<p>Factors Associated with Treatment Uptake Among Women with Acetic Acid/Lugol’s Iodine Positive Lesions of the Cervix in Cameroon</p>

Purpose

Treatment of cervical precancer is the primary aim in secondary prevention of cervical cancer. The purpose of this study was to examine factors associated with treatment uptake among women with acetic acid/Lugol’s iodine positive lesions identified by digital cervicography (DC) in a cervical cancer prevention program in Cameroon.

Patients and Methods

We conducted a cross-sectional survey of medical records from 2013 to 2018 of 755 women in Cameroon who screened positive with acetic acid/Lugol’s iodine in 2013.

Results

Of the 755 women, 422 (55.9%) had treatment/biopsy on the same day or followed up later, but only 344 (45.6%) received treatment/biopsy and 333 (44.1%) were lost to follow-up. Overall, 180 (52.3%) of the 344 women were treated/biopsied the same day they were screened, and 164 (47.7%) were treated/biopsied after the initial visit. Women aged 30–49 and HIV-positive women were significantly more likely to have received treatment or returned for treatment than women less than 30 and HIV-negative women. Of the 266 women who followed up at a later date, the lesions of 78 (29.3%) women regressed spontaneously without treatment. Women with low-grade lesions, HIV-negative women and women who had follow-up more than a year after the initial exam were significantly more likely to have spontaneous regression with regression rates of 30.6%, 32.1% and 62.2%, respectively (p<0.001). Age was not a significant determinant of spontaneous regression (p=0.149).

Conclusion

Efforts to increase treatment uptake are needed in this population, including adherence to same day “See and treat” policies.

Maternal Decision-Making and Uptake of Health Services for the Prevention of Mother-to-Child HIV Transmission: A Secondary Analysis

Objectives We investigated whether a woman's role in household decision-making was associated with receipt of services to prevent mother-to-child HIV transmission (PMTCT). Methods We conducted a secondary analysis of the PEARL study, an evaluation of PMTCT effectiveness in Cameroon, Cote d'Ivoire, South Africa, and Zambia. Our exposure of interest was the women's role (active vs. not active) in decision-making about her healthcare, large household purchases, children's schooling, and children's healthcare (i.e., four domains). Our primary outcomes were self-reported engagement at three steps in PMTCT: maternal antiretroviral use, infant antiretroviral prophylaxis, and infant HIV testing. Associations found to be significant in univariable logistic regression were included in separate multivariable models. Results From 2008 to 2009, 613 HIV-infected women were surveyed and provided information about their decision-making roles. Of these, 272 (44.4%) women reported antiretroviral use; 281 (45.9%) reported infant antiretroviral prophylaxis; and 194 (31.7%) reported infant HIV testing. Women who reported an active role were more likely to utilize infant HIV testing services, across all four measured domains of decision-making (adjusted odds ratios [AORs] 2.00-2.89 all p < .05). However, associations between decision-making and antiretroviral use-for both mother and infant-were generally not significant. An exception was active decision-making in a woman's own healthcare and reported maternal antiretroviral use (AOR 1.69, p < 0.05). Conclusions for Practice Associations between decision-making and PMTCT engagement were inconsistent and may be related to specific characteristics of individual health-seeking behaviors. Interventions seeking to improve PMTCT uptake should consider the type of health-seeking behavior to better optimize health services.

Risk Factors and Prediction of Stroke in a Population with High Prevalence of Diabetes: The Strong Heart Study

BACKGROUND AND OBJECTIVE

American Indians have a high prevalence of diabetes and higher incidence of stroke than that of whites and blacks in the U.S. Stroke risk prediction models based on data from American Indians would be of clinical and public health value.

METHODS AND RESULTS

A total of 3483 (2043 women) Strong Heart Study participants free of stroke at baseline were followed from 1989 to 2010 for incident stroke. Overall, 297 stroke cases (179 women) were identified. Cox models with stroke-free time and risk factors recorded at baseline were used to develop stroke risk prediction models. Assessment of the developed stroke risk prediction models regarding discrimination and calibration was performed by an analogous C-statistic (C) and a version of the Hosmer-Lemeshow statistic (HL), respectively, and validated internally through use of Bootstrapping methods.

RESULTS

Age, smoking status, alcohol consumption, waist circumference, hypertension status, an-tihypertensive therapy, fasting plasma glucose, diabetes medications, high/low density lipoproteins, urinary albumin/creatinine ratio, history of coronary heart disease/heart failure, atrial fibrillation, or Left ventricular hypertrophy, and parental history of stroke were identified as the significant optimal risk factors for incident stroke.

DISCUSSION

The models produced a C = 0.761 and HL = 4.668 (p = 0.792) for women, and a C = 0.765 and HL = 9.171 (p = 0.328) for men, showing good discrimination and calibration.

CONCLUSIONS

Our stroke risk prediction models provide a mechanism for stroke risk assessment designed for American Indians. The models may be also useful to other populations with high prevalence of obesity and/or diabetes for screening individuals for risk of incident stroke and designing prevention programs.

Is Psychological Distress a Risk Factor for the Incidence of Diabetes Among American Indians? The Strong Heart Study

This study was conducted to determine if psychological distress increases the risk of type2 diabetes in American Indians. A prospective cohort study of 919 individuals free of diabetes from 13 Native communities was conducted to determine who developed diabetes. Psychological distress was assessed at baseline (1993-1995) by the Mental Component Summary (MCS) of the Short Form-36. The risk of diabetes was estimated at follow-up (1997-1999) according to quartiles of the MCS score. There was no evidence of a trend between psychological distress and the development of diabetes (ptrend = .73). The risk of diabetes in individuals in the highest quartile (17.5%) was nearly identical to that in the lowest quartile (16.5%) (odds ratio = 1.1, 95% confidence interval 0.7-1.7). The absence of association persisted even after adjustment for known risk factors for diabetes. Thus the study concludes that psychological distress is not related to the incidence of diabetes in American Indians.

Association of diabetes and cancer mortality in American Indians: the Strong Heart Study

PURPOSE

The metabolic abnormalities that accompany diabetes mellitus are associated with an increased risk of many cancers. These associations, however, have not been well studied in American Indian populations, which experience a high prevalence of diabetes. The Strong Heart Study is a population-based, prospective cohort study with extensive characterization of diabetes status.

METHODS

Among a total cohort of 4,419 participants who were followed for up to 20 years, 430 cancer deaths were identified.

RESULTS

After adjusting for sex, age, education, smoking status, drinking status, and body mass index, participants with diabetes at baseline showed an increased risk of gastric (HR 4.09; 95% CI 1.42-11.79), hepatocellular (HR 2.94; 95% CI 1.17-7.40), and prostate cancer mortality (HR 3.10; 95% CI 1.22-7.94). Further adjustment for arsenic exposure showed a significantly increased risk of all-cause cancer mortality with diabetes (HR 1.27; 95% CI 1.03-1.58). Insulin resistance among participants without diabetes at baseline was associated with hepatocellular cancer mortality (HR 4.70; 95% CI 1.55-14.26).

CONCLUSIONS

Diabetes mellitus, and/or insulin resistance among those without diabetes, is a risk factor for gastric, hepatocellular, and prostate cancer in these American Indian communities, although relatively small sample size suggests cautious interpretation. Additional research is needed to evaluate the role of diabetes and obesity on cancer incidence in American Indian communities as well as the importance of diabetes prevention and control in reducing the burden of cancer incidence and mortality in the study population.

Psychological trauma symptoms and Type 2 diabetes prevalence, glucose control, and treatment modality among American Indians in the Strong Heart Family Study

AIMS

The aims of this paper are to examine the relationship between psychological trauma symptoms and Type 2 diabetes prevalence, glucose control, and treatment modality among 3776 American Indians in Phase V of the Strong Heart Family Study.

METHODS

This cross-sectional analysis measured psychological trauma symptoms using the National Anxiety Disorder Screening Day instrument, diabetes by American Diabetes Association criteria, and treatment modality by four categories: no medication, oral medication only, insulin only, or both oral medication and insulin. We used binary logistic regression to evaluate the association between psychological trauma symptoms and diabetes prevalence. We used ordinary least squares regression to evaluate the association between psychological trauma symptoms and glucose control. We used binary logistic regression to model the association of psychological trauma symptoms with treatment modality.

RESULTS

Neither diabetes prevalence (22%-31%; p=0.19) nor control (8.0-8.6; p=0.25) varied significantly by psychological trauma symptoms categories. However, diabetes treatment modality was associated with psychological trauma symptoms categories, as people with greater burden used either no medication, or both oral and insulin medications (odds ratio=3.1, p<0.001).

CONCLUSIONS

The positive relationship between treatment modality and psychological trauma symptoms suggests future research investigate patient and provider treatment decision making.

Measuring coverage in MNCH: population HIV-free survival among children under two years of age in four African countries

BACKGROUND

Population-based evaluations of programs for prevention of mother-to-child HIV transmission (PMTCT) are scarce. We measured PMTCT service coverage, regimen use, and HIV-free survival among children ≤24 mo of age in Cameroon, Côte D'Ivoire, South Africa, and Zambia.

