Are people with particular blood types more susceptible to infectious diseases such as malaria?

Madhav Dhodapkar, M.B.B.S., is the chief of hematology at Yale School of Medicine, and also a professor of immunobiology. He answers: 

“Yes. There is some suggestion that the nature of blood type may impact the susceptibility to malaria. The findings emanate from studies based on epidemiology (mostly from Africa), as well as studies in the laboratory.

“While the underlying mechanism is still under study, it appears that patients with a blood group called ‘type O’ might be relatively protected (compared to those with other types such as A, B or AB) from severe infections caused by a type of malaria called ‘plasmodium falciparum.’

“It has been suggested that the blood group antigen may play a role in binding of parasites to red cells. However, as mentioned earlier, this is an area of ongoing investigation.”

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What are the warning signs of pancreatic cancer? Is there a test that can diagnose it before symptoms appear? And, is there any way to prevent it?

We turned to Yale pancreatic cancer expert Ronald Salem, M.D., professor of surgery and section chief of surgical oncology at Yale School of Medicine.  He writes: 

“Despite the many advances in cancer therapy, pancreas cancer remains one of the most difficult cancers to treat. In part this is due to the lack of early warning signs and the difficulty in detecting the condition early. Certain individuals, however, are at increased risk of developing this cancer, and careful screening of this population may allow the cancer to be picked up at an early stage.

“People who have a strong family history of cancer, a history of certain genetic disorders such as the BRCA2 population with breast cancer, for example, have a higher risk of developing pancreas cancer. Heightened attention to vague abdominal symptoms with appropriate radiological evaluation (as necessary) may help identify the condition earlier.

“Individuals who are found to have abnormal liver function tests during routine blood work need to be evaluated further. An increasing number of individuals are being found to have cysts of the pancreas during evaluation for other disorders, and while many of these have no cancer potential, some have the propensity to transform into pancreas cancer. These individuals need to be evaluated by an expert team to determine if intervention is necessary prior to the development of cancer.

“CT scans, MRI and endoscopic ultrasound are the best radiologic tests available to evaluate the pancreas. Often these tests will pick up pancreas abnormalities long before the development of clinical symptoms, allowing intervention to be carried out at an earlier stage.”

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What causes bad breath, and how can I cure it?

We turned to Mark Bianchi, M.D., ear, nose and throat specialist at Yale Medical Group. He writes: 

Bad breath or halitosis can come from chronic tonsillitis, acid reflux (GERD), allergies, smoking, diet, and lack of adequate dental care and oral hygeine.

“Consultation with a dentist or otolaryngologist may be helpful. Consideration of diet, particularly in the evening, may shed some light on this problem, especially if you are consuming coffee, alcohol or spicy foods.

“Bad breath in younger people often results from the tonsils. However, halitosis is often of unknown cause and can be more of a problem in older people.”

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Why does my own snoring not wake me up?

For this we turned to Meir Kryger, M.D., professor of pulmonary and critical care at Yale School of Medicine, and sleep medicine specialist. He writes:

“Our nervous system is continuously bombarded with information that it uses to control the many processes that keep us alive and healthy and out of danger. For example it receives information from sensors that measure oxygen and carbon dioxide to regulate breathing.

“The brain also handles sensory information so that we can see, hear, feel, taste, and smell and are able to respond to these sensations. When we sleep, the brain continues to process vital information (for example, breathing is still controlled) but it ignores the information from the sensory organs. We are disengaged from our sensations. The information is still bombarding the nervous system, but brain centers actively filter the information.

“Thus a sleeper will not hear their own snoring even when it is loud, because the brain has decided that it will not react to the snoring noise. The noise is actively filtered so that the brain will respond to a new noise or an important noise (for example a baby crying).

“If the snoring turns to apnea (breathing stops) the information from sensors that include those that measure oxygen and carbon dioxide bombard the brain and the brain will awaken the sleeper, resulting in the resumption of breathing. If this ability to awaken to danger were not present, many people would die in their sleep.”

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Is there a connection between very low blood pressure and major depressive disorder?

We turned to Gerard Sanacora, M.D., Ph.D., professor of psychiatry at Yale School of Medicine and director of the Yale Depression Research Program. He writes:

“The medical opinion on the connection between low blood pressure (hypotension) and major depressive disorder has vacillated over the years.  Prior to the 1940s, it was common for physicians to ascribe mental symptoms such as lassitude, fatigue, dizziness, sleep disturbances, anxiety and depression to a ‘constitutional hypotension’ or a ‘hypotensive syndrome.’

