Kronmal, Richard A.

Moritz F Sinner, 2012 Finalist and Presenting Author

Introduction: Recent reports have linked visit-to-visit blood pressure (BP) variability to risk of mortality and stroke, independent of the effect of mean BP level. We sought to confirm these findings in the Cardiovascular Health Study (CHS), a cohort study of cardiovascular risk factors. Hypothesis: Variability in visit-to-visit SBP, defined as intraindividual SBP SD, is directly associated with risk of mortality, myocardial infarction (MI), and stroke, independent of intraindividual SBP mean and trend over time. Methods: Participants from CHS were eligible if they attended their first five annual clinic visits and did not have stroke, MI, or death by the 5th visit (N=3513). Follow-up started at the 5th visit and extended through June 2008. Analyses were further restricted to subjects who used no antihypertensive medications during the entire 5-year baseline period (non-users, n=1570) and subjects who used the same antihypertensive regimen during that time (users, n=978). Intraindividual SBP variables were defined using each subject’s 5-visit BPs. Cox proportional hazards models estimated adjusted hazard ratios (HR) per standard deviation (SD) increase in intraindividual SD (iSD) SBP or intraindividual mean (iMean) SBP. Results were stratified on medication use or non-use. Results: Participants’ mean age was 71 years, 42% were men, and 95% were white. Mean(SD) of iSD SBP was 9.8(4.6) mmHg for anti-hypertensive medications non-users and 12.0(6.0) mmHg for users. iMean SBP was significantly associated with all 3 outcomes among non-users and with stroke among users (table). iSD SBP was significantly associated with mortality in all participants and with MI among non-users; associations for stroke were not significant. Conclusion: Long-term visit-to-visit SBP variability may be an important determinant of MI and mortality risk in the elderly. Results for stroke are not consistent with other, previous reports. More research is needed to determine the clinical implications.

Background: The new 2013 ACC/AHA cholesterol guidelines recommend statin therapy to reduce atherosclerotic cardiovascular disease. Statins inhibit cholesterol biosynthesis which may impair gonadal steroidogenesis. Higher levels of estradiol (E2) and lower levels of sex hormone binding globulin (SHBG) are associated with greater central obesity, metabolic syndrome and diabetes in both men and postmenopausal women. There is however limited information regarding the impact of statins on endogenous sex hormones in large population studies. Methods: We included 3163 men and 1977 women from the baseline examination of the MESA study who had measurement of serum sex hormones: total and bioavailable testosterone (T), E2, dehydroepiandrosterone (DHEA) and SHBG, and excluded those on hormone replacement therapy and non-statin lipid medications. Results: Of the 5140 individuals examined, statin users (n=812) were 67 + 9 years old, 57% males, 41% Whites, 29% Blacks, 11% Chinese and 19% Hispanics. After adjustment for age, gender and race, total cholesterol, HDL-c and BMI, compared to non-users of statins, statin users had significantly lower SHBG by 4.5 nmol/L (95% CI; -6.1, -2.9) and DHEAS by 0.9 nmol/L (95% CI; -1.4, -0.4). No significant gender interaction with statin was seen. No association was noted between statin use and E2, total and bioavailable T. Conclusion: Statin use is associated inversely with serum SHBG and DHEA levels. This is particularly interesting in light of the association of statin use and diabetes, raising the possibility of mediation by endogenous hormones.

Background Tools for the prediction of atrial fibrillation ( AF ) may identify high‐risk individuals more likely to benefit from preventive interventions and serve as a benchmark to test novel putative risk factors. Methods and Results Individual‐level data from 3 large cohorts in the U nited S tates (Atherosclerosis Risk in Communities [ ARIC ] study, the Cardiovascular Health Study [ CHS ], and the Framingham Heart Study [ FHS ]), including 18 556 men and women aged 46 to 94 years (19% A frican A mericans, 81% whites) were pooled to derive predictive models for AF using clinical variables. Validation of the derived models was performed in 7672 participants from the Age, Gene and Environment—Reykjavik study ( AGES ) and the Rotterdam Study ( RS ). The analysis included 1186 incident AF cases in the derivation cohorts and 585 in the validation cohorts. A simple 5‐year predictive model including the variables age, race, height, weight, systolic and diastolic blood pressure, current smoking, use of antihypertensive medication, diabetes, and history of myocardial infarction and heart failure had good discrimination (C‐statistic, 0.765; 95% CI , 0.748 to 0.781). Addition of variables from the electrocardiogram did not improve the overall model discrimination (C‐statistic, 0.767; 95% CI , 0.750 to 0.783; categorical net reclassification improvement, −0.0032; 95% CI , −0.0178 to 0.0113). In the validation cohorts, discrimination was acceptable ( AGES C‐statistic, 0.664; 95% CI , 0.632 to 0.697 and RS C‐statistic, 0.705; 95% CI , 0.664 to 0.747) and calibration was adequate. Conclusion A risk model including variables readily available in primary care settings adequately predicted AF in diverse populations from the U nited S tates and E urope.