METHODS AND FINDINGS

We randomly sampled households in 26 communities and offered participation if a child had been born to a woman living there during the prior 24 mo. We tested consenting mothers with rapid HIV antibody tests and tested the children of seropositive mothers with HIV DNA PCR or rapid antibody tests. Our primary outcome was 24-mo HIV-free survival, estimated with survival analysis. In an individual-level analysis, we evaluated the effectiveness of various PMTCT regimens. In a community-level analysis, we evaluated the relationship between HIV-free survival and community PMTCT coverage (the proportion of HIV-exposed infants in each community that received any PMTCT intervention during gestation or breastfeeding). We also compared our community coverage results to those of a contemporaneous study conducted in the facilities serving each sampled community. Of 7,985 surveyed children under 2 y of age, 1,014 (12.7%) were HIV-exposed. Of these, 110 (10.9%) were HIV-infected, 851 (83.9%) were HIV-uninfected, and 53 (5.2%) were dead. HIV-free survival at 24 mo of age among all HIV-exposed children was 79.7% (95% CI: 76.4, 82.6) overall, with the following country-level estimates: Cameroon (72.6%; 95% CI: 62.3, 80.5), South Africa (77.7%; 95% CI: 72.5, 82.1), Zambia (83.1%; 95% CI: 78.4, 86.8), and Côte D'Ivoire (84.4%; 95% CI: 70.0, 92.2). In adjusted analyses, the risk of death or HIV infection was non-significantly lower in children whose mothers received a more complex regimen of either two or three antiretroviral drugs compared to those receiving no prophylaxis (adjusted hazard ratio: 0.60; 95% CI: 0.34, 1.06). Risk of death was not different for children whose mothers received a more complex regimen compared to those given single-dose nevirapine (adjusted hazard ratio: 0.88; 95% CI: 0.45, 1.72). Community PMTCT coverage was highest in Cameroon, where 75 of 114 HIV-exposed infants met criteria for coverage (66%; 95% CI: 56, 74), followed by Zambia (219 of 444, 49%; 95% CI: 45, 54), then South Africa (152 of 365, 42%; 95% CI: 37, 47), and then Côte D'Ivoire (3 of 53, 5.7%; 95% CI: 1.2, 16). In a cluster-level analysis, community PMTCT coverage was highly correlated with facility PMTCT coverage (Pearson's r = 0.85), and moderately correlated with 24-mo HIV-free survival (Pearson's r = 0.29). In 14 of 16 instances where both the facility and community samples were large enough for comparison, the facility-based coverage measure exceeded that observed in the community.

CONCLUSIONS

HIV-free survival can be estimated with community surveys and should be incorporated into ongoing country monitoring. Facility-based coverage measures correlate with those derived from community sampling, but may overestimate population coverage. The more complex regimens recommended by the World Health Organization seem to have measurable public health benefit at the population level, but power was limited and additional field validation is needed.

Blood alcohol levels for American Indian mothers and newborns

Very little is known about the alcohol elimination rates of newborns who have had chronic alcohol exposure in utero. In these case reports, blood alcohol levels were taken immediately before delivery, at delivery, and postdelivery for 2 mothers who drank alcohol during their pregnancies and 3 single-birth newborns. Newborn A1 of Mother A had no physical characteristics of fetal alcohol syndrome (FAS). The initial blood alcohol level for this newborn was 38.4 mg/dL 129 minutes after birth, with a subsequent blood alcohol level of 5.5 mg/dL 304 minutes after delivery, resulting in an alcohol elimination rate of 11.3 mg/dL per hour. The blood alcohol level for Mother A was 87.4 mg/dL 66 minutes before delivery. Newborn A2 of mother A had FAS. Sixty minutes after delivery, the blood alcohol level for this newborn was 39.5 mg/dL, and the alcohol level of the mother was 42.1 mg/dL. Newborn B1 of mother B had FAS. At 67 minutes after birth, newborn B1 had a blood alcohol level of 246.5 mg/dL, which dropped to 178.7 mg/dL 302 minutes after birth, resulting in an alcohol elimination rate of 17.3 mg/dL per hour. This alcohol elimination rate is within the metabolism range (15-49 mg/dL per hour) of adults with alcoholism. The maternal blood alcohol level was 265.9 mg/dL 27 minutes before delivery. Blood alcohol levels drawn on both the mother and newborn at delivery and 2 or 3 hourly follow-up levels can provide evidence that fetal alcohol dehydrogenase activity is induced by chronic maternal alcohol use.

Fasting plasma glucose and hemoglobin A1c in identifying and predicting diabetes: the strong heart study

OBJECTIVE

To compare fasting plasma glucose (FPG) and HbA(1c) in identifying and predicting type 2 diabetes in a population with high rates of diabetes.

RESEARCH DESIGN AND METHODS

Diabetes was defined as an FPG level ≥ 126 mg/dL or an HbA(1c) level ≥ 6.5%. Data collected from the baseline and second exams (1989-1995) of the Strong Heart Study were used. RESULTS For cases of diabetes identified by FPG ≥ 126 mg/dL, using HbA(1c) ≥ 6.5% at the initial and 4-year follow-up diabetes screenings (or in identifying incident cases in 4 years) among undiagnosed participants left 46% and 59% of cases of diabetes undetected, respectively, whereas for cases identified by HbA(1c) ≥ 6.5%, using FPG ≥ 126 mg/dL left 11% and 59% unidentified, respectively. Age, waist circumference, urinary albumin-to-creatinine ratio, and baseline FPG and HbA(1c) levels were common significant risk factors for incident diabetes defined by either FPG or HbA(1c); triglyceride levels were significant for diabetes defined by HbA(1c) alone, and blood pressure and sibling history of diabetes were significant for diabetes defined by FPG alone. Using both the baseline FPG and HbA(1c) in diabetes prediction identified more people at risk than using either measure alone. CONCLUSIONS Among undiagnosed participants, using HbA(1c) alone in initial diabetes screening identifies fewer cases of diabetes than FPG, and using either FPG or HbA(1c) alone cannot effectively identify diabetes in a 4-year periodic successive diabetes screening or incident cases of diabetes in 4 years. Using both criteria may identify more people at risk. The proposed models using the commonly available clinical measures can be applied to assessing the risk of incident diabetes using either criterion.

Acute myocardial infarction quality of care: the Strong Heart Study

OBJECTIVES

Evaluate the quality of care provided patients with acute myocardial infarction and compare with similar national and regional data.

DESIGN

Case series.

SETTING

The Strong Heart Study has extensive population-based data related to cardiovascular events among American Indians living in three rural regions of the United States.

PARTICIPANTS

Acute myocardial infarction cases (72) occurring between 1/1/2001 and 12/31/2006 were identified from a cohort of 4549 participants.

OUTCOME MEASURES

The proportion of cases that were provided standard quality of care therapy, as defined by the Healthcare Financing Administration and other national organizations.

RESULTS

The provision of quality services, such as administration of aspirin on admission and at discharge, reperfusion therapy within 24 hours, prescription of beta blocker medication at discharge, and smoking cessation counseling were found to be 94%, 91%, 92%, 86% and 71%, respectively. The unadjusted, 30 day mortality rate was 17%.

CONCLUSION

Despite considerable challenges posed by geographic isolation and small facilities, process measures of the quality of acute myocardial infarction care for participants in this American Indian cohort were comparable to that reported for Medicare beneficiaries nationally and within the resident states of this cohort.

Models of population-based analyses for data collected from large extended families

Large studies of extended families usually collect valuable phenotypic data that may have scientific value for purposes other than testing genetic hypotheses if the families were not selected in a biased manner. These purposes include assessing population-based associations of diseases with risk factors/covariates and estimating population characteristics such as disease prevalence and incidence. Relatedness among participants however, violates the traditional assumption of independent observations in these classic analyses. The commonly used adjustment method for relatedness in population-based analyses is to use marginal models, in which clusters (families) are assumed to be independent (unrelated) with a simple and identical covariance (family) structure such as those called independent, exchangeable and unstructured covariance structures. However, using these simple covariance structures may not be optimally appropriate for outcomes collected from large extended families, and may under- or over-estimate the variances of estimators and thus lead to uncertainty in inferences. Moreover, the assumption that families are unrelated with an identical family structure in a marginal model may not be satisfied for family studies with large extended families. The aim of this paper is to propose models incorporating marginal models approaches with a covariance structure for assessing population-based associations of diseases with their risk factors/covariates and estimating population characteristics for epidemiological studies while adjusting for the complicated relatedness among outcomes (continuous/categorical, normally/non-normally distributed) collected from large extended families. We also discuss theoretical issues of the proposed models and show that the proposed models and covariance structure are appropriate for and capable of achieving the aim.

Coverage of nevirapine-based services to prevent mother-to-child HIV transmission in 4 African countries

CONTEXT

Few studies have objectively evaluated the coverage of services to prevent transmission of human immunodeficiency virus (HIV) from mother to child.

OBJECTIVE

To measure the coverage of services to prevent mother-to-child HIV transmission in 4 African countries.

DESIGN, SETTING, AND PATIENTS

Cross-sectional surveillance study of mother-infant pairs using umbilical cord blood samples collected between June 10, 2007, and October 30, 2008, from 43 randomly selected facilities (grouped as 25 service clusters) providing delivery services in Cameroon, Côte d'Ivoire, South Africa, and Zambia. All sites used at least single-dose nevirapine to prevent mother-to-child HIV transmission and some sites used additional prophylaxis drugs.

MAIN OUTCOME MEASURE

Population nevirapine coverage, defined as the proportion of HIV-exposed infants in the sample with both maternal nevirapine ingestion (confirmed by cord blood chromatography) and infant nevirapine ingestion (confirmed by direct observation).

RESULTS

A total of 27,893 cord blood specimens were tested, of which 3324 were HIV seropositive (12%). Complete data for cord blood nevirapine results were available on 3196 HIV-seropositive mother-infant pairs. Nevirapine coverage varied significantly by site (range: 0%-82%). Adjusted for country, the overall coverage estimate was 51% (95% confidence interval [CI], 49%-53%). In multivariable analysis, failed coverage of nevirapine-based services was significantly associated with maternal age younger than 20 years (adjusted odds ratio [AOR], 1.44; 95% CI, 1.18-1.76) and maternal age between 20 and 25 years (AOR, 1.28; 95% CI, 1.07-1.54) vs maternal age of older than 30 years; 1 or fewer antenatal care visits (AOR, 2.91; 95% CI, 2.40-3.54), 2 or 3 antenatal care visits (AOR, 1.93; 95% CI, 1.60-2.33), and 4 or 5 antenatal care visits (AOR, 1.56; 95% CI, 1.34-1.80) vs 6 or more antenatal care visits; vaginal delivery (AOR, 1.22; 95% CI, 1.03-1.44) vs cesarean delivery; and infant birth weight of less than 2500 g (AOR, 1.34; 95% CI, 1.11-1.62) vs birth weight of 3500 g or greater.

