Phenotypic predictors of response to simvastatin therapy among African-Americans and Caucasians: the Cholesterol and Pharmacogenetics (CAP) Study

Although statins are effective lipid-lowering agents, the phenotypic and demographic predictors of such lowering have been less well examined. We enrolled 944 African-American and white men and women who completed an open-label, 6-week pharmacogenetics trial of 40 mg of simvastatin. The phenotypic and demographic variables were examined as predictors of the change in lipids and lipoproteins using linear regression analysis. On average, treatment with simvastatin lowered low-density lipoprotein (LDL) cholesterol by 54 mg/dl and increased high-density lipoprotein (HDL) cholesterol by 2 mg/dl. Compared with African-Americans, whites had a 3-mg/dl greater LDL reduction and a 1-mg/dl higher HDL elevation, independent of other variables, including baseline lipoprotein levels (p <0.01). Multivariate analyses revealed moderate subgroup differences, with older participants having a larger decrease in LDL cholesterol and apolipoprotein B levels compared with younger participants (p <0.001), women having larger increases in HDL than men (p <0.01), nonsmokers having larger decreases in LDL and triglyceride levels compared with smokers (p <0.05), those with hypertension having smaller decreases in apolipoprotein B than those without hypertension (p <0.05), and those with a larger waist circumference having a diminished lowering of triglycerides in response to treatment with simvastatin (p <0.01). In conclusion, treatment with simvastatin produced favorable lipid and lipoprotein changes among all participants. The magnitude of the lipid and lipoprotein responses, however, differed among participants according to a number of phenotypic and demographic characteristics.

Lack of a relation between vitamin and mineral antioxidants and bone mineral density: results from the Women's Health Initiative

BACKGROUND

Antioxidant defenses are one possible mechanism for decreasing oxidative damage and its potentially negative effects on age-related bone mass.

OBJECTIVE

This study cross-sectionally examined whether higher dietary intakes, total intakes, and serum concentrations of antioxidants may be associated with higher bone mineral density (BMD).

DESIGN

Total hip (and subregions), spine, and total-body BMDs were measured in 11,068 women aged 50-79 y enrolled in the Women's Health Initiative Observational Study and Clinical Trial at 3 clinics. Antioxidant intakes from diet (vitamin A, retinol, beta-carotene, vitamin C, vitamin E, and selenium) were estimated by using a self-reported food-frequency questionnaire. Antioxidants from supplements were estimated with an interviewer-administered questionnaire. A random subset (n = 379) had serum concentrations of retinol, carotenoids, and tocopherols measured.

RESULTS

After adjustment for important BMD-related covariates, increasing intakes of antioxidants were not independently associated with BMD. A significant interaction effect was observed between intake of total vitamin C (lower three-fourths compared with highest one-fourth) and use of hormone therapy (HT) (P < 0.01). The beneficial effect of current HT use on femoral neck BMD appeared to be greater in women with higher concentrations of total vitamin C. This interaction was also significant for total-body (P < 0.045), spine (P = 0.03), and total-hip BMDs (P = 0.029).

CONCLUSIONS

Our results do not support independent associations between dietary intake, total intake, or serum concentrations of antioxidants and BMD in women participating in the Women's Health Initiative. The extent to which HT use may interact with vitamin C intake and BMD warrants further exploration.

The relation of postmenopausal hormone therapy to serum uric acid and the risk of coronary heart disease events: the Heart and Estrogen-Progestin Replacement Study (HERS)

PURPOSE

To determine whether baseline serum uric acid (UA) levels and estrogen-progestin (E+P)-associated change in serum UA in postmenopausal women with coronary disease are associated with recurrent coronary heart disease (CHD) events.

METHODS

2763 postmenopausal women enrolled in the Heart and Estrogen-Progestin Replacement Study (HERS) were randomly assigned to take conjugated E+P or placebo in a secondary CHD prevention study. The primary outcome for these analyses was nonfatal myocardial infarction or CHD death during a mean follow up of 4.1 years.

RESULTS

The baseline serum UA for the cohort was 5.4 mg/dl and, compared with placebo, E+P on average lowered serum UA levels slightly (0.2 mg/dl) at one year of follow up (p<0.0001). Baseline serum UA levels were associated in simple proportional hazards models with CHD events; each standard deviation increase (1.3 mg/dl) was associated with a 22% increased risk of primary CHD events (p=.0001). This association, however, was no longer statistically significant after multivariable adjustment (p=0.36). There was no association between on-study change in serum UA level and any CHD outcome.

