Update From the Medical Journals: August 2012 - What Your Doctor Is Reading - Harvard Commentaries

What's the latest news in the medical journals this month? Find out what your doctor is reading.

Test Could Diagnose Heart Attack in One Hour
Diabetics Who Are Normal Weight When Diagnosed Die Sooner
More News in Brief: Removing Cataracts May Lower Fracture Risk; Childhood Radiation Increases Diabetes Risk; Injected Antibiotics Are Now Needed to Cure Gonorrhea Infection; Brain Hormone May Be Possible Memory-Loss Treatment

Test results to check for a heart attack can be normal within the first few hours after an attack. So, if doctors suspect a possible heart attack, they watch and closely monitor patients for 12 to 16 hours in an emergency room or hospital.

Doctors mainly use two tests to tell whether a person is having a heart attack: the electrocardiogram (ECG) and a cardiac troponin blood test. Troponin is released into the blood stream when heart muscle cells are injured. To rule out a heart attack, doctors may repeat a troponin test every 6 to 8 hours.

Now there's a new troponin test that is much more sensitive. It's called a high-sensitivity troponin test. It can detect heart damage much sooner after symptoms start.

A study in the August 13 issue of Archives of Internal Medicine reported the results of a new faster approach to diagnosing heart attacks. Researchers used the usual ECGs. They also used the new high-sensitivity troponin test.

Instead of waiting 6 to 8 hours between tests, they did a high-sensitivity troponin blood test when the patient arrived and repeated it in 1 hour. If the test result was normal and the troponin did not increase from the first to the second test, it was safe to say the patient didn't have a heart attack. Using this method, the researchers ruled out heart attack in 60% of patients. They found evidence of heart attack in 17%. And the other 23% of patients were observed and monitored further.

The Swiss study took place from April 2006 to June 2009. It included almost 900 patients who visited the ER with chest pain.

If you are overweight, you are more likely to have diabetes. And if you have diabetes, losing weight can improve your health. But about 12% of people with type 2 diabetes have a normal body mass index (a normal weight, adjusted for height) at the start of their diabetes. A new study finds that these people are more likely to die early compared with people who are overweight when they are diagnosed with diabetes. The Journal of the American Medical Association published the study August 8.

Researchers combined the results from 5 long-term studies. They included 2,600 people with diabetes. They were all over age 40. During follow-up, about 450 people died. Researchers adjusted the numbers to account for other factors, such as smoking, that affect death risk. They found that death rates during the study were 2.32 times higher among people who were not overweight when diagnosed.

One way doctors can explain this finding is by looking at body shapes. People with diabetes who have a normal body mass index are not necessarily "thin." They may have a normal weight (for their height), but still have belly fat that expands their waistlines. Doctors have known that belly fat (also called visceral fat) causes more problems for metabolism than fat in the hips, buttocks, thighs and upper arms. In this case, fat is also found inside internal organs, such as the liver.

Belly fat increases your risk of heart disease, stroke and other blood vessel diseases, in addition to diabetes. From a risk standpoint, if your BMI is high, you're better off not carrying the fat around your waist. In this study, overweight and even slightly obese people with diabetes who had a reasonable waist size (and therefore not too much belly fat) lived longer. But people of normal weight with large waists had the highest risk of early death in this study. High blood levels of triglycerides also increased risk. Triglyceride levels tend to be higher in people with more belly fat.

If you have diabetes and your waist size is greater than normal, exercise — especially weight training to build more muscle mass — is especially important.

Removing Cataracts May Lower Fracture Risk. Poor vision is one reason why older people fall. A new study has shown that people who have had cataract surgery suffer fewer hip fractures. The Journal of the American Medical Association published the study August 1.

Removing cataracts that cloud vision is a quick operation. Success rates are high. Normally, the surgery doesn't need a hospital stay. The new study focused on 1.1 million Medicare patients who were diagnosed with cataracts. Researchers compared people who had surgery with those who did not. They looked at the rate of hip fractures in the year after surgery. People who had surgery were 16% less likely to have a hip fracture. Benefit was greater for people who had severe cataracts, were at least 75 years old or had many medical problems. These groups had 22% to 28% less risk of hip fractures. This study looked only at hip fractures, not wrist fractures or other fall-related injuries. It's possible even more injuries could be prevented.

According to previous research, bifocal lenses in glasses increase the risk for falls. This is due to the way they can distort visual perception of steps. If you have fallen or have balance problems that put you at risk for falls, it's a good idea to get your eyes checked.

Childhood Radiation Increases Diabetes Risk. The Lancet Oncology reported August 22 that survivors of childhood cancer were more likely to develop diabetes as an adult if the pancreas was exposed to radiation during treatment. Kidney tumors, such as nephroblastoma, and Wilms tumor are treated with radiation. The risk for developing diabetes in adulthood is about three times greater. The pancreas produces insulin, the hormone that helps the body to use glucose (sugar).

Injected Antibiotics Are Now Needed to Cure Gonorrhea Infection. The Centers for Disease Control (CDC) has alerted doctors that gonorrhea — a common sexually transmitted infection — is getting harder to treat. Gonorrhea causes pelvic inflammatory disease and can cause infertility in women. And it causes urethritis (burning and penis discharge) in men. Less common problems from gonorrhea are arthritis and prostate infection.

Gonorrhea has become more and more resistant to antibiotics. In its latest recommendation, the CDC suggests giving an injected antibiotic, ceftriaxone, in combination with an oral antibiotic (azithromycin or doxycycline). Previously, this infection could be treated with antibiotic pills alone (no shots). Experts also recommend that all people who have the infection get retested after treatment to make sure the infection is gone. The new recommendations were published in the Morbidity and Mortality Weekly Report on August 10.

Brain Hormone May Be Possible Memory Loss Treatment. The Archives of Neurology published exciting new research online August 6. It looks at a new way to treat memory loss using a hormone that is naturally released by the brain. The hormone is "growth hormone-releasing hormone" (GHRH). With advancing age, the brain releases less of this hormone.

The study included 137 adults ages 55 to 87. Sixty-one of the patients had mild cognitive impairment (memory loss that was less severe than dementia). The other participants did not have memory loss problems. Some participants were treated with GNRH, and others were treated with a placebo. The treatment lasted for up to 20 weeks. Researchers tested the participants' memories and other cognitive skills at 30 weeks. Test scores were higher for people who received GNRH, whether or not they had memory loss at the start of the study.

This treatment has potential, but we need to study the possible side effects. We can expect longer and larger studies about the potential benefit and risks for GNRH supplements for treating some people with cognitive decline.

Mary Pickett, M.D. is an Associate professor at Oregon Health & Science University where she is a primary care doctor for adults. She supervises and educates residents in the field of Internal Medicine, for outpatient and hospital care. She is a Lecturer for Harvard Medical School and a Senior Medical Editor for Harvard Health Publications.