Richard E. Scranton

The Association Between Statins and Cancer Incidence in a Veterans Population

BACKGROUND Meta-analyses of trials of 3-hydroxy-3-methyl-glutaryl-CoA reductase inhibitors or statins for cardiovascular disease prevention have failed to show any statistically significant benefit of statins for cancer prevention. However, these trials included relatively young participants, who develop few cancers, and their follow-up periods may have been too short to detect an association between statin use and cancer incidence. We investigated this association in a population of veterans. METHODS We identified patients using antihypertensive medications but no cholesterol-lowering medications (n = 25,594) and patients using statins (n = 37,248) who were enrolled in the Veterans Affairs New England Healthcare System between January 1, 1997, and December 31, 2005. Age- and multivariable-adjusted Cox proportional hazards models were used to calculate the hazard ratio (HR) and its 95% confidence interval (CI) for cancer incidence, excluding nonmelanoma skin cancer, among patients taking statins compared with patients taking antihypertensive medications and among patients grouped by statin dose (as equivalent simvastatin dose). All statistical tests were two-sided. RESULTS The absolute incidence of total cancers was 9.4% among statin users and 13.2% among nonusers (difference = 3.8%, 95% CI = 3.3% to 4.3%, P(difference) < .001). Statin users had a statistically significant lower risk for total cancer than nonusers after adjustment for age (HR = 0.76, 95% CI = 0.73 to 0.80) and multiple potential confounders (HR = 0.74, 95% CI = 0.70 to 0.78). After multivariable adjustment, a statistically significantly decreased risk of all cancers was also associated with increasing statin use (P(trend) < .001). CONCLUSIONS Patients using statins may be at lower risk for developing cancer. Additional observational studies and randomized trials of statins for cancer prevention are warranted.

Randomized clinical trial of quick-release bromocriptine among patients with type 2 diabetes on overall safety and cardiovascular outcomes.

OBJECTIVE Quick-release bromocriptine (bromocriptine-QR), a D2 dopamine receptor agonist, is indicated as a treatment for type 2 diabetes. The Cycloset Safety Trial, a 52-week, randomized, double-blind, multicenter trial, evaluated the overall safety and cardiovascular safety of this novel therapy for type 2 diabetes. RESEARCH DESIGN AND METHODS A total of 3,095 patients with type 2 diabetes were randomized 2:1 to bromocriptine-QR or placebo in conjunction with the patients usual diabetes therapy (diet controlled only or up to two antidiabetes medications, including insulin). The all-cause–safety end point was the occurrence of any serious adverse event (SAE), with a hazard ratio (HR) noninferiority margin of 1.5. In a prespecified analysis, the frequency of cardiovascular disease (CVD) events defined as a composite of myocardial infarction, stroke, coronary revascularization, and hospitalization for angina or congestive heart failure was evaluated using modified intent-to-treat analysis (clinicaltrials.gov, NCT00377676). RESULTS In the bromocriptine-QR group, 176 (8.6%) people reported SAEs compared with 98 (9.6%) in the placebo group (HR 1.02 [96% one-sided CI 1.27]). Fewer people reported a CVD end point in the bromocriptine-QR group versus the placebo group (37 [1.8%] vs. 32 [3.2%], respecively) (HR 0.60 [95% two-sided CI 0.35–0.96]). Nausea was the most commonly reported adverse event in the bromocriptine-QR group. CONCLUSIONS The frequency of SAEs was comparable between the treatment arms. Compared with patients in the placebo arm, fewer patients taking bromocriptine-QR experienced a cardiovascular end point.