“Studies at the time reporting symptoms of anxiety and depression to be associated with lower blood pressure measures fostered the general acceptance that low blood pressure was related to the syndrome. However, a series of reports highlighting the various health benefits of lower blood pressure measures and evidence that individuals with the highest levels of stamina and endurance actually maintained very low blood pressure, shifted the thinking of the field away from this belief.

“More recently, this association has been reexamined with a fresh perspective.  Several studies conducted over the last decade have again reported a clear association between hypotension and symptoms of depression and anxiety, especially in the geriatric population.

“Of special interest, a large Norwegian study of 65,648 men and women found a significant association of low blood pressure with anxiety and depression. The investigators reported an approximately 40% increase in the risk for anxiety or depression in individuals with systolic blood pressure measures in the lowest 5% of the population. Although there are several potential variables that may account for this finding such as the gender, age, use of specific antihypertensive medications, and the general health of the low blood pressure subjects, considering these variables in the analysis did not change the significance of the association in the study. Thus, there is again an increasing belief that some form of relationship exists between very low blood pressures and depressive symptoms.

“It is important to be clear that the evidence of an association between low blood pressure and depressive symptoms does not mean hypotension is causing depression. The association only means that hypotension and depression are more commonly seen in the same individuals.  However, there is now interest in identifying what could be some of the common mechanisms underlying this relationship including difference in physical activity and stress reactivity, altered neuroendocrine, immune and/or autonomic regulation, and possible dysfunction of neurotransmitter systems and brain circuits regulating processes such as blood pressure and mood within the brain.”

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Will exercise make my asthma better or worse?

Geoffrey Chupp, M.D., is an associate professor of pulmonary and critical care at Yale School of Medicine, and a leading practitioner of bronchial thermoplasty, a non-drug procedure for adults with severe asthma that is not well-controlled with inhaled medications. Dr. Chupp writes: 

“Regular exercise is critically important to a healthy lifestyle, especially in individuals with chronic inflammatory diseases of the airways such as asthma and chronic obstructive lung disease (COPD). Exercise recruits the ventilation of areas of the lung that are not utilized during sedentary activities and causes the airways to dilate, enhancing lung health in all individuals.

“One of the goals of asthma management is for patients to have a normal lifestyle, including the ability to exercise without difficulty.  Since many patients with asthma have symptoms during and after exercise (cough, shortness of breath) it is recommended that patients take their rescue inhaler approximately 20 minutes before exercising. This allows the rescue medication to reach its maximal effect in preventing airway constriction prior to the onset of exercise.

“This is adequate treatment for nearly all individuals with asthma, including athletes who compete in the Olympics in aerobic sports such as swimming and long distance running.

“The Yale Center for Asthma and Airway Diseases recommends that all patients with asthma exercise regularly and use their rescue inhaler prior to exercise.  If symptoms persist while with this regimen, a visit to your physician is warranted to consider additional treatments or alternative explanations for exercise-induced symptoms.”

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Can children with type 1 diabetes live a normal life? What are the latest advances in treatment?

Although people of any age can get type 1 diabetes (which used to be referred to as ‘juvenile diabetes’), it most often strikes adolescents and teenagers. Beginning with diagnosis, diabetics must learn to inject themselves with insulin on a regular schedule, as determined by their physicians, and they have to constantly monitor what they eat and drink and the impact of what they take in on their blood sugar levels. Living with diabetes may be particularly hard for adolescents and teenagers, who do not want to be considered “different” from their peers.  But physicians say there is no reason they can’t have a normal life. For more on living with type 1 diabetes and the latest research and treatments, we turned to Yale School of Medicine clinical fellow Miladys Palau Collazo, who writes:

“Type 1 diabetes (T1D) is one of the most common, chronic diseases of childhood. It is caused by a disorder of the immune system.  The immune system, which is supposed to help us fight against bacteria and viruses, malfunctions and starts attacking and killing the insulin producing cells of the pancreas.

“Discovering that your child has T1D is overwhelming for all families.  Because the patient with T1D ends up with no insulin producing cells, parents and the children need to learn to think and act like the pancreas.

“But, if you really want me to answer the question ‘Can children with type 1 diabetes live a normal life?’, the answer is ABSOLUTELY!  It’s just a different definition of ‘normal.’  Children with diabetes can do everything children without diabetes do, like ride a bike, play competitive sports, grow up and go to college, get married and have kids of their own – it just takes extra steps and extra attention to get there.  Monitoring their blood glucose, counting carbohydrates, injecting insulin, recognizing and treating symptoms of hypoglycemia (low blood sugar) or hyperglycemia (high blood sugar), are things that children and their family have to deal with everyday.  Although diabetes care is difficult, parents and their children become experts on the condition and it quickly becomes part of their everyday routine.