CONCLUSION

Treatment with E+P lowered serum UA levels slightly, but neither baseline UA nor change in UA affected CHD risk.

Yeast as a model system for anticancer drug discovery

Saccharomyces cerevisiae has been used extensively as a model for higher eukaryotes in the study of basic cellular processes. The high degree of conservation in terms of sequence similarity and function has made this organism useful in elucidating biological pathways, both yeast and human. Among these are pathways responsible for DNA damage repair and cell cycle control. This review presents an overview of opportunities for using yeast as a model system for anticancer drug discovery. It covers screens directed against specific cancer-related targets as well as contexts created by cancer-related alterations. The methodologies covered include pharmacological and genetic screens, as well as genome-wide approaches to drug target identification.

Bupropion for Smoking Cessation

BACKGROUND

Bupropion hydrochloride is recommended for smoking cessation; however, there have been relatively few clinical trials examining its efficacy.

METHODS

A total of 244 current smokers were enrolled in an outpatient randomized blinded smoking cessation trial conducted at the San Francisco Veterans Affairs Medical Center, San Francisco, Calif. Of the 244 participants, 121 received a 7-week course of bupropion and 123 received placebo. All participants received 2 months of transdermal nicotine replacement therapy and 3 months of cognitive-behavioral counseling. We determined on-medication treatment, end-of-medication treatment, 3-month, 6-month, and 1-year quit rates.

RESULTS

During treatment with bupropion vs placebo, there was a trend toward increased quit rates among participants randomized to bupropion; the self-reported end-of-medication treatment quit rates were 64% for the bupropion group vs 57% for the placebo group (P =.23). The trend favoring bupropion persisted at 3 months of follow-up (P =.12) but was not apparent at 6 months and 1 year of follow-up (both P>.78). The 12-month quit rates, validated by either saliva cotinine or spousal proxy, were 22% in the bupropion group and 28% in the placebo group (P =.31). Based on biochemical validation, 19% of the bupropion group vs 24% of the placebo group had quit smoking by 1 year (P =.36).

CONCLUSIONS

In this randomized blinded trial of mostly veteran participants, the addition of a brief 7-week bupropion trial to treatment with nicotine replacement therapy and counseling did not significantly increase smoking cessation rates.

Statin use and stroke outcomes in the Heart and Estrogen-Progestin Replacement Study (HERS)

The authors investigated the relationship between statin use and the risk of stroke in the Heart and Estrogen-Progestin Replacement Study (HERS). Despite large reductions in relative risk point estimates, statin use was not associated with differences in the risks of all fatal stroke (relative hazard [RH] 0.52, 95% CI 0.23 to 1.18, p = 0.12), fatal ischemic stroke (RH 0.51, 95% CI 0.18 to 1.45, p = 0.21), fatal hemorrhagic stroke (RH 0.18, 95% CI 0.02 to 1.46, p = 0.11), or TIA (RH 1.32, 95% CI 0.84 to 2.09, p = 0.23).

Relation of ascorbic acid to coronary artery calcium: the Coronary Artery Risk Development in Young Adults Study

Ascorbic acid is an antioxidant nutrient possibly related to the development of atherosclerosis. To examine the relation between ascorbic acid and coronary artery calcium, an indicator of subclinical coronary disease, the authors analyzed data from 2,637 African-American and White men and women aged 18-30 years at baseline who were enrolled in the Coronary Artery Risk Development in Young Adults (CARDIA) Study (1985-2001). Participants completed diet histories at enrollment and year 7, and plasma ascorbic acid levels were obtained at year 10. Coronary artery computed tomography was performed at year 15. The authors calculated odds ratios in four biologically relevant plasma ascorbic acid categories, adjusting for possible confounding variables. When compared with men with high plasma ascorbic acid levels, men with low levels to marginally low levels had an increased prevalence of coronary artery calcium (multivariate odds ratio = 2.68, 95% confidence interval: 1.31, 5.48). Among women, the association was attenuated and nonsignificant (multivariate odds ratio = 1.50, 95% confidence interval: 0.58, 3.85). Ascorbic acid intakes from diet alone and diet plus supplements were not associated with coronary artery calcium. Low to marginally low plasma ascorbic acid levels were associated with a higher prevalence of coronary artery calcium among men but not among women.

