Common Substances That May Contribute to Resistant Hypertension, and Recommendations for Limiting Their Clinical Effects

EPO and EPO-Receptor System as Potential Actionable Mechanism for the Protection of Brain and Heart in Refractory Epilepsy and SUDEP

The most important activity of erythropoietin (EPO) is the regulation of erythrocyte production by activation of the erythropoietin receptor (EPO-R), which triggers the activation of anti-apoptotic and proliferative responses of erythroid progenitor cells. Additionally, to erythropoietic EPO activity, an antiapoptotic effect has been described in a wide spectrum of tissues. EPO low levels are found in the central nervous system (CNS), while EPO-R is expressed in most CNS cell types. In spite of EPO-R high levels expressed during the hypoxicischemic brain, insufficient production of endogenous cerebral EPO could be the cause of determined circuit alterations that lead to the loss of specific neuronal populations. In the heart, high EPO-R expression in cardiac progenitor cells appears to contribute to myocardial regeneration under EPO stimulation. Several lines of evidence have linked EPO to an antiapoptotic role in CNS and in heart tissue. In this review, an antiapoptotic role of EPO/EPO-R system in both brain and heart under hypoxic conditions, such as epilepsy and sudden death (SUDEP) has been resumed. Additionally, their protective effects could be a new field of research and a novel therapeutic strategy for the early treatment of these conditions and avoid SUDEP.

Erythropoietin improves cardiovascular function in adult rats after acute hemorrhage

Erythropoietin (EPO) has been linked to cardioprotective effects. However, its effects during the aging process are little known. We investigated the effect of EPO administration on hemodynamic parameters, cardiac function, oxidative damage, and erythropoietin receptor (EPOR) expression pattern in the hypovolemic state. EPO was administered (1000 IU/kg/3 days) and then acute hemorrhage (20% blood loss) was induced in young and adult rats. There was no difference in plasmatic EPO in either age group. The hemodynamic basal condition was similar, without alterations in renal function and hematocrit, in both age groups. After bleeding, both EPO-treated age groups had increased blood pressure at the end of the experimental protocol, being greater in adult animals. EPO attenuated the tachycardic effect. Ejection fraction and fractional shortening were higher in adult EPO-treated rats subjected to hemorrhage. In the left ventricle, young and adult EPO-treated rats subjected to bleeding showed an increased EPOR expression. A different EPOR expression pattern was observed in the adult right atrial tissue, compared with young animals. EPO treatment decreased oxidative damage to lipids in both age groups. EPO treatment before acute hemorrhage improves cardiovascular function during the aging process, which is mediated by different EPOR pattern expression in the heart tissue.

Resistant Hypertension: Diagnosis and Management

Resistant hypertension is defined as high blood pressure requiring 3 or more medications for adequate control or controlled blood pressure requiring 4 or more medications. Considering the growing prevalence of hypertension and the strong link with cardiovascular disease, it is vital to understand the causes and treatment of resistant hypertension. This review article starts with an overview of the prevalence and little-known pathophysiology of resistant hypertension. Afterward, we discuss the evaluation and management of suspected secondary resistant hypertension in 2 broad categories: pseudoresistant hypertension and true resistant hypertension. Strategies for the identification and management of pseudoresistant hypertension are addressed. In addition, causes of true resistant hypertension, such as obstructive sleep apnea, primary aldosteronism, and renal artery stenosis, are examined along with their respective treatments. Finally, treatment of resistant hypertension is reviewed including pharmacologic treatments and novel procedural interventions for resistant hypertension. Overall, the review hopes to provide practitioners with a cohesive approach for the diagnosis and treatment of resistant hypertension.

Obesity as an effect modifier of the association between menstrual abnormalities and hypertension in young adult women: Results from Project ELEFANT

BACKGROUND

The menstrual cycle is regulated by reproductive hormones such as estrogen which has been implicated in the pathogenesis of hypertension and is associated with obesity. However, to date there has scant study of hypertension in relation to menstrual characteristics and abnormalities. We hypothesize that adverse menstrual characteristics are associated with an increase the prevalence of hypertension and that this relationship is exacerbated by obesity.

METHODS

Our study leverages 178,205 healthy female participants (mean age = 29) in a population-based cross-sectional study in Tianjin, China. Menstrual characteristics including menstrual cycle length and regularity, menstrual bleeding length, menstrual blood loss and dysmenorrhea were assessed by self-reported questionnaires, and hypertension was diagnosed by physician. Multiple logistic regression models were used to assess the relationships between menstrual characteristics and hypertension.

RESULTS

Normal length menstrual cycle (OR = 1.21, 95% CI: 1.03-1.41), oligomenorrhea (OR = 1.54, 95% CI: 1.12-2.07), irregular cycle (OR = 1.54, 95% CI: 1.22-1.93), and light menstrual blood loss (OR = 1.36, 95% CI: 1.06-1.72) were associated with hypertension among women who are overweight or obese, but not among women who are normal weight. Longer menstrual bleeding duration (OR = 1.44, 95% CI: 1.24-1.67) and dysmenorrhea were associated with increased prevalence of hypertension (OR = 1.20, 95% CI: 1.14-1.41) in all young women.

