Long-term intraindividual cholesterol variability: natural course and adverse impact on morbidity and mortality--the Framingham Study.

We examined intraindividual variability in serum TC in 2912 men and women having TC measured at each of biennial examinations 2 through 7 of the FHS. RMSE described variability around the linear slope of an individual's TC during the baseline decade. Average biennial difference +/- SD was +3.7 +/- 6.7 mg/dl in men, +6.6 +/- 8.8 mg/dl in women. RMSE was < 7 mg/dl in half the group, but in the teens and twenties in the highest quartile of variability. Age-adjusted analyses showed positive associations with all-cause mortality over a 24-year period in men and a positive relation to cardiovascular and coronary incidence and mortality in both sexes. Risk ratios for highest versus lowest quartile of TC variability ranged up to 1.75. High TC variability portends excess mortality risk, and women in particular must include TC variability among their risk factors for coronary death.