The influence of social connectedness and self-esteem on participant retention in a bi-ethnic longitudinal study

In prospective studies it is essential that the study sample accurately represents the target population for meaningful inferences to be drawn. Understanding why some individuals do not participate, or fail to continue to participate, in longitudinal studies can provide an empirical basis for the development of effective recruitment and retention strategies to improve response rates. This study examined the influence of social connectedness and self-esteem on long-term retention of participants, using secondary data from the “San Antonio Longitudinal Study of Aging” (SALSA), a population-based study of Mexican Americans (MAs) and European Americans (EAs) aged over 65 years residing in San Antonio, Texas. We tested the effect of social connectedness, self-esteem and socioeconomic status on participant retention in both ethnic groups. In MAs only, we analyzed whether acculturation and assimilation moderated these associations and/or had a direct effect on participant retention. ^ Low income, low frequency of social contacts and length of recruitment interval were significant predictors of non-completer status. Participants with low levels of social contacts were almost twice as likely as those with high levels of social contacts to be non-completers, even after adjustment for age, sex, ethnic group, education, household income, and recruitment interval (OR = 1.95, 95% CI: 1.26–3.01, p = 0.003). Recruitment interval consistently and strongly predicted non-completer status in all the models tested. Depending on the model, for each year beyond baseline there was a 25–33% greater likelihood of non-completion. The only significant interaction, or moderating, effect observed was between social contacts and cultural values among MAs. Specifically, MAs with both low social contacts and low acculturation on cultural values (i.e., placed high value on preserving Mexican cultural origins) were three and half times more likely to be non-completers compared with MAs in other subgroups comprised of the combination of these variables, even after adjustment for covariates. ^ Long term studies with older and minority participants are challenging for participant retention. Strategies can be designed to enhance retention by paying special attention to participants with low social contacts and, in MAs, participants with both low social contacts and low acculturation on cultural values. Minimizing the time interval between baseline and follow-up recruitment, and maintaining frequent contact with participants during this interval should also be is integral to the study design.^

The contribution of change in ethnic composition to prevalence of obesity and overweight

Objective. The prevalence of overweight and obesity differs substantially among children of different ethnic origin in the United States. The objective of this project is to estimate to what extent changes in ethnic composition since 1980 have contributed to the current general “obesity epidemic” in the childhood population of the United States.^ Methods. Populations by single year of age, 0 to 19, male and female, for Hispanics, non-Hispanic whites, and non-Hispanic blacks, from the US Census’ July estimates for 1985, 1990, 1995, 2000 and 2005 were taken and compared to the population and percentage of those groups from 1980. Age, sex, and ethnicity specific prevalence rates for overweight in 1980 were then applied to the populations by age for the specified year and differences in expected and actual overweight populations were assessed.^ Result. The results from this investigation provide estimates of the contribution that different ethnic groups have made to the overall prevalence of overweight and obesity in the childhood population of the United States. Assuming that the 1976-1980 prevalence rates had remained unchanged, and then comparing the population had there been no change in ethnic composition with the population given the actual change in ethnicity, the percentage increase was 1.06% in 1985, 1.72% in 1990, 2.57% in 1995, 3.95% in 2000, and 4.39% in 2005.^ Conclusion. The changes in ethnic composition of the population, independent of changes in ethnicity-specific prevalence, have contributed substantially to the current overall prevalence of obesity in the United States childhood population. There are a number of factors that may be responsible for the apparent susceptibility of Mexican-Americans and non-Hispanic blacks to overweight and obesity. Further research is needed on specific characteristics of those populations.^