CONCLUSION

In this random sampling of sites with services to prevent mother-to-child HIV transmission, only 51% of HIV-exposed infants received the minimal regimen of single-dose nevirapine.

Relationship between glycemic control and depression among American Indians in the Strong Heart Study

OBJECTIVES

To examine the relationship between depression and glycemic control in the Strong Heart Study (SHS), a longitudinal study of cardiovascular disease in American Indians.

METHODS

This cross-sectional analysis focused on the relationship between depression, diabetes and glycemic control among 2832 individuals aged > or =15 years. Depression was measured by the Center for Epidemiologic Studies of Depression Scale and diabetes by American Diabetes Association criteria. An ordered logit regression model was used to assess whether diabetes was related to level of depression (none, mild, moderate, severe). Multiple logistic regression was used to explore the relationship between A1c and severe depression in participants with diabetes.

RESULTS

Rates of depression were higher in men and women with diabetes when compared to those without diabetes, respectively (P<.05). For every 1-U increase in A1c, the odds of severe depression increased by 22% (OR 1.22, 95% CI: 1.05-1.42). Female sex (OR 2.97, 95% CI: 1.32-6.69) and body mass index (BMI) (OR 1.04, 95% CI: 1.00-1.08) also were significantly associated with increased risk for severe depression. Although BMI appears to be significantly associated with increased risk for severe depression, the magnitude of this effect was small.

CONCLUSIONS

Individuals with diabetes have higher rates of depression than those without diabetes, consistent with other populations. There is a positive relationship between severity of depression and A1c levels; men and women with severe depression have higher A1c levels than those with moderate-to-no depression.

Hospitalizations of children who have fetal alcohol syndrome or incomplete fetal alcohol syndrome

INTRODUCTION

The study describes the hospitalization rates and medical diagnoses of children with fetal alcohol syndrome (FAS) and incomplete FAS.

METHODS

Two retrospective case-control studies were conducted of Northern Plains American Indian children with FAS or incomplete FAS identified from 1981-93 by using the ICD-9-CM code 760.71. Children who had FAS or incomplete FAS were compared to each other and to children who did not have FAS.

RESULTS

Compared to the controls, the 43 children with FAS (Study 1) and 35 children with incomplete FAS (Study 2) were hospitalized more often with otitis media (51.2 percent OR=4.32 and 31.4 percent OR=3.02 respectively), pneumonia (46.5 percent OR=4.21 and 34.3 percent OR=2.54), fetal alcohol syndrome (32.6 percent p=.001 and 14.3 percent p=.007), dehydration (23.3 percent OR=9.29 and 17.1 percent OR=4), and anemia (11.6 percent OR=10 and 17.1 percent p=.002) respectively. Children with FAS were hospitalized more often with failure to thrive (32.6 percent p=.001) and neglect (23.3 percent OR=10.0) than children with incomplete FAS and controls. Children with FAS were hospitalized with child sexual abuse (11.6 percent OR=10.0) and feeding problems (11.6 percent p=.007), and children with incomplete FAS were hospitalized with gastroenteritis (22.9 percent OR=14.55) and bronchitis (22.9 percent OR=3.0) more than control children.

CONCLUSIONS

Children with FAS or incomplete FAS had more hospitalizations and longer average length of stays than control children.

Characteristics of children whose siblings have fetal alcohol syndrome or incomplete fetal alcohol syndrome

OBJECTIVE

To describe the clinical features of American Indian children born just before and just after a sibling with fetal alcohol syndrome or incomplete fetal alcohol syndrome.

METHODS

Two retrospective case-control studies were conducted of Northern Plains American Indian children with fetal alcohol syndrome or incomplete fetal alcohol syndrome identified from 1981 to 1993 by using International Classification of Diseases, Ninth Revision, Clinical Modification code 760.71.

RESULTS

Compared with the controls, the 39 siblings born just before children with fetal alcohol syndrome (study 1) and 30 siblings born just before children with incomplete fetal alcohol syndrome (study 2) had more facial dysmorphology (23.1% and 16.7%, respectively), growth delay (38.5% and 10.0%), and central nervous system impairment (48.7% and 33.3%). The 20 siblings born just after children with fetal alcohol syndrome (study 1) and 22 siblings born just after children with incomplete fetal alcohol syndrome (study 2) had more facial dysmorphology (20.0% and 9.1%, respectively), growth delay (45.0% and 22.7%), and central nervous system impairment (50.0% and 31.8%) than the control siblings.

CONCLUSIONS

The "before" siblings had characteristics of fetal alcohol syndrome that could have predicted that the next child was at risk for fetal alcohol syndrome. The "after" siblings had better outcomes than the previous siblings with fetal alcohol syndrome, a finding that was associated with a decrease in maternal alcohol consumption during the after-sibling pregnancy.

Incidence and risk factors for stroke in American Indians: the Strong Heart Study

BACKGROUND

There are few published data on the incidence of fatal and nonfatal stroke in American Indians. The aims of this observational study were to determine the incidence of stroke and to elucidate stroke risk factors among American Indians.

METHODS AND RESULTS

This report is based on 4549 participants aged 45 to 74 years at enrollment in the Strong Heart Study, the largest longitudinal, population-based study of cardiovascular disease and its risk factors in a diverse group of American Indians. At baseline examination in 1989 to 1992, 42 participants (age- and sex-adjusted prevalence proportion 1132/100 000, adjusted to the age and sex distribution of the US adult population in 1990) had prevalent stroke. Through December 2004, 306 (6.8%) of 4507 participants without prior stroke suffered a first stroke at a mean age of 66.5 years. The age- and sex-adjusted incidence was 679/100 000 person-years. Nonhemorrhagic cerebral infarction occurred in 86% of participants with incident strokes; 14% had hemorrhagic stroke. The overall age-adjusted 30-day case-fatality rate from first stroke was 18%, with a 1-year case-fatality rate of 32%. Age, diastolic blood pressure, fasting glucose, hemoglobin A(1c,) smoking, albuminuria, hypertension, prehypertension, and diabetes mellitus were risk factors for incident stroke.

CONCLUSIONS

Compared with US white and black populations, American Indians have a higher incidence of stroke. The case-fatality rate for first stroke is also higher in American Indians than in the US white or black population in the same age range. Our findings suggest that blood pressure and glucose control and smoking avoidance may be important avenues for stroke prevention in this population.

Alcohol use, injuries, and prenatal visits during three successive pregnancies among American Indian women on the Northern Plains who have children with fetal alcohol syndrome or incomplete fetal alcohol syndrome

INTRODUCTION

The purpose of the study was to compare three sequential pregnancies of American Indian women who have children with FAS or children with incomplete FAS with women who did not have children with FAS.

METHODS

Two retrospective case-control studies were conducted of Northern Plains American Indian children with fetal alcohol syndrome (FAS) (Study 1) or incomplete FAS (Study 2) in 1981-1993. Three successive pregnancies ending in live births of 43 case mothers who had children with FAS, and 35 case mothers who had children with incomplete FAS were compared to the pregnancies of 86 and 70 control mothers who did not have children with FAS, respectively, in the two studies. Prenatal records were abstracted for the index child (child with FAS or incomplete FAS) and siblings born just before and just after the index child, and comparable prenatal records for the controls.

RESULTS

Compared to the controls, significantly more case mothers used alcohol before and after all three pregnancies and during pregnancy with the before sibling and the index child. Mothers who had children with FAS reduced their alcohol use during the pregnancy following the birth of the index child. All Study 1 case mothers (100%) and 60% of Study 2 case mothers used alcohol during the pregnancy with the index child compared to 20 and 9% of respective control mothers. More study 1 case mothers experienced unintentional injuries (OR 9.50) and intentional injuries during the index pregnancy (OR 9.33) than the control mothers. Most case mothers began prenatal care in the second trimester.

CONCLUSIONS

Alcohol use was documented before, during and after each of the three pregnancies. Women of child-bearing age should be screened for alcohol use whenever they present for medical services. Mothers who had a child with FAS decreased their alcohol consumption with the next pregnancy, a finding that supports the importance of prenatal screening throughout pregnancy. Women who receive medical care for injuries should be screened for alcohol use and referred for appropriate treatment. Protective custody, case management and treatment services need to be readily available for women who use alcohol.

Characteristics of grandmothers who have grandchildren with fetal alcohol syndrome or incomplete fetal alcohol syndrome

INTRODUCTION

Characteristics of Northern Plains American Indian maternal grandmothers who had grandchildren with fetal alcohol syndrome (FAS) or incomplete FAS are described to more effectively prevent fetal FAS and alcohol use during pregnancy.

METHODS

Study 1 had 27 maternal grandmothers who had grandchildren with FAS and Study 2 had 18 grandmothers with grandchildren who had incomplete FAS (cases) which were compared with 119 maternal grandmothers who had grandchildren without FAS (controls). The grandchildren were born between 1981 and 1993 on the Northern Plains. Medical records were manually reviewed for each case and control grandmother. Data were analyzed using Mantel-Haenszel chi square.

RESULTS

Study 1 case grandmothers were more likely to experience medical problems (70.4%) including trauma (48.1%) and injuries (51.9%) than the controls. Most of the Study 1 and 2 case grandmothers (92.6% and 77.8%, respectively) had alcohol use documented in their medical records compared to less than half of the control grandmothers. Seven (15.6%) of the case grandmothers had more than one grandchild in either Study 1 or Study 2.

