Simes J.,University of Sydney |
Voysey M.,University of Sydney |
O'Connell R.,University of Sydney |
Glasziou P.,University of Oxford |
And 7 more authors.
PLoS ONE | Year: 2010
Background: When rates of uptake of other drugs differ between treatment arms in long-term trials, the true benefit or harm of the treatment may be underestimated. Methods to allow for such contamination have often been limited by failing to preserve the randomization comparisons. In the Fenofibrate Intervention and Event Lowering in Diabetes (FIELD) study, patients were randomized to fenofibrate or placebo, but during the trial many started additional drugs, particularly statins, more so in the placebo group. The effects of fenofibrate estimated by intention-to-treat were likely to have been attenuated. We aimed to quantify this effect and to develop a method for use in other long-term trials. Methodology/Principal Findings:We applied efficacies of statins and other cardiovascular drugs from meta-analyses of randomized trials to adjust the effect of fenofibrate in a penalized Cox model. We assumed that future cardiovascular disease events were reduced by an average of 24% by statins, and 20% by a first other major cardiovascular drug. We applied these estimates to each patient who took these drugs for the period they were on them. We also adjusted the analysis by the rate of discontinuing fenofibrate. Among 4,900 placebo patients, average statin use was 16% over five years. Among 4,895 assigned fenofibrate, statin use was 8% and nonuse of fenofibrate was 10%. In placebo patients, use of cardiovascular drugs was 1% to 3% higher. Before adjustment, fenofibrate was associated with an 11% reduction in coronary events (coronary heart disease death or myocardial infarction) (P = 0.16) and an 11% reduction in cardiovascular disease events (P = 0.04). After adjustment, the effects of fenofibrate on coronary events and cardiovascular disease events were 16% (P = 0.06) and 15% (P = 0.008), respectively. Conclusions/Significance:This novel application of a penalized Cox model for adjustment of a trial estimate of treatment efficacy incorporates evidence-based estimates for other therapies, preserves comparisons between the randomized groups, and is applicable to other long-term trials. In the FIELD study example, the effects of fenofibrate on the risks of coronary heart disease and cardiovascular disease events were underestimated by up to one-third in the original analysis. Trial Registration: Controlled-Trials.com ISRCTN64783481. © 2010 Simes et al.
Best J.D.,University of Melbourne |
Drury P.L.,Auckland Diabetes Center |
Davis T.M.E.,University of Western Australia |
Taskinen M.-R.,University of Helsinki |
And 5 more authors.
Diabetes Care | Year: 2012
OBJECTIVE - Glycemic control in type 2 diabetes generally worsens over time, requiring intensification of therapy. The Fenofibrate Intervention and Event Lowering in Diabetes (FIELD) trial provided the opportunity to observe glycemic control in a real-world setting. We assessed the adequacy of metformin, sulfonylureas, and insulin to maintain glycemic control and their effects on weight. RESEARCH DESIGNANDMETHODS - Diabetes control was measured at baseline and yearly for a median of 5 years in the 4,900 patients from the nonintervention arm of this study allocated to placebo. RESULTS - Median HbA 1c was 6.9% at baseline and increased by an average of 0.22% over 5 years (P < 0.001). Median weight was 86.3 kg at baseline and decreased by 0.4 kg over 5 years (P = 0.002). Baseline therapy was lifestyle measures only in 27%, oral agents without insulin in 59%, and insulin in 14%(7%also taking oral agents). Over 5 years, insulin use increased to 32% (21% also taking oral agents). Use of oral agents remained similar at 56%. Only 2% of patients at baseline and 4% after 5 years were taking oral agents other than metformin or sulfonylureas. Initiation of insulin therapy in 855 patients produced a sustained reduction of HbA 1c from a median of 8.2 to 7.7%, with a weight gain of 4.6 kg over 5 years. CONCLUSIONS - With intensification of traditional therapies, glycemic control deteriorated very little over 5 years in a large cohort of type 2 diabetes. However, the requirement for insulin therapy doubled, at the expense of significant weight gain and risk of hypoglycemia. © 2012 by the American Diabetes Association.
Risk of stroke and cardiovascular events after ischemic stroke or transient ischemic attack in patients with type 2 diabetes or metabolic syndrome: Secondary analysis of the stroke prevention by aggressive reduction in cholesterol levels (SPARCL) trial
Callahan A.,Vanderbilt University |
Amarenco P.,University Paris Diderot |
Goldstein L.B.,Duke University |
Sillesen H.,Copenhagen University |
And 8 more authors.
Archives of Neurology | Year: 2011
Objective: To perform a secondary analysis of the Stroke Prevention by Aggressive Reduction in Cholesterol Levels (SPARCL) trial, which tested the effect of treatment with atorvastatin in reducing stroke in subjects with a recent stroke or transient ischemic attack, to explore the effects of treatment in subjects with type 2 diabetes mellitus or metabolic syndrome (MetS). Methods: The 4731 subjects enrolled in the SPARCL trial were classified as having type 2 diabetes mellitus at enrollment (n = 794), MetS retrospectively (n = 642), or neither diabetes nor MetS (n = 3295, the reference group) based on data collected at baseline. Cox regression models were used to determine whether the effect of treatment on the primary end point (combined risk of nonfatal and fatal stroke) and secondary end points (major coronary events, major cardiovascular events, any coronary heart disease event, and any revascularization procedure) varied based on the presence of type 2 diabetes mellitus or MetS. Results: Subjects with type 2 diabetes mellitus had increased risks of stroke (hazard ratio [HR] = 1.62; 95% confidence interval [CI], 1.33-1.98; P < .001), major cardiovascular events (HR = 1.66; 95% CI, 1.39-1.97; P < .001), and revascularization procedures (HR = 2.39; 95% CI, 1.78-3.19; P < .001) compared with the reference group. Subjects with MetS were not at increased risk for stroke (P = .78) or major cardiovascular events (P = .38) but more frequently had revascularization procedures (HR = 1.78; 95% CI, 1.26-2.5; P = .001). There were no treatment X subgroup interactions for the SPARCL primary end point (P = .47). Conclusions: The SPARCL subjects with type 2 diabetes were at higher risk for recurrent stroke and cardiovascular events. This exploratory analysis found no difference in the effect of statin treatment in reducing these events in subjects with or without type 2 diabetes or MetS. Trial Registration: clinicaltrials.gov Identifier: NCT00147602 ©2011 American Medical Association. All rights reserved.
