabetes after adjustment for hyperinsulinemia.

CONCLUSIONS

Pre-diabetes was highly prevalent among adolescents. Hyperinsulinemia was independently associated with pre-diabetes and may account for the association of overweight and clustering of cardiometabolic risk factors with pre-diabetes.

Prevalence and trends of receipt of cancer screenings among US women with diagnosed diabetes

BACKGROUND

Diabetes increases the risk of breast and colorectal cancers and has an undetermined relationship to cervical cancer. Improved screenings for these cancers are effective in reducing cancer mortality.

OBJECTIVES

To examine the prevalence of receiving recommended screenings for these cancers and to assess the trends in the screening rates over time among US women with diagnosed diabetes in comparison with women without diabetes.

DESIGN

Cross-sectional.

PARTICIPANTS

A total of 63,650 to 182,168 adult women participated in the 1996-2006 (biennially) Behavioral Risk Factor Surveillance System.

METHODS

The prevalence of receiving cancer screenings was age-standardized to the 2000 US population. The adjusted prevalence and adjusted odds ratios (AORs) with 95% confidence intervals (CIs) were estimated using logistic regression analyses. The linear trends in the screening rates were tested using orthogonal polynomial contrasts.

RESULTS

In 2006, women with diabetes had a lower adjusted prevalence (74% versus 79%, P < 0.05) and the AOR (0.73, 95% CI: 0.66-0.81) for receiving cervical cancer screenings, but had a higher adjusted prevalence (63% versus 60%, P < 0.05) and the AOR (1.14, 95% CI: 1.04-1.24) for receiving colorectal cancer screenings compared to those without. In both women with diabetes and those without, the screening rate for colorectal cancer increased linearly during 2002-2006, whereas the screening rates for breast and cervical cancers changed little during 1996-2006.

CONCLUSION

Women with diabetes were equally likely to be screened for breast cancer, less likely to be screened for cervical cancer, but more likely to be screened for colorectal cancer compared to those without. Overall, the screening rates in both groups remain below the recommended levels.

Prevalence and correlates of undiagnosed depression among U.S. adults with diabetes: the Behavioral Risk Factor Surveillance System, 2006

AIMS

Many people with depression may be undiagnosed and thus untreated. We sought to assess the prevalence and correlates of undiagnosed depression among adults with diabetes.

METHODS

Data of U.S. adults from the Behavioral Risk Factor Surveillance System in 2006 were analyzed. Cox proportional hazard regression analysis was used to estimate prevalence ratios (PRs) and 95% confidence intervals (CIs) of correlates for undiagnosed depression.

RESULTS

The unadjusted and age-adjusted prevalences of undiagnosed depression were 8.7% and 9.2%. About 45% of diabetes patients with depression were undiagnosed. After adjustments for all correlates, female gender (PR, 1.4; 95% CI: 1.1-1.8), poor or fair health (PR, 2.8; 95% CI: 2.1-3.6), lack of social and emotional support (PR, 2.5; 95% CI: 1.8-3.3), life dissatisfaction (PR, 3.5; 95% CI: 2.2-5.5), use of special equipment (PR, 1.4; 95% CI: 1.1-1.8), no leisure-time physical activity (PR, 1.5; 95% CI: 1.2-1.9), and comorbid cardiovascular disease (PR, 1.5; 95% CI: 1.2-1.9) were associated with undiagnosed depression.

CONCLUSIONS

Undiagnosed depression among people with diabetes was common. Because depression is associated with increased risk of diabetes-related complications, early detection of depression is needed in clinical settings.

Full accounting of diabetes and pre-diabetes in the U.S. population in 1988-1994 and 2005-2006

OBJECTIVE

We examined the prevalences of diagnosed diabetes, and undiagnosed diabetes and pre-diabetes using fasting and 2-h oral glucose tolerance test values, in the U.S. during 2005-2006. We then compared the prevalences of these conditions with those in 1988-1994.

