Evaluating genetic susceptibility to Staphylococcus aureus bacteremia in African Americans using admixture mapping.

The incidence of Staphylococcus aureus bacteremia (SAB) is significantly higher in African American (AA) than in European-descended populations. We used admixture mapping (AM) to test the hypothesis that genomic variations with different frequencies in European and African ancestral genomes influence susceptibility to SAB in AAs. A total of 565 adult AAs (390 cases with SAB; 175 age-matched controls) were genotyped for AM analysis. A case-only admixture score and a mixed χ2(1df) score (MIX) to jointly evaluate both single-nucleotide polymorphism (SNP) and admixture association (P<5.00e-08) were computed using MIXSCORE. In addition, a permutation scheme was implemented to derive multiplicity adjusted P-values (genome-wide 0.05 significance threshold: P<9.46e-05). After empirical multiplicity adjustment, one region on chromosome 6 (52 SNPs, P=4.56e-05) in the HLA class II region was found to exhibit a genome-wide statistically significant increase in European ancestry. This region encodes genes involved in HLA-mediated immune response and these results provide additional evidence for genetic variation influencing HLA-mediated immunity, modulating susceptibility to SAB.

Simple methods for assessing haplotype-environment interactions in case-only and case-control studies.

For investigating haplotype-environment interactions in case-control studies, one can implement statistical methods based either on a retrospective likelihood (modeling the probability of haplotype and environment conditional on disease status) or a prospective likelihood (modeling the probability of disease status conditional on haplotype and environment). Retrospective approaches are generally more powerful than prospective approaches, but require an explicit model of the joint distribution of haplotype and environmental factors in the sample with the latter being particularly unattractive to specify. To resolve this issue, we propose a number of simple retrospective procedures for haplotype-environment interaction analysis that do not require explicit modeling of environmental covariates in the sample. We first consider a cases-only procedure, followed by a simple likelihood for case-control data that is proportional to the full-retrospective likelihood. Finally, we consider a retrospective procedure for inference on haplotype-environment interaction effects in matched or finely-stratified case-control studies. Our methods are based on the assumptions that haplotypes and environmental covariates are independent in the target population and that disease is rare. We illustrate our approaches using case-control data from the Finland-United States Investigation of Non-Insulin Dependent Diabetes Mellitus (FUSION) genetic study and simulated data.

Involving the male partner for interpreting the basal body temperature graph.

OBJECTIVE: To determine if the male cohabiting partner of a woman may serve as a control for exogenous influences on basal body temperature (BBT). METHODS: Twelve couples from the Atlanta area were enrolled for a total of 41 couple-cycles. Couples recorded their oral temperatures daily and used urinary test kits for luteinizing hormone to estimate the day of ovulation. The covariability between the pre-ovulatory temperature of the women and their partners was assessed. The gaps in the couples' temperatures (female temperature minus male temperature) were compared in the pre- and postovulatory phases. RESULTS: Considerable covariability was found between temperatures of partners in the pre-ovulatory phase (covariance parameter = 0.49; P <.001). The pre- and postovulatory temperature gaps for all couples were significantly different in size (P <.001). For all couple-cycles, the size of the mean postovulatory temperature gap was at least 0.3-degree Fahrenheit greater than the mean pre-ovulatory temperature gap. CONCLUSION: Recording the BBT of women's partners may improve interpretation and accuracy of the BBT method. An increase in the size of a couple's temperature gap accompanies the transition from the pre- to the postovulatory phase. By this method, a given couple could determine their unique temperature gap indicating this transition.

Alcohol consumption is negatively associated with the prevalence of coronary heart disease in the New Mexico Elder Health Survey.

OBJECTIVE: To compare the prevalence of coronary heart disease (CHD) and the effects of various risk factors, including alcohol consumption, on prevalence rates in a randomly selected sample of older Hispanic and non-Hispanic white (NHW) men and women. DESIGN AND SETTING: A cross-sectional study of equal numbers of Hispanic and NHW men and women, selected randomly from Health Care Financing Authority (Medicare) rolls, recruited for a home interview followed by a 4-hour interview/examination in a senior health clinic. PARTICIPANTS: A total of 883 volunteers, mean age 74.1, years were interviewed/examined. MEASUREMENTS: CHD was identified by interview and electrocardiogram. Risk factors were identified by interview (hypertension, diabetes, medications, smoking, alcohol consumption) and by direct measurements (glucose tolerance, serum lipids, blood pressure, anthropometry). RESULTS: The age-adjusted prevalences of CHD were not significantly different when Hispanic men and women were compared with their NHW counterparts. Age-, ethnicity-, and gender-adjusted relative risk of CHD was inversely associated with alcohol consumption (OR .46; 95% CI, .28-.73; P < .001). Hypertension, diabetes mellitus, and male gender were also significant risk factors; age, anthropometric measurements, smoking, serum lipid concentrations, and level of education were not. HDL cholesterol levels were significantly lower in nondrinkers; other lipid levels were not associated with alcohol consumption. The type of alcoholic beverage was not associated with the prevalence of CHD. CONCLUSIONS: No significant differences in CHD prevalence existed between Hispanic and NHW participants despite a higher prevalence of diabetes and central obesity in Hispanics. Alcohol consumption was strongly negatively associated with the prevalence of CHD identified in this older, biethnic population.