Genome-wide association study of LDL-cholesterol over ApoB ratio

Genome-Wide Association Study analytical (GWAS) methods were applied in a large biracial sample of individuals to investigate variation across the genome for its association with a surrogate low-density lipoprotein (LDL) particle size phenotype, the ratio of LDL-cholesterol level over ApoB level. Genotyping was performed on the Affymetrix 6.0 GeneChip with approximately one million single nucleotide polymorphisms (SNPs). The ratio of LDL cholesterol to ApoB was calculated, and association tests used multivariable linear regression analysis with an additive genetic model after adjustment for the covariates sex, age and BMI. Association tests were performed separately in African Americans and Caucasians. There were 9,562 qualified individuals in the Caucasian group and 3,015 qualified individuals in the African American group. Overall, in Caucasians two statistically significant loci were identified as being associated with the ratio of LDL-cholesterol over ApoB: rs10488699 (p<5 x10-8, 11q23.3 near BUD13) and the SNP rs964184 (p<5 x10-8 11q23.3 near ZNF259). We also found rs12286037 ((p<4x10-7) (11q23.3) near APOA5/A4/C3/A1 with suggestive associate in the Caucasian sample. In exploratory analyses, a difference in the pattern of association between individuals taking and not taking LDL-cholesterol lowering medications was observed. Individuals who were not taking medications had smaller p-value than those taking medication. In the African-American group, there were no significant (p<5x10-8) or suggestive associations (p<4x10-7) with the ratio of LDL-cholesterol over ApoB after adjusting for age, BMI, and sex and comparing individuals with and without LDL-cholesterol lowering medication. Conclusions: There were significant and suggestive associations between SNP genotype and the ratio of LDL-cholesterol to ApoB in Caucasians, but these associations may be modified by medication treatment.^

Food availability in the home and dietary intake of the Harris County Department of Education Head Start population

Background. The prevalence of obesity and overweight children has been an ongoing health epidemic in the US for the last several decades. The problem has consistently worsened and has disproportionately been the most prevalent among low socioeconomic status (SES) populations. Food availability in the home has been suggested to be a potential factor related to overweight and obesity, as availability is likely associated with intake. Food availability of low SES preschool aged children has not been well examined. The purpose of this study was to explore the food environment of the Harris County Department of Education (HCDE) Head Start population, and describe reported frequency of intake of particular food groups. The effect of food availability on reported intake was also examined.^ Methods. This was a cross-sectional study of secondary data analysis. Data obtained from 17 HCDE Head Start Centers was analyzed using PASW 18 Statistical Software. Demographic analyses included population, age, gender, race, parent occupation, type of home, and language spoken in the home. Descriptive statistics included reported availability of foods in the home as well as frequency of intake.^ Regression analysis examined the relationship of availability of foods on intake. The food categories included were: dark leafy green and orange vegetables, other vegetables, fruits, soda, salty snacks, and sweet snacks. For both vegetable categories reported intake of fresh, frozen, and canned vegetables were included. For the fruit category, intake of fresh, frozen, canned, and dried fruits were reported.^ Results. Results showed that 90-95% of parents reported having vegetables and fruits available in the home. However, the only significant relationship between availability and intake was for fresh fruit and dried fruit. No associations were seen among the vegetable groups. Other vegetables (bell peppers, eggplant, tomatoes, onions, iceberg lettuce, asparagus) that were frozen, approached significance for availability on intake, however once adjusted for confounders the relationship was no longer present. Among soda, salty snacks, and sweet snacks the only significant relationship was seen for soda availability and intake. Salty snacks and sweet snacks presence in the home was not a predictor of increased frequency of intake.^ Conclusions. This research supported the hypothesis that availability of foods has an impact on intake for fresh fruits, dried fruits and soda. No associations were seen for vegetables, salty snacks and sweet snacks. Additionally, most of the parents reported having fruits and vegetables in the home, but reported intakes were not meeting the Dietary Guidelines for Americans recommendations. Strengths of the study included the large sample size taken from numerous HCDE Head Start Centers. Limitations included questionable reliability of participant’s responses, ability to generalize to other populations, and the use of secondary data rather than prospectively collected data.^

