Prevalence case-control study of epilepsy in three Burkina Faso villages.

PURPOSE: To estimate the association between the prevalence of epilepsy and potential risk factors in three Burkina Faso villages. METHODS: Three villages were selected based on local reports of high numbers of epilepsy cases and pig-rearing practices. One person aged 7 or older was selected at random from all households of selected concessions for epilepsy screening and blood sampling. Epilepsy was confirmed by a physician using the ILAE definition. The cross-sectional associations between epilepsy and selected factors and seroresponse to the antigens of Taenia solium were estimated using a Bayesian hierarchical logistic regression. Prevalence odds ratios (POR) and their 95% Bayesian Credible Intervals (95% BCI) were estimated. RESULTS: Of 888 individuals interviewed, 39 of 70 screened positive were confirmed to have epilepsy for a lifetime prevalence of 4.5% (95% CI: 3.3; 6.0). The prevalence of epilepsy was associated with a positive reaction to cysticercosis Ag-ELISA serology (POR = 3.1, 95% BCI = 1.0; 8.3), past pork consumption (POR = 9.7, 95% BCI = 2.5; 37.9), and being salaried or a trader compared to a farmer or housewife (POR = 2.9, 95% BCI = 1.2; 6.4). DISCUSSION: Several factors were associated with prevalent epilepsy, with Ag-ELISA suggesting the presence of neurocysticercosis. The association between epilepsy and some occupations may reflect differences in local attitudes toward epilepsy and should be further explored.

Coated-platelet levels and progression from mild cognitive impairment to Alzheimer disease.

OBJECTIVES: Coated-platelets are a subset of platelets produced by dual-agonist activation with collagen and thrombin. These platelets retain full-length amyloid precursor protein on their surface, are elevated in patients with amnestic as compared to nonamnestic mild cognitive impairment (MCI), and correlate with disease progression in Alzheimer disease (AD). Prompted by these findings, we investigated the association between coated-platelet production in amnestic MCI and rate of progression to AD. METHODS: Coated-platelet levels were assayed in 74 patients with amnestic MCI who were subsequently followed longitudinally for up to 36 months in an outpatient dementia clinic. Levels are reported as percent of cells converted into coated-platelets. Subjects were categorized into tertiles of coated-platelet levels. The distributions of time to progression to AD were estimated for each tertile using cumulative incidence curves and compared statistically using a log-rank test. Cox proportional hazards regression was used to adjust for potential confounders. RESULTS: The 24-month cumulative incidence of progression to AD was different among tertiles: 4% for the first tertile (lowest coated-platelet levels), 13% for the second tertile, and 37% for the third tertile (overall log-rank test, p = 0.02). The hazard rate of progression to AD for patients in the highest coated-platelet tertile was 5.1 times that for patients in the lowest tertile (p = 0.04), whereas the hazard rate for the middle tertile was similar to that for the lowest tertile (hazard rate ratio = 1.5, p = 0.7). CONCLUSIONS: Elevated coated-platelet levels in patients with amnestic MCI are associated with increased risk for progression to AD.

Coffee consumption and the incidence of type 2 diabetes in men and women with normal glucose tolerance: the Strong Heart Study.

BACKGROUND AND AIMS: It was reported that high coffee consumption was related to decreased diabetes risk. The aim of this study is to examine the association between coffee consumption and the incidence of type 2 diabetes in persons with normal glucose tolerance in a population with a high incidence and prevalence of diabetes. METHODS AND RESULTS: In a prospective cohort study, information about daily coffee consumption was collected at the baseline examination (1989-1992) in a population-based sample of American Indian men and women 45-74 years of age. Participants with normal glucose tolerance (N = 1141) at the baseline examination were followed for an average of 7.6 years. The incidence of diabetes was compared across the categories of daily coffee consumption. The hazard ratios of diabetes related to coffee consumption were calculated using Cox proportional hazards models, adjusted for potential confounders. Levels of coffee consumption were positively related to levels of current smoking and inversely related to body mass index, waist circumference, female gender, and hypertension. Compared to those who did not drink coffee, participants who drank 12 or more cups of coffee daily had 67% less risk of developing diabetes during the follow-up (hazard ratio: 0.33, 95% confidence interval: 0.13, 0.81). CONCLUSION: In this population, a high level of coffee consumption was associated with a reduced risk of deterioration of glucose metabolism over an average 7.6 years of follow-up. More work is needed to understand whether there is a plausible biological mechanism for this observation.

