Study Calls for Standardization in Measuring Testosterone Levels
Testosterone blood tests, long questioned as being unreliable, should be used in conjunction with a physical exam to determine treatment
Mar 6, 2014
While the number of men in the United States diagnosed with low testosterone has increased considerably over the last decade, a team of experts, led by Dr. Darius A. Paduch from NewYork-Presbyterian/Weill Cornell Medical Center, has found that relying on a blood test alone is an insufficient method of diagnosing the condition.
The largest review and analysis of its kind — on published data from more than 10,000 patients — appears online today at goldjournal.net and will be in the May issue of Urology. The initiative was spearheaded by the American Urological Association (AUA) and was conducted by a panel of physicians representing six major U.S. institutions.
Despite advances in technology, inconsistent laboratory practices, among other issues, leads to unreliable blood test results. "In some cases, testosterone (T) levels, tested on the same day from a blood sample taken from a single patient, differed by as much 30 percent from one lab to the next," says the study's lead author, Dr. Paduch, a urologist and male sexual medicine specialist at NewYork-Presbyterian/Weill Cornell Medical Center and associate professor of urology and reproductive medicine at Weill Cornell Medical College.
Given the result of the review, Dr. Paduch notes that a stringent reliance on blood test results alone can lead to both under — and overtreatment of low testosterone levels in men, also known as hypogonadism. Instead, he notes, the data demonstrate that "it's critical to primarily focus on treating the patient and his symptoms, while using the T level from a blood test as a secondary guideline." Symptoms may include fatigue, loss of libido, and erectile dysfunction.
Low testosterone has often been thought of as a condition affecting men age 65 and older. But the incidence of diabetes and obesity in younger men, conditions that are also associated with low testosterone, has led to an increase in its diagnosis. Of note, testosterone therapy may help with diabetes and weight control for some men.
The medical community has long questioned the reliability of blood tests to diagnose hypogonadism. What makes these latest findings significant are the stringent criteria used for the study, which included an exhaustive review of hundreds of papers, as well as input from a large multidisciplinary team of medical professional societies and clinical experts from diverse fields and representatives from government agencies and medical equipment manufacturers.
Although variable blood test results can be attributed to a host of factors, one of the biggest problems the study uncovered is a lack of consistency in laboratory practices — from collecting and storing blood samples to using different methods to analyze the results. To address these concerns, Dr. Paduch advises doctors and other health care providers to insist on labs that follow standardized guidelines for testosterone testing issued by the Centers for Disease Control (CDC). Dr. Paduch and his colleagues would also like to see testing standards for testosterone that are comparable to those for the hemoglobin A1C test, which provides information about a person's average levels of blood glucose to diagnose diabetes. "Since the A1C test has been standardized throughout the U.S. and Europe, the same result can be easily replicated," says Dr. Paduch.
Dr. Paduch and his colleagues are working with the CDC to establish evidence-based T-level norms, another challenge associated with diagnosing low testosterone.
Study co-authors include Robert E Brannigan, Eugene F. Fuchs, Edward D. Kim, Joel L. Marmar and Jay I. Sandlow.
NewYork-Presbyterian/Weill Cornell Medical Center
NewYork-Presbyterian/Weill Cornell Medical Center, located in New York City, is one of the leading academic medical centers in the world, comprising the teaching hospital NewYork-Presbyterian and Weill Cornell Medical College, the medical school of Cornell University. NewYork-Presbyterian/Weill Cornell provides state-of-the-art inpatient, ambulatory and preventive care in all areas of medicine, and is committed to excellence in patient care, education, research and community service. Weill Cornell physician-scientists have been responsible for many medical advances — including the development of the Pap test for cervical cancer; the synthesis of penicillin; the first successful embryo-biopsy pregnancy and birth in the U.S.; the first clinical trial for gene therapy for Parkinson's disease; the first indication of bone marrow's critical role in tumor growth; and, most recently, the world's first successful use of deep brain stimulation to treat a minimally conscious brain-injured patient. NewYork-Presbyterian Hospital also comprises NewYork-Presbyterian/Columbia University Medical Center, NewYork-Presbyterian/Morgan Stanley Children's Hospital, NewYork-Presbyterian/Westchester Division, NewYork-Presbyterian/The Allen Hospital, and NewYork-Presbyterian/Lower Manhattan Hospital. NewYork-Presbyterian is the #1 hospital in the New York metropolitan area and is consistently ranked among the best academic medical institutions in the nation, according to U.S.News & World Report. Weill Cornell Medical College is the first U.S. medical college to offer a medical degree overseas and maintains a strong global presence in Austria, Brazil, Haiti, Tanzania, Turkey and Qatar.
Weill Cornell Medical College
Weill Cornell Medical College, Cornell University's medical school located in New York City, is committed to excellence in research, teaching, patient care and the advancement of the art and science of medicine, locally, nationally and globally. Physicians and scientists of Weill Cornell Medical College are engaged in cutting-edge research from bench to bedside, aimed at unlocking mysteries of the human body in health and sickness and toward developing new treatments and prevention strategies. In its commitment to global health and education, Weill Cornell has a strong presence in places such as Qatar, Tanzania, Haiti, Brazil, Austria and Turkey. Through the historic Weill Cornell Medical College in Qatar, the Medical College is the first in the U.S. to offer its M.D. degree overseas. Weill Cornell is the birthplace of many medical advances — including the development of the Pap test for cervical cancer, the synthesis of penicillin, the first successful embryo-biopsy pregnancy and birth in the U.S., the first clinical trial of gene therapy for Parkinson's disease, and most recently, the world's first successful use of deep brain stimulation to treat a minimally conscious brain-injured patient. Weill Cornell Medical College is affiliated with NewYork-Presbyterian Hospital, where its faculty provides comprehensive patient care at NewYork-Presbyterian Hospital/Weill Cornell Medical Center. The Medical College is also affiliated with Houston Methodist. For more information, visit Weill Cornell Medical College.
About the American Urological Association: Founded in 1902 and headquartered near Baltimore, Maryland, the American Urological Association is a leading advocate for the specialty of urology, and has more than 20,000 members throughout the world. The AUA is a premier urologic association, providing invaluable support to the urologic community as it pursues its mission of fostering the highest standards of urologic care through education, research and the formulation of health policy.
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