Gender differences in exercise and recovery blood pressure responses in normal volunteers given diltiazem

Practice Patterns of Rate Control In Atrial Fibrillation and Clinical Outcomes From A Nationwide Cohort

Atrial fibrillation (AF) is common, but limited data to guide selection of rate control medication (RCM). Reasons for selection are multivariable, and the impact on outcomes is unknown. We investigated prescribing patterns of RCM among patients with AF. Using a nationwide database, we identified 135,927 patients with AF. We stratified by baseline presence of heart failure with reduced ejection fraction (HFrEF) and examined prescription rates of RCM as a function of clinical variables. We also evaluated associations with clinical outcomes. Beta blockers (BB) were most commonly prescribed (44.6%), then calcium channel blockers (CCB) (14.0%) and digoxin (8.6%). Patients prescribed BB were more likely male (45.6% vs 43.4%, p < 0.0001), patients prescribed CCB were less likely male (12.0% vs 16.3%, p < 0.0001). There were higher rates of HF hospitalization (HFH) among females and those with Medicaid. Randomized trials are needed to define optimal choice of RCM.

Sex and gender differences in the treatment of arterial hypertension

INTRODUCTION

Arterial hypertension represents the leading modifiable risk factor for all-cause death and early development of cardiovascular disease in women. Current clinical guidelines for the treatment of hypertension noted that women respond to antihypertensive drugs similarly to men and, therefore, treatment recommendations remain the same for both sexes. However, clinical evidence suggests the existence of sex- and gender-related differences (SGRD) in the prevalence, pathophysiology, pharmacodynamics (efficacy and safety) and pharmacokinetics of antihypertensive drugs.

AREAS COVERED

This review summarizes SGRD in the prevalence of hypertension, hypertension-mediated organ damage and blood pressure control, prescription patterns, and pharmacokinetics/ pharmacodynamics and doses of antihypertensive drugs.

EXPERT OPINION

There is limited information on SGRD in antihypertensive drug efficacy because of the underrepresentation of women in randomized clinical trials and, more important, because few trials reported results stratified by sex or performed sex-specific analyses. However, there are SGRD in hypertension-mediated organ damage, drug pharmacokinetics and, particularly, in drug safety. Prospective trials specifically designed to better understand the basis for SGRD in the pathophysiology of hypertension and in the efficacy and safety of antihypertensive drugs are needed to achieve a more personalized treatment of hypertension and hypertension-mediated organ damage in women.

Pharmacogenomics, pharmacokinetics and pharmacodynamics: interaction with biological differences between men and women

Pharmacological response depends on multiple factors and one of them is sex-gender. Data on the specific effects of sex-gender on pharmacokinetics, as well as the safety and efficacy of numerous medications, are beginning to emerge. Nevertheless, the recruitment of women for clinical research is inadequate, especially during the first phases. In general, pharmacokinetic differences between males and females are more numerous and consistent than disparities in pharmacodynamics. However, sex-gender pharmacodynamic differences are now increasingly being identified at the molecular level. It is now even becoming apparent that sex-gender influences pharmacogenomics and pharmacogenetics. Sex-related differences have been reported for several parameters, and it is consistently shown that women have a worse safety profile, with drug adverse reactions being more frequent and severe in women than in men. Overall, the pharmacological status of women is less well studied than that of men and deserves much more attention. The design of clinical and preclinical studies should have a sex-gender-based approach with the aim of tailoring therapies to an individual's needs and concerns.

