The Heart

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Women with type 2 diabetes at greater cardiovascular risk than men

While it is well established that individuals with diabetes are at higher risk for cardiovascular disease, a new scientific statement from the American Heart Association claims this risk may be significantly greater for women with the condition.
[A woman clutching her chest]
Women with type 2 diabetes are twice as likely to develop coronary heart disease than men, according to the new statement.

Published in the journal Circulation, the statement also says women with type 2 diabetes may need to take more action than men to lower their risk for heart attack and stroke.

Type 2 diabetes accounts for around 90-95% of all diabetes cases in the US, affecting men and women at similar rates; around 12.6 million women and 13 million men aged 20 and older have the condition.

According to the American Heart Association (AHA), adults with diabetes are around two to four times more likely to have heart disease or stroke than those without diabetes, primarily because diabetes patients are at greater risk for high blood pressure, high cholesterol and obesity - key risk factors for cardiovascular problems.

Increasingly, however, studies have suggested that cardiovascular risks among adults with diabetes may vary by sex, and such findings are reflected in the new AHA scientific statement.

Judith G. Regensteiner, PhD, chair of the AHA's statement writing group and professor of medicine and director of the Center for Women's Health Research at the University of Colorado School of Medicine, and coauthors claim that women with type 2 diabetes are more than twice as likely to develop coronary heart disease - the most common form of heart disease - than men.

Fast facts about diabetes

Around 29.1 million people in the US have diabetes - 1 in 11 Americans Around 86 million adults in the US have pre-diabetes As well as heart disease, diabetes can cause blindness, kidney failure and lower-extremity amputations, among other serious health complications.

Black and Hispanic women with type 2 diabetes are also disproportionately affected by coronary heart disease compared with men, the authors note.

Women with type 2 diabetes are more likely to have heart attacks earlier in life than men and are more likely to die after a first heart attack, according to the statement.

Compared with men with type 2 diabetes, women with the condition may need to engage in more frequent and intense exercise in order to lower their risk for cardiovascular disease.

Regensteiner and colleagues also point to differences between men and women with type 2 diabetes in the use of strategies to protect cardiovascular health. For example, women were less likely than men to use cholesterol-lowering drugs - such as statins - blood pressure-lowering medications and aspirin.

Women with type 2 diabetes were also less likely to have their blood pressure under control than men and were less likely to undergo procedures to open blocked arteries, such as angioplasty.

Additionally, the statement authors found women with type 2 diabetes develop the condition based on sex-specific variances, including the presence of polycystic ovary syndrome (PCOS) and gestational diabetes.

Commenting on what the statement shows, Regensteiner says:

"Cardiovascular disease may be more deadly for women with type 2 diabetes than it is for men.

While we don't fully understand how the inherent hormonal differences between men and women affect risk, we do know that some risk factors for heart disease and stroke affect women differently than men and there are disparities in how these risk factors are treated."

The authors say further research is required in order to gain a better understanding of why women with type 2 diabetes are at greater cardiovascular risk than men, as well as the reasons why women of certain ethnicities appear to be at greater risk.

"To improve health equity in women and men with diabetes, we need to understand and improve both the biological reasons for the disparities and also control cardiovascular risk factors equally in both women and men," explains Regensteiner. "This statement is a call for action to do the compelling research that is so important for all people with diabetes."

Last month, Medical News Today reported on a study that linked exposure to air pollution among women with type 2 diabetes to increased risk of cardiovascular disease and stroke.

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Chronic kidney disease patients benefit from pacing left and right ventricles

Treatment may prevent hospitalization due to heart failure, though randomized studies needed.

Patients with moderate-to-severe chronic kidney disease who received cardiac resynchronization therapy with defibrillator had a lower risk of hospitalization for heart failure or death from this condition compared to patients who received only an implantable cardioverter defibrillator, according to a study published in the Journal of the American College of Cardiology.

An implantable cardioverter defibrillator is a device implanted in the chest that detects life-threatening abnormal heartbeats and treats them with an electric shock. Cardiac resynchronization therapy with defibrillator works in a similar way, with the difference being that, in addition to delivering a shock, it can pace both ventricles at the same time.

