Below are summaries of 36 key research findings published in fiscal year 2011 that advanced our knowledge of blood, cardiovascular, and lung diseases. All studies had funding support from the NHLBI.
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The antibiotic azithromycin is prescribed for bacterial infections such as pneumonia and strep throat. In August 2011, researchers reported that this medicine can help control sudden exacerbations — such as coughing, wheezing, and labored breathing — typically caused by infections in people with COPD (chronic obstructive pulmonary disease), a progressive disease that makes it hard to breathe. If this treatment proves safe in the long term, it could help many of the 12 million Americans living with COPD.
Bacterial lung infections can cause sudden worsening of COPD symptoms and lead to increased morbidity and mortality. In April 2011, researchers found that a compound in broccoli called sulforaphane helped fight serious lung infections. The compound stimulated a substance known as Nrf2, which boosted the ability of white blood cells called macrophages to engulf and destroy two types of bacteria that commonly cause lung infections. Further research could lead to new treatments for people with COPD.
Some people with asthma don't benefit as much as others from inhaled corticosteroids, the medicine most commonly used for long-term asthma control. In September 2011, researchers announced the discovery of a genetic variant that may explain why. By analyzing the DNA of children and adults enrolled in five studies, the researchers found that people with two copies of the gene variant responded only one-third as well to inhaled corticosteroids as those with two copies of the regular gene.
Scientists have known for a while that cystic fibrosis is caused by variants in a gene known as CFTR on chromosome 7. However, they couldn't explain why people with cystic fibrosis have different symptoms when they have the same CFTR variants. In June 2011, researchers reported that genetic variants on regions of chromosomes 11 and 20 can make disease symptoms milder or worse. The findings could lead to personalized treatments for cystic fibrosis.
In October 2011, researchers reported a finding that could lead to new ways to treat pneumonia. Analyzing lung fluid from people and mice with pneumonia, they found higher than normal levels of a fatty substance called cardiolipin. Additional experiments showed that elevated cardiolipin levels damaged lung tissue. The researchers found that blocking cardiolipin activity — or boosting a substance in lung cells that keeps cardiolipin in check — reduced lung injury and improved survival.
LAM, short for lymphangioleiomyomatosis, is a rare lung disease in which cancer-like cells invade and grow in the lungs, destroying lung tissue. As reported in April 2011, a clinical trial demonstrated that the transplant anti-rejection drug sirolimus can keep lung function stable for people with LAM, in addition to improving their quality of life and providing other health benefits.
To try to understand the cause of pulmonary fibrosis (scar tissue in the lungs) and identify new treatments, researchers studied families in which more than one member has the disease. In April 2011, they reported the discovery of a gene variant that leads to increased production of a lung mucus component. Relative to study participants without the variant, those with one copy of the variant were 7 times as likely to develop pulmonary fibrosis, while those with two copies were 22 times as likely.
Funding from the American Recovery and Reinvestment Act of 2009 helped bring together a national team of researchers to find groups of genes (genetic loci) in ethnically diverse groups that raise people's risk of asthma. In July 2011, after studying the genes of 18,000 people of various geographical backgrounds, with and without asthma, they reported the discovery of a gene variant associated with asthma when present in Americans and Caribbeans of African heritage.
A few small studies had suggested that albuterol, commonly used for asthma, was an effective treatment for critically ill people with acute lung injury. In May 2011, NHLBI researchers reported otherwise. Albuterol failed to control fluid accumulation, reduce time spent on ventilators, or lower the chance of death. The results — since supported by a European study — show how important it is to examine treatments that seem promising in order to confirm or refute their benefits.
Scientists have known that a protein called PAR2 promotes inflammation in allergies, arthritis, cancer, cardiovascular disease, and some lung diseases, including asthma. After many years of effort by the scientific community, in May 2011 one research team reported that they were able to design a molecule that blocks PAR2 activity and prevents severe inflammation in mice. The finding lays the foundation for treating diseases that involve PAR2 — and for developing molecules that block other inflammation-promoting proteins.
As reported in May 2011, results from a study called BABY HUG showed that hydroxyurea, a successful treatment for sickle cell disease in adults, is also safe and effective for 8- to 19-month-old children. The drug not only reduced the frequency of pain episodes and acute chest syndrome, but also improved spleen and kidney function and lowered the risk of swelling in the hands and feet. Children on hydroxyurea also needed fewer hospitalizations and blood transfusions.
Hydroxyurea works by stimulating the production of fetal hemoglobin, which alleviates sickle cell disease symptoms by making red blood cells less likely to deform and clog blood vessels. In November 2011, scientists announced a possible new way to raise fetal hemoglobin levels. By blocking a protein that stops the production of fetal hemoglobin, they were able to raise fetal hemoglobin in mice with sickle cell disease, without affecting other steps in blood formation.
