Cholesterol reduction yields clinical benefits: meta-analysis including recent trials.
BACKGROUND
Previous meta-analyses reported by Gould et al found significant decreases of 15% in the risk for coronary heart disease (CHD)-related mortality and 11 % in risk for all-cause mortality per decrease of 10% in total cholesterol (TC) level.


OBJECTIVE
To evaluate the effects of reducing cholesterol on clinical events after including data from recent clinical trials.


METHODS
Using a literature search (MeSH key terms, including: bezafibrate, coronary disease, efficacy, gemfibrozil, hydroxymethylglutaryl-CoA reductase inhibitors, hypercholesterolemia, niacin [nicotinic acids], randomized controlled trials, and treatment outcome; years: 1999-2005), we identified trials published in English that assessed the effects of lipid-modifying therapies on CHD end points, including CHD-related death, myocardial infarction, and angina pectoris. We also included all studies from the previously published meta-analysis. Using the same analytic approach as previously, we determined the effects of net absolute reductions (1 mmol/L [38.7 mg/dL]) in TC and low-density lipoprotein cholesterol (LDL-C) on the relative risks (RRs) for all-cause mortality, CHD-related mortality, any CHD event (mortality or nonfatal myocardial infarction), and non-CHD-related mortality.


RESULTS
We included 62 studies involving 216,616 patients, including 126,474 from 24 randomized controlled trials the findings of which were published since the previous meta-analysis (1998). Among all patients, for every 1-mmol/L decrease in TC, there was a 17.5 reduction in RR for all-cause mortality; 24.5 %, for CHD-related mortality; and 29.5% for any CHD event. Corresponding reductions for every 1-mmol/L decrease in LDL-C were 15.6%, 28.0%, and 26.6%, respectively. Similar relationships were observed in patients without CHD. No significant relationship was found between lipid reduction and non-CHD-related mortality risk.


CONCLUSIONS
The results from the present analysis support conclusions from previous meta-analyses that cholesterol lowering is clinically beneficial in patients with CHD or at elevated CHD risk. These results also support the previous finding that non-CHD-related mortality is unrelated to lipid reductions.
Gould
A Lawrence
AL
Merck Research Laboratories, West Point, Pennsylvania, USA. Electronic address: goulda@merck.com.
Davies
Glenn M
GM
Merck Research Laboratories, West Point, Pennsylvania, USA.
Alemao
Evo
E
OutComes Research, Merck & Co., Inc., Whitehouse Station, Newjersey, USA.
Yin
Donald D
DD
OutComes Research, Merck & Co., Inc., Whitehouse Station, Newjersey, USA.
Cook
John R
JR
Merck Research Laboratories, West Point, Pennsylvania, USA.
D000924:Anticholesteremic Agents / Q000627:therapeutic use*; D002784:Cholesterol / Q000097:blood; D008078:Cholesterol, LDL / Q000097:blood; D003327:Coronary Disease / Q000453:epidemiology / Q000401:mortality / Q000517:prevention & control*; D006801:Humans; D009203:Myocardial Infarction / Q000453:epidemiology / Q000517:prevention & control; D016896:Treatment Outcome
D000924:Anticholesteremic Agents; D008078:Cholesterol, LDL; D002784:Cholesterol