Using data from the National Cardiovascular Data Registry ICD Registry linked with claims from the Centers for Medicare and Medicaid, researchers examined records of 10,628 patients with kidney disease who were eligible for either of these devices between January 2006 and December 2009. Of that group, 87 percent received cardiac resynchronization therapy with defibrillator.

After adjusting for many factors, including age, sex, level of chronic kidney disease, and presence of atrial fibrillation or flutter, researchers found a 15 to 20 percent reduction in the risk of hospitalization for heart failure or death from heart failure in patients who received cardiac resynchronization therapy compared with those who received an implantable cardioverter defibrillator.

Daniel J. Friedman, M.D., the study's lead author and a fellow in cardiology at Duke University Hospital, in Durham, North Carolina, said that the results from the study corroborate the observed association between cardiac resynchronization with defibrillator and improved outcomes for patients with advanced kidney disease. But the study also showed that cardiac resynchronization therapy was no more effective than implantable cardioverter defibrillators in reducing progression to advanced kidney disease.

"Taken in sum, the results from this study support the use of cardiac resynchronization therapy independent of kidney function. The treatment is associated with a reduction in risk of heart failure hospitalization and mortality. These results, however, should be confirmed by prospective randomized studies," Friedman said.

In an accompanying editorial, John G.F. Cleland, M.D., Ph.D., professor of medicine at the National Heart and Lung Institute in London, said that with only a modest reduction in hospitalization risk for heart failure and death, it is unclear whether this population actually benefits from the treatment, especially without data from a device-free control group.

"Within three years, 61 percent of those with end-stage kidney disease who received an implantable cardiac defibrillator and 54 percent who received cardiac resynchronization therapy with defibrillator had died," Cleland said. In these instances, it may be better not to "implant, at some risk and discomfort, an expensive piece of technology, which may be attended by substantial morbidity" and instead "have a frank discussion with the patient about the limits of modern medicine," he said.

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Too few adults in US taking cholesterol-lowering drugs

Nearly half of those eligible for medications to lower cholesterol are not taking them, according to findings published in the Morbidity and Mortality Weekly Report.
[high cholesterol]
Many of those eligible for cholesterol-lowering interventions are not taking them up.

From 2007-14 there was a decline in the rate of high blood levels of  cholesterol among Americans, and there has been a recent increase in the use of cholesterol-lowering medications.

However, a high blood level of LDL cholesterol, also known as "bad" cholesterol, remains a major risk factor for heart disease and stroke.

In the US, there are 78.1 million adults with high LDL cholesterol and a risk of heart disease.

These people are advised to take preventive action combining cholesterol-lowering medications with lifestyle changes, such as regular exercise, a heart-healthy diet and weight loss.

Yet, fewer than half of those eligible for the medications are taking them, and fewer than half make the recommended lifestyle changes.

Black people and Mexican Americans are particularly affected.

Who should take the medication?

The American College of Cardiology (ACC) and the American Heart Association (AHA) recommend cholesterol-lowering medications for:

Heart disease, a prior heart attack or some types of stroke, or angina LDL cholesterol levels of 190 mg/dL or more Diabetes plus LDL cholesterol levels of 70-189 mg/dL in those aged 40-75 years LDL cholesterol levels of 70-189 mg/dL and an estimated 10-year risk of heart disease of 7.5% or more in those aged 40-75 years.

Researchers from the Centers for Disease Control and Prevention (CDC) examined data from the 2005-12 National Health and Nutrition Examination Surveys.

How many people follow the advice?

Overall, 36.7% of adults in the US aged 21 years and older were eligible for cholesterol-lowering medication or were already taking it.

Of these, 55.5% were currently taking cholesterol-lowering medication, and 46.6% reported making lifestyle changes; 37.1% reported making lifestyle modifications and taking medication; 35.5% were doing neither.