Relation of serum ascorbic acid to Helicobacter pylori serology in US adults: the Third National Health and Nutrition Examination Survey

PURPOSE

To examine the relation between serum ascorbic acid and Helicobacter pylori serology from a probability sample of US adults.

SUBJECTS AND METHODS

Data from 6,746 adults (ages 20 to 90 years) enrolled in the Third National Health and Nutrition Examination Survey (NHANES III), 1988-1994 were analyzed. Multiple logistic regression models were examined taking into account sample weights and the complex survey design of NHANES III, and controlling for the effects of potential confounders. Because race appeared to modify the association between serum ascorbic acid and seropositivity to H. pylori, we conducted the analyses stratified by race.

RESULTS

A total of 2,189 adults (32%) had a positive serology for H. pylori, and, of these, 1,175 (54%) were positive for the CagA antigen. Among whites, a 0.50 mg/dL increase in serum ascorbic acid level was associated with decreased seroprevalence of H. pylori (Odds Ratio (OR) = 0.89, 95% confidence interval (CI) CI 0.82-0.96, p < 0.01). In analyses that controlled for seroprevalence of H. pylori, a 0.50 mg/dL increase in serum ascorbic acid level among whites was independently associated with a decreased seroprevalence of the pathogenic cagA-positive strain of H. pylori (OR = 0.31, 95% CI 0.12-0.79, p < 0.05). Serum ascorbic acid levels were not significantly associated with H. pylori serology among non-whites (all p > 0.05).

CONCLUSIONS

Higher serum levels of ascorbic acid were associated with a decreased seroprevalence of H. pylori and of the pathogenic cagA-positive strain of H. pylori among whites. If these associations are related causally and are not the result of residual confounding by factors such as socioeconomic status, ascorbic acid may affect the risk of H. pylori infection and in turn, the risk for peptic ulcer disease and gastric cancer among white Americans.

Intensive smoking cessation counseling versus minimal counseling among hospitalized smokers treated with transdermal nicotine replacement: a randomized trial

PURPOSE

To determine whether an intensive cognitive-behavioral intervention begun during hospitalization when combined with transdermal nicotine replacement therapy is more effective than a minimal counseling intervention combined with transdermal nicotine replacement therapy in helping inpatients to quit smoking.

METHODS

A total of 223 patients who smoked were enrolled in a hospital-based randomized smoking cessation trial at the San Francisco Veterans Affairs Medical Center. One hundred and seven participants (48%) received intensive counseling and outpatient telephone follow-up; 116 participants (52%) received minimal counseling. All study participants received 2 months of transdermal nicotine replacement therapy. We determined 6-month quit rates by self-report and measured saliva cotinine levels or obtained proxy reports to confirm self-reported smoking cessation at 12 months. Analyses adjusted for baseline differences in the distribution of coronary disease.

RESULTS

At 6 months, 35% (36/103) of the intensive intervention group reported quitting, compared with 21% (23/109) of the comparison group (relative risk [RR] = 1.7; 95% confidence interval [CI]: 1.1 to 2.7). At 12 months, the self-reported quit rate was 33% (33/99) in the intensive intervention group versus 20% (21/103) in the comparison group (RR = 1.7; 95% CI: 1.1 to 2.7). Based on biochemical or proxy confirmation, 29% (30/102) in the intensive intervention group versus 20% (21/107) in the comparison group quit smoking at 12 months (RR = 1.6; 95% CI: 0.96 to 2.5).

CONCLUSION

Hospital-initiated smoking cessation interventions that include transdermal nicotine replacement therapy can improve long-term quit rates.

