Dataset Information

Effect on cardiovascular risk of high density lipoprotein targeted drug treatments niacin, fibrates, and CETP inhibitors: meta-analysis of randomised controlled trials including 117,411 patients.

ABSTRACT:

Objective

To investigate the effects on cardiovascular outcomes of drug interventions that increase high density lipoprotein levels.

Design

Meta-analysis.

Studies reviewed

Therapeutic benefit of niacin, fibrates, and cholesteryl ester transfer protein (CETP) inhibitors on cardiovascular events (all cause mortality, coronary heart disease mortality, non-fatal myocardial infarction, and stroke).

Results

117,411 patients were randomised in a total of 39 trials. All interventions increased the levels of high density lipoprotein cholesterol. No significant effect was seen on all cause mortality for niacin (odds ratio 1.03, 95% confidence interval 0.92 to 1.15, P=0.59), fibrates (0.98, 0.89 to 1.08, P=0.66), or CETP inhibitors (1.16, 0.93 to 1.44, P=0.19); on coronary heart disease mortality for niacin (0.93, 0.76 to 1.12, P=0.44), fibrates (0.92, 0.81 to 1.04, P=0.19), or CETP inhibitors (1.00, 0.80 to 1.24, P=0.99); or on stroke outcomes for niacin (0.96, 0.75 to 1.22, P=0.72), fibrates (1.01, 0.90 to 1.13, P=0.84), or CETP inhibitors (1.14, 0.90 to 1.45, P=0.29). In studies with patients not receiving statins (before the statin era), niacin was associated with a significant reduction in non-fatal myocardial infarction (0.69, 0.56 to 0.85, P=0.0004). However, in studies where statins were already being taken, niacin showed no significant effect (0.96, 0.85 to 1.09, P=0.52). A significant difference was seen between these subgroups (P=0.007). A similar trend relating to non-fatal myocardial infarction was seen with fibrates: without statin treatment (0.78, 0.71 to 0.86, P<0.001) and with all or some patients taking statins (0.83, 0.69 to 1.01, P=0.07); P=0.58 for difference.

Conclusions

Neither niacin, fibrates, nor CETP inhibitors, three highly effective agents for increasing high density lipoprotein levels, reduced all cause mortality, coronary heart disease mortality, myocardial infarction, or stroke in patients treated with statins. Although observational studies might suggest a simplistic hypothesis for high density lipoprotein cholesterol, that increasing the levels pharmacologically would generally reduce cardiovascular events, in the current era of widespread use of statins in dyslipidaemia, substantial trials of these three agents do not support this concept.

SUBMITTER: Keene D

PROVIDER: S-EPMC4103514 | biostudies-literature |

REPOSITORIES: biostudies-literature

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Project description:BackgroundThe effects of increasing high-density lipoprotein cholesterol on cardiovascular outcomes remain uncertain.DesignWe conducted a meta-analysis to investigate the effects of high-density lipoprotein cholesterol modifiers (niacin, fibrates and cholesteryl ester transfer protein inhibitors) on cardiovascular outcomes.MethodsThirty-one randomized controlled trials (154,601 patients) with a follow-up of 6 months or more and a sample size of 100 or more patients were selected using MEDLINE, EMBASE and CENTRAL database (inception January 2018).ResultsHigh-density lipoprotein cholesterol modifiers had no statistically significant effect on cardiovascular mortality in terms of relative risk (RR) (RR 0.94, 95% confidence interval (CI) 0.89-1.00, P = 0.05, I2 = 13%) or absolute risk (risk difference -0.0001, 95% CI -0.0014, 0.0011, P = 0.84, I2 = 28%). High-density lipoprotein cholesterol modifiers reduced the RR of myocardial infarction (RR 0.87, 95% CI 0.82-0.93, P < 0.001, I2 = 37%). This significant effect was derived by the use of fibrates (RR 0.80, 95% CI 0.73-0.87, P < 0.001, I2 = 22%) and meta-regression analysis showed that this benefit was consistent with an absolute reduction in low-density lipoprotein cholesterol. High-density lipoprotein cholesterol modifiers had no effect on stroke (RR 1.00, 95% CI 0.93-1.09, P = 0.94, I2 = 25%) or all-cause mortality (RR 1.02, 95% CI 0.97-1.08, P = 0.48, I2 = 49%). Meta-regression analyses failed to demonstrate a significant association of pharmacologically increased high-density lipoprotein cholesterol with key endpoints. In studies with background statin therapy, high-density lipoprotein cholesterol modifiers had no statistically significant impact on cardiovascular mortality, myocardial infarction, stroke or all-cause mortality ( P > 0.05).ConclusionThe use of high-density lipoprotein cholesterol modifying treatments had no significant effect on cardiovascular mortality, stroke or all-cause mortality. The beneficial effect on myocardial infarction was lost when drugs were used with statin therapy.

Project description:To examine the effects of treatments with niacin or anacetrapib (an inhibitor of cholesteryl ester transfer protein) on the ability of high-density lipoprotein (HDL) to promote net cholesterol efflux and reduce toll-like receptor-mediated inflammation in macrophages.A total of 18 patients received niacin, 2 g/d, for 4 weeks; 20 patients received anacetrapib, 300 mg/d, for 8 weeks; and 2 groups (n=4 and n=5 patients) received placebo. HDL samples were isolated by polyethylene glycol precipitation or ultracentrifugation, tested for the ability to promote cholesterol efflux in cholesterol-loaded THP-I or mouse peritoneal macrophages, or used to pretreat macrophages, followed by lipopolysaccharide exposure. HDL cholesterol levels were increased by 30% in response to niacin and by approximately 100% in response to anacetrapib. Niacin treatment increased HDL-mediated net cholesterol efflux from foam cells, primarily by increasing HDL concentration, whereas anacetrapib treatment increased cholesterol efflux by both increasing HDL concentration and causing increased efflux at matched HDL concentrations. The increased efflux potential of anacetrapib-HDL was more prominent at higher HDL cholesterol concentrations (>12 microg/mL), which was associated with an increased content of lecithin-cholesterol acyltransferase (LCAT) and apolipoprotein E and completely dependent on the expression of ATP binding cassette transporters (ABCA1 and ABCG1). Potent antiinflammatory effects of HDL were observed at low HDL concentrations (3 to 20 microg/mL) and were partly dependent on the expression of ABCA1 and ABCG1. All HDL preparations showed similar antiinflammatory effects, proportionate to the HDL cholesterol concentration.Niacin treatment caused a moderate increase in the ability of HDL to promote net cholesterol efflux, whereas inhibition of cholesteryl ester transfer protein via anacetrapib led to a more dramatic increase in association with enhanced particle functionality at higher HDL concentrations. All HDLs exhibited potent ability to suppress macrophage toll-like receptor 4-mediated inflammatory responses, in a process partly dependent on cholesterol efflux via ABCA1 and ABCG1.

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