Lower coated-platelet levels are associated with early hemorrhagic transformation in patients with non-lacunar brain infarction.

BACKGROUND: Coated-platelets, representing a subset of platelets with procoagulant potential, are elevated in patients with non-lacunar ischemic stroke and decreased in patients with spontaneous intracerebral hemorrhage. However, within the non-lacunar patient population there are individuals with lower levels of coated-platelets, which raises the possibility that these individuals would be susceptible to early hemorrhagic transformation (HT) of ischemic stroke. OBJECTIVE: Because extremes in coated-platelet potential may be associated with either thrombotic or hemorrhagic events, we undertook a pilot study to investigate whether there is an association between coated-platelet production and the presence of early HT in patients with non-lacunar ischemic stroke. PATIENTS AND METHODS: Coated-platelet levels were determined in 115 consecutive eligible patients with a diagnosis of non-lacunar ischemic stroke. Early HT was determined on CT scan examination and confirmed by MRI studies. The distribution of coated-platelet levels was summarized using the median and interquartile range (25th-75th percentiles) and compared statistically between patients with and without early HT using the non-parametric Wilcoxon rank sum test. RESULTS: The median coated-platelet level in all non-lacunar stroke patients was 38.0% (interquartile range 30.5-48.3%). Early HT was detected in 11 patients (9.6%), and these patients had significantly lower coated-platelet levels compared with those without early HT [median 25.1% (interquartile range 20.4-35.5%) vs. 39.2% (31.6-49.5%), P = 0.003]. CONCLUSIONS: Lower levels of coated-platelets are associated with the presence of early HT in patients with non-lacunar ischemic stroke.

Cumulative incidence of vitamin B12 deficiency in patients with Alzheimer disease.

BACKGROUND: Although vitamin B12 is routinely measured in patients with Alzheimer disease (AD) at the time of the initial diagnosis, it is not known if repeat vitamin B12 measurements are indicated to detect new deficiency cases. We aimed to determine the incidence of de-novo vitamin B12 deficiency over a period of 3 years in a cohort of AD patients without a prior diagnosis of vitamin B12 deficiency and with initial vitamin B12 levels greater than 350 ng/L. METHODS: Vitamin B12 levels were measured at the time of AD diagnosis and repeated 3 years later in 102 consecutive patients, unless a diagnosis of B12 deficiency was made in the interim. RESULTS: Vitamin B12 deficiency was diagnosed in 7 patients, corresponding to a cumulative incidence in the cohort studied of 7.6% after 3 years of follow-up. Statistical comparison of initial and repeat vitamin B12 measurements in patients that completed follow-up showed a significant reduction in levels (p=0.003). Among the 79 subjects with follow-up, 17 patients (22%, 95% CI, 13%-32%) had a repeat level less than 350 ng/L. No significant correlates of deficiency incidence were identified. CONCLUSION: Our pilot data indicate that vitamin B12 levels decreased in this cohort of AD patients putting a substantial percentage at risk of deficiency and reaching deficiency state in a meaningful number of patients. Repeat screening for B12 deficiency after approximately 2 years of follow-up seems warranted in order to prevent hematological and neurological manifestations that may significantly alter their quality of life.

Estimation of the cost of Taenia solium cysticercosis in Eastern Cape Province, South Africa.

OBJECTIVES: To provide a comprehensive estimate of the societal costs of Taenia solium cysticercosis for the Eastern Cape Province (ECP), South Africa, as an objective measure of its impact in this endemic area. METHODS: Epidemiological data on the prevalence of epilepsy, proportion of epilepsy cases due to neurocysticercosis (NCC) and consequences of cysticercosis were gathered from published and unpublished sources. Economical data were mostly obtained from governmental sources. Three methods were used for estimating productivity losses. Monte Carlo sampling was used to represent the uncertainty of the estimates with 95% Credible Intervals (95% CI). The estimation is for 1 year using a societal approach. All costs are reported in 2004 US Dollars. RESULTS: Overall, there were an estimated 34 662 (95% CI: 17 167-54 068) NCC-associated cases of epilepsy in ECP in 2004. The overall monetary burden (in million of US Dollars) was estimated to vary from US Dollars 18.6 (95% CI: US Dollars 9.0-32.9) to US Dollars 34.2 (95% CI: US Dollars 12.8-70.0) depending on the method used to estimate productivity losses. The agricultural sector contributed an average of Dollars 5.0 million. The prevalence of epilepsy, proportion of productivity reduction and the proportion of epilepsy cases attributable to NCC had the largest impact on the overall estimates. CONCLUSION: This preliminary estimate suggests that T. solium cysticercosis results in considerable monetary costs to a region that is already economically constrained. Because this infection is preventable, these results could guide stakeholders in deciding where to invest scarce health and agricultural resources in their countries.

