Differential effects of hyperemia and passive leg raising on QRS to Korotkoff sound time intervals in hypertensive patients

Abstract

Introduction: Statin therapy is widely used to treat dyslipidemia. However, recent reports suggest that statin therapy increases the risk for type 2 diabetes mellitus (DM). Fitness lowers the risk of developing DM. The interaction between fitness, statin therapy and the risk of DM has not been investigated. Methods: We identified 3,161 hypertensive individuals on statin therapy for at least 6 months (mean age: 59.0 10.7) and no evidence of type 2 diabetes mellitus (DM) prior to initiation of statin therapy. All completed an exercise stress test at two VA Medical Centers (Washington, DC and Palo Alto, CA. We established five age-adjusted fitness categories based on peak metabolic equivalents (METs) achieved: Least-Fit ( 20%; 4.6 0.98 METs; n1⁄4733); Low-Fit (20.1%-40%; 6.2 0.80 METs; n1⁄4807); Moderate-Fit (40.1%-60%; 7.6 0.70 METs; n1⁄4799), Fit (60.1%-80%; 8.7 0.64; n1⁄4450) and High-Fit (>75%; 9.6 1.0 METs; n1⁄4377). Multivariable Cox proportional hazard model, adjusted for age, BMI, cardiac risk factors, and cardiac medications was used to assess the association between exercise capacity and the risk for developing DM2. The Least-Fit category was used as the referent. P-values <0.05 using two sided tests were considered statistically significant. Results: During a median follow-up period of 8.9 years, 1,172 developed DM2 (41.9/1,000 person-years). Exercise capacity was inversely related to DM2 incidence. The risk was 6% lower (hazard ratio, 0.94; 95% CI, 0.91-0.98) for every 1-MET increase in exercise capacity. Compared with the Least-Fit individuals, hazard ratios were: 0.78 (95% CI: 0.63-0.96) for Fit and 0.73 (95% CI: 0.58-0.93) for HighFit individuals. Conclusion: Moderate and high levels of cardiorespiratory fitness attenuated the risk of developing DM in hypertensive patients on statin therapy.