Lifetime changes in body mass index and risk of breast cancer in minority women

Introduction: Obesity is an epidemic in the United States, especially among Hispanics and African-Americans. Studies of obesity and breast cancer risk and subtype have been conducted primarily in non-Hispanic whites. Obesity is inversely associated with premenopausal breast cancer, but both obesity and weight gain increase the risk of postmenopausal disease. Obesity has been associated with breast cancer subtype in many studies. Methods: To assess the association between changes in body mass index (BMI) over the lifetime, weight gain, and breast cancer in Mexican-American women, we conducted a case-control study using 149 cases and 330 age-matched controls. In a second study, we identified 212 African-American and 167 Mexican-American women with breast cancer in the ongoing ELLA Bi-National Breast Cancer Study, abstracted medical charts to classify tumors as ER+/PR+, HER2+, or ER-/PR-/HER2-, and assessed the association between lifetime changes in body mass index, weight gain, and breast cancer subtype. In both studies, growth mixture modeling was use to identify trajectories of change in BMI over the lifetime, and these trajectories were used as exposures in a logistic regression model to calculate odds ratios (OR). Results: There was no association between trajectories of change in BMI and breast cancer risk in Mexican-American women. In addition, BMI at ages 15 and 30 and at diagnosis was not associated with breast cancer. However, adult weight gain was inversely associated with breast cancer risk (per 5kg, OR=0.92, 95% CI: 0.85-0.99). The case-only analysis found no association between obesity at ages 15 and 30 and at diagnosis and breast cancer subtype. Further, there was no association between adult weight gain (defined as weight change from age 15 to time of diagnosis) and breast cancer subtype. Conclusions: Obesity was not associated with breast cancer risk in Mexican-American women, while adult weight gain reduced the risk independently of menopausal status. These results are contradictory of those in non-Hispanic white women and suggest that the etiology of breast cancer may differ by race/ethnicity. Further, obesity was not associated with breast cancer subtype in African-American and Mexican-American women, contrary to results in non-Hispanic white women. ^

Racial differences in heart failure with preserved ejection fraction in the ambulatory heart failure population

Racial differences in heart failure with preserved ejection fraction (HFpEF) have rarely been studied in an ambulatory, financially "equal access" cohort, although the majority of such patients are treated as outpatients. ^ Retrospective data was collected from 2,526 patients (2,240 Whites, 286 African American) with HFpEF treated at 153 VA clinics, as part of the VA External Peer Review Program (EPRP) between October 2000 and September 2002. Kaplan Meier curves (stratified by race) were created for time to first heart failure (HF) hospitalization, all cause hospitalization and death and Cox proportional multivariate regression models were constructed to evaluate the effect of race on these outcomes. ^ African American patients were younger (67.7 ± 11.3 vs. 71.2 ± 9.8 years; p < 0.001), had lower prevalence of atrial fibrillation (24.5 % vs. 37%; p <0.001), chronic obstructive pulmonary disease (23.4 % vs. 36.9%, p <0.001), but had higher blood pressure (systolic blood pressure > 120 mm Hg 77.6% vs. 67.8%; p < 0.01), glomerular filtration rate (67.9 ± 31.0 vs. 61.6 ± 22.6 mL/min/1.73 m2; p < 0.001), anemia (56.6% vs. 41.7%; p <0.001) as compared to whites. African Americans were found to have higher risk adjusted rate of HF hospitalization (HR 1.52, 95% CI 1.1 - 2.11; p = 0.01), with no difference in risk-adjusted all cause hospitalization (p = 0.80) and death (p= 0.21). ^ In a financially "equal access" setting of the VA, among ambulatory patients with HFpEF, African Americans have similar rates of mortality and all cause hospitalization but have an increased risk of HF hospitalizations compared to whites.^

A survey of statural changes with age in the adult population of the United States

A study of the patterns of height loss with age in the Anglo, black, and Mexican-American populations of the United States has been undertaken. The study was based on data gathered by the United States Public Health Service in the Second National Health and Nutrition Examination Survey and the Hispanic Health and Nutrition Examination Survey. Estimates of height loss were obtained by subtracting present stature from a calculated maximum attained height derived from sex- and race/ethnic-specific regression equations relating stature to subischial length. Anglo women have greater height losses than Anglo, black, or Mexican-American males, and black or Mexican-American females. Between 24 and 74 years of age, Anglo women average 3.8 cm. loss in stature. The black populations lose less height than Anglos or Mexican-Americans. Mexican-Americans lose less height than Anglos from 24 to 54 years and then have a greatly increased height loss so that by age 74 their total height loss is the same as Anglos. Standing height, sitting height, body mass index, and the Poverty Index were found to be negatively correlated with height loss. Age was positively correlated to height loss. The most important determinants of the magnitude of height loss with age were sex and ethnicity. ^

Thrombolytic therapy for acute myocardial infarction: A cohort study to evaluate a selective approach to invasive diagnosis and therapy. The Corpus Christi Heart Project