Assessing the burden of Taenia solium cysticercosis and echinococcosis.

This collection of articles provides an account of the papers delivered at the 19th International Conference of the World Association for the Advancement of Veterinary Parasitology (WAAVP)(held in New Orleans, LA, USA, from 10 to 14 August 2003) in a symposium session on assessing the burden of Taenia solium cysticercosis and echinococcosis organised and chaired by A. Lee Willingham III from the WHO/FAO Collaborating Center for Research and Training on Emerging and other Parasitic Zoonoses in Denmark and Peter M. Schantz from the Parasitic Diseases Division of the US Centers for Disease Control and Prevention, USA. The focus was on the persistence of the zoonotic parasitic diseases cysticercosis, caused by the pork tapeworm T. solium, and echinococcosis,caused by species of the tapeworm Echinococcus, and why these diseases are given very little attention on the national and international agendas in spite of the availability of tools to detect, treat,control and prevent them when it is quite clear in most instances that they are clearly associated with and help perpetuate poverty. A major reason for this is that in many endemic areas the presence and impact of these diseases are not known due to the lack of investigation and information thus policymakers are not aware of their burden and benefits of their control. Documentation is also needed to help increase awareness of the international community and hopefully result in financial and technical support being made available. Thus, burden assessments of cysticercosis and echinococcosis provide an essential evidence base for securing political will and financial and technical support as well as providing a basis for cost-benefit analysis of prevention and control efforts. In order to make an appropriate and full burden assessment one must consider the health, agricultural, social and other impacts of these parasitic zoonoses comprehensively. During the symposium presentations were given concerning current ongoing initiatives to assess the burden of cysticercosis and echinococcosis and examples of the impact of these diseases in both developing and developed countries were provided. In addition, cost factors related to vaccines for these cestode diseases were discussed and the possibilities for technical and financial support from multilateral agencies for assessments and interventions presented.

Clinical correlates of white-matter abnormalities on head magnetic resonance imaging.

We undertook this study to investigate the relationship between white-matter abnormalities (seen on brain magnetic resonance imaging [MRI]) and muscle tone and muscle stretch reflexes on clinical examination. We identified all patients less than 5 years of age who had undergone cranial MRI studies at Riley Hospital for Children between June 30, 1999, and July 1, 2000, whose scans were read as showing white-matter abnormalities. We measured two ratios and the thickness of the corpus callosum as indicators of the quantity of cerebral white matter. The ratios were R1, the ratio of the thickness of the white matter at the level just above the body of the lateral ventricle compared with the width of the hemisphere, and R2, the ratio of the thickness of the white matter to the width of the hemisphere at the level of the trigone of the lateral ventricle. The thickness of the corpus callosum was measured at the junction of the anterior two thirds and the posterior third. We also evaluated the signal intensity of the cerebral white matter by reviewing the fluid-attenuated inversion-recovery images and grading the signal as normal to severely abnormal depending on the degree and extent of high signal intensity seen (0 = normal to 4+). Thirty-eight children less than 5 years of age who underwent MRI scans between June and August 2000 and who were found to have normal tone prospectively and normal MRI scan on review served as a control group. We identified 215 patients who had white-matter abnormalities; of these, only 142 (66%) had documented tone assessments in their medical record. Our study group was divided into three groups: increased (n = 35), decreased (n = 53), and normal tone (n = 54). All three measurements of white matter in each of the three study groups were significantly below values for control children. The children with white-matter abnormalities and decreased tone had significantly less signal intensity abnormality than the other study groups. Children with white-matter abnormalities and increased tone had a greater frequency of increased reflexes and tended to have more signal abnormalities than the other groups. The group of children with white-matter abnormalities and normal tone had the least amount of cerebral white-matter deficiency of the three study groups. In patients with strikingly decreased quantities of cerebral white matter, those with normal signal-intensity white matter are likely to be hypotonic with normal reflexes and those with increased signal intensity in the white matter are likely to be spastic.

