Background: High serum low-density lipoprotein(LDL) cholesterol and low high-density lipoprotein (HDL) cholesterol are major vascular risk factors. National surveys indicate that 40% of individuals in the United States have borderline-high LDL cholesterol, and 13-34% have low HDL. The lifetime risk of developing dyslipidemia is unknown, however.
Methods: We estimated the 10- to 30-year long-term risks of developing "borderline-high" LDL cholesterol (> or =130 mg/dL [3.4 mmol/L]), "high" LDL cholesterol (> or =160 mg/dL [4.1 mmol/L]) and "low" HDL cholesterol (<40 mg/dL [1.0 mmol/L]) in 4701 Framingham Offspring Study participants (53% women) who attended at least 2 examinations between 1971 and 2000. We performed sex-specific analyses (for age groups 30-34, 40-44, 50-54 years), and estimated risks conditional on surviving without the lipid abnormality up to the baseline age. We also estimated risks accounting for baseline prevalence of dyslipidemia (elevated LDL, low HDL).
Results: Over a 30-year period, approximately 6 of 10 participants developed borderline-high LDL, 4 of 10 people developed high LDL, and 2 (women) to 4 (men) of 10 individuals developed low HDL levels; estimates were generally similar for different age groups. Adjustment for baseline prevalence of dyslipidemia increased these estimates: 30-year risks exceeded 80% for borderline-high LDL, 50% for high LDL, and 25% (women) to 65% (men) for low HDL; 20-50% had or developed a low HDL along with a high LDL level. The 30-year estimates approximate the lifetime risk in 50-year-olds.
Conclusions: The long term risks of developing dyslipidemia are substantial in both sexes, and considerably exceed prevalence estimates from cross-sectional surveys.