CONCLUSION

Maternal grandmothers who had grandchildren with FAS had significantly higher rates of alcohol use and alcohol-related medical problems than control grandmothers. Antenatal care providers should screen pregnant women for alcohol use at their first visit. The provider needs to ask the women who are using alcohol about their mothers' use of alcohol to provide appropriate care and counseling for the women and prevent FAS.

The effect of maternal smoking and drinking during pregnancy upon (3)H-nicotine receptor brainstem binding in infants dying of the sudden infant death syndrome: initial observations in a high risk population

The high rate of the sudden infant death syndrome (SIDS) in American Indians in the Northern Plains (3.5/1000) may reflect the high incidence of cigarette smoking and alcohol consumption during pregnancy. Nicotine, a neurotoxic component of cigarettes, and alcohol adversely affect nicotinic receptor binding and subsequent cholinergic development in animals. We measured (3)H-nicotine receptor binding in 16 brainstem nuclei in American Indian SIDS (n = 27) and controls (n = 6). In five nuclei related to cardiorespiratory control, (3)H-nicotinic binding decreased with increasing number of drinks (P < 0.03). There were no differences in binding in SIDS compared with controls, except upon stratification of prenatal exposures. In three mesopontine nuclei critical for arousal there were reductions (P < 0.04) in binding in controls exposed to cigarette smoke compared with controls without exposure; there was no difference between SIDS cases with or without exposure. This study suggests that maternal smoking and alcohol affects (3)H-nicotinic binding in the infant brainstem irrespective of the cause of death. It also suggests that SIDS cases are unable to respond to maternal smoking with the "normal" reduction seen in controls. Future studies are needed to establish the role of adverse prenatal exposures in altered brainstem neurochemistry in SIDS.

Prevalence and Prognostic Significance of Wall-Motion Abnormalities in Adults Without Clinically Recognized Cardiovascular Disease

Background— Left ventricular wall motion (WM) abnormalities have recognized prognostic significance in patients with coronary or other heart diseases; however, whether abnormal WM predicts adverse events in adults without overt cardiovascular disease has not been assessed. Our objective was to determine whether echocardiographic WM abnormalities predict subsequent cardiovascular events in a population-based sample.

Methods and Results— Participants (n=2864, mean age 60±8 years, 64% women) without clinically evident cardiovascular disease in the second Strong Heart Study examination who had complete echocardiographic WM assessment were studied. Echocardiographic assessment revealed that 5% of participants (n=140) had focal hypokinesia, and 1.5% (n=42) had WM abnormalities. Relationships between WM abnormalities and fatal and nonfatal cardiovascular events (including myocardial infarction, stroke, coronary artery disease, and heart failure; n=554) and cardiovascular death (n=182) during 8±2 years follow-up were examined. In Cox regression, after adjustment for age, gender, waist/hip ratio, systolic blood pressure, and diabetes mellitus, segmental WM abnormalities were associated with a 2.5-fold higher risk of cardiovascular events and a 2.6-fold higher risk of cardiovascular death (both P <0.0001). In similar multivariable models, global WM abnormalities were associated with a 2.4-fold higher risk of cardiovascular events ( P =0.001) and a 3.4-fold higher risk of cardiovascular death ( P =0.003).

Conclusions— Echocardiographic left ventricular WM abnormalities in adults without overt cardiovascular disease are associated with 2.4- to 3.4-fold higher risks of cardiovascular morbidity and mortality, independent of established risk factors.

The burden of chronic kidney disease among the Zuni Indians: the Zuni Kidney Project

The Zuni Indians of New Mexico are experiencing an epidemic of chronic kidney disease (CKD). The Zuni Pueblo created the Zuni Kidney Project (ZKP) to decrease the burden of CKD in the community. The aim of this study was to estimate the prevalence of CKD among Zuni Indians using National Kidney Foundation Kidney Disease Outcomes Quality Initiative criteria. The ZKP conducted a population-based, cross-sectional survey to estimate the prevalence of CKD and related risk factors among Zuni Indians aged > or =20 yr (n = 1113). GFR was estimated using equations based on serum creatinine, and urine albumin:creatinine ratio was calculated in a single spot urine sample. ESRD counts were obtained from health care providers. The age- and sex-adjusted prevalence of CKD among the Zuni Indians was >2.5-fold higher than that among the US composite population. The estimated prevalence of CKD stages 1 and 2 combined was three- to four-fold higher than that of CKD stages 3 and 4 combined. This ratio was significantly higher than that in the US composite population (1.4-fold). The prevalence of CKD stage 5 was eight-fold higher among the Zuni Indians than among the composite US population. The Zuni Indians have an expanded pool of CKD that contributes to the high burden of ESRD. The high prevalence of CKD stages 1 and 2 provides a unique opportunity to develop innovative treatment programs to reduce the burden of CKD in Zuni Pueblo.

Asthma in American Indian adults: the Strong Heart Study

BACKGROUND

Despite growing recognition that asthma is an important cause of morbidity among American Indians, there has been no systematic study of this disease in older adults who are likely to be at high risk of complications related to asthma. Characterization of the impact of asthma among American Indian adults is necessary in order to design appropriate clinical and preventive measures.

METHODS

A sample of participants in the third examination of the Strong Heart Study, a multicenter, population-based, prospective study of cardiovascular disease in American Indians, completed a standardized respiratory questionnaire, performed spirometry, and underwent allergen skin testing. Participants were > or = 50 years old.

RESULTS

Of 3,197 participants in the third examination, 6.3% had physician-diagnosed asthma and 4.3% had probable asthma. Women had a higher prevalence of physician-diagnosed asthma than men (8.2% vs 3.2%). Of the 435 participants reported in the asthma substudy, morbidity related to asthma was high: among those with physician-diagnosed asthma: 97% reported trouble breathing and 52% had severe persistent disease. The mean FEV(1) in those with physician-diagnosed asthma was 61.3% of predicted, and 67.2% reported a history of emergency department visits and/or hospitalizations in the last year, yet only 3% were receiving regular inhaled corticosteroids.

CONCLUSIONS

The prevalence of asthma among older American Indians residing in three separate geographic areas of the United States was similar to rates in other ethnic groups. Asthma was associated with low lung function, significant morbidity and health-care utilization, yet medications for pulmonary disease were underutilized by this population.

Aging and the prevalence of cardiovascular disease risk factors in older American Indians: the Strong Heart Study

OBJECTIVES

To describe longitudinal changes in the prevalence of major cardiovascular disease (CVD) risk factors in aging American Indians.

DESIGN

Population-based ongoing epidemiological study.

SETTING

The Strong Heart Study is a study of CVD and its risk factors. Standardized examinations were repeated in 1993 to 1995 and again in 1997 to 1999.

PARTICIPANTS

A diverse cohort of 4,549 American Indians aged 45 to 74 at the initial examinations in 1989 to 1991.

MEASUREMENTS

Changes in the prevalence of hypertension, low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), current smoking, and type 2 diabetes mellitus.

RESULTS

The prevalence of hypertension rose rapidly and steadily with aging. A nonsignificant decrease in LDL-C was seen in men, and men and women initially had rapid increases in the prevalence of low HDL-C. The prevalence of smoking decreased, but the prevalence of diabetes mellitus continued to rise for men and women.

CONCLUSION

Overall, unfavorable changes in CVD risk factors were seen in the aging participants and will likely be reflected in worsening morbidity and mortality.

Gender differences in left ventricular systolic function in American Indians (from the Strong Heart Study)

Data from population-based studies indicate that men have a higher incidence and worse prognoses of congestive heart failure than women. Echocardiography was used to compare left ventricular (LV) myocardial and chamber contractility between 490 male and 861 female American Indian participants in the second Strong Heart Study examination. After adjusting for fat-free mass, baseline hypertension, diabetes mellitus, coronary heart disease, and alcohol consumption, LV ejection fractions were higher in women than men (66 +/- 8% vs 63 +/- 9%, p = 0.002), as were stress-corrected mid-wall shortening (106 +/- 13% vs 104+/-15%, p = 0.006) and the circumferential end-systolic stress/end-systolic volume index (7.1 x 10(4) +/- 1.9 x 10(4) vs 6.5 x 10(4) +/- 2.1 x 10(4) kdyne/cm3, all p values <0.001). LV ejection fractions were less than the predefined partition value in 4.7% of women and in 16.7% of men (odds ratio 0.25, 95% confidence interval 0.18 to 0.34, p <0.001). Stress-corrected mid-wall shortening was less than the predetermined lower limit of normal in 2.9% of women and in 6.2% of men (odds ratio 0.45, 95% confidence interval 0.29 to 0.70, p <0.001). There was no significant gender difference in supranormal function by either measure of LV systolic function. Estimated mean independent effects of female gender were a 3% greater ejection fraction, 2.7% greater stress-corrected mid-wall shortening, and a 0.4 x 10(4) kdyne/cm3 greater circumferential end-systolic stress/end-systolic volume index. In conclusion, in a population-based sample aged 45 to 74 years, women had greater LV myocardial and chamber function than men. Gender-specific partition values for measures of LV systolic function may be necessary to detect abnormal contractility in clinical and epidemiologic studies.

Characteristics of fathers who have children with fetal alcohol syndrome or incomplete fetal alcohol syndrome

OBJECTIVES

Determine alcohol use, referrals to treatment, receiving treatment, and medical problems related to alcohol among fathers who have children with FAS or incomplete FAS.

METHODS

Fathers who had American Indian children with FAS (Study 1) or incomplete FAS (Study 2) were compared with fathers whose children did not have FAS.

RESULTS

About half of case and control fathers had alcohol use and alcohol-related medical problems documented in their medical records. Case fathers were more likely to receive alcohol treatment and have injuries related to alcohol abuse.