A population-based assessment of left ventricular systolic dysfunction in middle-aged and older adults: the Strong Heart Study.

BACKGROUND: Although clinical congestive heart failure (CHF) is increasingly common, few data document the prevalence and correlates of underlying left ventricular (LV) systolic dysfunction (D) in population-based samples. METHODS: Echocardiography was used in the second Strong Heart Study (SHS) examination to identify mild and severe LVD (LV ejection fraction [EF] 40%-54% and <40%, respectively) in 3184 American Indians. RESULTS: Mild and severe LVD were more common in men than women (17.4% vs 7.2% and 4.7% vs 1.8%) and in diabetic than nondiabetic participants (12.7% vs 9.1% and 3.5% vs 1.6%). Stepwise increases were observed from participants with normal EF to those with mild and severe LVD in age (mean 60 vs 61 and 63 years, P <.001), prevalence of overt CHF (2% vs 6% and 28%) and definite coronary heart disease (3% vs 11% and 32%), systolic pressure (129 vs 135 and 136 mm Hg), serum creatinine level (0.98 vs 1.34 and 2.16 mg/dL), and log urinary albumin/creatinine level (3.2 vs 3.7 and 4.7); a negative relation was seen with body mass index (31.1 vs 31.0 and 28.4 kg/m(2)) (all P <.001). In multivariate analyses lower LVEFs were independently associated with clinical CHF and coronary heart disease, lower myocardial contractility, male sex, hypertension, overweight, arterial stiffening (higher pulse pressure/stroke volume) and renal dysfunction (higher serum creatinine level), higher LV mass, and lower relative wall thickness. CONCLUSIONS: LVD, present in approximately 14% of middle-aged to elderly adults, is independently associated with overt heart failure and coronary heart disease, male sex, hypertension, overweight, arterial stiffening, and renal target organ damage and, less consistently, with older age and diabetes.

The relation between newborn hemoglobin F fractions and risk factors for sudden infant death syndrome.

OBJECTIVES: The aims of this study were to determine and compare fetal hemoglobin (HbF) fractions at birth in newborns exposed and not exposed to selected factors that have been reported to increase the risk of sudden infant death syndrome (SIDS). Previous studies have implicated HbF in the etiology of SIDS by finding higher fractions in infants dying from SIDS compared to age-matched control infants. DESIGN: We performed a cross-sectional study using high-performance liquid chromatography to measure HbF fractions in newborn cord blood samples. Exposure to selected risk factors for SIDS was assessed through review of medical records. PARTICIPANTS: Six hundred thirty-three infants born at Via Christi Regional Medical Center-St Francis Campus, Wichita, Kan, from February 28 through August 5, 1997. MAIN OUTCOME MEASURE: Hemoglobin F fractions at birth were compared in newborns exposed and not exposed to selected risk factors associated with increased incidence of SIDS. RESULTS: Mean HbF fractions were significantly higher in preterm newborns of mothers who smoked and in term newborns with intrauterine growth restriction, pregnancy weight gain less than or equal to 9 kg, and pregnancy complications associated with reduced placental blood flow. An elevated newborn HbF fraction, defined as 77% or greater, was significantly associated with maternal smoking, maternal anemia, intrauterine growth restriction, and pregnancy complications associated with reduced placental blood flow. CONCLUSION: This study suggests a possible mechanism (HbF) by which previously identified factors may increase the risk of SIDS.

Outcomes of a small group educational intervention for urinary incontinence: health-related quality of life.

OBJECTIVES: This article examines change in general and condition-specific measures of health-related quality of life (HRQL) among participants in a randomized trial of a community-based intervention for urinary incontinence (UI). METHODS: Participants were randomized into intervention or wait control conditions. Participants were women aged 65 or older with urinary incontinence residing in Oklahoma. General HRQL measures included the Physical Function, Mental Health, Vitality, and Health Perceptions subscales of the Medical Outcomes Study Short Form-36. Condition-specific measures included the Impact of UI and self-management strategies. RESULTS: There were no significant group effects for the general HRQL measures. Intervention participants reported decreased Impact of UI and greater change in self-management strategies than control participants. DISCUSSION: The intervention affected condition-specific quality of life and self-management but not general HRQL. The intervention's impact on quality of life involves change in how the condition is seen as impacting on life and on selection of self-management behaviors.