RESEARCH DESIGN AND METHODS

In 2005-2006, the National Health and Nutrition Examination Survey included a probability sample of 7,267 people aged > or =12 years. Participants were classified according to glycemic status by interview for diagnosed diabetes and by fasting and 2-h glucoses measured in subsamples.

RESULTS

In 2005-2006, the crude prevalence of total diabetes in people aged > or =20 years was 12.9%, of which approximately 40% was undiagnosed. In people aged > or =20 years, the crude prevalence of impaired fasting glucose was 25.7% and of impaired glucose tolerance was 13.8%, with almost 30% having either. Over 40% of individuals had diabetes or pre-diabetes. Almost one-third of the elderly had diabetes, and three-quarters had diabetes or pre-diabetes. Compared with non-Hispanic whites, age- and sex-standardized prevalence of diagnosed diabetes was approximately twice as high in non-Hispanic blacks (P < 0.0001) and Mexican Americans (P = 0.0001), whereas undiagnosed diabetes was not higher. Crude prevalence of diagnosed diabetes in people aged > or =20 years rose from 5.1% in 1988-1994 to 7.7% in 2005-2006 (P = 0.0001); this was significant after accounting for differences in age and sex, particularly in non-Hispanic blacks. Prevalences of undiagnosed diabetes and pre-diabetes were generally stable, although the proportion of total diabetes that was undiagnosed decreased in Mexican Americans.

CONCLUSIONS

Over 40% of people aged > or =20 years have hyperglycemic conditions, and prevalence is higher in minorities. Diagnosed diabetes has increased over time, but other conditions have been relatively stable.

Depression and anxiety among US adults: associations with body mass index

BACKGROUND

Obesity is associated with an increased risk of developing a variety of chronic diseases, most of which are associated with psychiatric disorders. We examined the associations of depression and anxiety with body mass index (BMI) after taking into consideration the obesity-related comorbidities (ORCs) and other psychosocial or lifestyle factors.

METHODS

We analyzed the data collected from 177,047 participants (aged>or=18 years) in the 2006 Behavioral Risk Factor Surveillance System. Current depression was assessed by the Patient Health Questionnaire-8 diagnostic algorithm. Lifetime diagnoses of depression, anxiety and ORCs were self-reported. The prevalence of the three psychiatric disorders was age standardized to the 2000 US population. Multivariate-adjusted prevalence ratios were computed to test associations of depression and anxiety with BMI using SUDAAN software.

RESULTS

The age-adjusted prevalence of current depression, lifetime diagnosed depression and anxiety varied significantly by gender. Within each gender, the prevalence of the three psychiatric disorders was significantly higher in both men and women who were underweight (BMI<18.5 kg/m(2)), in women who were overweight (BMI: 25-<30 kg/m(2)) or obese (BMI>or=30 kg/m(2)), and in men who had class III obesity (BMI>or=40 kg/m(2)) than in those with a normal BMI (18.5-<25 kg/m(2)). After adjusting for demographics, ORCs, lifestyle or psychosocial factors, compared with men with a normal BMI, men with a BMI>or=40 kg/m(2) were significantly more likely to have current depression or lifetime diagnosed depression and anxiety; men with a BMI<18.5 kg/m(2) were also significantly more likely to have lifetime diagnosed depression. Women who were either overweight or obese were significantly more likely than women with a normal BMI to have all the three psychiatric disorders.

CONCLUSIONS

Our results demonstrate that disparities in the prevalence of depression and anxiety exist among people with different BMI levels independent of their disease status or other psychosocial or lifestyle factors.

Metabolic syndrome and risk of incident diabetes: findings from the European Prospective Investigation into Cancer and Nutrition-Potsdam Study

BACKGROUND

Several aspects concerning the relationship between the metabolic syndrome and incident diabetes are incompletely understood including the magnitude of the risk estimate, potential gender differences in the associations between the metabolic syndrome and incident diabetes, the associations between the components of the metabolic syndrome and incident diabetes, and whether the metabolic syndrome provides additional prediction beyond its components. To shed light on these issues, we examined the prospective association between the metabolic syndrome defined by the National Cholesterol Education Program (NCEP) and International Diabetes Federation (IDF) and diabetes.