Gender, race and ethnicity made a difference:

Of 40.8% of all men eligible for or already on medication, 52.9% were taking it Of 32.9% of all women eligible for or already on medication, 58.6% were taking it Of 24.2% of all Mexican-Americans eligible for or already on medication, 47.1% were taking it Of 39.5% of all black adults eligible for or already on medication, 46% were taking it Of 38.4% of all white adults eligible for or already on medication, 58% were taking it.

Black people who did not have a routine place for health care had the lowest rate of taking recommended cholesterol-lowering medication, at 5.7%.

People who had adopted a heart-healthy lifestyle were most likely to be taking cholesterol-lowering medication, at 80%.

Dr. Carla Mercado, a scientist in the CDC's Division for Heart Disease and Stroke Prevention, says:

"Nearly 800,000 people die in the US each year from cardiovascular diseases, that is 1 in every 3 deaths, and high cholesterol continues to be a major risk factor. This study reveals opportunities to reduce existing disparities through targeted patient education and cholesterol-management programs."

The US Department of Health and Human Services' "Million Hearts" initiative aims to prevent 1 million heart attacks and strokes by 2017 through various targets, including getting 65% of Americans to manage their high LDL cholesterol. 

While the study included all forms of cholesterol-lowering medication, a statin was used in nearly 90% of cases.

Medical News Today recently reported on research showing that many people give up using statins as a result of negative news stories about the drugs.

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Can cancer itself damage the heart?

Both treated and untreated cancer patients had impaired heart function.

Research presented today at EuroEcho-Imaging 2015 raises the possibility that cancer itself may damage heart muscle irrespective of exposure to cancer drug therapies. Researchers from the UK's first dedicated cardio-oncology clinic found that both treated and untreated cancer patients had impaired heart function.

The annual meeting of the European Association of Cardiovascular Imaging (EACVI), a registered branch of the European Society of Cardiology (ESC), is held 2 to 5 December 2015 in Seville, Spain.

"It is well known that chemotherapy is potentially toxic to the heart, making cancer patients more prone to cardiovascular complications such as heart failure, hypertension or myocardial ischaemia," said Dr Rajdeep S. Khattar, last author of the abstract and consultant cardiologist at the Royal Brompton Hospital in London, UK. "Our study raises the possibility that tumour growth itself may also damage the heart which could have important implications for monitoring."

The definition of cardiotoxicity is based on a reduced ejection fraction (less than 55%) and symptoms of heart failure. Ejection fraction is a coarse measure of left ventricular function and is assessed by echocardiography. It refers to the percentage of blood pumped into the circulation when the heart contracts. For example, if there is 100 ml of blood in the left ventricle and 65 ml is pumped out, the ejection fraction is 65%.

The current study applied a more subtle measure of left ventricular function using echocardiography called strain. It indicates how well the myocardial fibres contract. Previous studies have shown that cancer patients who have had chemotherapy can have a normal ejection fraction but reduced strain and that this may predict subsequent cardiotoxicity.

Dr Khattar said: "Our study carried this finding a step further to see if untreated cancer patients with a normal ejection fraction also had reduced strain measurements."

The study compared myocardial strain in three groups with a normal ejection fraction (55% or more): 43 patients with cancer who were currently being treated or had received treatment in the past, 36 patients with as yet untreated cancer, and 20 healthy individuals matched to the cancer groups for age and gender.

The researchers found that both groups of cancer patients had similarly reduced strain measurements, indicating impaired heart function, compared to the healthy individuals.

"All of the cancer patients had a preserved ejection fraction so by this coarse measure their hearts were functioning normally," said Dr Khattar. "But the strain measurements showed that they did have myocardial dysfunction."

He continued: "What was really new was the finding of reduced strain, and therefore myocardial dysfunction, in the group of patients with cancer who had not yet received treatment. This raises the possibility that the tumour itself may have a direct and deleterious effect on the function of the heart."

Patients with reduced strain before they start their cancer drug therapies may be predisposed to developing heart failure during the course of their treatment. "These patients might need closer monitoring," said Dr Khattar. "This would be a real change because at the moment, cancer patients don't, as a matter of routine, have a cardiovascular risk assessment by a cardiologist."