Statins and Prostate Cancer Diagnosis and Grade in a Veterans Population

BACKGROUND Although prostate cancer is commonly diagnosed, few risk factors for high-grade prostate cancer are known and few prevention strategies exist. Statins have been proposed as a possible treatment to prevent prostate cancer. METHODS Using electronic and administrative files from the Veterans Affairs New England Healthcare System, we identified 55,875 men taking either a statin or antihypertensive medication. We used age- and multivariable-adjusted Cox proportional hazard models to calculate hazard ratios (HRs) and 95% confidence intervals (CIs) for prostate cancer incidence among patients taking statins (n = 41,078) compared with patients taking antihypertensive medications (n = 14,797). We performed similar analyses for all lipid parameters including total cholesterol examining each lipid parameter as a continuous variable and by quartiles. All statistical tests were two-sided. RESULTS Compared with men taking an antihypertensive medication, statin users were 31% less likely (HR = 0.69, 95% CI = 0.52 to 0.90) to be diagnosed with prostate cancer. Furthermore, statin users were 14% less likely (HR = 0.86, 95% CI = 0.62 to 1.20) to be diagnosed with low-grade prostate cancer and 60% less likely (HR = 0.40, 95% CI = 0.24 to 0.65) to be diagnosed with high-grade prostate cancer compared with antihypertensive medication users. Increased levels of total cholesterol were also associated with both total (HR = 1.02, 95% CI = 1.00 to 1.05) and high-grade (HR = 1.06, 95% CI = 1.02 to 1.10) prostate cancer incidence but not with low-grade prostate cancer incidence (HR = 1.01, 95% CI = 0.98 to 1.04). CONCLUSIONS Statin use is associated with statistically significantly reduced risk for total and high-grade prostate cancer, and increased levels of serum cholesterol are associated with higher risk for total and high-grade prostate cancer. These findings indicate that clinical trials of statins for prostate cancer prevention are warranted.

Bromocriptine--unique formulation of a dopamine agonist for the treatment of type 2 diabetes.

Importance to the field: There is a large unmet need for new therapies to treat type 2 diabetes (T2DM) which reduce fasting and postprandial glucose without increasing insulin levels and which are not associated with weight gain or hypoglycemia. The quick-release formulation of bromocriptine (bromocriptine-QR; Cycloset™) represents such a therapy. Areas covered in the review: Bromocriptine-QRs proposed mechanism of action, unique formulation and clinical efficacy and safety will be discussed. A Medline search was conducted using the terms: bromocriptine quick-release, circadian rhythms, treatment type 2 diabetes, insulin resistance, beta-cell dysfunction (years 1985 – 2009). What the reader will gain: The reader will gain an understanding of the importance of the brain as a target for the treatment of type 2 diabetes. In addition the safety, efficacy and indication for use of a first-in-class dopamine agonist as a treatment option for type 2 diabetes are discussed. Take home message: Bromocriptine-QR is indicated to be used alone or in conjunction with all available treatments for type 2 diabetes. Although the mechanism of action is not fully understood, bromocriptine-QRs action points to a central target in the brain (hypothalamus) which may explain the observed peripheral improvements in metabolic parameters.

Effect of Bromocriptine-QR (a Quick-Release Formulation of Bromocriptine Mesylate) on Major Adverse Cardiovascular Events in Type 2 Diabetes Subjects

