Endogenous ouabain: physiological activity and pathophysiological implications.

OBJECTIVES: To compare the potential years of life saved (YOLS) associated with risk factor modification in the primary and secondary prevention of cardiovascular disease (CVD). METHODS: The CVD life expectancy model estimates the risk of death due to coronary disease, stroke, and other causes based on the levels of independent risk factors (such as age, blood pressure, and blood lipid levels) found in the cohort of the Lipid Research Clinics. The model was validated by comparing its predictions with the observed fatal outcomes of 9 randomized clinical trials. We then estimated the YOLS associated with treating hyperlipidemia or hypertension among hypothetical patient groups with and without CVD at baseline. We defined high-risk patients as those with 3 risk factors (hyperlipidemia, cigarette smoking, and hypertension) and low-risk patients as those with isolated hypertension or hyperlipidemia. RESULTS: The fatal events predicted by the model were consistent with the clinical trial results. Among men and women with hyperlipidemia without CVD, the forecasted benefits of lipid therapy were substantially greater among high-risk groups vs low-risk groups (4.74-0.78 YOLS vs 2.50-0.25 YOLS, respectively). Among those with CVD, the forecasted benefits of treatment were similar for both high-risk and low-risk groups (4.65-0.65 YOLS vs 3.84-0.58 YOLS, respectively). The results for hypertension therapy also demonstrated greater benefits for high-risk vs low-risk patients undergoing primary prevention therapy (1.34-0.29 YOLS vs 0.85-0.13 YOLS, respectively), and the forecasted benefits in secondary prevention were similar (1.26-0.23 YOLS vs 1.00-0.23 YOLS, respectively). CONCLUSIONS: The clinical approach to risk factor modification in primary prevention should be different from that in secondary prevention. The forecasted benefits of therapy among patients without CVD are greatest in the presence of other risk factors. Among those with CVD, the benefits of therapy are equivalent, thereby obviating the need to target high-risk patients.

Cardiovascular Diseases↗

PubMed1998

Mortality after the treatment of hyperthyroidism with radioactive iodine.

BACKGROUND: Hyperthyroidism affects many organ systems, but the effects are usually considered reversible. The long-term effects of hyperthyroidism on mortality are not known. METHODS: We conducted a population-based study of mortality in a cohort of 7209 subjects with hyperthyroidism who were treated with radioactive iodine in Birmingham, United Kingdom, between 1950 and 1989. The vital status of the subjects was determined on March 1, 1996, and causes of death were ascertained for those who had died. The data on the causes of death were compared with data on age-specific mortality in England and Wales. The standardized mortality ratio was used as a measure of relative risk, and the effect of covariates on mortality was assessed by regression analysis. RESULTS: During 105,028 person-years of follow-up, 3611 subjects died; the expected number of deaths was 3186 (standardized mortality ratio, 1.1; 95 percent confidence interval, 1.1 to 1.2; P<0.001). The risk was increased for deaths due to thyroid disease (106 excess deaths; standardized mortality ratio, 24.8; 95 percent confidence interval, 20.4 to 29.9), cardiovascular disease (240 excess deaths; standardized mortality ratio, 1.2; 95 percent confidence interval, 1.2 to 1.3), and cerebrovascular disease (159 excess deaths; standardized mortality ratio, 1.4; 95 percent confidence interval, 1.2 to 1.5), as well as fracture of the femur (26 excess deaths; standardized mortality ratio, 2.9; 95 percent confidence interval, 2.0 to 3.9). The excess mortality was most evident in the first year after radioiodine therapy and declined thereafter. CONCLUSIONS: Among patients with hyperthyroidism treated with radioiodine, mortality from all causes and mortality due to cardiovascular and cerebrovascular disease and fracture are increased.

Cardiovascular Diseases↗