Coronary perfusion with thrombolytic therapy and selective reperfusion by percutaneous transluminal coronary angioplasty (PTCA) were examined in the Corpus Christi Heart Project, a population-based surveillance program for hospitalized acute myocardial infarction (MI) patients in a biethnic community of Mexican-Americans (MAs) and non-Hispanic whites (NHWs). Results were based on 250 (12.4%) patients who received thromobolytic therapy in a cohort of 2011 acute MI cases. Out of these 107 (42.8%) underwent PTCA with a mean follow-up of 25 months. There were 186 (74.4%) men and 64 (25.6%) women; 148 (59.2%) were NHWs, 86 (34.4%) were MAs. Thrombolysis and PTCA were performed less frequently in women than in men, and less frequently in MAs than in NHWs.^ According to the coronary reperfusion interventions used, patients were divided in two groups, those that received no-PTCA (57.2%) and the other that underwent PTCA (42.8%) after thrombolysis. The case-fatality rate was higher in no-PTCA patients than in the PTCA (7.7% versus 5.6%), as was mortality at one year (16.2% versus 10.5%). Reperfusion was successful in 48.0% in the entire cohort and (51.4% versus 45.6%) in the PTCA and no-PTCA groups. Mortality in the successful reperfusion patients was 5.0% compared to 22.3% in the unsuccessful reperfusion group (p = 0.00016, 95% CI: 1.98-11.6).^ Cardiac catheterization was performed in 86.4% thrombolytic patients. Severe stenosis ($>$75%) obstruction was present most commonly in the left descending artery (52.8%) and in the right coronary artery (52.8%). The occurrence of adverse in-hospital clinical events was higher in the no-PTCA as compared to the PTCA and catheterized patients with the exception of reperfusion arrythmias (p = 0.140; Fisher's exact test p = 0.129).^ Cox regression analysis was used to study the relationship between selected variables and mortality. Apart from successful reperfusion, age group (p = 0.028, 95% CI: 2.1-12.42), site of acute MI index (p = 0.050) and ejection-fraction (p = 0.052) were predictors of long-term survival. The ejection-fraction in the PTCA group was higher than (median 78% versus 53%) in the no-PTCA group. Assessed by logistic regression analysis history of high cholesterol ($>$200mg/dl) and diabetes mellites did have significant prognostic value (p = 0.0233; p = 0.0318) in long-term survival irrespective of treatment status.^ In conclusion, the results of this study support the idea that the use of PTCA as a selective intervention following thrombolysis improves survival of patients with acute MI. The use of PTCA in this setting appears to be safe. However, we can not exclude the possibility that some of these results may have occurred due to the exclusion from PTCA of high risk patients (selection bias). ^

For health's sake: Cervical and breast cancer screening

African-Americans make up twelve percent of the United States population, yet they experience morbidity and mortality at a rate that, in some cases, is disproportionate to their numbers. There are numerous health areas, including cancer, in which disparities exist. There are also numerous reasons which have been suggested to explain the high rates of cancer morbidity and mortality experienced by African-Americans. Among the reasons given to explain these differences are lack of knowledge and lack of access to medical care (1). This study sought to increase the knowledge, attitudes, and behavioral intentions of African-American women attending a Baptist church in Houston with regard to cervical cancer, breast cancer, Pap smear, and mammography. It was hypothesized that a church-based cancer education program would produce the desired change in knowledge, attitudes, and behavioral intentions.^ The quasi-experimental design of the study was untreated control group with pretest and posttest and untreated control group with posttest only. Female members of Mount Ararat Baptist Church took part in an eight-week, cancer education program based on social cognitive theory. Baseline data were collected before the start of the program at Mount Ararat and at Solid Rock Baptist Church, control group one. At the end of the program, the follow-up survey was administered at the program church, control church one, and in a third church, Damascus Missionary Baptist Church, which served as the posttest only group. The data were analyzed by Fisher's exact and paired t-test to determine if the program supported the project's hypotheses.^ Results of data analyses supported the major study hypotheses, the exception being behavioral intention to have Pap smear performed. Although the program appeared to have generally influenced changes in the desired direction, the results are limited due to the quasi-experimental design and small sample size. Longer term studies with larger sample sizes are needed to more fully develop and evaluate programs which impact the health of African-Americans. ^

Incidence of breast cancer in first-degree female relatives of men with newly diagnosed prostate cancer