Background Bromocriptine-QR (a quick-release formulation of bromocriptine mesylate), a dopamine D2 receptor agonist, is a US Food and Drug Administrration–approved treatment for type 2 diabetes mellitus (T2DM). A 3070-subject randomized trial demonstrated a significant, 40% reduction in relative risk among bromocriptine-QR-treated subjects in a prespecified composite cardiovascular (CV) end point that included ischemic-related (myocardial infarction and stroke) and nonischemic-related (hospitalization for unstable angina, congestive heart failure [CHF], or revascularization surgery) end points, but did not include cardiovascular death as a component of this composite. The present investigation was undertaken to more critically evaluate the impact of bromocriptine-QR on cardiovascular outcomes in this study subject population by (1) including CV death in the above-described original composite analysis and then stratifying this new analysis on the basis of multiple demographic subgroups and (2) analyzing the influence of this intervention on only the “hard” CV end points of myocardial infarction, stroke, and CV death (major adverse cardiovascular events [MACEs]). Methods and Results Three thousand seventy T2DM subjects on stable doses of ≤2 antidiabetes medications (including insulin) with HbA1c ≤10.0 (average baseline HbA1c=7.0) were randomized 2:1 to bromocriptine-QR (1.6 to 4.8 mg/day) or placebo for a 52-week treatment period. Subjects with heart failure (New York Heart Classes I and II) and precedent myocardial infarction or revascularization surgery were allowed to participate in the trial. Study outcomes included time to first event for each of the 2 CV composite end points described above. The relative risk comparing bromocriptine-QR with the control for the cardiovascular outcomes was estimated as a hazard ratio with 95% confidence interval on the basis of Cox proportional hazards regression. The statistical significance of any between-group difference in the cumulative percentage of CV events over time (derived from a Kaplan–Meier curve) was determined by a log-rank test on the intention-to-treat population. Study subjects were in reasonable metabolic control, with an average baseline HbA1c of 7.0±1.1, blood pressure of 128/76±14/9, and total and LDL cholesterol of 179±42 and 98±32, respectively, with 88%, 77%, and 69% of subjects being treated with antidiabetic, antihypertensive, and antihyperlipidemic agents, respectively. Ninety-one percent of the expected person-year outcome ascertainment was obtained in this study. Respecting the CV-inclusive composite cardiovascular end point, there were 39 events (1.9%) among 2054 bromocriptine-QR-treated subjects versus 33 events (3.2%) among 1016 placebo subjects, yielding a significant, 39% reduction in relative risk in this end point with bromocriptine-QR exposure (P=0.0346; log-rank test) that was not influenced by age, sex, race, body mass index, duration of diabetes, or preexisting cardiovascular disease. In addition, regarding the MACE end point, there were 14 events (0.7%) among 2054 bromocriptine-QR-treated subjects and 15 events (1.5%) among 1016 placebo-treated subjects, yielding a significant, 52% reduction in relative risk in this end point with bromocriptine-QR exposure (P<0.05; log-rank test). Conclusions These findings reaffirm and extend the original observation of relative risk reduction in cardiovascular adverse events among type 2 diabetes subjects treated with bromocriptine-QR and suggest that further investigation into this impact of bromocriptine-QR is warranted. Clinical Trial Registration URL: http://clinicaltrials.gov. Unique Identifier: NCT00377676

A randomized, double-blind, placebo-controlled trial to assess safety and tolerability during treatment of type 2 diabetes with usual diabetes therapy and either Cycloset™ or placebo

BackgroundCycloset™ is a quick-release formulation of bromocriptine mesylate, a dopamine agonist, which in animal models of insulin resistance and type 2 diabetes acts centrally to reduce resistance to insulin- mediated suppression of hepatic glucose output and tissue glucose disposal. In such animals, bromocriptine also reduces hepatic triglyceride synthesis and free fatty acid mobilization, manifesting decreases in both plasma triglycerides and free fatty acids. In clinical trials, morning administration of Cycloset™ either as monotherapy or adjunctive therapy to sulfonylurea or insulin reduces HbA1c levels relative to placebo by 0.55–1.2. Cycloset™ therapy also reduces plasma triglycerides and free fatty acid by approximately 25% and 20%, respectively, among those also receiving sulfonylurea therapies. The effects of once-daily morning Cycloset™ therapy on glycemic control and plasma lipids are demonstrable throughout the diurnal portion of the day (7 a.m. to 7 p.m.) across postprandial time points.Methods/Design3,095 individuals were randomized in a 2:1 ratio into a one year trial aimed to assess the safety and efficacy of Cycloset™ compared to placebo among individuals receiving a variety of treatments for type 2 diabetes. Eligibility criteria for this randomized placebo controlled trial included: age 30–80, HbA1c ≤ 10%, diabetes therapeutic regimen consisting of diet or no more than two hypoglycemic agents or insulin with or without one additional oral agent (usual diabetes therapy; UDT). The primary safety endpoint will test the hypothesis that the rate of all-cause serious adverse events after one year of usual diabetes therapy (UDT) plus Cycloset™ is not greater than that for UDT plus placebo by more than an acceptable margin defined as a hazard ratio of 1.5 with a secondary endpoint analysis of the difference in the rate of serious cardiovascular events, (myocardial infarction, stroke, coronary revascularization or hospitalization for or angina or congestive heart failure). Efficacy analyses will evaluate effects of Cycloset™ versus placebo on change from baseline in HbA1c, fasting glucose, body weight, waist circumference, blood pressure and plasma lipids.DiscussionThis study will extend the current data on Cycloset™ safety, tolerability and efficacy in individuals with type 2 diabetes to include its effects in combination with thiazolodinediones, insulin secretagogues, metformin, alpha-glucosidase inhibitors and exogenous insulin regimens.Trial registrationclinical trials.gov NCT00377676