METHODS

We used data for 2796 men and women aged 35-65 years from the European Prospective Investigation into Cancer and Nutrition-Potsdam Study followed for an average of 6.9 years. This analysis employed a case-cohort design that included 697 participants who developed diabetes and 2099 participants who did not. Incident diabetes was identified on the basis of self-reports and verified by contacting the patient's attending physician.

RESULTS

The adjusted hazard ratio for the NCEP definition was 4.62 (95% confidence interval [CI]: 3.90-5.48) and that for the IDF definition was 4.59 (95% CI: 3.84-5.50). The adjusted hazard ratios for the NCEP but not IDF definition were higher for women than men. When participants who had no cardiometabolic abnormalities were used as the reference group for the NCEP definition, the adjusted hazard ratio for having 3 or more abnormalities increased to 22.50 (95% CI: 11.21-45.19). Of the five components, abdominal obesity and hyperglycemia were most strongly associated with incident diabetes.

CONCLUSION

In this study population, both definitions of the metabolic syndrome provided similar estimates of relative risk for incident diabetes. The increase in risk for participants with the metabolic syndrome according to the NCEP definition was very large when contrasted with the risk among those who had no cardiometabolic abnormalities.

Epidemiology of obesity in the Western Hemisphere

CONTEXT

Obesity has emerged as a global public health challenge. The objective of this review was to examine epidemiological aspects of obesity in the Western Hemisphere.

EVIDENCE ACQUISITION

Using PubMed, we searched for publications about obesity (prevalence, trends, correlates, economic costs) in countries in North America, Central America, South America, and the Caribbean. To the extent possible, we focused on studies that were primarily population based in design and on four countries in the Western Hemisphere: Brazil, Canada, Mexico, and the United States.

EVIDENCE SYNTHESIS

Data compiled by the International Obesity Task Force show a substantial level of obesity in all of or selected areas of the Bahamas, Barbados, Canada, Chile, Guyana, Mexico, Panama, Paraguay, Peru, St. Lucia, Trinidad and Tobago, the United States, and Venezuela. Furthermore, countries such as Brazil, Canada, Mexico, and the United States have experienced increases in the prevalence of obesity. In many countries, the prevalence of obesity is higher among women than men and in urban areas than in rural areas. The relationship between socioeconomic status and obesity depends on the stage of economic transition. Early in the transition, the prevalence of obesity is positively related to income whereas at some point during the transition the prevalence becomes inversely related to income.

CONCLUSIONS

Like other countries in the Western Hemisphere, the four countries that we focused on have experienced a rising tide of obesity. The high and increasing prevalence of obesity and its attendant comorbidities are likely to pose a serious challenge to the public health and medical care systems in these countries.

Metabolic syndrome and incident diabetes: current state of the evidence

OBJECTIVE

Our objective was to perform a quantitative review of prospective studies examining the association between the metabolic syndrome and incident diabetes.

RESEARCH DESIGN AND METHODS

Using the title terms "diabetes" and "metabolic syndrome" in PubMed, we searched for articles published since 1998.

RESULTS

Based on the results from 16 cohorts, we performed a meta-analysis of estimates of relative risk (RR) and incident diabetes. The random-effects summary RRs were 5.17 (95% CI 3.99-6.69) for the 1999 World Health Organization definition (ten cohorts); 4.45 (2.41-8.22) for the 1999 European Group for the Study of Insulin Resistance definition (four cohorts); 3.53 (2.84-4.39) for the 2001 National Cholesterol Education Program definition (thirteen cohorts); 5.12 (3.26-8.05) for the 2005 American Heart Association/National Heart, Lung, and Blood Institute definition (five cohorts); and 4.42 (3.30-5.92) for the 2005 International Diabetes Federation definition (nine cohorts). The fixed-effects summary RR for the 2004 National Heart, Lung, and Blood Institute/American Heart Association definition was 5.16 (4.43-6.00) (six cohorts). Higher number of abnormal components was strongly related to incident diabetes. Compared with participants without an abnormality, estimates of RR for those with four or more abnormal components ranged from 10.88 to 24.4. Limited evidence suggests fasting glucose alone may be as good as metabolic syndrome for diabetes prediction.