“Although T1D in children requires constant care, advances in treatment have improved current management of T1D and are leading the way to an even brighter future.

“Pioneering work on insulin pump therapy was done at Yale by endocrinology specialists  William Tamborlane, Robert Sherwin and Myron Genel in the late 1970’s, and the current ‘smart’ insulin pumps make managing diabetes much better. New glucose monitoring systems, devices that measure blood sugar levels every 5 minutes throughout the day, allow patients to make real-time adjustments of their treatment regimen based on a continuous stream of blood glucose data.

“Even more exciting is the fact that our researchers are working to combine these two technologies with the help of sophisticated computer programs to develop an artificial pancreas.  How does it work? The computer reads the sensor data and tells the pump how much insulin to inject into the body.  Although it is not the cure for T1D, it will make control of diabetes much better and living with diabetes much easier.  The goal is to develop a device will be the size of a cell phone, easy to use and available to all of those that endure the daily battles of T1D.”

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Do I need to supplement my Vitamin D? I hear it is so important for cancer protection and other health benefits.

For the answer, we turned to Yale endocrinologist Elizabeth Holt, M.D., Ph.D., assistant professor at Yale School of Medicine.  Dr. Holt writes: 

“Vitamin D is needed to help calcium from your food reach the skeleton, where it keeps bones strong. Vitamin D is found in certain foods (fortified milk and cereals, oily fish, for example). In addition, your body will produce vitamin D when sunlight hits your skin during warm weather months.

“People at risk for vitamin D deficiency include the elderly, individuals with darker complexions, and those who avoid sunlight or vitamin D rich foods. The recommended daily allowance of vitamin D for adults is 600-800 international units (I.U.) daily. Higher doses of vitamin D are needed to start with for people whose levels are very low. Taking a vitamin D supplement is not necessary for everyone, but it is especially important for those who are at risk for vitamin D deficiency.

“Preliminary research studies have shown a role for vitamin D in cancer prevention.  The dose of vitamin D needed for this benefit is not yet known.

“With vitamin D supplements, there is such a thing as ‘too much of a good thing.’ Vitamin D is stored in the fat tissue and is slow to leave the body when levels are too high. High levels of vitamin D in the body can have dangerous side effects.  Therefore, it is not a good idea to take more than the recommended daily dose without a doctor’s supervision.”

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Can seizure medication (such as Keppra) cause delayed reactions, or difficulty in thinking fast?

Two epilepsy specialists at Yale, Drs. Richard Mattson and Lawrence J. Hirsch, have been the principal investigators on research in this area and have published on the tolerability of medications for epilepsy. We turned to Dr. Hirsch for an answer to this question. He writes:

“The short answer is yes, it’s possible that seizure medication can cause slower thinking.  The longer answer is that all medications that have effects on the brain could potentially slow down or affect thinking speed.  However, this is typically only at higher doses and is completely reversible.  Furthermore, the specific medication mentioned (Keppra, also known as levetiracetam), is known to be less likely to have unwanted cognitive effects such as this than some other medications.  Medications known to have more significant unwanted effects on thinking include phenobarbital and topiramate, but these medications are also well tolerated by many people.  Finally, if you are having potential side effects from your medication, please discuss this with your prescribing physician; there are many good anti-seizure medications, and it should be possible to find one that has no side effects at all for you.”

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Are antibiotics always necessary to cure a sinus infection?

Mark Bianchi, M.D., is an assistant professor of surgery at Yale School of Medicine who specializes in allergies and sinus problems.  He writes:

“Sinus infections (sinusitis) can be either viral (i.e. a common cold or flu) or bacterial. Only the bacterial infections respond to antibiotics.

“The common cause of prolonged infection is swelling and sinus obstruction or blockage. Using decongestants either in pill form (Pseudofed) or topically in the form of a spray (Afrin or Neosynephrine) can help prevent a prolonged sinus infection. Use caution not to use decongestant sprays for more than a few days or they will make you worse. Sinus rinse and nasal steroid sprays may also be useful.

“Most sinusitis is related to a cold or flu virus and does not require antibiotics. If symptoms persist for more than 5 days or come on without other associated symptoms of a cold, or are particularly severe, consult a physician for consideration of antibiotic therapy.  People with allergies or structural abnormalities such as deviated septum (the wall between the two nasal cavities) are at increased risk for sinusitis.”

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