CONCLUSIONS

The prevalence of hypertension is higher among women with menstrual abnormalities, and this association is modified by overweight and obesity.

Use of Prescription Medications That Potentially Interfere With Blood Pressure Control in New-Onset Hypertension and Treatment-Resistant Hypertension

BACKGROUND

Withdrawing medications that interfere with blood pressure (BP) is recommended in patients with uncontrolled BP, yet real-world use of such agents is not well characterized among individuals with hypertension. We aimed to evaluate the use of BP-interfering prescription medications among US patients with hypertension.

METHODS

This retrospective drug utilization study used medical and prescription claims (January 2008 to December 2014) in the MarketScan commercial claims database. We included adults, aged 18-65 years, with a hypertension diagnosis (International Classification of Diseases, Ninth Revision, code 401) and ≥1 antihypertensive medication fill. Two hypertension cohorts were examined-new antihypertensive drug users (incident hypertension) and patients requiring titration to a fourth antihypertensive (incident treatment-resistant hypertension [TRH]). Patient-level exposure to BP-interfering medications was assessed 6 months before and after the index date, defined as the first prescription fill of an antihypertensive drug or the first occurrence of overlapping use of ≥4 antihypertensive drugs.

RESULTS

We identified 521,028 patients with incident hypertension and 131,764 patients with incident TRH. The most prevalent BP-interfering prescription medications were nonsteroidal anti-inflammatory drugs (NSAIDs), acetaminophens, and hormones. Overall, 18.3% of the incident hypertension cohort and 17.6% of the incident TRH cohort initiated a BP-interfering medication following antihypertensive titration. Among patients previously taking a BP-interfering medication, 57.6% with incident hypertension and 64.9% with incident TRH refilled that medication after antihypertensive intensification.

CONCLUSIONS

The use of prescription BP-interfering medications, especially NSAIDs, is prevalent among patients requiring intensification of their antihypertensive regimen. Greater efforts to limit the use of these medications, where feasible, may be required among patients with uncontrolled hypertension.

Antenatal exposure to nonsteroidal anti-inflammatory drugs and risk of neonatal hypertension

Nonsteroidal anti-inflammatory drugs (NSAIDs) are used as tocolytics, which are medications that suppress uterine contractions for preterm birth prevention. Their effect on cerebral/systemic vascular beds poses the question of whether antenatal NSAID exposure is associated with neonatal hypertension. We performed a retrospective case-control study in a tertiary neonatal intensive care unit, including 40 hypertension cases (hospitalized neonates ≥ 35 weeks with systolic BP > 100 mm Hg on three consecutive days) compared to 134 controls matched by gestational age at delivery, plurality, and delivery date. Cases and controls were compared by antenatal NSAID exposure, other common tocolytics, and maternal/neonatal characteristics and complications. Multivariable logistic regression was used to estimate the odds of hypertension among those with prenatal exposure to NSAIDs versus those without exposure. Newborns with hypertension had a lower gestational age at delivery and increased incidence of neonatal complications, including respiratory distress syndrome, bronchopulmonary dysplasia, surfactant administration, longer duration of ventilation, and history of umbilical artery catheterization. Days of indomethacin exposure were positively associated with greater odds of neonatal hypertension (OR 1.17 [1.00 to 1.38], P = 0.055), even after adjustment for other factors associated with neonatal hypertension. Newborns with hypertension were less likely to have been exposed to calcium channel blockers as a tocolytic. The results of our study suggest an association between prenatal exposure to nonsteroidal anti-inflammatory drugs and neonatal hypertension. Furthermore, our data suggest that prenatal calcium channel blocker exposure may protect against the development of neonatal hypertension. Future multicenter studies are needed to understand the risks of tocolytics and subsequent consequences in preterm infants.

Erythropoietin in diabetic retinopathy

Over the past years, knowledge has expanded with regards to the multiple roles played by erythropoietin (EPO) in the body. Once believed to be a hormone synthesised in the kidney and involved only in the modulation of erythrocyte production, it is recognised now that EPO can be produced in many tissues, including the retina, and by many cells. In these tissues EPO is released in response to "tissue injury" and appears to have protective functions. Despite the extensive research conducted to date, the cues leading to release of EPO and its effects in the normal and diseased retina have not been fully elucidated. In vitro and in vivo experimental studies as well as small interventional clinical studies suggest a potential beneficial effect of externally administered EPO in early diabetic retinopathy and diabetic macular oedema. In contrast, controversy exists with regards to the possible use of EPO in proliferative diabetic retinopathy. Non-erythropoietic EPO-derived peptides, produced with the aim of increasing effectiveness and reducing side effects of EPO, are currently under investigation in early phase clinical trials.