In August 2011, scientists reported results of a comparison study of two treatments for severe aplastic anemia, a rare, life-threatening blood disorder. ATGAM (the only approved treatment in the United States) improved blood cell counts and patient survival significantly more than Thymoglobulin (a similar treatment used abroad). Because Thymoglobulin is the only option available in many countries, this study and necessary follow-ups may affect treatment internationally.
People with a certain type of hereditary hemorrhagic telangiectasia are likely to develop artery-and-vein tangles in the brain called arteriovenous malformations, or AVMs, which can cause strokes. Scientists assumed that brain AVMs were invariably congenital (present at birth) until recently, when researchers were able to cause their formation in adult mice by deleting a gene and injecting a growth factor. The finding not only offers a new way of thinking about brain AVMs but also provides a mouse model for future research.
People with blood disorders known as myelodysplastic syndromes don't make enough blood cells and are at high risk of developing leukemia. Treatments are tailored to each patient based on the patient's predicted outcome. In June 2011, researchers studying the genes of more than 400 people with the syndromes reported the identification of mutations in 18 genes that were linked to clinical outcomes. The discovery may one day help doctors choose the right treatments and better predict how patients will fare.
Transplants of hematopoietic (blood cell-forming) stem cells can treat certain diseases by replacing abnormal blood cells with healthy new ones. To improve outcomes, researchers have been trying to observe blood cells in the first few days after transplantation — but it's hard to see deep inside bones, where they've migrated. In January 2011, one team made a breakthrough. They developed an innovative procedure allowing them to peer inside a thin skull bone in mice and watch the cells in real time.
Previous studies suggested that some people with chronic fatigue syndrome had xenotropic murine leukemia virus-related virus (XMRV) or polytropic murine leukemia viruses (P-MLVs) in their blood, raising concerns that the syndrome could be spread through blood transfusions. However, a September 2011 study was unable to reproducibly detect the viruses in blood samples from those people. This led federal officials to conclude that the viruses do not appear to pose a threat to the nation's blood supply, so screening blood donors for them is not warranted.
High blood pressure affects more than a billion people. An international team of scientists studied the genomes of 200,000 people, looking for differences (variants) in DNA related to blood pressure. The study, published in October 2011, found a number of previously unsuspected variants that influence blood pressure, providing new insights into the genetics and biology of blood pressure.
In April 2011, scientists reported that they had developed a three-dimensional model of the main protein component of HDL as it occurs naturally in the body. HDL's nickname "good" cholesterol comes from its ability to grab artery-clogging cholesterol from cells and help dispose of it. Knowing the structure of this HDL protein should help researchers mimic its function and perhaps ultimately develop new drugs to prevent atherosclerosis.
Some people who have a disorder called long QT syndrome type 1 are at high risk for sudden death. Their heart muscle cells have defective ion channels (which control how charged molecules move through the cells) that can result in arrhythmias. A study published in March 2011 showed that certain mutations in the ion channel gene were specifically linked with increased risk for sudden death.
Study results published in February 2011 suggest that elevated C-reactive protein levels and abnormal heart rate turbulence may be risk factors for heart disease in older adults who would typically be classified as low risk using traditional criteria. Heart rate turbulence is a momentary alteration in the heart rate after a rhythm disturbance known as premature ventricular contraction. Both factors were found to be associated with increased risk of death from heart disease, regardless of whether other risk factors were present.
Diabetes causes serious damage to multiple organs over time, but the condition is often present for years before diagnosis. In April 2011, scientists reported that unusually high blood levels of five naturally occurring amino acids signaled the future development of diabetes. This finding may point to opportunities for early detection and prevention of diabetes.
As reported in September 2011, researchers made a surprising link between Parkinson's disease and fat metabolism. When a gene known to be involved in early-onset Parkinson's disease was removed from mice, they did not gain weight when fed a high-fat diet. The researchers then collected and studied cells from people enrolled in the NIH Parkinson's Clinic, and learned that the human cells had difficulty absorbing fat.
As reported in February 2011, for a brief period after birth the mammalian heart appears to be able to mend itself. After scientists removed a small portion of the hearts of day-old mice, healthy and scarless heart tissue grew back fully within three weeks, but that was not the case with 7-day-old mice. The findings will guide future study of factors that enable the heart to heal, with the hope that the capacity for regeneration may someday be extended to older ages.
Heart disease is often diagnosed years after damage has already occurred in the body's blood vessels. For example, the cholesterol buildup that clogs arteries often starts in adolescence. Although atherosclerosis is known to be caused by both unhealthy diet and genetic factors, researchers have more to learn. A study published in September 2011 identified five DNA regions linked to atherosclerosis, which may provide new clues for early prevention and treatment.