CONCLUSIONS

The metabolic syndrome, however defined, has a stronger association with incident diabetes than that previously demonstrated for coronary heart disease. Its clinical value for diabetes prediction remains uncertain.

Body mass index and headaches: findings from a national sample of US adults

The objective was to study the cross-sectional association between body mass index (BMI) and the prevalence of severe headaches or migraines in a national sample of US adults. We used data from 7601 men and women aged > or = 20 years who participated in the National Health and Nutrition Examination Survey 1999-2002. The age-adjusted prevalence of severe headaches or migraines during the previous 3 months was 34.0, 18.9, 20.7 and 25.9% among participants with a BMI < 18.5, 18.5 to < 25, 25 to < 30 and > or = 30 kg/m(2), respectively. After adjusting for a variety of covariates in a logistic regression model, those with a BMI < 18.5 kg/m(2)[odds ratio (OR) 2.01; 95% confidence interval (CI) 1.34, 3.02] or > or = 30 kg/m(2 )(OR 1.37; 95% CI 1.09, 1.72) had a significantly elevated OR for having a headache compared with participants with a BMI of 18.5-< 25 kg/m(2). BMI is associated with the prevalence of severe headaches or migraines in a non-linear manner.

Clustering of cardiovascular disease risk factors and health-related quality of life among US adults

OBJECTIVE

To assess the association of clusters of multiple cardiovascular disease (CVD) risk factors with health-related quality of life (HRQOL) among US adults aged 18 years or older in 2003.

METHODS

Data from the 2003 Behavioral Risk Factor Surveillance System were analyzed. The four HRQOL questions developed by the Centers for Disease Control and Prevention were used. The CVD risk factors included diabetes, hypertension, high cholesterol, obesity, and current smoking.

RESULTS

The adjusted odds ratios of having four or more CVD risk factors were 14.0 (95% confidence interval [CI] 12.4-16.0) for poor or fair health, 6.4 (95% CI 5.6-7.3) for 14 or more physically unhealthy days, 4.8 (95% CI 4.2-5.6) for 14 or more mentally unhealthy days, and 8.0 (95% CI6.8-9.3) for 14 or more impaired activity days compared to having none of the five risk factors. A greater number of CVD risk factors was significantly associated with an increasing likelihood of having poor or fair health (P(1) < 0.0001 for linear trend, P(2) < 0.0001 for quadratic trend), 14 or more physically unhealthy days (P(1) < 0.0001, P(2) < 0.0001), 14 or more mentally unhealthy days (P(1) < 0.0001, P(2) = 0.02), and 14 or more impaired activity days (P(1) < 0.0001, P(2) < 0.0001).

CONCLUSIONS

A greater number of multiple CVD risk factors may be associated with more detrimental impairment of HRQOL. Preventing or reducing the clustering of multiple CVD risk factors to improve HRQOL is needed among adults.

Diabetes and anxiety in US adults: findings from the 2006 Behavioral Risk Factor Surveillance System

AIMS

Anxiety disorders may cause substantial impairment in patient functioning and well-being. Little is known about the relationship between diabetes and anxiety. We estimated the prevalence of lifetime diagnosis of anxiety in adults aged > or = 18 years with and without diabetes in the USA.

METHODS

We analysed data from the 2006 Behavioral Risk Factor Surveillance System (total, N = 201 575; 20 142 with diabetes; 39.4% men, 77.9% non-Hispanic Whites, 8.1% non-Hispanic Blacks and 7.7% Hispanics; mean age 52.4 years). Diabetes and lifetime diagnosis of anxiety were self-reported. A multivariable log-binomial model was used to estimate prevalence ratios (PR) and associated 95% confidence intervals (CI) of anxiety based on diabetes status.

