Low-Dose Pravastatin and Age-Related Differences in Risk Factors for Cardiovascular Disease in Hypercholesterolaemic Japanese Analysis of the Management of Elevated Cholesterol in the Primary Prevention Group of Adult Japanese (MEGA Study)

Background: Limited data are available regarding the relationship between age and the effect of HMG-CoA reductase inhibitor (statin) treatment. Objective: The aim of the present analysis was to evaluate the relationships between age, baseline patient characteristics, and pravastatin treatment with respect to the development of cardiovascular disease (CVD) in the Management of Elevated Cholesterol in the Primary Prevention Group of Adult Japanese (MEGA) study, a large-scale clinical study conducted in Japanese patients with mild or moderate hyperlipidaemia to evaluate the primary preventive effect of pravastatin against coronary heart disease. Methods: To compare the prevalence of CVD risk factors, the incidence of CVD in relation to each risk factor, and final values and changes in lipid parameters, the 7832 patients were classified into six age groups: <45, 45-49, 50-54, 55-59, 60-64 and >= 65 years. The relationship between pravastatin (10-20 mg/day) treatment efficacy and aging and the incidence of events in relation to the age groups were compared using the multivariable Cox proportional hazards model. Results: The prevalences of diabetes mellitus and hypertension were higher in older men than in younger men, while the prevalences of smoking and obesity were higher in younger men. However, a similar difference in risk factors was not seen in women. High-density lipoprotein cholesterol was higher in women than in men across all age groups. Triglycerides were higher in younger men than in older men and all groups of women. The mean follow-up levels of total cholesterol and low-density lipoprotein cholesterol were lower in older patients than in younger patients. Pravastatin (10-20 mg/day) reduced the risk of CVD by about 30-40% across all age groups, and there was no difference between men and women. Of particular note in this analysis, CVD risk was markedly reduced in older women compared with younger women (53% vs 30% in women aged >= 65 vs >= 45 years). Conclusion: A similar satisfactory risk reduction for CVD was achieved with low-dose pravastatin in all men and in older women in particular, despite differences in the prevalence of risk factors