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Biomedical subjects

S B Hulley

Publications and source records attributed to S B Hulley.

At least 37 records · Page 2Linked to original sources

Seven-year trends in plasma low-density-lipoprotein-cholesterol in young adults: the CARDIA Study.

To identify determinants of recent secular trends in lipids and characterize their influence on age-related increases in LDL-cholesterol, we examined a cohort of black and white men and women aged 18-30 in 1985-1986. Secular trends were determined by comparing participants aged 25-30 at baseline with those aged 25-30 at year 7 (2788 and 1395 participants, respectively). LDL-cholesterol was lower among those 25-30 at year 7 (5.9 to 10.2 mg/dL, depending on race-sex group; P < 0.001); weight was higher (8.3 to 12.5 lb; P < 0.001); Keys score was lower (-4.2 to -7.3 units; P < 0.001); and use of oral contraceptives was greater (white women only, P < 0.01). Among 4086 participants followed for 7 years, LDL-cholesterol changed little or decreased, despite substantial weight increases in all groups (11.6 to 19.0 lb; P < 0.001). Keys scores decreased by 6.1 to 8.0 units, and use of oral contraceptives decreased (P < 0.001). Declining secular trends in LDL-cholesterol occurred despite upward trends in weight; the decline was associated with lower dietary fat and cholesterol and offset expected age-related increases in LDL-cholesterol.

Adult↗

Serum fatty acids and the risk of coronary heart disease.

To examine the relation between serum fatty acids and coronary heart disease (CHD), the authors conducted a nested case-control study of 94 men with incident CHD and 94 men without incident CHD who were enrolled in the Usual Care group of the Multiple Risk Factor Intervention Trial between December 1973 and February 1976. After confirming the stability of the stored serum samples, the authors measured serum fatty acid levels by gas-liquid chromatography and examined their association with CHD. In all multivariate models, levels of the cholesterol ester saturated fatty acid palmitic acid (16:0) were directly associated with CHD risk (standardized odds ratio = 1.68; 95% confidence interval 1.10-2.55 in the model that adjusted for total plasma cholesterol level). Levels of the phospholipid omega-3 fatty acid docosapentaenoic acid (22:5) were inversely associated with CHD risk in the two multivariate models that controlled for the effects of total plasma cholesterol level or high density lipoprotein cholesterol to total plasma cholesterol ratio (standardized odds ratio = 0.58; 95% confidence interval 0.38-0.89 in the first model that controlled for total plasma cholesterol level). In contrast to the first two multivariate models, levels of the docosahexaenoic acid (22:6) were inversely associated with CHD risk in a third multivariate model that controlled for the effects of high density lipoprotein cholesterol to low density lipoprotein cholesterol ratio (standardized odds ratio = 0.57; 95% confidence interval 0.36-0.90). These findings are consistent with other evidence indicating that saturated fatty acids are directly correlated with CHD and that omega-3 polyunsaturated fatty acids are inversely correlated with CHD. Because these associations were present after adjustment for blood lipid levels, other mechanisms, such as a direct effect on blood clotting, may be involved.

Adult↗

Problems with the report of the Expert Panel on blood cholesterol levels in children and adolescents.

An Expert Panel convened by the National Cholesterol Education Program has recommended selective screening and treatment of children for high blood cholesterol levels, based on family history of cardiovascular disease or high blood cholesterol. This recommendation is problematic for several reasons. First, the recommended diets are likely to cause only a slight decrease in low-density lipoprotein cholesterol levels, the projected benefits of which will be offset by a similar decrease in high-density lipoprotein cholesterol levels. Lack of efficacy of the recommended diets could lead to use of more restrictive diets or to cholesterol lowering drugs. Second, even under optimistic assumptions, beneficial effects of cholesterol intervention will be small and delayed for many decades. As a result, childhood cholesterol-lowering efforts will not be cost-effective. Third, the Expert Panel's recommendations do not address important gender differences. Girls have higher average cholesterol levels than boys. They will therefore qualify for more dietary and drug treatment despite their lower age-adjusted risk of heart disease and the lack of association between cholesterol levels and cardiovascular mortality in women. Finally, recent evidence from randomized trials, cohort studies, and animal experiments suggests that cholesterol lowering may have serious adverse effects. This evidence was not discussed in the Expert Panel's report. Given current evidence, any screening and treatment of children for high blood cholesterol levels is, at best, premature.

Adolescent↗

HIV infection and risk behaviors among heterosexuals in alcohol treatment programs.