RESULTS

The overall age-adjusted prevalence of lifetime diagnosis of anxiety was 19.5 and 10.9% in people with and without diabetes, respectively. After adjustment for educational level, marital status, employment status, current smoking, leisure-time physical activity and body mass index, people with diabetes had a 20% higher prevalence of lifetime diagnosis of anxiety than those without (PR 1.20; 95% CI 1.12, 1.30). There were no significant differences in the PR by gender (P = 0.06). However, the ratios differed significantly by age (P = 0.04) and by race/ethnicity (P < 0.01), indicating that people aged 18-29 years (PR 1.70; 95% CI 1.19, 2.43) and Hispanics (PR 1.69; 95% CI 1.33, 2.15) had a higher ratio than their counterparts.

CONCLUSION

Diabetes was significantly associated with anxiety in adults in this large population-based sample, particularly in Hispanics and young adults.

The pediatric metabolic syndrome

The metabolic syndrome is a frequent subject of attention, discussion, and debate in medical research, because of its linkages to the growing problem of obesity on the one hand and both diabetes mellitus and cardiovascular disease on the other. It is also the grounds for contention, as respected researchers disagree on its definition and even on its validity as a construct. This clustering of obesity, dyslipidemia, elevated blood pressure, impaired glucose metabolism, and acute phase reactants can be seen in children as well as in adults. There are at least five definitions of adult metabolic syndrome promulgated by different societies and organizations, and as many as 40 different definitions of the syndrome have been used in pediatric studies. In 2007, the International Diabetes Federation published a definition of pediatric metabolic syndrome; whether it unifies the field remains to be seen. In addition, long term cohort studies have furnished data showing that clusters of the factors used to identify metabolic syndrome do predict the presence of type 2 diabetes and cardiovascular disease defined as myocardial infarction, stroke, coronary artery bypass graft, and/or positive angiogram. In addition, longitudinal studies have demonstrated compromised vascular function in young adults with metabolic syndrome, variously defined, as children and adolescents. This review discusses the background and development of the concept of a metabolic syndrome, the inter-relationships among its constitutive elements, the debates surrounding the uses of the concept and possible treatment avenues.

Liver enzymes and incident diabetes: findings from the European Prospective Investigation into Cancer and Nutrition (EPIC)-Potsdam Study

OBJECTIVE

We sought to examine the association between plasma concentrations of liver enzymes gamma-glutamyltransferase (GGT) and alanine transaminase (ALT) and incident diabetes, prospectively.

RESEARCH DESIGN AND METHODS

We conducted a case-cohort analysis of data from participants mainly aged 35-65 years in the European Prospective Investigation into Cancer and Nutrition-Potsdam Study. The analytic sample included 787 participants with incident diabetes and 2,224 participants without diabetes.

RESULTS

Concentrations of GGT and ALT were significantly associated with incident diabetes after extensive adjustment. Compared with participants in the lowest quintile of GGT, the adjusted hazard ratios for increasing quintiles were 1.13 (95% CI 0.66-1.93), 1.67 (1.01-2.77), 2.77 (1.71-4.49), and 2.67 (1.63-4.37), respectively (P for linear trend <0.001). Compared with participants in the lowest quintile of ALT, the adjusted hazard ratios for incident diabetes were 0.93 (0.56-1.53) for quintile 2, 1.28 (0.83-1.96) for quintile 3, 1.35 (0.88-2.07) for quintile 4, and 1.93 (1.27-2.92) for quintile 5 (P for linear trend = 0.002). The magnitude of the associations were higher among men than women for GGT (P = 0.004) but did not differ significantly between men and women for ALT (P = 0.307).

CONCLUSIONS

Concentrations of GGT and ALT were significant predictors of incident diabetes in this study, even at concentrations still considered to be within the normal range.

Haemoglobin A1c, fasting glucose, serum C-peptide and insulin resistance in relation to serum uric acid levels--the Third National Health and Nutrition Examination Survey

OBJECTIVE

To evaluate haemoglobin A1c (HbA1c), fasting glucose, serum C-peptide and insulin resistance in relation to serum uric acid levels in a nationally representative sample of men and women.

