A meta-analysis of 27 prospective studies published before 2000 found a significant association between elevated plasma lipoprotein(a) [Lp(a)] levels and an increased risk of coronary heart disease (CHD). The study included 5436 CHD cases and a weighted mean follow-up of 10 years. Comparing individuals in the top third of baseline Lp(a) measurements with those in the bottom third yielded a combined risk ratio of 1.6 (95% CI 1.4 to 1.8), with similar findings in 18 general population studies (1.7, 95% CI 1.4 to 1.9). There was no significant heterogeneity among the results from these studies. Lp(a) was only weakly correlated with classical vascular risk factors, and adjusting for these factors had little effect on the risk ratios. The study concluded that while there is a clear association between Lp(a) and CHD, further research is needed to determine if this association is causal. The results suggest that individuals with higher Lp(a) levels have approximately a 70% increased risk of CHD compared to those with lower levels. However, the association was less pronounced in studies involving patients with preexisting disease, though these studies may be less relevant to establishing causality. The study also noted that Lp(a) concentrations are not strongly correlated with classical vascular risk factors, and that adjustments for these factors did not significantly alter the risk ratios. The meta-analysis avoided bias by comparing cases directly with controls within the same studies, and there was no significant heterogeneity in the risk ratios among the 18 population-based studies. However, the study acknowledged potential limitations, including the possibility of underestimation due to regression dilution and suboptimal blood storage conditions. Further research is needed to determine the role of Lp(a) in the causation of CHD, particularly with the use of individual participant data and studies on genetic polymorphisms associated with Lp(a) concentrations.A meta-analysis of 27 prospective studies published before 2000 found a significant association between elevated plasma lipoprotein(a) [Lp(a)] levels and an increased risk of coronary heart disease (CHD). The study included 5436 CHD cases and a weighted mean follow-up of 10 years. Comparing individuals in the top third of baseline Lp(a) measurements with those in the bottom third yielded a combined risk ratio of 1.6 (95% CI 1.4 to 1.8), with similar findings in 18 general population studies (1.7, 95% CI 1.4 to 1.9). There was no significant heterogeneity among the results from these studies. Lp(a) was only weakly correlated with classical vascular risk factors, and adjusting for these factors had little effect on the risk ratios. The study concluded that while there is a clear association between Lp(a) and CHD, further research is needed to determine if this association is causal. The results suggest that individuals with higher Lp(a) levels have approximately a 70% increased risk of CHD compared to those with lower levels. However, the association was less pronounced in studies involving patients with preexisting disease, though these studies may be less relevant to establishing causality. The study also noted that Lp(a) concentrations are not strongly correlated with classical vascular risk factors, and that adjustments for these factors did not significantly alter the risk ratios. The meta-analysis avoided bias by comparing cases directly with controls within the same studies, and there was no significant heterogeneity in the risk ratios among the 18 population-based studies. However, the study acknowledged potential limitations, including the possibility of underestimation due to regression dilution and suboptimal blood storage conditions. Further research is needed to determine the role of Lp(a) in the causation of CHD, particularly with the use of individual participant data and studies on genetic polymorphisms associated with Lp(a) concentrations.