Hostility predicts recurrent events among postmenopausal women with coronary heart disease

Psychosocial characteristics may be associated with an increased risk of coronary heart disease (CHD). Whether hostility predicts recurrent coronary events is unknown. A total of 792 women in the Heart and Estrogen/progestin Replacement Study (HERS) were evaluated prospectively to determine the role of hostility as a risk factor for secondary CHD events (nonfatal myocardial infarction and CHD death). The mean age of study participants was 67 years, and the average length of follow-up was 4.1 years. The study was conducted between 1993 and 1998, and all study sites were in the United States. High Cook-Medley hostility scores were associated with greater body mass index (p = 0.01) and higher levels of serum triglycerides (p = 0.05), and they were inversely associated with high density lipoprotein cholesterol (p = 0.04), self-rated general health (p < 0.001), age (p = 0.05), and education (p = 0.001). Compared with women in the lowest hostility score quartile, women in the highest quartile were twice as likely to have had a myocardial infarction (relative hazard = 2.03, 95% confidence interval: 1.02, 4.01). The relation between hostility and CHD events was not mediated or confounded by the biologic, behavioral, and social risk factors studied. In this study, hostility was found to be an independent risk factor for recurrent CHD events in postmenopausal women.

Factor V Leiden, hormone replacement therapy, and risk of venous thromboembolic events in women with coronary disease

Oral contraceptive use in women with factor V Leiden is associated with increased rates of venous thromboembolic events (VTEs). However, the effects of hormone replacement therapy (HRT) in postmenopausal women with factor V Leiden are not known. A nested case-control study was conducted among women with established coronary disease enrolled in 2 randomized clinical trials of HRT, the Heart and Estrogen/Progestin Replacement Study (HERS) and the Estrogen Replacement and Atherosclerosis (ERA) trial. The Leiden mutation was present in 8 (16.7%) of 48 cases with VTE compared with only 7 (6.3%) of 112 controls (odds ratio [OR](Leiden) 3.3, 95% CI 1.1 to 9.8; P=0.03). In women without the factor V Leiden mutation, risk associated with HRT use was significantly increased (OR(HRT) 3.7, 95% CI 1.4 to 9.4; P<0.01). On the other hand, in women with the factor V Leiden mutation, the estimated risk associated with HRT was increased nearly 6-fold, although the CIs were wide and included unity (OR(HRT) 5.7, 95% CI 0.6 to 53.9; P=0.13). The OR for women with the Leiden mutation who were also assigned to HRT compared with wild-type women assigned to placebo was 14.1 (95% CI 2.7 to 72.4, P=0.0015). In women with the factor V Leiden mutation who were treated with HRT, the estimated absolute incidence of VTE was 15.4 of 1000 per year compared with 2.0 of 1000 per year in women without the mutation who were taking a placebo (P=0.0015). On the basis of these data, in women with coronary disease, the estimated number needed to screen for factor V Leiden to avoid an HRT-associated VTE during 5 years of treatment is 376. If factor V Leiden genotyping becomes less expensive, it could be cost effective to screen for the presence of the mutation before instituting HRT in women with coronary disease.

Subgroup interactions in the Heart and Estrogen/Progestin Replacement Study: lessons learned

BACKGROUND

The Heart and Estrogen/Progestin Replacement Study (HERS) showed no overall benefit of postmenopausal hormone treatment in women with coronary heart disease (CHD). We analyzed the HERS data to determine whether there were specific subgroups of women who responded differently to treatment, either during the first year or in the overall study.

METHODS AND RESULTS

In the search for significant treatment interactions, we analyzed a total of 86 subgroups defined by baseline characteristics. These included demographics and lifestyle factors, laboratory and physical examination variables, medical history and symptoms by self-report, medication use, and prior CHD history by chart review. We examined within-subgroup treatment effects for baseline variables that significantly interacted with treatment assignment. Under the null hypothesis, 4 (5%) of the 86 interactions would be expected to be nominally significant (P<0.05) by chance alone at each time point. Six of the interaction values were P<0.05 at 1 year, and 3 were P<0.05 at trial completion. The findings are discussed in the context of known mechanisms of action and prior scientific knowledge. Use of digitalis and history of myocardial infarction emerged as 2 possible modifiers of the effect of hormone therapy during the first year, and lipoprotein(a) emerged as a possible modifier during the overall study.

CONCLUSIONS

Extensive post hoc analyses did not identify any subgroup of HERS participants in which postmenopausal hormone treatment was clearly beneficial or harmful, but several possibilities emerged for testing in future trials.