METHODS

Using data from 14,664 participants aged 20 yrs and older in The US Third National Health and Nutrition Examination Survey (1988-1994), we examined the relation between the levels of HbA1c, other biomarkers and serum uric acid levels using multivariate linear regressions stratified by gender.

RESULTS

The serum uric acid levels increased with increasing serum HbA1c levels up to the category of 6-6.9%, and thereafter decreased with further increasing HbA1c levels (a bell-shaped relation). Compared with a HbA1c level of < 5%, the multivariate differences among women were 26.8 micromol/l for HbA1c of 6-6.9% and -25.6 micromol/l (95% CI -42.8, -8.3) for HbA1c > or = 9%. The corresponding multivariate differences among men were 8.3 micromol/l (95% CI -3.0, 19.6) and -64.8 micromol/l (95% CI -46.0, -84.5), which were both significantly different from those among women (P-values for interaction by sex <0.001). Fasting glucose levels also showed a bell-shaped relation with serum uric acid levels. Individuals with diabetes showed lower serum uric acid levels and the association was larger among men (P-value for interaction, 0.007). Serum uric acid levels increased linearly with increasing fasting serum C-peptide levels, serum insulin levels or insulin resistance (multivariate P-values for trend, <0.001).

CONCLUSIONS

Individuals with moderately elevated HbA1c levels (i.e. pre-diabetes) may be at a higher risk of hyperuricaemia and gout, particularly in women, whereas individuals with diabetes or highly elevated HbA1c levels may be at a lower risk of these conditions, particularly in men.

Obesity and self-reported general health, Hawaii BRFSS: are Polynesians at higher risk?

OBJECTIVE

This study compared the relationship between fair/poor general health status among overweight and obese Polynesians with that among other overweight and obese persons in Hawaii.

METHODS AND PROCEDURES

Data were pooled from the 1998-2003 Hawaii Behavioral Risk Factor Surveillance System (BRFSS) and logistic regression used to examine the predictors of fair/poor health status.

RESULTS

Polynesians were significantly more likely to be obese than non-Polynesians; overweight Polynesians were more likely than other overweight individuals to report fair/poor health status. After adjusting for confounders, among Polynesians, being obese was no longer associated with fair/poor health. Non-Polynesians who were obese (odds ratio 1.9; 95% confidence interval: 1.4-2.6), older, less educated, smokers, diabetic, hypertensive, and physically inactive were more likely to report fair/poor health.

DISCUSSION

Although Polynesians were significantly more obese than the rest of the Hawaii population, their weight was not independently associated with their odds for fair/poor health as it was with non-Polynesians. The difference may be that, for Polynesians, hypertension and diabetes overrode the effect of obesity on general health status or this group maintains different cultural perceptions of body size. Regardless, these findings show a major health risk among Polynesians and suggest the need for culturally specific health interventions.

Are United States adults with coronary heart disease meeting physical activity recommendations?

Cardiovascular disease remains the leading cause of death in the United States. The benefits of physical activity in reducing the risk for cardiovascular disease have led to recommendations that patients with heart disease increase their levels of physical activity. This study was conducted to investigate the degree of compliance with national and/or American Heart Association and American College of Cardiology guidelines for physical activity in United States adults with coronary heart disease (CHD) in comparison with subjects without CHD using data from the 2005 Behavioral Risk Factor Surveillance System (BRFSS). Information on CHD or physical activity was self-reported. A total of 297,145 participants aged > or =18 years were included in the analyses. The age-standardized prevalence and the odds ratios for meeting total, moderate, or vigorous physical activity recommendations were calculated. Patients with CHD participated less in physical activity at recommended levels than those without CHD (40%, 32%, and 22% vs 49%, 37%, and 29%, respectively, for meeting total, moderate, and vigorous physical activity recommendations, p <0.01 for all). The unadjusted odds ratios for adults with CHD who met total, moderate, and vigorous physical activity were 0.61 (95% confidence interval 0.58 to 0.65), 0.76 (95% confidence interval 0.72 to 0.80), and 0.45 (95% confidence interval 0.42 to 0.49), respectively. These odds ratios were attenuated slightly but remained significant even after multivariate adjustment. In conclusion, the findings of this study demonstrate that patients with CHD are less likely to comply with physical activity recommendations than subjects without CHD. Intensive physical activity counseling is needed for patients with CHD to increase their physical activity levels if no contraindications to increased physical activity exist.