Prostate cancer is the most common incident cancer and the second leading cause of death in men in the United States. Although numerous attempts have been made to identify risk factors associated with prostate cancer, the results have been inconsistent and conflicting. The only established risk factors are age and ethnicity. A positive family history of prostate cancer has also been shown to increase the risk two- to three-fold among close relatives.^ There are several similarities between breast and prostate cancer that make the relationship between the two of interest. (1) Histologically, both cancers are predominantly adenocarcinomas, (2) both organs have a sexual and/or reproductive role, (3) both cancers occur in hormone-responsive tissue, (4) therapy often consists of hormonal manipulation, (5) worldwide distribution patterns of prostate and breast cancer are positively correlated.^ A family history study was conducted to evaluate the aggregation of prostate cancer and co-aggregation of breast cancer in 149 patients referred to The University of Texas, M.D. Anderson Cancer Center with newly diagnosed prostate cancer. All patients were white, less than 75 years of age at diagnosis and permanent residents of the United States. Through a personal interview with the proband, family histories were collected on 1,128 first-degree relatives. Cancer diagnoses were verified through medical records or death certificate. Standardized incidence ratios were calculated using a computer program by Monson incorporating data from Connecticut Tumor Registry.^ In this study, familial aggregation of prostate cancer was verified only among the brothers, not among fathers. Although a statistically significant excess of breast cancer was not found, the increased point estimates in mothers, sisters and daughters are consistent with a co-aggregation hypothesis. Rather surprising was the finding of a seven-fold increased risk of prostate cancer and a three-fold increased risk of breast cancer among siblings in the presence of a maternal history of any cancer. Larger family history studies including high risk (African-Americans) and lower-risk groups (Hispanics) and incorporating molecular genetic evaluations should be conducted to determine if genetic differences play a role in the differential incidence rates across ethnic groups. ^

Genetic susceptibility, cigarette smoking, and wood dust exposure in lung cancer: Case control analyses

This case control study was conducted to assess the association between lung cancer risk, mutagen sensitivity (a marker of cancer susceptibility), and a putative lung carcinogen, wood dust exposure. There were 165 cases (98 African-Americans, 67 Mexican-Americans) with newly diagnosed, previously untreated lung cancer, and 239 controls, frequency-matched on age, sex, and ethnicity.^ Mutagen sensitivity ($\ge$1 break/cell) was associated with a statistically significant elevated risk for lung cancer (odds ratio (OR) = 4.1, 95% confidence limits (CL) = 2.3,7.2). Wood dust exposure was also a significant predictor of risk (OR = 2.8, 95% CL = 1.2,6.6) after controlling for smoking and mutagen sensitivity. When stratified by ethnicity, wood dust exposure was a significant risk factor for African-Americans (OR = 4.0, 95% CL = 1.4,11.5), but not for Mexican-Americans (OR = 1.5, 95% CL = 0.3,7.1). Stratified analysis suggested a greater than multiplicative interaction between wood dust exposure and both mutagen sensitivity and smoking.^ The cases had significantly more breaks on chromosomes 4 and 5 than the controls did with ORs of 4.9 (95% CL = 2.0, 11.7) and 3.9 (95% CL = 1.6, 9.3), respectively. Breaks at 4p14, 4q27, 4q31, 5q21-22, 5q31, and 5q33 were significantly more common in lung cancer patients than in controls. Lung cancer risk had a dose-response relationship with breaks on chromosomes 4 and 5. Cigarette smoking had a strong interaction with breaks on chromosomes 2, 4, and 5.^ In a molecular cytogenetic study, using chromosome painting and G-banding, we showed that: (1) the proportion of chromosome 5 abnormalities surviving as chromosome-type aberrations remained significantly higher in cells of lung cancer cases (14%) than in controls (5%) (P $<$ 0.001). However, no significant differences were detected in chromosome 4 abnormalities between cases and controls; (2) the proportion of chromosome 5q13-22 abnormalities was 5.3% in the cases and 0.7% in the controls (P $<$ 0.001). 5q13-22 regions represented 40% of all abnormalities on chromosome 5 in the cases and only 14% in the controls.^ This study suggests that mutagen sensitivity, wood dust exposure, and cigarette smoking were independent risk factors for lung cancer, and the susceptibility of particular chromosome loci to mutagenic damage may be a genetic marker for specific types of lung cancer. ^

The use of invasive myocardial revascularization procedures following myocardial infarction and the effectiveness of these procedures in the biethnic community of Nueces County, Texas, 1988--1991