Cardiovascular Benefit of Magnitude of Low-Density Lipoprotein Cholesterol Reduction A Comparison of Subgroups by Age

Background— We examined the effect of the magnitude of low-density lipoprotein cholesterol (LDL-C) reduction across subjects of various ages in a retrospective cohort study. Methods and Results— We selected 20 132 male veterans at high risk for an acute cardiovascular event and who had 2 or more LDL-C measurements before their first documented acute myocardial infarction, revascularization, death, or censoring date. LDL-C reduction was categorized as no reduction (<10 mg/dL; reference), small reduction (between 10 and 40 mg/dL), moderate reduction (between 40 and 70 mg/dL), or large reduction (≥70 mg/dL). The primary outcome was combined acute myocardial infarction or revascularization. The first and last LDL-C levels in the databases were used to calculate the LDL-C reduction in patients who experienced no outcome or who died. Within each age quartile and in a subgroup of patients ≥80 years of age, a Cox proportional hazards model was used to determine hazard ratios for each category of LDL-C reduction compared with the reference category, with adjustment for age, body mass index, current smoking status, medications, and comorbidities. In all age groups, the magnitude of LDL-C reduction was proportional to the magnitude of cardiovascular risk reduction. Risk reduction for the combined outcome in patients who achieved a large LDL-C reduction was similar in all age quartiles, with multivariate-adjusted hazard ratios of approximately 0.30. Conclusions— In a cohort of veterans at high risk for cardiovascular events, patients of all ages, including those 80 years or older, benefitted the most from large reductions in LDL-C.

Effect of bromocriptine-QR on glycemic control in subjects with uncontrolled hyperglycemia on one or two oral anti-diabetes agents.

OBJECTIVE To investigate the effect of Bromocriptine-QR on glycemic control in patients with type 2 diabetes whose glycemia is poorly controlled on one or two oral anti-diabetes agents. METHODS Five hundred fifteen Type 2 Diabetes Mellitus (T2DM) subjects (ages 18 to 80 and average body mass index [BMI] of 32.7) with baseline HbA1c ≥ 7.5 and on one or two oral anti-diabetes (OAD) medications (metformin, sulfonylurea, and/or thiazolidinediones) were randomized 2:1 to bromocriptine-QR (1.6 to 4.8 mg/day) or placebo for a 24 week treatment period. Study investigators were allowed to adjust, if necessary, subject anti-diabetes medications during the study to attempt to achieve glycemic control in case of glycemic deterioration. The impact of bromocriptine-QR treatment intervention on glycemic control was assessed in subjects on any one or two OADs (ALL treatment category) (N = 515), or on metformin with or without another OAD (Met/OAD treatment category) (N = 356), or on metformin plus a sulfonylurea (Met/SU treatment category) (N = 245) 1) by examining the between group difference in change from baseline a) concomitant OAD medication changes during the study, and b) HbA1c and 2) by determining the odds of reaching HbA1c of ≤ 7.0% on bromocriptine-QR versus placebo. RESULTS Significantly more patients (approximately 1.5 to 2-fold more; P<.05) intensified concomitant anti-diabetes medication therapy during the study in the placebo versus the bromocriptine-QR arm. In subjects that did not change the intensity of the baseline diabetes therapy (72%), and that were on any one or two OADs (ALL), or on metformin with or without another OAD (Met/OAD), or on metformin plus sulfonylurea (Met/SU), the HbA1c change for bromocriptine-QR versus placebo was -0.47 versus +0.22 (between group delta of -0.69, P<.0001), -0.55 versus +0.26 (between group delta of -0.81, P<.0001) and -0.63 versus +0.20 (between group delta of -0.83, P<.0001) respectively, after 24 weeks on therapy. The odds ratio of reaching HbA1c of ≤ 7.0% was 6.50, 12.03 and 11.45 (P<.0002) for these three groups, respectively. CONCLUSION In T2DM subjects whose hyperglycemia is poorly controlled on one or two oral agents, bromocriptine-QR therapy for 24 weeks can provide significant added improvement in glycemic control relative to adding placebo.

