Effect of estrogen receptor modulator tamoxifen on blood pressure, plasma renin activity, and renal sodium excretion

Development of cardiometabolic risk factors following endocrine therapy in women with breast cancer

PURPOSE

Studies comparing the effect of aromatase inhibitor (AI) and tamoxifen use on cardiovascular disease (CVD) risk factors in hormone receptor-positive breast cancer (BC) survivors report conflicting results. We examined associations of endocrine therapy use with incident diabetes, dyslipidemia, and hypertension.

METHODS

The Pathways Heart Study examines cancer treatment exposures with CVD-related outcomes in Kaiser Permanente Northern California members with BC. Electronic health records provided sociodemographic and health characteristics, BC treatment, and CVD risk factor data. Hazard ratios (HR) and 95% confidence intervals (CI) of incident diabetes, dyslipidemia, and hypertension in hormone receptor-positive BC survivors using AIs or tamoxifen compared with survivors not using endocrine therapy were estimated using Cox proportional hazards regression models adjusted for known confounders.

RESULTS

In 8985 BC survivors, mean baseline age and follow-up time was 63.3 and 7.8 years, respectively; 83.6% were postmenopausal. By treatment, 77.0% used AIs, 19.6% used tamoxifen, and 16.0% used neither. Postmenopausal women who used tamoxifen had an increased rate (HR 1.43, 95% CI 1.06-1.92) of developing hypertension relative to those who did not use endocrine therapy. Tamoxifen use was not associated with incident diabetes, dyslipidemia, or hypertension in premenopausal BC survivors. Postmenopausal AI users had higher hazard rates of developing diabetes (HR 1.37, 95% CI 1.05-1.80), dyslipidemia (HR 1.58, 95% CI 1.29-1.92), and hypertension (HR 1.50, 95% CI 1.24-1.82) compared with non-endocrine therapy users.

CONCLUSION

Hormone receptor-positive BC survivors treated with AIs may have higher rates of developing diabetes, dyslipidemia, and hypertension over an average 7.8 years post-diagnosis.

Development of cardiometabolic risk factors following endocrine therapy in women with breast cancer

PURPOSE

Studies comparing the effect of aromatase inhibitor (AI) and tamoxifen use on cardiovascular disease (CVD) risk factors in hormone-receptor positive breast cancer (BC) survivors report conflicting results. We examined associations of endocrine therapy use with incident diabetes, dyslipidemia, and hypertension.

METHODS

The Pathways Heart Study examines cancer treatment exposures with CVD-related outcomes in Kaiser Permanente Northern California members with BC. Electronic health records provided sociodemographic and health characteristics, BC treatment, and CVD risk factor data. Hazard ratios (HR) and 95% confidence intervals (CI) of incident diabetes, dyslipidemia, and hypertension in hormone-receptor positive BC survivors using AIs or tamoxifen compared with survivors not using endocrine therapy were estimated using Cox proportional hazards regression models adjusted for known confounders.

RESULTS

In 8,985 BC survivors, mean baseline age and follow-up time was 63.3 and 7.8 years, respectively; 83.6% were postmenopausal. By treatment, 77.0% used AIs, 19.6% used tamoxifen, and 16.0% used neither. Postmenopausal women who used tamoxifen had an increased rate (HR: 1.43, 95% CI: 1.06-1.92) of developing hypertension relative to those who did not use endocrine therapy. Tamoxifen use was not associated with incident diabetes, dyslipidemia, or hypertension in premenopausal BC survivors. Postmenopausal AI users had higher hazard rates of developing diabetes (HR: 1.37, 95% CI: 1.05-1.80), dyslipidemia (HR: 1.58, 95% CI: 1.29-1.92) and hypertension (HR: 1.50, 95% CI: 1.24-1.82) compared with non-endocrine therapy users.

CONCLUSION

Hormone-receptor positive BC survivors treated with AIs may have higher rates of developing diabetes, dyslipidemia, and hypertension over an average 7.8 years post-diagnosis.

Increased cardiovascular risk factors in breast cancer survivors identified by routine measurements of body composition, resting heart rate and arterial blood pressure

Purpose

The main objective of this prospective study was to obtain a better understanding of the body composition and vital sign measures of cancers survivors (CS) when compared to regular (R) patients.

Methods

A total of 9,315 female patients were evaluated: 476 CS and 8,839 R patients. Kinesiologists worked side by side with the medical/oncology team to collect a number of base-line measurements on body composition, resting heart rate, and blood pressure as part of the standard intake evaluation during the female patients’ annual checkup.

Results

CS were more likely to have a higher BMI (P = 0.001) and a larger waist circumference (P = 0.001) than R patients. CS were also shown to have higher blood pressure values: diastolic pressure of 76.9 mmHg ± 10.5 VS 75.5 mmHg ± 9.9, (P = 0.01) and systolic pressure of 129.8 mmHg ± 17.2 VS 126.7 mmHg ±17.4 (P = 0.001) compared to R patients, respectively. Regression analysis looking at the relationship between mean arterial pressure and waist circumference did not show any difference between the two groups (CS vs R).

Conclusion

CS who had a higher BMI, a larger waist circumference and higher blood pressure levels, are probably at greater risk for developing cardiovascular disease, diabetes, various musculoskeletal problems as well as an increased risk for various forms of cancers including reoccurrence of previously treated cancer when compared to R patients. Changes in body composition should be considered by the medical team when looking at preventative healthcare strategies for their CS patients.

Knockdown of parathyroid hormone related protein in smooth muscle cells alters renal hemodynamics but not blood pressure

Parathyroid hormone-related protein (PTHrP) belongs to vasoactive factors that regulate blood pressure and renal hemodynamics both by reducing vascular tone and raising renin release. PTHrP is expressed in systemic and renal vasculature. Here, we wanted to assess the contribution of vascular smooth muscle cell endogenous PTHrP to the regulation of cardiovascular and renal functions. We generated a mouse strain (SMA-CreERT2/PTHrPL2/L2 or premutant PTHrPSM-/-), which allows temporally controlled, smooth muscle-targeted PTHrP knockdown in adult mice. Tamoxifen treatment induced efficient recombination of PTHrP-floxed alleles and decreased PTHrP expression in vascular and visceral smooth muscle cells of PTHrPSM-/- mice. Blood pressure remained unchanged in PTHrPSM-/- mice, but plasma renin concentration and creatinine clearance were reduced. Renal hemodynamics were further analyzed during clearance measurements in anesthetized mice. Conditional knockdown of PTHrP decreased renal plasma flow and glomerular filtration rate with concomitant reduction in filtration fraction. Similar measurements were repeated during acute saline volume expansion. Saline volume expansion induced a rise in renal plasma flow and reduced filtration fraction; both were blunted in PTHrPSM-/- mice leading to impaired diuresis. These findings show that endogenous vascular smooth muscle PTHrP controls renal hemodynamics under basal conditions, and it is an essential factor in renal vasodilation elicited by saline volume expansion.