Having unhealthy blood cholesterol levels raises a person's risk of developing heart disease. Lowering LDL ("bad" cholesterol) decreases the risk of cardiovascular events such as heart attacks and strokes, but raising HDL ("good" cholesterol) has not been shown to do so. A clinical trial called AIM-HIGH evaluated the impact of raising HDL via high-dose, extended-release niacin in patients who already had cardiovascular disease and were given statin drugs for LDL control. As reported in December 2011, even though the niacin raised HDL substantially, it did not reduce the occurrence of cardiovascular events.
HDL guards heart health by grabbing cholesterol and helping remove it from the bloodstream. A study published in January 2011 showed that one measure of HDL function — cholesterol efflux capacity, an indicator of how well HDL collects cholesterol from white blood cells called macrophages — may be a better gauge of heart disease risk than the amount of HDL in the blood.
Genetics and diet are known to affect heart disease risk. In a study published in April 2011, researchers identified another possible culprit. They found a novel pathway linking dietary fat intake, harmless intestinal bacteria ("gut flora"), and heart disease. When the gut flora metabolize a fat (phosphatidylcholine), by-products are formed that promote development of atherosclerosis. This finding suggests that variations in gut flora may influence the development of heart disease.
In heart failure, the heart can't pump enough blood to meet the body's needs. A recent clinical trial in patients with chronic heart failure and severe coronary heart disease compared two treatments: bypass surgery combined with medications or medications alone. After following study participants for five years, scientists reported in April 2011 that medication and surgery together resulted in fewer heart-related hospital stays and deaths from cardiovascular causes than medication alone. There was no significant difference between the two treatments in the primary outcome, deaths from any cause.
Most people whose heart suddenly stops beating die before they reach the hospital. As reported in January 2011, a new cardiopulmonary resuscitation (CPR) technique that uses two new devices has been shown to improve survival rates of people who have cardiac arrest outside of a hospital setting. The two devices improve blood circulation by enhancing chest rebound and controlling air flow into the lungs.
It is well known that lifestyle choices affect type 2 diabetes risk. In a study published in September 2011, researchers examined how combinations of recommended behaviors — following a healthy diet, keeping a healthy weight, being physically active, limiting alcohol use, and not smoking — related to risk reduction. They found that each behavior alone reduced risk of developing diabetes, and people who practiced all five behaviors were substantially less likely to develop diabetes.
Until recently, researchers hypothesized that if people with diabetes maintained unusually strict control of their blood glucose (sugar) levels, they could prevent heart attacks, strokes, and death. As published in March 2011, long-term follow-up of participants in the Action to Control Cardiovascular Risk in Diabetes (ACCORD) trial confirmed that an intensive glucose-lowering treatment strategy did not lower participants' risk for cardiovascular events. Researchers also found that the intensive glucose-lowering strategy resulted in more deaths than did usual care.
In April 2011, researchers reported analysis of health outcomes in postmenopausal women with a previous hysterectomy who had taken estrogen for an average of six years in the Women's Health Initiative estrogen-alone trial. They found that excess rates of stroke and blood clots among estrogen users — reasons for halting the trial in 2004 — disappeared during the ensuing four years. Estrogen use during the trial did not increase or decrease the subsequent risks for death, heart disease, colorectal cancer, or hip fractures, and breast cancer risk decreased. Health outcomes were better for younger women than for older women.
Scientists reported in July 2011 that a gene therapy treatment for heart failure tested well in a pig model. In this study, a harmless virus was used as a carrier to deliver a corrective gene to the hearts of pigs in which heart failure had been induced. After gene therapy, the pigs' heart function had improved and no toxicity was detected. If the findings are confirmed in future clinical trials, this therapy could become an important component of treatment for patients with end-stage heart failure.
About 80 percent of people who experience thoracic aortic aneurysms — "ballooning" weaknesses in artery walls that can be fatal if they burst or dissect — have no identifiable risk factors and therefore receive no preventive treatment. In September 2011, researchers who studied the DNA of 1,300 people with sporadic aneurysms or dissections reported the discovery of several associated genetic variants. Because the variants are near the mutation that causes Marfan syndrome, a known risk factor for aneurysms, researchers hope emerging treatments for Marfan syndrome might also benefit the people with sporadic disease.
Studies have shown that sleep apnea (pauses in breathing or shallow breaths during sleep) can raise people's risk of cardiovascular disease and other conditions. In August 2011, researchers conducting the Multi Ethnic Study of Atherosclerosis (MESA) reported that adults with sleep apnea were twice as likely as adults without sleep apnea to develop cardiovascular problems or to die of any cause over a period of about 7.5 years. The risk couldn't be explained by age or other factors known to influence cardiovascular disease development.
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Last Updated: February 2012