High levels of poverty and unemployment, and low levels of health insurance coverage may pose barriers to obtaining cardiac care by Mexican Americans. We undertook this study to investigate differences in the use of invasive myocardial revascularization procedures received within the 4-month period following hospitalization for a myocardial infarction (MI) between Mexican Americans and non-Hispanic whites in the Corpus Christi Heart Project (CCHP). The CCHP is a population-based surveillance program for hospitalized MI, percutaneous transluminal coronary angioplasty (PTCA), and aortocoronary bypass surgery (ACBS). Medical record data were available for 1706 patients identified over a three-year period. Mexican Americans had significantly lower rates of receiving a PTCA following MI than non-Hispanic Whites (RR: 0.56, 95% CI: 0.44-0.70). No meaningful ethnic difference was seen in the rates of ACBS use. History of PTCA use appeared to interact with ethnicity. Among patients without a history of PTCA use, Mexican Americans were less likely to receive a PTCA than non-Hispanic whites (RR: 0.59; 95% CI: 0.46-0.76). Among patients with a history of PTCA use, however, Mexican Americans were more likely to receive a PTCA than non-Hispanic whites (RR: 1.47; 95% CI: 0.75-2.87).^ Differences in the effectiveness of a first-time PTCA and first-time ACBS between Mexican Americans and non-Hispanic whites in the CCHP were also investigated. Mexican Americans were more likely to receive a 2nd PTCA (RR: 1.56, 95% CI: 1.11-2.17) and suffer a subsequent MI (RR: 1.42, 95% CI: 1.03-1.96) following a first-time PTCA than non-Hispanic whites. No meaningful ethnic differences were found in the rates of death and rates of ACBS following a first-time PTCA. Also, no significant ethnic differences were found in the rates of any of the events following a first-time ACBS. After adjusting for potential demographic, socioeconomic, clinical and angiographic confounders using Cox regression analysis, Mexican Americans were still more likely to receive a 2nd PTCA (HR: 1.38; 95% CI: 0.99-1.93) following a first-time PTCA than non-Hispanic whites. A significant difference in the rates of a subsequent MI following a first-time PTCA persisted (HR: 1.39, 95% CI: 1.01-1.93). (Abstract shortened by UMI.) ^

Macular edema in Hispanics with non-insulin dependent diabetes mellitus in Starr County, Texas: Prevalence, incidence and risk factors

This project is based on secondary analyses of data collected in Starr County, Texas from 1981 till 1991 to determine the prevalence, incidence and risk factors for macular edema in Hispanics with non-insulin-dependent diabetes in Starr County, Texas. Two studies were conducted. The first study examined the prevalence of macular edema in this population. Of the 310 diabetics that were included in the study 22 had macular edema. Of these 22 individuals 9 had clinically significant macular edema. Fasting blood glucose was found to be significantly associated with macular edema. For each 10 mg/dl increase in fasting blood glucose there was a 1.07 probability of an increase in the risk of having macular edema. Individuals with fasting blood glucose $\ge$200 mg/dl were found to be more than three times at risk of having macular edema compared to those with fasting blood glucose $<$200 mg/dl.^ In the second study the incidence and the risk factors that could cause macular edema in this Hispanic population were examined. 240 Hispanics with non-insulin-dependent diabetes mellitus and without macular edema were followed for 1223 person-years. During the follow-up period 27 individuals developed macular edema (2.21/100 person-years). High fasting blood glucose and glycosylated hemoglobin were found to be strong and independent risk factors for macular edema. Participants taking insulin were 3.9 times more at risk of developing macular edema compared to those not taking insulin. Systolic blood pressure was significantly related to macular edema, where each 10 mmHg increase in systolic blood pressure was associated with a 1.3 increase in the risk of macular edema.^ In summary, this study suggests that hyperglycemia is the main underlying factor for retinal pathological changes in this diabetic population, and that macular edema probably is not the result of sudden change in the blood glucose level. It also determined that changes in blood pressure, particularly systolic blood pressure, could trigger the development of macular edema.^ Based on the prevalence reported in this study, it is estimated that 35,500 Hispanic diabetics in the US have macular edema. This imposes a major public health challenge particularly in areas with high concentration of Mexican Americans. It also highlights the importance of public health measures directed to Mexican Americans such as health education, improved access to medical care, and periodic and careful ophthalmologic examination by ophthalmologists knowledgeable and experienced in the management of diabetic macular edema. ^