CONCLUSION

Significantly more fathers of children with FAS were referred for alcohol treatment, received alcohol treatment, experienced injuries, and had delirium tremens than control fathers. Fathers of children with incomplete FAS were significantly more likely to drink alcohol, to have received alcohol treatment, and to have alcohol-related medical problems and injuries than control fathers.

Prediction of coronary heart disease in a population with high prevalence of diabetes and albuminuria: the Strong Heart Study

BACKGROUND

The present article presents equations for the prediction of coronary heart disease (CHD) in a population with high rates of diabetes and albuminuria, derived from data collected in the Strong Heart Study, a longitudinal study of cardiovascular disease in 13 American Indian tribes and communities in Arizona, North and South Dakota, and Oklahoma.

METHODS AND RESULTS

Participants of the Strong Heart Study were examined initially in 1989-1991 and were monitored with additional examinations and mortality and morbidity surveillance. CHD outcome data through December 2001 showed that age, gender, total cholesterol, low-density lipoprotein (LDL) cholesterol, high-density lipoprotein cholesterol, smoking, diabetes, hypertension, and albuminuria were significant CHD risk factors. Hazard ratios for ages 65 to 75 years, hypertension, LDL cholesterol > or = 160 mg/dL, diabetes, and macroalbuminuria were 2.58, 2.01, 2.44, 1.66, and 2.11 in men and 2.03, 1.69, 2.17, 2.26, and 2.69 in women, compared with ages 45 to 54 years, normal blood pressure, LDL cholesterol <100 mg/dL, no diabetes, and no albuminuria. Prediction equations for CHD and a risk calculator were derived by gender with the use of Cox proportional hazards model and the significant risk factors. The equations provided good discrimination ability, as indicated by a c statistic of 0.70 for men and 0.73 for women. Results from bootstrapping methods indicated good internal validation and calibration.

CONCLUSIONS

A "risk calculator" has been developed and placed on the Strong Heart Study Web site, which provides predicted risk of CHD in 10 years with input of these risk factors. This may be valuable for diverse populations with high rates of diabetes and albuminuria.

A Longitudinal Study of Hypertension Risk Factors and Their Relation to Cardiovascular Disease

This study estimated hypertension incidence and explored hypertension risk factors and their association with cardiovascular disease. Data collected from 4549 American Indian participants in the 3 exams of the Strong Heart Study were used. Hypertension was defined as systolic blood pressure ≥140 mm Hg, diastolic blood pressure ≥90 mm Hg, or current use of antihypertensive medication. Generalized linear models were used to identify the risk factors for hypertension and the correlates of blood pressures. Cox proportional models with time-dependent covariates and the mixed models were used to explore the association of hypertension with cardiovascular disease. There was no sex difference in hypertension. After adjustment for other risk factors, the risks of developing hypertension among subgroups in each characterized group were as follows: prehypertensive versus normotensive, 3.21 times; macroalbuminuria and microalbuminuria versus normal, 3.47 and 1.72; diabetic versus nondiabetic, 1.56; overweight and obese versus normal weight, 1.30 and 1.51; and current alcohol drinking versus not, 1.22. Moreover, systolic blood pressure was significantly and positively associated with age, obesity, and albuminuria and negatively with smoking. After adjusting all other risk factors, those pretreated, untreated, controlled, and uncontrolled hypertensive participants had &1.74, 1.81, 2.19, and 2.77 times higher risks of developing cardiovascular disease compared with normotensive participants, respectively. In 45- to 74-year-old American Indians, the risk of developing hypertension was rising. Prehypertensive participants had 3.2/1.74 times higher risk of developing hypertension/cardiovascular disease than normotensive participants. Age, diabetes, and macro/microalbuminuria were independently significant risk factors of both hypertension and cardiovascular disease.

Different factor loadings for SF36: The Strong Heart Study and the National Survey of Functional Health Status

BACKGROUND

To increase our understanding of the psychometric characteristics and factor structure of the SF36 in older American Indian populations.

METHODS

Between 1993 and 1995, SF36 data were collected from 3,488 Phase II participants of the Strong Heart Study (SHS) between the ages of 48 and 81. Comparison data were provided by an age- and gender-matched sample (n = 695) from the National Survey of Functional Health Status (NSFHS) conducted in 1989 and 1990.

RESULTS

Generally, the basic psychometric analyses showed that the SF36 performed adequately in these older American Indians. Exploratory factor analyses indicated that a one-factor model best fit the data for both older groups. On the other hand, confirmatory factor analyses showed that a two-factor model with correlated factors provided a superior fit to the data than a one-factor model. An assumption of equivalent factor loadings for the SHS and NSFHS groups was untenable.

CONCLUSION

These analyses demonstrate that use of summary scores assuming a differentiated physical/mental functioning structure is likely improper in at least some populations. The SF36 provides an important opportunity to understand cultural differences in the conceptualization and measurement of health-related quality of life.

Cardiovascular disease risk factor awareness in American Indian communities: the strong heart study

OBJECTIVE

To use data from the longitudinal Strong Heart Study (SHS) to determine the level of awareness about risk factors for heart disease among 13 populations of American Indians in Arizona, Oklahoma, and South/ North Dakota. The aim of this study is to assess awareness of nine major risk factors for heart disease among participants in SHS.

METHODS

During July 1993 to December 1995 (phase II of SHS), 3638 participants ages 46 to 80 years (mean age 60) were asked if nine known risk factors for cardiovascular disease affect a person's chances of getting heart disease; 3226 (89%) participants completed the study and met the method reliability criteria for inclusion.

RESULTS

Among each of the nine risk factors, the percentage of correct answers provided by study participants ranged from 70% (family history of heart disease) to 90% (being very overweight). Participants with hypertension (90% vs 86%, P<.05) and diabetes mellitus (81% vs 71%, P<.05) were more likely than those without these disorders to know they were heart disease risk factors. For all nine risk factors, the percentage of correct answers was lower (P<.05) among smokers than among nonsmokers. In multivariate logistic regression analyses, female sex, advanced education, and being from Oklahoma were significantly associated with heart disease awareness.

CONCLUSION

Although overall risk factor awareness for heart disease was high, subgroups were identified who could benefit from culturally appropriate health education and other interventions to motivate health prevention actions, especially for smoking.

Risk factors for arterial hypertension in adults with initial optimal blood pressure: the Strong Heart Study

Whether metabolic factors and their change over time influence development of arterial hypertension in adults with initially optimal blood pressure (BP) is unknown. We analyzed associations of BP in the optimal range (<120/80 mm Hg), metabolic risk factors, and their changes over 4-year follow-up, with 8-year incident hypertension, in a cohort of American Indians with a high prevalence of obesity. At baseline, 967 participants with optimal BP and no prevalent cardiovascular disease (69.5% women; mean age, 54+/-7 years) were evaluated and reexamined after 4 (second examination) and 8 years to evaluate predictors of 8-year incident arterial hypertension. In participants with normal glucose tolerance, baseline BP and decrease in high-density lipoprotein cholesterol from baseline to the second examination were the most potent predictors of 8-year arterial hypertension (both P<0.0001), with additional effects of baseline waist circumference and its increase, increase in BP, and presence of diabetes at the second examination (all P<0.04). In participants with impaired glucose tolerance or diabetes, the most potent predictor of 8-year incident hypertension was diabetes at the second examination (P<0.0001) followed by a increase in BP and LDL cholesterol over the first 4 years (both P<0.001). Thus, incident arterial hypertension can be predicted by initial metabolic profile and unfavorable metabolic variations over time, in addition to initial BP. At optimal levels of initial BP, increasing abdominal obesity, and abnormal lipid profile are major predictors of development of arterial hypertension. Possible implications of these findings for primary cardiovascular prevention should be tested in prospective studies.

Mitral Annular Calcification, Aortic Valve Sclerosis, and Incident Stroke in Adults Free of Clinical Cardiovascular Disease

Background and Purpose— Mitral annular calcification (MAC) and aortic valve (AV) sclerosis have each been linked to cardiovascular disease. Whether MAC and AV sclerosis are risk factors for stroke independent of other echocardiographic or laboratory predictors has not been established. We evaluated the relationship between MAC, AV sclerosis, and first stroke events in a population-based cohort.

Methods— Our study cohort consisted of 2723 American Indians participating in the Strong Heart Study who were free of prevalent cardiovascular disease. Participants underwent standardized clinical, echocardiographic, and laboratory evaluation, and incident stroke was ascertained using validated methods.

Results— During a median follow-up of 7 years, 86 strokes occurred. Age- and sex-adjusted incidence rates of stroke were significantly increased for MAC (rate ratio [RR], 3.12; 95% CI, 1.77 to 5.25) but not for AV sclerosis (RR, 1.15; 95% CI, 0.45 to 2.49). MAC was also associated with a reduced time to first stroke events after adjustment for clinical variables and the inflammatory markers C-reactive protein and fibrinogen (hazard ratio [HR], 2.42; 95% CI, 1.39 to 4.21) or the echocardiographic covariates left ventricular hypertrophy and left atrial enlargement (HR, 1.89; 95% CI, 1.04 to 3.41). Individuals with and without AV sclerosis showed no significant difference in stroke-free survival in unadjusted analyses ( P =0.698). Crossing of the survival curves precluded multivariable analysis using Cox models.

Conclusions— In this cohort of American Indians without clinical cardiovascular disease, the presence of MAC, but not AV sclerosis, proved to be a strong risk factor for incident stroke after extensive adjustment for other predictors. Individuals exhibiting MAC may benefit from aggressive risk factor modification, but this will require further investigation.