Prevalence of the metabolic syndrome among U.S. adolescents using the definition from the International Diabetes Federation

OBJECTIVE

Our objective was to estimate the prevalence of the metabolic syndrome using the 2007 pediatric International Diabetes Federation (IDF) definition among adolescents in the U.S.

RESEARCH DESIGN AND METHODS

We used data from 2,014 participants aged 12-17 years of the National Health and Nutrition Examination Survey 1999-2004.

RESULTS

The prevalence of the metabolic syndrome for the period 1999-2004 was approximately 4.5% ( approximately 1.1 million adolescents aged 12-17 years in 2006). It increased with age, was higher among males (6.7%) than females (2.1%) (P = 0.006), and was highest among Mexican-American adolescents (7.1%). The prevalence of the metabolic syndrome was relatively stable across the 6-year period: 4.5% for 1999-2000, 4.4-4.5% for 2001-2002, and 3.7-3.9% for 2003-2004 (P for linear trend >0.050).

CONCLUSIONS

Our results provide the first estimates of the prevalence of the metabolic syndrome using the pediatric IDF definition among adolescents in the U.S.

Does the association of the triglyceride to high-density lipoprotein cholesterol ratio with fasting serum insulin differ by race/ethnicity?

Background

The triglyceride to high-density lipoprotein cholesterol (TG/HDL-C) ratio has been reported to be as closely correlated with insulin resistance as is the fasting serum insulin concentration (FSI), and therefore it is seen as a clinically useful way to identify the concomitant presence of insulin resistance and dyslipidemia. However, conflicting findings exist for the association of the TG/HDL-C ratio with FSI by race/ethnicity.

Methods

The associations of FSI concentration, serum triglyceride concentrations, and HDL-C were analyzed using log-binomial regression analyses and receiver operating characteristic (ROC) curve analysis among nondiabetic adults (n = 2652, aged ≥ 20 years, 51.2% men) in the United States.

Results

After adjustment for potential confounding effects, the prevalence ratio of hyperinsulinemia was 2.16 (95% confidence interval [CI], 1.74 to 2.08) when using a single cutoff point of 3.5, and 2.23 (95% CI, 1.83 to 2.72) when using race/ethnicity-specific cutoff points of 3.0 for non-Hispanic whites and Mexican Americans and 2.0 for non-Hispanic blacks for the TG/HDL-C ratio. The area under the ROC curve of the TG/HDL-C ratio for predicting hyperinsulinemia was 0.77 (95% CI, 0.74 to 0.79), 0.75 (95% CI, 0.69 to 0.77), and 0.74 (95% CI, 0.69 to 0.76) for non-Hispanic whites, non-Hispanic blacks, and Mexican Americans, respectively.

Conclusion

There was a significant association between the TG/HDL-C ratio and FSI among three major racial/ethnic groups in the United States. Our results add further support to the notion that the TG/HDL-C ratio may be a clinically simple and useful indicator for hyperinsulinemia among nondiabetic adults regardless of race/ethnicity.

Defining the metabolic syndrome in children and adolescents: will the real definition please stand up?

OBJECTIVES

To review the use of definitions of the metabolic syndrome in studies of children and adolescents and to review results from studies that used factor analysis to examine structure among cardiometabolic variables.

STUDY DESIGN

Literature review.

RESULTS

In 27 publications, authors used 40 unique definitions of the metabolic syndrome. Most of these definitions were adaptations of the adult definition developed by the National Cholesterol Education Program. In 11 studies that used exploratory factor analysis, the number of components ranged from 5 to 19, and the number of factors identified ranged from 1 to 5.

CONCLUSIONS

The use of multiple definitions of the metabolic syndrome argues strongly for the development of a standard pediatric definition.