Niacin and fibrate use among patients with high triglycerides and low high-density lipoprotein cholesterol

HDL-C Response Variability to Niacin ER in US Adults

Background. Niacin is the most effective treatment currently available for raising HDL-C levels. Objective. To evaluate if gender and baseline lipid levels have an effect on the HDL-C response of niacin ER and to identify factors that predict response to niacin ER at the 500 mg dose. Material and Methods. The change in HDL-C effect between baseline and follow-up levels was quantified in absolute change as well as dichotomized into high versus low response (high response was defined as an HDL-C effect of >15% increase and low response was HDL-C <5%) in a sample of 834 individuals. Results. Both males and females with low HDL-C levels at baseline exhibited a response to treatment in the multivariate model (males, HDL-C <40 mg/dL: OR = 5.18, 95% CI: 2.36–11.39; females, HDL-C <50 mg/dL: OR = 5.40, 95% CI: 1.84–15.79). There was also a significant difference in the mean HDL-C effect between baseline and follow-up HDL-C levels in the 500 mg niacin ER dose group for both males (mean HDL-C effect = 0.08, P < 0.001) and females (mean HDL-C effect = 0.10, P = 0.019). Conclusion. Baseline HDL-C levels are the biggest predictor of response to niacin ER treatment for both males and females among the factors evaluated.

Comparative effectiveness of statin plus fibrate combination therapy and statin monotherapy in patients with type 2 diabetes: use of propensity-score and instrumental variable methods to adjust for treatment-selection bias

PURPOSE

Type 2 diabetes is associated with increased cardiovascular risk. The comparative effectiveness of statin plus fibrate combination therapy and statin monotherapy in reducing risk of cardiovascular disease in real-world settings is unknown.

METHODS

A retrospective database analysis was performed using a large managed care claims database of patients identified with type 2 diabetes based on diagnosis codes from January 2002 through December 2003 and continuously enrolled for the entire study period, 5.5 years. A statin plus fibrate combination therapy group (patients who used statins less than 6 months and augmented with fibrates for more than 6 months) and a statin monotherapy group (patients who used statins persistently) among patients with type 2 diabetes were followed for 3 years to examine the relationship between the intervention and cardiovascular events using a multivariable logistic regression model, propensity score method, and instrumental variable approach.

RESULTS

The statin plus fibrate combination therapy group of 318 and the statin monotherapy group of 9928 were identified from 75,515 diabetics. After adjusting for factors that can impact cardiovascular outcomes, the combination therapy group did not significantly experience a reduction in cardiovascular disease, as compared with the statin monotherapy group (OR = 0.77; p = 0.083). The statin plus fibrate combination therapy group was significantly associated with a reduction in cardiovascular events after propensity matching (OR = 0.53; p = 0.002). Using the physician prescribing preference instrument to adjust for unmeasured confounding, we did not find evidence that subjects in the statin plus fibrate combination therapy group versus stain monotherapy group experienced a significant reduction in cardiovascular events (p = 0.124).

CONCLUSIONS

We did not find a difference in effectiveness regarding cardiovascular outcomes between the statin plus fibrate combination therapy and the statin monotherapy after controlling for hidden bias.

Impact of change in high-density lipoprotein cholesterol from baseline on risk for major cardiovascular events

INTRODUCTION

Low concentration of high-density lipoprotein cholesterol (HDL-C) has increasingly been recognized as a strong and independent predictor of cardiovascular risk. The aim of this study was to determine the association between change in HDL-C concentration from baseline and risk of a major cardiovascular event in a commercially insured population cohort with suboptimal HDL-C and low-density lipoprotein cholesterol (LDL-C) concentrations at baseline.

METHODS

A retrospective longitudinal survival analysis was conducted using claims data from a large, commercial US health plan. To be included, patients had to be > or =50 years of age on the index date (laboratory test date between January 1, 2000 and December 31, 2003 on which both their LDL-C and HDL-C were not at goal), be continuously enrolled for a minimum of 6 months prior to and 12 months after the index date, and had to have at least one other laboratory panel result within 1 year prior to the cardiovascular event or study disenrollment. Cox proportional hazards analysis was conducted to assess the association between change in HDL-C concentrations and risk of a major cardiovascular event (defined as a > or =1-day hospitalization for a cardiovascular disease [CVD] diagnosis or an invasive cardiovascular procedure) within 5 years of the index date, after adjusting for covariates.

RESULTS

A 0.026 mmol/L (1 mg/dL) increase in HDL-C from baseline was associated with a statistically significant 1.9% decreased risk of a major cardiovascular event (P<0.0001; hazard ratio: 0.981; 95% CI: 0.974, 0.989), after adjustment for covariates.

CONCLUSION

Our finding of an inverse association between change in HDL-C concentrations and risk of a major cardiovascular event confirms previously reported results. Increasing HDL-C concentrations may serve as an effective measure for preventing future cardiovascular events.