Integrating Prevention of Mother-to-Child HIV Transmission Into Routine Antenatal Care

With funds from Elizabeth Glaser Pediatric AIDS Foundation, the Cameroon Baptist Convention Health Board implemented a program to prevent mother-to-child transmission of HIV-1 (PMTCT) as part of its routine antenatal care, with single-dose maternal and infant peripartum nevirapine (NVP) prophylaxis of HIV-positive mothers and their babies. Nurses, midwives, nurse aides, and trained birth attendants counseled pregnant women, obtained risk factor data, and offered free HIV testing with same-day results. From February 2000 through December 2004, this program rapidly expanded to 115 facilities in 6 of Cameroon's 10 provinces, not only to large hospitals but to remote health centers staffed by trained birth attendants. We trained 690 health workers in PMTCT and counseled 68,635 women, 91.9% of whom accepted HIV testing. Of 63,094 women tested, 8.7% were HIV-1-positive. Independent risk factors for HIV-1 infection included young age at first sexual intercourse, multiple sex partners, and positive syphilis serology (P < 0.001 for each). We counseled 98.7% of positive and negative mothers on a posttest basis. Of 5550 HIV-positive mothers, we counseled 5433 (97.9%) on single-dose NVP prophylaxis. Consistent training and programmatic support contributed to rapid upscaling and high uptake and counseling rates.

Kidney disease among the Zuni Indians: The Zuni Kidney Project

BACKGROUND

There is an epidemic of kidney disease among the Zuni Indians. In collaboration with health care providers and research institutions, the Zuni Pueblo established the Zuni Kidney Project to reduce the burden of kidney disease.

METHODS

The Zuni Kidney Project conducted a population-based, cross-sectional survey to estimate the prevalence of albuminuria, hematuria, and related risk factors. Neighborhood household clusters served as the sampling frame. Participants completed a questionnaire, donated blood and urine samples, and had blood pressure, height, and weight measured. This survey provided the foundation for ongoing studies to identify genetic and environmental risk factors for disease susceptibility and progression.

RESULTS

Age and gender distributions among survey participants were similar to those in the eligible Zuni population. Prevalence of incipient albuminuria (IA) (0.03< or = urine albumin:creatinine ratio, UACR <0.3) and overt albuminuria (OA) (UACR < 0.3) were higher among diabetics [IA 34.3% (28.3, 40.4%); OA 18.6% (13.7, 23.6%)] than nondiabetics [IA 11.1% (9.3, 12.8%); OA 1.7% (1.0, 2.5%)]. Nondiabetics comprised 58.6% (52.2, 65.0%) and 30.9% (19.9, 41.9%) of participants with IA and OA, respectively. The prevalence of hematuria was higher among diabetics [> or = trace 47.0% (40.7, 53.4); > or =50 red blood cell/microL 25.8% (20.3, 31.4%)] than nondiabetics [> or = trace 31.1% (28.5, 33.7%); > or =50 red blood cell/microL 16.6% (14.5, 18.7%)]. Hypertension was associated with albuminuria among diabetic and nondiabetic participants. Hypercholesterolemia was associated with albuminuria among nondiabetic participants. Diabetes and alcohol use were associated with hematuria.

CONCLUSION

The high prevalences of albuminuria among nondiabetics and of hematuria among diabetics and nondiabetics are consistent with high rates of nondiabetic kidney disease among Zuni Indians with and without diabetes.

Association of Blood Pressure With Blood Viscosity in American Indians

Abnormalities in whole blood viscosity (WBV) have been implicated in hypertension. This study analyzes relations between WBV and blood pressure in the Strong Heart Study population of American Indians. We examined 676 participants (489 women, age 62±7 years) without prevalent cardiovascular disease or use of antihypertensive medications, digoxin, or aspirin. WBV was calculated from hematocrit and plasma protein concentration, at a shear rate of 208 seconds −1 , by a validated equation. Forty eight percent of participants were obese, 43% had diabetes, 19% had hypertension, and 30% were current smokers. WBV was higher in men, smokers, and participants with central obesity, but it was not associated with hypertension or diabetes, even accounting for confounders. After adjusting for gender, age, center, smoking, obesity, diabetes, and plasma creatinine, WBV was negatively related to pulse pressure (β=−0.13; P <0.001) and systolic pressure (β=−0.09; P <0.02), mainly because of negative relations with hematocrit (β=−0.11 and −0.10). Among hypertensive individuals, pulse pressure was positively related to age, diabetes, and female gender but not to WBV (multiple R =0.63; P <0.0001); in contrast, in normotensive individuals, pulse pressure was related negatively to WBV or hematocrit, independent of body mass index, without relation to diabetes ( R =0.42; P <0.0001). Thus, under normal physiological conditions, in vivo WBV is negatively related pulse pressure. In contrast, the presence of arterial hypertension makes this relation less evident.

Characteristics of children who have full or incomplete fetal alcohol syndrome

OBJECTIVE

To describe the clinical features and hospitalization rates of American Indian children with full or incomplete fetal alcohol syndrome (FAS).

STUDY DESIGN

Two retrospective case-control studies were conducted of Northern Plains American Indian children with presumed FAS identified from 1981 to 1993 by using the International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM), code 760.71. Children who had full or incomplete FAS were compared with each other and with children who did not have FAS.

RESULTS

Compared with the control children, the 43 children with FAS and the 35 children with incomplete FAS had more facial dysmorphology, growth deficiency, central nervous system dysfunction, and muscular problems and were hospitalized more frequently with otitis media, pneumonia, FAS, dehydration, and anemia. Case children were hospitalized more days than were control children. Case children were removed from their homes and placed in foster care more often than were control children.

CONCLUSIONS

Children with full or incomplete FAS had many health, learning, and social needs. Health care providers and community programs should identify the needs of these children and offer optimal services to meet those needs.

Incidence of lower-extremity amputation in American Indians: the Strong Heart Study

OBJECTIVE

To define incidence and predictors of nontraumatic lower-extremity amputation (LEA) in a diverse cohort of American Indians with diabetes.

RESEARCH DESIGN AND METHODS

The Strong Heart Study is a study of cardiovascular disease and its risk factors in 13 American-Indian communities. Data on the presence/absence of amputations were collected at each of three serial examinations (1989-1992, 1993-1995, and 1997-1999) by direct examination of the lower extremity. The logistic regression model was used to quantify the relationship between risk of LEA and potential risk factors, including diabetes duration, HbA(1c), peripheral arterial disease, and renal function.

RESULTS

Of the 1,974 individuals with diabetes and without prevalent LEA at baseline, 87 (4.4%) experienced an LEA during 8 years of follow-up, and a total of 157 anatomical sites were amputated among these individuals. Amputation of toes was most common, followed by below-the-knee and above-the-knee amputations. Age-adjusted odds of LEA were higher among individuals with unfavorable combinations of risk factors, such as albuminuria and elevated HbA(1c). Multivariable modeling indicated that male sex, renal dysfunction, high ankle-brachial index, longer duration of diabetes, less than a high school education, increasing systolic blood pressure, and HbA(1c) predicted LEA risk.

CONCLUSIONS

The 8-year cumulative incidence of LEA in American Indians with diabetes is 4.4%, with marked differences in risk by sex, educational attainment, renal function, and glycemic control.

Relation of lower-extremity amputation to all-cause and cardiovascular disease mortality in American Indians: the Strong Heart Study

OBJECTIVE

To compare risk of all-cause and cardiovascular disease (CVD) mortality in people with a lower-extremity amputation (LEA) attributable to diabetes and people without an LEA.

RESEARCH DESIGN AND METHODS

The Strong Heart Study is a study of CVD and its risk factors in 13 American-Indian communities. LEA was ascertained at baseline by direct examination of the legs and feet. Mortality surveillance is complete through 2000.

RESULTS

Of 2,108 participants with diabetes at baseline, 134 participants (6.4%) had an LEA. Abnormal ankle-brachial index (53%), albuminuria (87%), and long diabetes duration (mean 19.8 years) were common among diabetic subjects with LEA. Mean diabetes duration among diabetic participants without LEA and in those with toe and below-the-knee amputations was 11.9, 18.6, and 21.1 years, respectively. During 8.7 (+/-2.9) years of follow-up, 102 of the participants with LEA (76%) died from all causes and 35 (26%) died from CVD. Of the 1,974 diabetic participants without LEA at baseline, 604 (31%) died from all causes and 206 (10%) died from CVD. The unadjusted hazard ratios (HRs) for all-cause and CVD mortality in diabetic participants with LEA compared with those without were 4.0 and 4.1, respectively. Adjusting for known and suspected confounders, LEA persisted as a predictor of all-cause (HR 2.2, 95% CI 1.7-2.9) and CVD mortality (HR 1.9, 95% CI 1.3-2.9). We observed a significant interaction between baseline LEA and sex on CVD mortality, with female sex conferring added risk of CVD mortality.

CONCLUSIONS

LEA is a potent predictor of all-cause and CVD mortality in diabetic American Indians. The combination of female sex and LEA is associated with greater risk of CVD mortality than either factor alone.

Effect of maternal antibody on immunogenicity of hepatitis A vaccine in infants

OBJECTIVE

To determine the effect of maternal antibody on hepatitis A vaccine immunogenicity in infants. Study design Infants of mothers negative for antibody to hepatitis A virus (anti-HAV; group 1) were administered hepatitis A vaccine at 2, 4, and 6 months of age, and infants of anti-HAV-positive mothers were randomized to receive either hepatitis A vaccine (group 2) or hepatitis B vaccine (group 3) on the same schedule. Group 3 infants subsequently received hepatitis A vaccine at 8 and 10 months of age.

RESULTS

At 15 months of age, 100% of infants in group 1, 93% in group 2, and 92% in group 3 had protective levels of antibody. However, there were significant differences in the geometric mean concentration (GMC) of anti-HAV between groups. Group 1 GMC was 231 mIU/mL, compared with 85 mIU/mL for group 2 and 84 mIU/mL for group 3 (P<.001, group 1 vs group 3).