Randomized Clinical Trial Assessing the Efficacy and Safety of Bromocriptine-QR when Added to Ongoing Thiazolidinedione Therapy in Patients with Type 2 Diabetes Mellitus

Aims: To evaluate the glycemic control efficacy and cardio-metabolic safety of bromocriptine- quick release (Bromocriptine-QR) among subjects with type 2 diabetes who were taking a thiazolidinedione (TZD) at baseline. Methods: A subgroup from the Cycloset Safety trial who were taking a TZD at baseline with or without another oral anti-diabetes medication were randomized to receive additional once daily (morning) bromocriptine-QR (1.6 - 4.8 mg/day) or placebo for up to 52 weeks. Glycemic efficacy analyses were based on intent to treat modified (ITTm) and evaluable per protocol (EPP) population using general linear model after adjusting for baseline covariates and stratified by A1C level of <7.5 of ≥7.5. The odds ratio of participants achieving A1C ≤7% were calculated. Similar analyses for safety were performed on weight and hypoglycemia. Results: In this trial 495 subjects were taking a TZD at baseline and 122 also had a baseline A1C of ≥7.5. For subjects with an A1C of ≥7.5, bromocriptine-QR treatment led to significant reduction in A1C (ITTm -0.81%, p=0.001and EPP -0.91%, p=0.002), fasting plasma glucose (ITTm -21.5 mg/dl, p=0.03 and EPP -20.5 mg/dl, p=0.05), and higher frequency achieving an A1C≤7% (32.1% vs. 15.9%, p=0.05) when compared with placebo. For subjects with a baseline A1C of <7.5, subjects randomized to bromocriptine-QR had a greater odds of having an A1C level of ≤7.0 (OR 2.74, 95% CI 1.45, 5.15; p =0.002). Treatment with bromocriptine-QR had no adverse impact on weight or risk of hypoglycemia. Conclusion: Daily morning bromocriptine-QR added to ongoing TZD treatment for uncontrolled type 2 diabetes improved glycemic control and was well tolerated.

Timed Bromocriptine-QR Therapy Reduces Progression of Cardiovascular Disease and Dysglycemia in Subjects with Well-Controlled Type 2 Diabetes Mellitus

Background. Type 2 diabetes (T2DM) patients, including those in good glycemic control, have an increased risk of cardiovascular disease (CVD). Maintaining good glycemic control may reduce long-term CVD risk. However, other risk factors such as elevated vascular sympathetic tone and/or endothelial dysfunction may be stronger potentiators of CVD. This study evaluated the impact of bromocriptine-QR, a sympatholytic dopamine D2 receptor agonist, on progression of metabolic disease and CVD in T2DM subjects in good glycemic control (HbA1c ≤7.0%). Methods. 1834 subjects (1219 bromocriptine-QR; 615 placebo) with baseline HbA1c ≤7.0% derived from the Cycloset Safety Trial (this trial is registered with ClinicalTrials.gov Identifier: NCT00377676), a 12-month, randomized, multicenter, placebo-controlled, double-blind study in T2DM, were evaluated. Treatment impact upon a prespecified composite CVD endpoint (first myocardial infarction, stroke, coronary revascularization, or hospitalization for angina/congestive heart failure) and the odds of losing glycemic control (HbA1c >7.0% after 52 weeks of therapy) were determined. Results. Bromocriptine-QR reduced the CVD endpoint by 48% (intention-to-treat; HR: 0.52 [0.28−0.98]) and 52% (on-treatment analysis; HR: 0.48 [0.24−0.95]). Bromocriptine-QR also reduced the odds of both losing glycemic control (OR: 0.63 (0.47−0.85), p = 0.002) and requiring treatment intensification to maintain HbA1c ≤7.0% (OR: 0.46 (0.31−0.69), p = 0.0002). Conclusions. Bromocriptine-QR therapy slowed the progression of CVD and metabolic disease in T2DM subjects in good glycemic control.