Identification of a small molecule inhibitor of Sir2p

Sir2p is an NAD(+)-dependent histone deacetylase required for chromatin-dependent silencing in yeast. In a cell-based screen for inhibitors of Sir2p, we identified a compound, splitomicin, that creates a conditional phenocopy of a sir2 deletion mutant in Saccharomyces cerevisiae. Cells grown in the presence of the drug have silencing defects at telomeres, silent mating-type loci, and the ribosomal DNA. In addition, whole genome microarray experiments show that splitomicin selectively inhibits Sir2p. In vitro, splitomicin inhibits NAD(+)-dependent histone deacetylase activity (HDA) of the Sir2 protein. Mutations in SIR2 that confer resistance to the drug map to the likely acetylated histone tail binding domain of the protein. By using splitomicin as a chemical genetic probe, we demonstrate that continuous HDA of Sir2p is required for maintaining a silenced state in nondividing cells.

Effect of estrogen plus progestin on risk for biliary tract surgery in postmenopausal women with coronary artery disease. The Heart and Estrogen/progestin Replacement Study

BACKGROUND

Animal and observational epidemiologic studies have reported that estrogens may increase the risk for gallstones. No major clinical trials have examined the effect of estrogen plus progestin therapy in postmenopausal women on the risk for biliary tract surgery.

OBJECTIVE

To determine the effect of estrogen plus progestin on the risk for biliary tract surgery in postmenopausal women with known coronary artery disease.

DESIGN

Randomized, double-blind placebo-controlled trial of postmenopausal hormone therapy for coronary heart disease.

SETTING

20 U.S. clinical centers.

PARTICIPANTS

2253 postmenopausal women with a gallbladder, 44 to 79 years of age at baseline, in the Heart and Estrogen/progestin Replacement Study (HERS).

INTERVENTION

Conjugated equine estrogens, 0.625 mg, plus medroxyprogesterone acetate, 2.5 mg, daily in one tablet or identical placebo.

MEASUREMENTS

Documented biliary tract surgery.

RESULTS

A total of 147 women (7%) were hospitalized for biliary tract surgery in HERS. Treatment with estrogen plus progestin resulted in a marginally significant 38% increase in the relative risk for biliary tract surgery (P = 0.05). A small absolute difference in risk suggested that for every 185 women treated with estrogen plus progestin, one additional woman had biliary tract surgery per year. After adjustment for baseline and in-study statin use, the association was attenuated further (P = 0.09). After adjustment for treatment assignment and other variables, increased body mass index, fibric acid use, and a history of nonsurgical gallbladder disease were associated with an increased risk for biliary tract surgery, whereas statin use was associated with a decreased risk (for each comparison, P < 0.05).

CONCLUSION

Estrogen plus progestin therapy among postmenopausal women with known coronary disease resulted in a marginally significant increase in the risk for biliary tract surgery.

Renal insufficiency and cardiovascular events in postmenopausal women with coronary heart disease

OBJECTIVES

This study sought to determine the independent association of renal insufficiency with cardiovascular risk among women with known coronary heart disease (CHD).

BACKGROUND

Although patients with end-stage renal disease and proteinuria are at high risk for cardiovascular events, little is known about the cardiovascular risk associated with moderate renal insufficiency.

METHODS

The Heart and Estrogen/progestin Replacement Study (HERS) was a clinical trial among 2,763 women with coronary disease who were randomized to conjugated estrogen plus progestins or identical placebo and followed for a mean of 4.1 years. Women were categorized as having normal renal function (creatinine < 1.2 mg/dl; n = 2,012), mild renal insufficiency (1.2 mg/dl to 1.4 mg/dl; n = 567) and moderate renal insufficiency (>1.4 mg/dl; n = 182). We examined the independent association of renal function with incident cardiovascular events including CHD death, nonfatal myocardial infarction, hospitalization for unstable angina, stroke and transient ischemic attacks.

RESULTS

Compared with women with normal renal function, those with mild and moderate renal insufficiency were older, more likely to be black, have a history of hypertension and diabetes and have higher serum levels of triglycerides and lipoprotein(a). After multivariate adjustment, both mild (relative hazards [RH] = 1.24; 95% confidence interval [CI]: 1.0 to 1.5) and moderate renal insufficiency (RH = 1.57; 95% CI: 1.2 to 2.1) were independently associated with increased risk for cardiovascular events compared with women with normal renal function.

CONCLUSIONS

Renal insufficiency is an independent risk factor for cardiovascular events in postmenopausal women with known coronary artery disease. Renal function may add helpful information to CHD risk stratification.