Prevalences of type 2 diabetes, the insulin resistance syndrome, and coronary heart disease in an elderly, biethnic population.

OBJECTIVE: To compare the prevalences of type 2 diabetes, the various cardiovascular risk factors encompassing the insulin resistance syndrome (IRS), and coronary heart disease (CHD) in elderly Hispanics compared with non-Hispanic whites. RESEARCH DESIGN AND METHODS: Elderly Hispanics (n = 414) and non-Hispanic whites (n = 469), randomly selected from the Medicare rolls of Bernalillo County (Albuquerque, NM; age > or = 65 years), underwent a home interview followed by an interview/examination by a nurse-practitioner, nurse, and nutritionist that included an evaluation of glucose tolerance. Prevalences of total and central obesity, dyslipidemia, hypertension, and microalbuminuria also were determined. History of myocardial infarction, recent angina, and/or coronary bypass graft, and electrocardiograms (ECGs) were used to document CHD. RESULTS: Elderly Hispanics had twice the prevalence of type 2 diabetes compared with non-Hispanic whites, but the prevalence of impaired glucose tolerance was not increased in Hispanics. Mean serum fasting and 2-h post-glucola insulin concentrations, fasting insulin resistance indexes, and HbA1c were higher in Hispanics. Hispanics were shorter, weighed less, and had more total body and central obesity. The higher prevalences of dyslipidemia in Hispanics could be explained by a higher prevalence of diabetes. The prevalences of hypertension and CHD were not different for the two ethnic groups. CONCLUSIONS: Elderly Hispanics had twice the prevalence of diabetes and higher prevalences of cardiovascular risk factors associated with IRS. Prevalences of hypertension and CHD were similar in the two ethnic groups.

Outcome of recruitment and report on participation rate in the New Mexico Elder Health Survey.

The purpose of this paper is to report on the outcome of recruitment and participation rate in the New Mexico Elder Health Survey. This survey is the first community based epidemiological survey to examine health and health related issues of elderly (65 years or older) Hispanics and non-Hispanic whites in Bernalillo County (Albuquerque), New Mexico. This survey was conducted from May 1993 to September 1995. Subjects (N=2200) were randomly selected from the list of 50,700 Medicare recipients residing in Bernalillo County and stratified by ethnicity and gender. Hispanics were identified using a computer program that selects Hispanic surname patterns and ethnicity was verified by self report. Subjects participated in a home interview, followed by an interview and examination in a senior health clinic. Use of the Medicare list resulted in 75.7% (N=1666) of subjects being contacted. Of the 1666 subjects available, 1130 (67.8%) completed a home interview and 883 (54%) completed the full examination. There were no significant differences in participation by ethnicity, but there were significant differences by gender, with women less likely to participate. The mean age of participants was 74 years, age range 65 to 100. Hispanic elderly demonstrated greater economic poverty and lower levels of formal education. Our survey results show that the elderly and Hispanic elderly can be successfully recruited to participate in a research study. This paper is the first to summarize the details of the survey design, present the results of recruitment and participation, and describe the survey participants.

Does transplantation produce quality of life benefits? A quantitative analysis of the literature.

BACKGROUND: Despite numerous reports published since the early 1970s, it is frequently asserted that quality of life (QOL) outcomes of transplantation have seldom been investigated and/or that little is known about QOL. This view may have persisted due to lack of adequate cumulation and synthesis of existing data. We performed an exhaustive, quantitative literature review to determine the nature and degree of any QOL benefits associated with transplantation in adults. METHODS: All independent, peer-reviewed empirical, English-language QOL studies were retrieved for six areas of transplantation: kidney, pancreas/combined kidney-pancreas, heart, lung/combined heart-lung, liver, and bone marrow. Studies' findings were analyzed to determine whether the weight of evidence suggested that (a) QOL improved from pre- to posttransplant, (b) transplant recipient QOL was better than that of patient comparison groups, and (c) recipient QOL equaled that of healthy nonpatient samples. RESULTS: A total of 218 independent studies, evaluating a total of approximately 14,750 patients, were identified. The majority of studies demonstrated statistically significant (P<0.05) pre- to posttransplant improvements in physical functional QOL, mental health/cognitive status, social functioning, and overall QOL perceptions. The majority documented physical functional and global QOL advantages for transplant recipients relative to ill comparison groups. The studies did not indicate that recipient QOL in specific functional areas equaled that of healthy, nonpatient cohorts, although global QOL perceptions were often high. CONCLUSIONS: Although transplantation may not restore to the patient the "normal" life he/she may once have had, convergent evidence from six areas of transplantation, a variety of study designs, and demographically diverse study cohorts suggests that there are distinct QOL benefits of transplantation. Future work is required to identify background and personal factors that influence the degree of QOL benefits that any individual patient realizes from transplantation.

Perceived problems of occupational therapists: a subset of the professional curriculum.

Problem descriptions elicited from newly registered therapists were processed to produce 96 problem statements. These were clarified, assembled into a problem checklist, and mailed to 2,300 therapists registered subsequent to 1970 for the purpose of identifying the most frequent and bothersome problems encountered in practice. Factor analysis of the results revealed eight groups of problems, as well as four isolated problems, which were of statistical significance. This analysis suggested that basic skills of treatment planning and implementation are acquired by the new therapist before employment. Self-confidence and collaborative skills seem to be less well represented. It is suggested that these could be taught experientially by simulations within the classroom at several levels.