 | What Your Doctor Is Reading | | |
Update From the Medical Journals: November 2007
November 27, 2007  By Mary Pickett, M.D.
Harvard Medical School What's the latest news in the medical journals this month? Find out what your doctor is reading. Children Who Sleep Less Are More Likely To Become Overweight Does your child's bedtime determine whether he or she will become overweight in the next several years? It may, suggests a study in the November issue of Pediatrics. Researchers compared the sleep habits of 785 children. Those who slept 10 to 12 hours a day when they were third graders had a 12% chance of being obese by sixth grade. By contrast, 22% of those who slept fewer than nine hours a day in third grade were obese in sixth grade. The study does not prove that less sleep causes obesity. Sleep and obesity could be indirectly linked by changes in diet or exercise habits. For example, if a child is awake for more hours, he or she might eat more. A child who is tired from lack of sleep might be less active. Or the link between sleep and obesity may be hormonal, according to researchers. Levels of certain hormones change when people are deprived of sleep for a short time. Leptin, which causes people to feel full, decreases. Ghrelin, which promotes hunger, increases. Insulin peaks more sharply in people with less sleep. These changes could result in weight gain. Sleep may be one of the lifestyle factors contributing to the growing obesity problem among children. It's not the whole answer, but it certainly deserves more attention. Back to top Urine Test May Be a Sign of Heart Risk On November 19, Circulation published an article online that suggests subtle kidney disease increases the chances of dying from heart disease. Researchers studied 8,290 people over five years who had coronary artery disease, but no recent heart attacks or heart failure. They tested their urine for a protein called albumin. It can be a sign of subtle kidney disease when it's found in the urine. The researchers measured the concentration of albumin using a number called the albumin-to-creatinine ratio. Then they divided the patients into six groups based on their number. About three-fourths of the patients in the study had urine protein measurements that were considered "normal" by current standards. People in the group with the highest amount of albumin in their urine at the start of the study were twice as likely to die from heart disease or other causes during the study, compared with people who had the least amount of albumin in their urine. Patients with albumin tests that were at the high end of the normal range also had double the risk. Patients who developed higher amounts of albumin in their urine over time also had a higher risk for dying. This study was originally designed to test the effect of the drug, trandolapril, on patients with heart disease. (About half of the patients were assigned to take the drug in the study, and the other patients took a placebo pill.) Researchers noticed the link between albumin and death rates when they were analyzing the drug treatment findings. No significant differences in death rates or medical events were found between the treated and untreated groups. The drug did, however, diminish the amount of albumin in the urine. With more study time, it's possible that people who took trandolapril might eventually do better. Prior to this year, doctors didn't realize how closely related subtle kidney changes and heart disease risk were. This study may lead doctors to reset cut-offs for the "normal" range of albumin in the urine. More importantly, doctors may start to monitor heart disease patients using urine albumin tests to identify those at high risk of death or future heart problems. Back to top More News in Brief - Correcting Vision Improves Quality of Life for Nursing Home Residents. The November issue of the Archives of Ophthalmology reminds us how easy it can be to improve life for people who live in nursing homes. Researchers monitored the activity of 78 older residents who received prescription eyeglasses. For two months, they compared the quality of life for these individuals to residents who had not received eyeglasses. The group with eyeglasses read more and participated in more activities and hobbies. In addition, they were more social and reported fewer symptoms of depression.
- Anemia Drugs May Cause Tumor Growth in Cancer Patients. Cancer patients who are receiving chemotherapy often become anemic. Medicines such as erythropoietin (Procrit, Epogen) and darbopoetin (Aranesp) help treat anemia by boosting production of red blood cells in bone marrow. On November 8, the U.S. Food and Drug Administration (FDA) issued an alert about these medicines. It warned that these medicines can cause tumor growth and shorten survival in people who have breast cancer, head and neck cancer, non-small cell lung cancer, lymphoma or leukemia. The alert is based on results of six small but well-designed studies ranging in size from 70 to 989 patients. These studies are among the first long-term safety studies of this family of medicines; earlier studies have not had enough follow-up time to monitor length of survival.
- High Blood Pressure Throughout Adulthood Can Make Daily Tasks More Difficult As You Age. The December online issue of Hypertension includes a study of older adults that links disabilities in daily function to a history of hypertension. Researchers analyzed data on 999 men and women who participated in the Charleston Heart Study, which collected information on their blood pressure and functional status between 1960 and 2001. For this current study, researchers limited their analysis to people who had never been diagnosed with a stroke. Thirty-nine percent of the 999 study participants were African American. Patients answered questionnaires about their ability to perform common tasks, such as climbing stairs, performing heavy housework, bathing themselves, or walking a half mile without help. Those who had a diagnosis of hypertension at the beginning of the study reported more difficulty with these tasks by the end of the 40-year study period. This was true for people whether they took blood-pressure medication or not. People who had poorly controlled blood pressure appeared to be at the highest risk. Compared with subjects who had normal blood pressures, older adults who had hypertension were nearly one-third more likely to qualify as "disabled," based on the number of tasks that they could not perform. Side effects from medications might contribute to lost function. Even so, it seems likely that well-controlled high blood pressure can help you stay independent in your old age.
Back to top Mary Pickett, M.D. is a lecturer for Harvard Medical School and an assistant professor of medicine at Oregon Health & Science University. At OHSU, she is a director of student programs and she oversees teaching of students and medical residents. She practices general internal medicine in Portland, Ore.
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