Outcomes of a small group educational intervention for urinary incontinence: episodes of incontinence and other urinary symptoms.

OBJECTIVES: This community-based intervention to reduce urinary incontinence (UI) in elderly women used a small group educational approach. This article reports on change in episodes of incontinence and other urinary symptoms. METHODS: Participants were randomly assigned to intervention or wait control condition. This article is restricted to 49 intervention and 59 control participants with acceptable diaries. RESULTS: There was a significant treatment effect for a number of incontinent episodes. In the intervention group, 61% had a 50% or greater reduction in episodes, with more than one third having 100% reduction; 38% of the control group had a reduction of 50% or greater. One year postprogram, 75% of treated women reported subjective improvement. There was a reduction in frequency of daily, but not nocturnal, micturition. DISCUSSION: This community-based intervention is an encouraging option for behavioral treatment of UI. Public health models may be particularly appropriate with moderate levels of urinary incontinence.

New research directions in neuroepidemiology.

Many of the risk factors previously identified for disorders such as Alzheimer's disease, periventricular leukomalacia, multiple sclerosis, stroke, cerebral palsy, mental retardation, and acquired learning and attention disorders ultimately may be shown to damage the central and peripheral nervous systems through activation of inflammatory mediators. The challenge to epidemiologists in the future is to expand use of epidemiologic methods to explore how immune-mediated insults produce CNS disorders in human populations. Studies of the association of use of nonsteroidal anti-inflammatory drugs with risk of Alzheimer's disease and those of the association of immune parameters with risk of cerebral palsy are excellent examples of how epidemiology can contribute to our understanding of the causes of neurologic and/or neurodevelopmental disorders. Many of the immune parameters of interest have short half-lives and are difficult to measure outside of the laboratory setting. Questions also remain as to the proper timing of measurements in relation to the initial insult and, in some cases, which tissue is the most appropriate to sample. These measurement issues will need to be resolved before use of immune biomarkers in epidemiologic studies of the etiologies of neurologic disorders can be fully realized. Epidemiologists are most likely to help identify ways to prevent neurologic disorders if they are knowledgeable about the molecular biology of inflammation, modulators of CNS vulnerability, and genetic polymorphisms that influence both inflammation and CNS vulnerability and are prepared to become adept at biomarker epidemiology. This does not necessarily compel them to gain extensive knowledge of neurobiology. Rather, neuroepidemiology in the 21st century will require increased collaboration between epidemiologists, neurologists, and neurobiologists.

Relation of generalized and central obesity to cardiovascular risk factors and prevalent coronary heart disease in a sample of American Indians: the Strong Heart Study.

OBJECTIVE: To examine the hypothesis linking measures of obesity including body mass index (BMI), waist circumference (waist) and percentage body fat to coronary heart disease (CHD) prevalence and its risk factors in American Indians. DESIGN: The Strong Heart Study assesses the prevalence of CHD and its risk factors in American Indians in Arizona, Oklahoma and South/North Dakota. Participants underwent a physical examination and an electrocardiogram; anthropometric and blood pressure measurements were taken, as were measurements of glucose, lipoproteins, fibrinogen, insulin, hemoglobin A1c and urinary albumin. PARTICIPANTS: Data were available for 4549 men and women between 45 and 74 y of age. MEASUREMENTS: Obesity, measured using body mass index, waist circumference and percentage body fat, was correlated with prevalent CHD and its risk factors. RESULTS: More than 75% of participants were overweight (BMI>25 kg/m2). Measures of obesity were greater in women than in men, in younger than in older participants, and in participants with diabetes than in nondiabetic participants. CHD risk factors were associated with measures of obesity but, except for insulin concentration, changes in metabolic variables with increasing obesity were small. Associations were not stronger with waist than with BMI. The prevalence of CHD in those whose BMI and/or waist measurements lay in the lowest and highest quintiles, by gender and diabetic status, was similar. CONCLUSIONS: Although CHD risk factors are associated with obesity in American Indians, distribution of obesity (ie waist) is no more closely related to risk factors than is generalized obesity (ie BMI), and changes in CHD risk factors with obesity were small. Thus, the relations among obesity, body fat distribution and CHD risk may differ in this population.

Gravidity and parity in postmenopausal American Indian women: the Strong Heart Study.