A GENETIC MARKER STUDY OF NON - INSULIN DEPENDENT DIABETICS IN THE MEXICAN-AMERICAN COMMUNITY FROM STARR COUNTY, TEXAS (PLASMA GLUCOSE, HEMOGLOBIN ANALYSIS)

Diabetes mellitus occurs in two forms, insulin-dependent (IDDM, formerly called juvenile type) and non-insulin dependent (NIDDM, formerly called adult type). Prevalence figures from around the world for NIDDM, show that all societies and all races are affected; although uncommon in some populations (.4%), it is common (10%) or very common (40%) in others (Tables 1 and 2).^ In Mexican-Americans in particular, the prevalence rates (7-10%) are intermediate to those in Caucasians (1-2%) and Amerindians (35%). Information about the distribution of the disease and identification of high risk groups for developing glucose intolerance or its vascular manifestations by the study of genetic markers will help to clarify and solve some of the problems from the public health and the genetic point of view.^ This research was designed to examine two general areas in relation to NIDDM. The first aims to determine the prevalence of polymorphic genetic markers in two groups distinguished by the presence or absence of diabetes and to observe if there are any genetic marker-disease association (univariate analysis using two by two tables and logistic regression to study the individual and joint effects of the different variables). The second deals with the effect of genetic differences on the variation in fasting plasma glucose and percent glycosylated hemoglobin (HbAl) (analysis of Covariance for each marker, using age and sex as covariates).^ The results from the first analysis were not statistically significant at the corrected p value of 0.003 given the number of tests that were performed. From the analysis of covariance of all the markers studied, only Duffy and Phosphoglucomutase were statistically significant but poor predictors, given that the amount they explain in terms of variation in glycosylated hemoglobin is very small.^ Trying to determine the polygenic component of chronic disease is not an easy task. This study confirms the fact that a larger and random or representative sample is needed to be able to detect differences in the prevalence of a marker for association studies and in the genetic contribution to the variation in glucose and glycosylated hemoglobin. The importance that ethnic homogeneity in the groups studied and standardization in the methodology will have on the results has been stressed. ^

AN INVESTIGATION OF THE RELIABILITY AND VALIDITY OF THE CENTER FOR EPIDEMIOLOGIC STUDIES DEPRESSION SCALE IN THREE ETHNIC GROUPS

Epidemiologic studies of mental disorder have called attention to the need for identifying untreated cases and to the inadequacies of the instruments available for this purpose. Accurate case ascertainment devices are the basis of sound epidemiology. Without these, neither case classification nor analytic studies of risk factors is possible.^ The purpose of this research was to examine the reliability and validity of an instrument designed to measure depressive symptoms in community populations--the Center for Epidemiologic Studies Depression Scale (CES-D Scale). Two particular foci of the study were whether or not the scale had the same statistical structure across three ethnic groups and whether or not the magnitude and pattern of rates of symptoms for these groups were affected by one source of response error, that due to response tendencies. The effects of age and education on the pattern and magnitude of rates also were examined. In addition, the reliability and validity of the measures of response tendencies were assessed.^ The study population consisted of residents of Alameda County, California. A stratified sample of approximately 700 whites, blacks and Mexican-Americans was interviewed in the summer and fall of 1978.^ The results of the analysis indicated that the scale was reliable and measured a similar content domain across the three ethnic groups. The unadjusted sex- and ethnic-specific rates of depressive symptoms showed an ethnic pattern for both sexes: rates for whites were lowest, those for Mexican-Americans were highest, and those for blacks were intermediate. Measures of response tendencies--need for social approval, trait desirability, and acquiescence--affected the magnitude of the rates for most comparisons. Likewise, the pattern of rates changed somewhat from that originally observed. The one fairly consistent observation was that rates for Mexican-American women were higher than those for the other two female subgroups in most of the comparisons. These results must be considered in the context of the reliability and validity assessment of the measures of response tendencies which indicated the tenuousness of these measures.^ Age affected the ethnic pattern of rates for men in an inconsistent way; for women, Mexican-Americans continued to have higher rates than whites or blacks in all age categories. Education affected the magnitude of rates for women but not for men. For both men and women, Mexican-Americans had higher rates in all educational strata. Rates for women showed an inverse association with education while those for men did not. ^