OBJECTIVE: To measure the prevalence of human immunodeficiency virus (HIV) infection and high-risk behaviors among heterosexuals in alcohol treatment. DESIGN: Cross-sectional survey. SETTING: Five public alcohol treatment centers. SUBJECTS: Consecutive sample of 888 heterosexual clients entering treatment between October 1990 and December 1991. Respondents were 51% black, 10% Hispanic, 33% white, and 76% male. The overall response rate was 68%. MEASUREMENTS: Structured interview and serotesting for HIV antibodies. RESULTS: The overall seroprevalence of HIV infection was 5% (95% confidence interval, 3% to 6%). There were no significant differences in rates of infection by age, gender, or race. The prevalence of infection in heterosexual respondents without a history of injection drug use was 3% in men and 4% in women, several times higher than published estimates from a similar community-based heterosexual sample. Unsafe sexual practices were common: 54% of respondents reported multiple sexual partners in the previous year, 97% of nonmonogamous respondents did not use condoms during all sexual encounters, and few respondents consistently asked new sexual partners about previous high-risk behaviors. CONCLUSIONS: There is a substantial prevalence of HIV infection among heterosexual clients in San Francisco (Calif) alcohol treatment programs, much of which is not associated with injection drug use. Because of this and the high prevalence of unsafe sexual behaviors, there is a relatively high likelihood of heterosexual spread of HIV among the large population of clients seeking treatment for alcohol dependency. Interventions to prevent HIV spread should become a standard part of alcohol treatment programs.

AIDS Serodiagnosis↗

Levels of HIV testing and low validity of self-reported test results among alcoholics and drug users.

OBJECTIVES: To evaluate HIV testing behavior, validity of self-reported serostatus, and intention to test among alcoholics and drug users entering treatment. DESIGN: Longitudinal cohort study. METHODS: A total of 952 clients voluntarily entering three outpatient and two inpatient public alcohol treatment centers in San Francisco were enrolled. Seventy-six per cent were men, 50% black, 81% had used both alcohol and drugs during the last year, 43% had injected drugs and 9% of the men were homosexual. Subjects completed an interviewer-administered questionnaire and blindly-linked HIV-antibody test at entry and after 1 year (81% follow-up). RESULTS: Fifty-seven per cent of subjects reported that they had previously sought HIV testing. Factors associated with HIV testing included homosexual contact, injecting drug use, having a partner who had been tested, and using condoms. Hispanics were the least likely of all ethnic groups to report testing. Of 60 subjects with HIV antibodies, 47 (78%) said they had already been tested; however, 19 (40%) inaccurately reported that their serostatus was negative and another four (9%) had no collected their test results. Blacks were much more likely than other groups to misreport or be unaware of their HIV status. Only half of the 68% who said they planned to be tested during the following year did so. Five (42%) out of 12 HIV-positive individuals who were unaware of, or misreported their serostatus at baseline, and who sought another HIV test during the follow-up year continued to report themselves as uninfected. CONCLUSIONS: A large proportion of clients attending public alcohol treatment centers report having been HIV tested, much greater than that observed in other populations. However, misreporting of HIV test results was very common among seropositive subjects. Alcohol and drug treatment programs for this high-risk population should include interventions to optimize use of HIV testing for prevention and treatment, and improve understanding of test results.

Adolescent↗

Are bisexually identified men in San Francisco a common vector for spreading HIV infection to women?

OBJECTIVES: This article examines sexual risk taking among self-identified bisexual men in San Francisco and whether risk reduction has occurred, with respect to both homosexual and heterosexual behaviors, among human immunodeficiency virus (HIV) antibody-positive and HIV antibody-negative men. It also examines psychosocial correlates of unprotected anal and vaginal intercourse. METHODS: The participants were members of a population-based longitudinal cohort of 1034 single men aged 25 through 54 years recruited from the 19 census tracts in San Francisco that had the greatest prevalence of the acquired immunodeficiency syndrome in 1984. Of the total sample, 140 subjects initially identified themselves as bisexual; 85% of these men remained in the study. RESULTS: The participants reported dramatic reductions in sexual risk taking. Prevalences of unprotected anal sex with men were similar among HIV-positive bisexual men (89% in 1984-1985 and 18% in 1988-1989) and those who were HIV negative (65% and 20%). The prevalence of unprotected vaginal sex was much lower for HIV-positive men (16% in 1984-1985 and 2% in 1988-1989) than for HIV-negative men (35% and 20%). Unprotected intercourse was associated primarily with situational and interpersonal factors. CONCLUSIONS: Striking reductions in risk behaviors were reported. This subgroup of single, bisexually identified men appears unlikely to be a common vector for spreading HIV infection to women.

Adult↗

Decreased ankle/arm blood pressure index and mortality in elderly women.