The fertility of a large sample of American Indian women participating in the Strong Heart Study was examined to determine which factors are associated with variation in completed fertility among women in this population. The Strong Heart Study (SHS) is a study of cardiovascular disease (CVD) and its risk factors in American Indians living in Arizona, Oklahoma, and the Dakotas. Data were derived from a baseline examination between 1989 and 1992 of approximately 1,500 men and women, aged 45-74, from each of the 3 SHS centers. A personal interview elicited demographic information, family health history, and information on several life-style variables. A total of 1,955 ever-married, postmenopausal women were considered in these analyses. Women were considered to be postmenopausal if their menstrual cycles had stopped completely for at least 12 months, either because of natural or surgical processes. The average number of pregnancies (gravidity) for all women was 5.9, whereas the mean number of live births (parity) was 5.3. Women living in Arizona (5.6) and the Dakotas (5.8) had higher parity than those in Oklahoma (4.6). Furthermore, there was lower completed fertility in younger women: When American Indian women from all 3 centers were considered together, women born between 1910 and 1919 had a mean parity of 5.3, whereas women born between 1940 and 1949 had a mean parity of 4.0. Although previous research has suggested a relationship between parity and CVD risk factors, no linear associations between CVD risk factors and fertility were indicated in this population. We also examined the relationship of contraception, level of education, and income to fertility. While no significant relationship between contraception and the level of fertility was identified, there was a significant inverse linear relationship of both education and income with fertility. In summary, fertility rates in American Indian women are high, but appear to be decreasing in younger generations. Fertility is higher in those with less education and lower incomes.

Methods to improve the reliability of histopathological diagnoses in the placenta.

The interobserver reliability of histopathological features in the placenta was examined. Two pathologists independently reviewed slides from 250 placentas. The pathologists were given a morphological description of the placenta, but were blinded to clinical status, gestational age and original diagnoses. A protocol for diagnosis and grading of features was first developed and pilot-tested. Definitions and criteria were refined and elaborated. A range of features was examined including inflammatory lesions, features indicative of reduced uterine blood flow and other miscellaneous histopathological changes. Weighted kappa coefficients were calculated. The effect of multiple features on reliability was examined by stratifying on the presence of a second feature and calculating stratum-specific kappa coefficients. Results indicated good to excellent agreement for diagnoses of chorioamnionitis, cord vasculitis, funisitis and villitis (kappa(w) range 0.70-0.83). Agreement between observers was more variable for the diagnosis of reduced uterine blood flow states. Excellent agreement was observed for the diagnosis of meconium staining of the placenta (kappaw = 0.79). In general, lower levels of agreement were observed for features in the presence of a second feature. Reproducible measures are a prerequisite to using placental histopathology for diagnostic and prognostic information. This study demonstrated reliable placental diagnoses can be achieved through a standardised protocol.

LDL cholesterol as a strong predictor of coronary heart disease in diabetic individuals with insulin resistance and low LDL: The Strong Heart Study.

Diabetes has been shown to increase the risk of coronary heart disease in all populations studied. However, there is a lack of information on the relative importance of diabetes-associated risk factors for cardiovascular disease (CVD), especially the role of lipid levels, because low density lipoprotein (LDL) cholesterol often is not elevated in diabetic individuals. The objective of this analysis was to evaluate CVD risk factors in a large cohort of diabetic individuals and to compare the importance of dyslipidemia (ie, elevated triglycerides and low levels of high density lipoprotein [HDL] cholesterol) and LDL cholesterol in determining CVD risk in diabetic individuals. The Strong Heart Study assesses coronary heart disease and its risk factors in American Indians in Arizona, Oklahoma, and South/North Dakota. The baseline clinical examinations (July 1989 to January 1992) consisted of a personal interview, physical examination, and drawing of blood samples for 4549 study participants (2034 with diabetes), 45 to 74 years of age. Follow-up averaged 4.8 years. Fatal and nonfatal CVD events were confirmed by standardized record review. Participants with diabetes, compared with those with normal glucose tolerance, had lower LDL cholesterol levels but significantly elevated triglyceride levels, lower HDL cholesterol levels, and smaller LDL particle size. Significant independent predictors of CVD in those with diabetes included age, albuminuria, LDL cholesterol, HDL cholesterol (inverse), fibrinogen, and percent body fat (inverse). A 10-mg/dL increase in LDL cholesterol was associated with a 12% increase in CVD risk. Thus, even at concentrations well below the National Cholesterol Education Program target of 130 mg/dL, LDL cholesterol is a strong independent predictor of coronary heart disease in individuals with diabetes, even when components of diabetic dyslipidemia are present. These results support recent recommendations for aggressive control of LDL cholesterol in diabetic individuals, with a target level of <100 mg/dL.

