Thirteen RCTs (n=733), two of which were placebo-controlled, were included in the review.
Where reported, 2 trials were double-blinded and seven were open-labelled. Four trials used an intention-to-treat analysis and a further two were assumed to have done so. All but 2 trials failed to carried out an assessment of statistical power, and one of the two aforementioned trials failed to recruit sufficient numbers of patients to achieve 80% power. Where reported, losses to follow-up were minimal (usually one or two participants per treatment arm), with the exception of 2 trials of antiretroviral substitution where overall withdrawals were 24% and 23%; 2 trials reported no drop-outs.
Statins (3 RCTs).
One RCT reported collective reductions from baseline in Trig (34.8%), TC (25.2%) and LDL cholesterol (25.9%), with an increase in HDL cholesterol (23.9%), for pravastatin and fluvastatin, but no statistically significant differences between the two treatment arms. Similarly, a second RCT reported no statistically significant differences in TC between pravastatin with dietary advice and dietary advice alone. A third RCT reported decreases in TC (12%) and LDL cholesterol (23%) for cholestin, compared with increases in TC (4.1%) and LDL cholesterol (25.1%) for the placebo control.
Fibrates (3 RCTs).
One RCT reported collective reductions from baseline in Trig (40.7%), TC (21.9%) and LDL cholesterol (22.5%), with an increase in HDL cholesterol (19.9%), for gemfibrozil, fenofibrate and bezafibrate, but no statistically significant differences between the treatment arms. A second RCT reported reductions from baseline in Trig (40%), TC (14%), non-HDL cholesterol (17%) and LDL cholesterol (14%), with an increase in HDL cholesterol (15%), for fenofibrate, but no significant changes from baseline for vitamin E. A third RCT reported no statistically significant differences in lipid levels between gemfibrozil and placebo.
Antiretroviral substitution (6 RCTs).
All 6 RCTs reported that switching antiretrovirals was associated with overall reductions from baseline in a number of different lipid parameters, along with accompanying increases in HDL cholesterol. Positive effects were greater when switching from a protease inhibitor to abacavir versus continuing with a protease inhibitor (2 RCTs), and when switching from a protease inhibitor to efavirenz (1 RCT) or nevirapine (3 RCTs) versus continuing with a protease inhibitor.
Insulin sensitisers (1 RCT).
One RCT of metformin and rosiglitazone reported a 22% decrease in fasting Trig from baseline to follow-up in the metformin arm, whilst increases in TC (23%), LDL cholesterol (28%) and HDL cholesterol (38%) from baseline to follow-up were reported for the rosiglitazone arm.
Adverse events (13 RCTs).
Four trials (2 statin trials, an antiretroviral substitution trial and the insulin sensitiser trial) reported no adverse events. A further 4 trials (one statin, one fibrate and two antiretroviral substitution) reported no appreciable or significant differences in adverse events between the treatment and control arms. The remaining trials reported a variety of adverse events but many were mild or experienced by small numbers of participants; further details were reported in the review.