This is only the second study in humans which suggests that cancer might have a direct effect on the heart. A study published in September found elevated cardiovascular biomarkers in patients with as yet untreated cancer.2,3 "It could be that the tumour produces these inflammatory markers which then leads to the reduction in myocardial function that we found," said Dr Khattar.

Dr Khattar will continue to follow the patients in the current study to find out if their rates of heart failure and death are predicted by the strain measurements. He said: "If it transpires that the patients with reduced strain prior to cancer treatment are more prone to heart failure and death then it would be important to implement closer monitoring of patients with cancer than is conducted currently."

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Can meditating reduce blood pressure?

Transcendental Meditation involves sitting comfortably and closing the eyes for 20 minutes, twice a day, to achieve a quality of rest in the mind and body. A new study suggests the technique stimulates genes that produce telomerase - an enzyme linked with reduced blood pressure and mortality.
Person meditating
The new study demonstrates how Transcendental Meditation has increased telomerase gene expression in people with high blood pressure.

The new study is published in the journal PLOS One.

Previous studies have reported benefits linked to meditation; Medical News Today recently covered a study that suggested mindfulness meditation reduces pain.

And another study published earlier this year suggested meditation can reduce brain aging.

The researchers from this latest study - led by Dr. Robert Schneider, director of the Institute for Natural Medicine and Prevention at the Maharishi University of Management in Fairfield, IA - say other research into Transcendental Meditation (TM) has been linked the practice to lower rates of high blood pressure, heart attack, stroke and death.

According to the team, stress, lifestyle and telomere dysfunction contribute to hypertension and cardiovascular disease. Telomeres are stretches of DNA at the ends of chromosomes that protect our genetic data.

They have often been compared to the plastic tips on shoelaces, protecting chromosome ends from fraying, which would destroy our genetic information. Shortening of telomeres has been linked with aging, cancer and a higher risk of death.

Telomerase, meanwhile, is an enzyme made of protein and RNA units that elongates chromosomes by adding sequences to the ends.

TM shown to increase telomerase gene expression

Dr. Schneider and colleagues note that hypertension is a major risk factor for cardiovascular disease (CVD). Regarding prevalence of hypertension in the US, however, there are racial and ethnic disparities.

Namely, hypertension prevalence is 48% higher in black Americans than in white Americans, which may contribute to the 50% higher mortality rate from CVD in black Americans, compared with white Americans.

To further investigate techniques that could help with this issue, the researchers conducted a pilot trial involving 48 black men and women with high blood pressure, who were recruited and studied at Howard University Medical Center in Washington, DC.

Of the participants, half were assigned to a group that learned the TM technique and received a basic health education course, and the other half were assigned to a group that focused on achieving lifestyle modifications, including weight reduction, reducing salt intake, taking up regular physical activity and moderating alcohol intake.

Results show that after 16 weeks, both groups exhibited significant increases in telomerase gene expression and reductions in blood pressure. Furthermore, there were no major differences between the changes in the two groups.

"The finding that telomerase gene expression is increased, and that this is associated with a reduction in blood pressure in a high-risk population, suggests that this may be a mechanism by which stress reduction improves cardiovascular health," says Dr. Schneider.

He adds:

"These findings are very encouraging for prevention. They show that both the Transcendental Meditation technique and active lifestyle modification can contribute to heart health."

Study limitations

Although the findings are significant, the authors point to some study limitations.

Firstly, they did not have an inactive control group. As such, they suggest future research "might use a three-arm design, including an inactive or placebo control group."

Additionally, the sample size of the study group was quite small, at 48 participants. The team says a larger sample size "would generate the statistical power needed to either confirm or disprove these findings."

Still, coauthor Dr. Otelio Randall, from Howard University notes that their result "is valuable new information, relevant both to cardiovascular disease and to the molecular mechanisms involved in Transcendental Meditation."

In 2014, MNT published an article by Dr. Schneider that investigated meditation's benefits for mind and body.

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