OBJECTIVE: To evaluate the relationship of the ankle/arm blood pressure index to short-term mortality in women 65 years of age or older. DESIGN: Prospective cohort study with average follow-up of 4.3 years. SETTING: Rural community near Pittsburgh, Pa. PARTICIPANTS: A total of 1492 white women 65 years of age or older, living in the community and ambulatory without the help of another person. OUTCOME MEASURES: All-cause and cause-specific mortality. RESULTS: The ankle/arm index (the systolic pressure in the posterior tibial artery divided by that in the brachial artery) was measured in 1986 through 1988 and found to be 0.9 or less in 82 (5.5%) of the women, 67 of whom reported no symptoms of claudication. Comparing women with an index of 0.9 or less with those with an index greater than 0.9, the relative risk for all-cause mortality 4 years later (after adjustment for age, smoking, and other risk factors) was 3.1 (95% confidence interval [Cl], 1.7 to 5.5); for heart disease, 3.7 (95% Cl, 1.2 to 11.6); for cardiovascular diseases, 4.0 (95% Cl, 1.3 to 8.5); for cancer, 3.3 (95% Cl, 1.3 to 8.5); and for all other causes, 1.1 (95% Cl, 0.1 to 9.2). Similar levels of risk were found after excluding women with symptoms of claudication and/or a history of cardiovascular disease at baseline. CONCLUSIONS: Healthy, older women with an ankle/arm index of 0.9 or less are at high risk of death and therefore may be considered for aggressive therapy to modify cardiovascular risk factors.

Actuarial Analysis↗

Should we be measuring blood cholesterol levels in young adults?

Should we measure blood cholesterol levels in all adults, or only in those at high risk of coronary heart disease (CHD)? Most men under the age of 35 years and women under the age of 45 years--roughly half the adult population--are at very low short-term risk of CHD. One consequence is that drug treatment to lower high blood cholesterol levels in the average young adult is an extremely expensive means of prolonging life; the estimated $1 million to $10 million per year of life is 100 to 1000 times the cost of other approaches. Individualized dietary treatment is somewhat cheaper but relatively ineffective. Another consequence of the low CHD risk in young adults is the greater likelihood that intervention may have harmful effects that outweight the benefits. Meta-analysis of primary prevention trials in middle-aged men reveal an increase in non-CHD deaths among those randomized to cholesterol interventions, an unexpected finding that is more substantial than the decrease in CHD deaths. This raises the possibility that one or more of the cholesterol interventions could have very serious adverse effects among young adults, whose risk of non-CHD death is normally 100 times their risk of CHD death. We conclude that the policy of screening and treating high blood cholesterol levels in young adults is neither cost-effective, nor does it satisfy ethical standards requiring strong evidence that preventive interventions do more good than harm. Fortunately, cholesterol screening in young adults is also not necessary: most CHD events associated with high blood cholesterol levels in this population will not occur for decades and can be prevented by treatment that is begun in middle age. Cholesterol screening and treatment in young adults should be limited to individuals with known coronary disease or other unusual factors that place them at high short-term risk of CHD death.

Adult↗

Prevalence and correlates of lower extremity arterial disease in elderly women.

Although lower extremity arterial disease occurs in 15-20% of the population over the age of 75 years, little is known about the etiology of the disease in women. In this cross-sectional study involving 1,601 healthy elderly women (mean age, 71 years; range, 65-93 years), the occurrence of lower extremity arterial disease was assessed noninvasively by measuring brachial and ankle pressures bilaterally. Disease prevalence ranged from 2.9% in those aged 65-69 years to 15.5% in those aged 80 years or older. Approximately 20% of those with disease had symptoms of claudication. Age, systolic blood pressure, and current smoking status were strong independent risk factors for arterial disease; a history of arthritis, use of nonthiazide diuretics, current coffee drinking, and upper body obesity were also independent correlates. The number of pack-years in current and former smokers and the number of cigarettes per day used by current smokers showed a dose-response relation with disease. The population attributable risk for current smoking was 26%. The major correlates for symptomatic arterial disease were current smoking and systolic blood pressure. It is concluded that the major risk factors for lower extremity arterial disease in elderly women are similar to those in men. Preventive efforts should focus on smoking cessation and management of hypertension.

Aged↗

A novel use of the link-file system for longitudinal studies of HIV infection: a practical solution to an ethical dilemma.

BACKGROUND: Longitudinal studies that collect sensitive data, such as test results for HIV antibodies, present difficult ethical problems for investigators. Personal identifiers are needed for longitudinal follow-up, but current regulations in the United States require that all subjects be informed of their HIV test results when identifiers are retained. Therefore, subjects who do not wish to learn their HIV status must be excluded from prospective research. Because these subjects may be at particularly high risk for HIV infection, this situation may lead to substantial bias. METHODS: We describe a new application of a methodology for blinding such studies, based on the link-file system used for protecting subjects' sensitive research data. This design enables investigators to hold each subject's HIV test result and survey data for multiple ascertainments over time while effectively severing any link between this information and the subject's identity. This objective is achieved by a process of sequential coding, using at least two coders who are not associated with the study. CONCLUSIONS: The method described in this paper permits investigators in the United States to perform important prospective epidemiologic studies while adhering to current regulations for the conduct of such investigations.

Anonymous Testing↗