CONCLUSIONS

Passively acquired maternal anti-HAV resulted in a significantly lower final antibody response when infants were administered hepatitis A vaccine at 2, 4, and 6 months of age or at 8 and 10 months of age.

Associations of Postmenopausal Hormone Therapy with Markers of Hemostasis and Inflammation and Lipid Profiles in Diabetic and Nondiabetic American Indian Women: The Strong Heart Study

OBJECTIVES

To examine the associations of postmenopausal hormone therapy (PHT) with indicators of hemostasis and inflammation and with lipid profiles in American Indian women and to determine if diabetes modifies these associations.

METHODS

This report is a cross-sectional analysis of data from 1446 postmenopausal women who were free from cardiovascular disease (CVD) at the second Strong Heart Study examination (1993-1995). Diabetes was diagnosed by WHO criteria. Postmenopausal hormone use was ascertained by review of the medications brought to the examination or by medical record review. Lipoproteins, plasminogen activator inhibitor type 1 (PAI-1), fibrinogen, and C-reactive protein (CRP) were measured in fasting plasma samples.

RESULTS

Among nondiabetic women, current PHT users had lower mean fibrinogen, PAI1, and low-density lipoprotein cholesterol (LDLC) levels than those in never users (38.4 mg/dl, 8.68 ng/ml, and 14.16 mg/dl lower, respectively) but higher CRP and triglyceride levels (1.53 mg/l and 31.43 mg/dl higher, respectively). Multivariate adjustment did not alter any of these associations. In diabetic women, current PHT use was associated only with lower PAI-1 (5.48 ng/ml lower) and higher high-density lipoprotein cholesterol (HDLC) levels (3.33 mg/dl higher) compared with never users.

CONCLUSIONS

In American Indian women without diabetes, PHT was associated with lower levels of hemostatic markers but higher levels of an inflammatory marker. Associations were less marked in women with diabetes. The relation of PHT with lipid profiles also differed in nondiabetic and diabetic women. These data provide an additional rationale for considering diabetes status when deciding whether or not to use PHT.

Serotonergic brainstem abnormalities in Northern Plains Indians with the sudden infant death syndrome

The rate of the sudden infant death syndrome (SIDS) among American Indian infants in the Northern Plains is almost 6 times higher than in U.S. white infants. In a study of infant mortality among Northern Plains Indians, we tested the hypothesis that receptor binding abnormalities to the neurotransmitter serotonin (5-HT) in SIDS cases, compared with autopsied controls, occur in regions of the medulla oblongata that contain 5-HT neurons and that are critical for the regulation of cardiorespiration and central chemosensitivity during sleep, i.e. the medullary 5-HT system. Tritiated-lysergic acid diethylamide binding to 5-HT(1A-D) and 5-HT2 receptors was measured in 19 brainstem nuclei in 23 SIDS and 6 control infants using tissue receptor autoradiography. Binding in the arcuate nucleus, a part of the medullary 5-HT system along the ventral surface, in the SIDS infants (mean age-adjusted binding 7.1 +/- 0.8 fmol/mg tissue, n = 23) was significantly lower than in controls (mean age-adjusted binding 13.1 +/- 1.6 fmol/mg tissue, n = 5) (p = 0.003). Binding also demonstrated significant diagnosis x age interactions (p < 0.04) in 4 other nuclei that are components of the 5-HT system. These data suggest that medullary 5-HT dysfunction can lead to sleep-related, sudden death in affected SIDS infants, and confirm the same binding abnormalities reported by us in a larger dataset of non-American Indian SIDS and control infants. This study also links 5-HT abnormalities in the arcuate nucleus with exposure to adverse prenatal exposures, i.e. cigarette smoking (p = 0.011) and alcohol (p = 0.075), during the periconceptional period or throughout pregnancy. Prenatal exposure to cigarette smoke and/or alcohol may contribute to abnormal fetal medullary 5-HT development in SIDS infants.

Smoking cessation and its determinants among older American Indians: the Strong Heart Study

OBJECTIVE

To examine the relationship between sociodemographic, clinical, and smoking history factors, and smoking cessation among older American Indians.

DESIGN

Nested cohort study of cigarette smokers in the Strong Heart Study, a longitudinal study of cardiovascular disease among American Indians.

SETTING

Thirteen American Indian tribes from Arizona, Oklahoma, and North and South Dakota.

PARTICIPANTS

American Indian men and women (N = 998), aged 45-74 years, who identified themselves as smokers at the initial Strong Heart Study examination.

MEASUREMENTS AND MAIN RESULTS

Twenty-one percent of smokers quit during the 4-year follow-up period. Multivariate logistic regression was used to assess the relationship between baseline sociodemographic, clinical, and smoking history factors, and smoking cessation. Factors associated with smoking cessation included being 65-74 years old (odds ratio [OR] 2.1; 95% confidence interval [CI], 1.3 to 3.3), being examined at the Arizona regional center (OR 2.2; 95% CI 1.3, 3.7), being non-daily smokers (OR 5.4; 95% CI 1.3, 18.5), smoking fewer than 6 cigarettes daily (OR 2.8; 95% CI 1.3, 4.7), being a smoker for fewer years(OR 2.0; 95% CI 1.0, 3.9), beginning to smoke at an older age (17 years or older, OR 1.6; 95% CI 1.1, 2.4), and having a history of diabetes (OR 1.7; 95% CI 1.2, 2.3). Factors not associated with smoking cessation included gender, level of education, childhood exposure to tobacco smoking, and a history of cardiovascular diseases, cancer, or respiratory diseases.

CONCLUSION

Several determinants of smoking cessation among older American Indians identified in this study may have important implications for designing appropriate interventions for this special population.

Characteristics of mothers who have children with fetal alcohol syndrome or some characteristics of fetal alcohol syndrome

BACKGROUND

Health care providers can more effectively prevent fetal alcohol syndrome and prenatal alcohol exposure if they know more about mothers who have children with fetal alcohol syndrome (FAS) or some characteristics of FAS.

METHODS

We conducted two retrospective case-control studies of Northern Plains Indian children with FAS and some characteristics of FAS diagnosed from 1981 to 1993 by using the International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM), code 760.71. We compared mothers who had children with FAS or some characteristics of FAS with mothers who had children that did not have FAS.

RESULTS

Compared with control mothers, 43 mothers who had children with FAS and 35 mothers who had children with some characteristics of FAS were older, had fewer prenatal visits, more pregnancies, more mental health problems, and more injuries (both total and alcohol-related). Although the prevalence of drinking was high in both case and control mothers, case mothers had more alcohol-related medical problems, drank heavily, in binges, and daily more often than control mothers.

CONCLUSIONS

Women with injuries and mental health problems should be screened for substance use. Mothers of children with FAS or of some characteristics of FAS have numerous needs that must be addressed to prevent future prenatal alcohol exposure.

The Zuni kidney project: a collaborative approach to an epidemic of kidney disease

There is an epidemic of renal disease among the Zuni Indians. In contrast to most other American-Indian communities, the epidemic of renal disease among the Zuni Indians reflects high rates of diabetic and nondiabetic renal disease. Almost every Zuni Indian has a relative with end-stage renal disease. This epidemic offers a unique opportunity to advance our understanding of the risk factors for the susceptibility and/or progression of renal disease. Thus, Zuni Tribal leaders formed a research partnership with the University of New Mexico Health Sciences Center, Indian Health Service, Southwest Foundation for Biomedical Research and Dialysis Clinic Inc., to establish the Zuni Kidney Project (ZKP). The ZKP conducted a population-based, cross-sectional survey of the Zuni Pueblo. Age and gender distributions among survey participants were similar to those of the eligible Zuni population. Among diabetics the prevalence (95% confidence interval) of incipient albuminuria (IA) was 32.3% (25.1, 39.5) in women and 36.1% (24.7, 47.5) in men. The prevalence of IA among nondiabetics was 9.3% (6.9, 11.7) in women and 12.2% (9.7, 14.7) in men. Among diabetics, the prevalence of overt albuminuria (OA) was 17.7% (11.9, 23.5) in women and 20.8% (11.4, 30.2) in men. Among nondiabetics, OA was present in 1.2% (0.3, 2.1) of women and 2.3% (1.1, 3.5) of men. Although IA and OA were each more common among diabetics, the majority of participants with albuminuria were nondiabetics. Hematuria was common among both diabetics and nondiabetics. Among diabetics, the crude prevalence of hematuria was similar among men and women. Among nondiabetics, however, hematuria was more common among women. Diabetes and obesity were more common among women than men. In contrast, hypertension and hypercholesterolemia were more common among men than women. The ZKP is incorporating these preliminary data into planning for the development and implementation of primary and secondary prevention programs.

Association of albuminuria with systolic and diastolic left ventricular dysfunction in type 2 diabetes: the Strong Heart Study

OBJECTIVES

We sought to compare systolic and diastolic function in American Indians with diabetes mellitus (DM) based on albuminuria status.

BACKGROUND

Albuminuria has been shown to predict cardiovascular disease (CVD) in populations with DM. However, the mechanism of the association of albuminuria and CVD is unclear.

METHODS

We compared echo-derived indices of left ventricular (LV) systolic and diastolic function in three groups of American Indians with DM based on albuminuria status: I = no albuminuria (<30 mg albumin/g creatinine); II = microalbuminuria (30 to 300 mg/g); and III = macroalbuminuria (>300 mg/g).