Sex differences and the effects of sex hormones on hemostasis and vascular reactivity

Thrombus formation and vasospasm are involved in the initiation of acute ischemic events in the heart. Gender differences in persons with coronary artery disease and the incidence of myocardial ischemia have been clearly documented. In addition, it is well established that sex hormones influence the risk of developing coronary artery disease. Epidemiologic studies suggest that estrogen may exert a protective effect, yet the results of recently completed and ongoing prospective trials of estrogen and hormone (estrogen + progesterone) replacement suggest that these hormones can increase thrombotic events in postmenopausal women. This review focuses on sex (gender) differences in hemostasis and vascular reactivity and on the influence that sex hormones have on these physiologic systems. This review takes the novel approach of focusing on sex differences in hemostasis and vascular reactivity in healthy premenopausal women and men of a similar age. By comparing men and women in this age group, the confounding issues of age, pathology, or decline in sex hormone levels are avoided. Animal and in vitro investigations pertinent to examining potential cellular mechanism(s) of sex hormones in mediating these sex differences are discussed. We assume there is a relationship between the normal physiologic and pathologic effects of sex hormones; elucidating sex differences in normal cardiovascular function will help clarify the basis for sex differences in the incidence and manifestations of coronary heart disease and will aid in the future development of gender-specific therapies for cardiovascular disease.

Gender differences in cardiovascular regulation during recovery from exercise

Are women more susceptible to acute postexercise orthostatic hypotension compared with men? We hypothesized that decreases in arterial pressure during recovery from dynamic exercise are greater in women compared with men. We studied 8 men and 11 women during inactive and active recovery from cycling exercise. Heart rate, stroke volume (SV), cardiac output, mean arterial pressure (MAP), and total peripheral resistance (TPR) were measured during and after 3 min of exercise at 60% of calculated maximum heart rate. At 1 min after exercise, MAP decreased less (P < 0.05) during inactive recovery in men (-18 +/- 2 mmHg) compared with women (-30 +/- 2 mmHg). This difference was due to greater decreases in SV and less increase in TPR during inactive recovery from exercise in women compared with men. These differences persisted for 5 min after exercise. MAP decreased less during active recovery in men compared with women. These findings suggest that women may have increased risk of postexercise orthostatic hypotension and that active recovery from exercise may reduce this risk.

Obese female SHHF/Mcc-fa(cp) rats resist antihypertensive effects of renin-angiotensin system inhibition

Gender and obesity may influence response to pharmacological modulation of the renin-angiotensin system. We used SHHF/Mcc-fa(cp) rats to study effect of obesity and gender on the ability of an AT1 receptor antagonist to decrease blood pressure. After 2 weeks treatment with irbesartan (50 mg/kg), only lean and obese males showed significant decreases in blood pressure, while obese females were completely resistant. Lean females showed a trend toward lowering of pressure (p=0.06). However, irbesartan similarly shifted angiotensin II dose response curves to the right in all groups. Twelve weeks of irbesartan also failed to decrease blood pressure, but did significantly reduce heart weight in obese females. In untreated rats, obese females had lower plasma renin activity and serum angiotensin converting enzyme activity compared to lean males, while lean and obese females had increased urinary endothelin excretion. Despite an otherwise similar genetic background contributing to hypertension and heart failure, obese females have different patterns of humoral activation compared to lean males, which may contribute to their resistance to the depressor effects of irbesartan.

Effect of diltiazem on intraarterial blood pressure and heart rate during stress testing in patients with angina: a gender comparison study

The purpose of this study was to measure the blood pressure and electrocardiographic responses of a small, matched group of women (n = 8) and men (n = 9) who experienced typical, effort angina during an exercise on the treadmill (up to the second stage of a Bruce protocol). These responses were measured before and after therapy with diltiazem (60 mg four times daily for 1 week). Reports of previous studies have described significant gender differences in blood pressure responses to diltiazem in healthy volunteers tested with the same protocol. In contrast to the data in healthy individuals, gender differences in blood pressure responses to exercise before and after diltiazem administration were not observed. Results of analysis of pulse pressure responses to exercise were also similar in male and female patients with angina. A significant postexercise drop in blood pressure was observed, which was augmented by diltiazem. These data suggest that gender differences in drug action may be difficult to demonstrate in patients with vascular disease.