Secular trends in the prevalence of HIV infection among a population of males with hemophilia, 1988-1997: the Oklahoma Hemophilia Surveillance System.

Tracking the natural history of HIV/AIDS in the hemophilia community is useful for planning future health care needs and for adjusting estimates of the prevalence of hemophilia as the impact of HIV/AIDS wanes over time. The present study was designed to determine the annual prevalence of HIV infection from 1988 through 1997 in a population of males with hemophilia A or B. Data were obtained from the Oklahoma Hemophilia Surveillance System and were limited to individuals who were seen at the Oklahoma Hemophilia Treatment Center. In 1988, the prevalence rate of HIV infection was 34 percent. Rates have declined in each subsequent year through 1997. The highest rates of HIV infection were observed in persons with severe hemophilia and hemophilia A. The overall prevalence rates of HIV infection in this treatment center population are lower than those reported in other populations. No new cases of HIV infection were observed in persons with hemophilia born after 1985.

Rising tide of cardiovascular disease in American Indians. The Strong Heart Study.

BACKGROUND: Although cardiovascular disease (CVD) used to be rare among American Indians, Indian Health Service data suggest that CVD mortality rates vary greatly among American Indian communities and appear to be increasing. The Strong Heart Study was initiated to investigate CVD and its risk factors in American Indians in 13 communities in Arizona, Oklahoma, and South/North Dakota. METHODS AND RESULTS: A total of 4549 participants (1846 men and 2703 women 45 to 74 years old) who were seen at the baseline (1989 to 1991) examination were subjected to surveillance (average 4.2 years, 1991 to 1995), and 88% of those remaining alive underwent a second examination (1993 to 1995). The medical records of all participants were exhaustively reviewed to ascertain nonfatal cardiovascular events that occurred since the baseline examination or to definitively determine cause of death. CVD morbidity and mortality rates were higher in men than in women and were similar in the 3 geographic areas. Coronary heart disease (CHD) incidence rates among American Indian men and women were almost 2-fold higher than those in the Atherosclerosis Risk in Communities Study. Significant independent predictors of CVD in women were diabetes, age, obesity (inverse), LDL cholesterol, albuminuria, triglycerides, and hypertension. In men, diabetes, age, LDL cholesterol, albuminuria, and hypertension were independent predictors of CVD. CONCLUSIONS: At present, CHD rates in American Indians exceed rates in other US populations and may more often be fatal. Unlike other ethnic groups, American Indians appear to have an increasing incidence of CHD, possibly related to the high prevalence of diabetes. In the general US population, the rising prevalence of obesity and diabetes may reverse the decline in CVD death rates. Therefore, aggressive programs to control diabetes and its risk factors are needed.

Risk factor clustering in the insulin resistance syndrome. The Strong Heart Study.

The objective of this study was to examine how the major components of the insulin resistance syndrome relate to each other and to macrovascular disease in American Indians in the Strong Heart Study. The study cohort (4,228 resident tribal members 45-74 years old) underwent a personal interview and a physical examination between July 1989 and January 1992 at three centers: Arizona, Oklahoma, and North and South Dakota; blood samples were drawn and a 75-g oral glucose tolerance test was performed. Factor analysis was used to assess the clustering and interdependence of groups of insulin resistance syndrome variables. Within both diabetic and nondiabetic groups, three factors emerged. In nondiabetic participants, a cluster of glucose, body mass index, and insulin accounted for 35% (male) and 32% (female) of the total variance in all variables considered, and a cluster of systolic blood pressure and diastolic blood pressure accounted for 25% and 22% in men and women, respectively. Both clusters were positively associated with coronary heart disease but not peripheral vascular disease. In diabetic participants, the combination of systolic and diastolic blood pressures was the most important factor, but the cluster was not associated with coronary heart disease or peripheral vascular disease. A component containing high density lipoprotein cholesterol, triglycerides, and glucose had a positive association with coronary heart disease in diabetic women and with peripheral vascular disease in both sexes. The association of clusters of risk factors and their relations with coronary heart disease provide important clues that may be used in understanding the metabolic disorders associated with insulin resistance and diabetes.