RESULTS

Group II and III were slightly older than Group I with no significant gender difference between groups. Systolic blood pressure increased and body mass index decreased from Group I to Group III. Left ventricular systolic function was lower in the groups with albuminuria with step-wise decreases in ejection fraction and stress-corrected midwall shortening (MWS) from Group I to Group III. Similar findings were noted in diastolic LV filling with lower mitral E/A ratios and longer deceleration times in groups with albuminuria. The proportion of participants with abnormal MWS and abnormal LV diastolic relaxation showed step-wise increases from no albuminuria to macroalbuminuria. In multivariate analysis, albuminuria status remained independently associated with both systolic and diastolic dysfunction after adjusting for age, gender, body mass index, systolic blood pressure, duration of diabetes, coronary artery disease, and LV mass.

CONCLUSIONS

Albuminuria is independently associated with LV systolic and diastolic dysfunction in type 2 DM; this may explain in part the relationship of albuminuria to increased cardiovascular (CV) events in the DM population. Screening for albuminuria identifies individuals with high CV risk and possible cardiac dysfunction.

Relation of insulin resistance to markers of preclinical cardiovascular disease: the Strong Heart Study

BACKGROUND AND AIMS

To investigate whether insulin-resistance influences echocardiographic markers of preclinical disease, independent of significant confounders.

METHODS AND RESULTS

We examined 1,471 (59 +/- 8 years) non-diabetic individuals (WHO criteria) with available echocardiograms from the Strong Heart Study cohort. Among them, 530 subjects had arterial hypertension (62% on medications), 152 had impaired glucose tolerance (GT) and 460 were normotensive, non-obese with normal GT. Insulin resistance was estimated by the Homeostasis Model Assessment (HOMA). LV mass, systolic function measured at the endocardium and the midwall (also correcting for circumferential wall stress) and arterial compliance (stroke volume/pulse pressure as a percent of predicted from body weight, age and heart rate [delta %SV/PP]) were measured by echocardiography, as prognostically validated markers of preclinical disease. HOMA-index was related positively to body mass index (BMI), waist/hip ratio (WHR), blood pressure, left ventricular (LV) mass, and negatively to arterial compliance (all p < 0.005) in the whole population, as well as in separate normotensive or hypertensive groups. In multiple regression models, relation of HOMA-index with the markers of risk was adjusted for age, sex, WHR, body mass index, presence of hypertension and number of antihypertensive medications. In this analysis, neither LV mass nor indices of systolic function were independently related to HOMA-index. In contrast, HOMA-index maintained a significant negative association with delta %SV/PP, independent of demographics, hypertension, treatment and body fat distribution. Also, HOMA-index maintained an independent relation with LV mass, when WHR and BMI were not included in the regression model.

CONCLUSIONS

After accounting for relevant biological covariates, including body mass and fat distribution, insulin-resistance measured by HOMA is not an independent correlate of LV mass and function, but negatively influences arterial compliance.

Prevalence of hematuria among Zuni Indians with and without diabetes: The Zuni kidney Project

BACKGROUND

There is an epidemic of kidney disease among the Zuni Indians. In contrast to other American Indian tribes, the epidemic among the Zuni Indians is attributable to diabetic and nondiabetic renal disease.

METHODS

The Zuni Kidney Project, established to reduce the burden of renal disease, conducted a population-based cross-sectional survey of Zuni Indians aged 5 years or older to precisely estimate the prevalence of hematuria. The survey used neighborhood household clusters as the sampling frame to maximize ascertainment and minimize bias. During the survey, we administered a questionnaire; collected blood and urine samples; and measured blood pressure, height, and weight.

RESULTS

Age and sex distributions in our sample (n = 1,469) were similar to those of the eligible Zuni population (n = 9,228). Prevalences of hematuria, defined as dipstick of trace or greater and 50 red blood cells/microL or greater, age- and sex-adjusted to the Zuni population aged 5 years or older, were 33.2% (95% confidence interval [CI], 30.7 to 35.6) and 17.8% (95% CI, 15.8 to 19.8), respectively. Hematuria of trace or greater was more common among females (40.6%; 95% CI, 37.0 to 44.1) than males (25.1%; 95% CI, 21.8 to 28.4). Hematuria of trace or greater was common among Zuni Indians without diabetes (females, 39.7%; 95% CI, 35.7 to 43.8; males, 22.7%; 95% CI, 19.4 to 26.1) and with diabetes (females, 47.5%; 95% CI, 39.8 to 55.2; males, 45.8%; 95% CI, 34.3 to 57.3). Diabetes and alcohol use for greater than 10 years were associated with hematuria among males, but not females.

CONCLUSION

The prevalence of hematuria is high among Zuni Indians with and without diabetes. These findings are consistent with the hypothesis that nondiabetic kidney disease is common among Zuni Indians with and without diabetes.

Epidemic of diabetic and nondiabetic renal disease among the Zuni Indians: the Zuni Kidney Project

There is an epidemic of renal disease among the Zuni Indians. The prevalence of end-stage renal disease among the Zuni Indians is 18.4-fold and 7.4-fold higher than among European Americans and American Indians/Alaskan Natives, respectively. In contrast to other American Indian tribes, nondiabetic renal disease accounts for a significant percent of the renal disease burden among the Zuni Indians. To explore this hypothesis, a community epidemiologic study of the Zuni Pueblo was conducted. A questionnaire was administered, blood and urine samples were collected, and BP, height, and weight were measured. Neighborhood household clusters were used as the sampling frame to maximize ascertainment and minimize bias. Age and gender distributions in the sample (n = 1483) were similar to those of the eligible Zuni population (n = 9228). The prevalence, age-adjusted and gender-adjusted to the Zuni population, of incipient (0.03 < or = UACR < 0.3) albuminuria (IA) (15.0% [95% confidence interval, 13.1 to 16.9%]), and overt (UACR > or = 0.3) albuminuria (OA) (4.7% [3.6 to 5.8%]) was high. The prevalence estimates for IA and OA were higher among diabetic participants (IA: 33.6% [27.6 to 39.7%]; OA: 18.7% [13.7 to 23.7%]) than nondiabetic participants (IA: 10.8% [9.0 to 12.6%]; OA: 1.8% [1.0 to 2.5%]). However, there were more nondiabetic participants; therefore, they comprised 58.0% [51.4 to 64.6%] and 30.9% [20.0 to 41.7%] of participants with IA and OA, respectively. In contrast to most other American Indian tribes, nondiabetic renal disease contributes significantly to the overall burden of renal disease among the Zuni Indians.

Evidence for joint action of genes on diabetes status and CVD risk factors in American Indians: the strong heart family study

OBJECTIVES

Previous research among American Indians of the strong heart family study (SHFS) has demonstrated significant heritabilities for CVD risk factors and implicated diabetes as an important predictor of several of the phenotypes. Moreover, we recently demonstrated that genetic effects on CVD risk factors differed in diabetic and nondiabetic individuals. In this paper, we investigated whether a significant genetic influence on diabetes status could be identified, and whether there is evidence for joint action of genes on diabetes status and related CVD risk factors.

METHODS AND RESULTS

Approximately 950 men and women, age 18 or older, in 32 extended families, were examined between 1997 and 1999. We estimated the effects of genes and environmental covariates on diabetes status using a threshold model and a maximum likelihood variance component approach. Diabetes status exhibited a residual heritability of 22% (h2=0.22). We also estimated the genetic and environmental correlations between diabetes susceptibility and eight risk factors for CVD. All eight CVD risk factors displayed significant genetic correlations with diabetes status (BMI (rhoG=0.55), fibrinogen (rhoG=0.40), HDL-C (rhoG=-0.37), ln triglycerides (rhoG=0.65), FAT (rhoG=0.38 ), PAI-1 (rhoG=0.67), SBP (rhoG=0.57), and WHR (rhoG=0.58)). Three of eight traits (HDL-C (rhoE=-0.32), ln triglycerides (rhoE=0.33), and fibrinogen (rhoE=0.20)) displayed significant environmental correlations with diabetes status.

CONCLUSIONS

These findings suggest that in the context of a high prevalence of diabetes, still unidentified diabetes genes may play an important role in influencing variation in CVD risk factors.

An appraisal of echocardiography as an epidemiological tool. The Strong Heart Study

PURPOSE

Despite the prognostic importance of left ventricular (LV) mass (LVM) by M-mode echocardiography, concern exists about bias introduced by missing data. The American Society of Echocardiography has made recommendations for linear measurements of LV wall thickness and internal dimension used to calculate LVM, but it is unknown whether their substitution for suboptimal M-modes improves measurement yield and reduces bias.

METHODS

LVM measurement yield and associations of missing data with risk factors were assessed in 3487 American Indian participants in Strong Heart Study (SHS) Phase II and compared to data from other large-scale studies.

RESULTS

In SHS, LVM was measurable in 3188 (91%) participants compared to 4947/6148 (80%) Framingham participants studied by classic M-mode technique, with less decrease in measurement yield with age in SHS. In univariate SHS analyses, missing LVM was significantly associated with male gender, older age, greater height, body mass index, fat-free mass, waist/hip ratio, fibrinogen and, marginally, diabetes but not smoking, blood pressure, or lipids. In logistic regression analysis, missing LVM was independently associated with male gender, older age, greater body mass index and lower forced expiratory volume (FEV(1)) (with a low multiple R(2) [.04]), but not other risk factors. Doppler stroke volume, a measure of hemodynamic volume load, was measurable in 96% of SHS participants; missing values were weakly associated with older age, higher creatinine and lower FEV(1). During 48 +/- 11 months of follow-up, inability to measures LV mass or stroke volume was not associated with higher rates of cardiovascular events or death (p = 0.25 to 0.96).

CONCLUSIONS

Improvements in echocardiographic methods have increased the yield of LVM in middle-aged and older adults and allow even more consistent assessment of cardiac volume load. Despite small persistent biases, due to associations of missing LVM and Doppler stroke volume data with male gender, greater obesity, lower FEV(1) and (for LVM only) older age, individuals with missing measurement are not at higher risk of cardiovascular events.