Volkova E.,University of Otago |
Willis J.A.,Lipid and Diabetes Research Group |
Wells J.E.,University of Otago |
Robinson B.A.,University of Otago |
And 2 more authors.
British Journal of Cancer | Year: 2011
Background:This study investigated the relationship of obesity, insulin resistance, inflammation and angiogenesis with cancer progression and survival in a colorectal cancer cohort.Methods:Clinical and pathological data, along with anthropometric and follow-up data, were collected from 344 consecutive colorectal cancer patients. Serum samples at diagnosis were analysed by immunoassay for adiponectin, C-reactive protein (CRP), vascular endothelial growth factor-A (VEGF-A), angiopoietin-2 (Ang-2), insulin-like growth factor-1 (IGF-1), insulin and C-peptide.Results:Serum Ang-2 and VEGF-A levels increased with tumour T stage (P0.007 and P<0.025, respectively) and N stage (P<0.02 and P0.03, respectively), and correlated with CRP levels (r0.43, P0.001 and r0.23, P=0.001, respectively). Angiopoietin-2 correlated with C-peptide (r0.14, P=0.007) and VEGF-A with IGF-1 in males (r0.25, P<0.001). Kaplan-Meier analysis showed that patients with high serum levels of CRP and Ang-2 had significantly reduced survival (both P=0.001). After adjusting for tumour stage and age, Ang-2 remained a significant predictor of survival. The CRP levels were inversely associated with survival in American Joint Committee on Cancer stage II patients (P≳0.038), suggesting that CRP could be used to support treatment decisions in this subgroup. Serum markers and anthropometric measures of obesity correlated with each other, but not with survival.Conclusion:Our study supports the concept that obesity-related inflammation, rather than obesity itself, is associated with colorectal cancer progression and survival. The study confirms serum Ang-2 as a predictive marker for outcome of colorectal cancer. © 2011 Cancer Research UK All rights reserved.
Waldman B.,University of Sydney |
Jenkins A.J.,University of Sydney |
Davis T.M.E.,University of Western Australia |
Taskinen M.-R.,Heart and Lung Center |
And 5 more authors.
Diabetes Care | Year: 2014
OBJECTIVE: Low HDL cholesterol (HDL-C) and small HDL particle size may directly promote hyperglycemia. We evaluated associations of HDL-C, apolipoprotein A-I (apoA-I), and HDL-C/apoA-I with insulin secretion, insulin resistance, HbA1c, and long-term glycemic deterioration, reflected by initiation of pharmacologic glucose control. RESEARCH DESIGN AND METHODS: The 5-year Fenofibrate Intervention and Event Lowering in Diabetes (FIELD) study followed 9,795 type 2 diabetic subjects. We calculated baseline associations of fasting HDL-C, apoA-I, and HDL-C/apoA-I with HbA1c and, in those not taking exogenous insulin (n = 8,271), with estimated β-cell function (homeostasis model assessment of β-cell function [HOMA-B]) and insulin resistance (HOMA-IR). Among the 2,608 subjects prescribed lifestyle only, Cox proportional hazards analysis evaluated associations of HDL-C, apoA-I, and HDL-C/apoA-I with subsequent initiation of oral hypoglycemic agents (OHAs) or insulin. RESULTS: Adjusted for age and sex, baseline HDL-C, apoA-I, and HDL-C/apoA-I were inversely associated with HOMA-IR (r = 20.233, 20.134, and 20.230; all P < 0.001; n = 8,271) but not related to HbA1c (all P > 0.05; n = 9,795). ApoA-I was also inversely associated with HOMA-B (r = 20.063; P = 0.002; n = 8,271) adjusted for age, sex, and HOMA-IR. Prospectively, lower baseline HDL-C and HDL-C/apoA-I levels predicted greater uptake (per 1-SD lower: hazard ratio [HR] 1.13 [CI 1.07-1.19], P < 0.001; and HR 1.16 [CI 1.10-1.23], P < 0.001, respectively) and earlier uptake (median 12.9 and 24.0 months, respectively, for quartile 1 vs. quartile 4; both P < 0.01) of OHAs and insulin, with no difference in HbA1c thresholds for initiation (P = 0.87 and P = 0.81). Controlling for HOMA-IR and triglycerides lessened both associations, but HDL-C/apoA-I remained significant. CONCLUSIONS: HDL-C, apoA-I, and HDL-C/apoA-I were associated with concurrent insulin resistance but not HbA1c. However, lower HDL-C and HDL-C/apoA-I predicted greater and earlier need for pharmacologic glucose control. © 2014 by the American Diabetes Association.