News Brief from The Endocrine Society - October 27, 2011
Thursday, October 27, 2011
1. Older Men with Higher Testosterone Levels Lose Less Muscle Mass as They Age
1. Older Men with Higher Testosterone Levels Lose Less Muscle Mass as They Age
Study shows higher testosterone levels may help older men preserve muscle mass and delay frailty as they age
A recent study accepted for publication in The Endocrine Society’s Journal of Clinical Endocrinology & Metabolism (JCEM) found that higher levels of testosterone were associated with reduced loss of lean muscle mass in older men, especially in those who were losing weight. In these men, higher testosterone levels were also associated with less loss of lower body strength.
Loss of muscle mass and strength contribute to frailty and are associated with falls, mobility limitations and fractures. Men lose more muscle mass and strength than women as they age, suggesting that sex steroids, and testosterone in particular, may contribute to body composition and physical function changes. This study sought to better understand the relationship between testosterone levels and healthy aging in older men and found that higher testosterone levels may help older men preserve muscle mass and delay frailty as they age.
“Our study finds that men, aged 65 years and older, with higher testosterone levels lost less muscle mass, especially in their arms and legs, than men this age who had lower testosterone levels,” said Erin LeBlanc, MD, of Kaiser Permanente Northwest in Portland, OR and lead author of the study. “Men who had higher testosterone levels before they lost weight also lost less leg function and could stand up more easily from a chair than men who had lower testosterone levels before they lost weight.”
In this study, researchers used data from 1,183 men aged 65 years or older and tested the hypothesis that higher baseline measures of sex steroids are associated with lesser declines in lean mass and maintenance of physical performance over an average follow-up of 4.5 years. Body composition was measured using dual energy x-ray absorptiometry (DXA) scans and physical performance was measured through a series of exercises that assessed grip strength, lower extremity power, walking speed and the ability to rise from a chair without the use of arms.
“The amount of testosterone men have in their bodies may contribute to how much muscle and strength they lose as they get older,” said LeBlanc. “Our study adds evidence to the growing body of literature that suggest higher levels of endogenous testosterone may be favorably associated with some key components of healthy aging in men.”
Other researchers working on the study include: Patty Wang, Christine Lee, Lynn Marshall and Eric Orwoll of Oregon Health & Science University in Portland; Elizabeth Barrett-Connor and Gail Laughlin of the University of California, San Diego in La Jolla, CA; Jane Cauley of the University of Pittsburgh in PA; and Andrew Hoffman of Stanford University in CA.
The article, “Higher testosterone levels are associated with less loss of lean body mass in older men,” appears in the December 2011 issue of JCEM.
2. Childhood Diet Lower in Fat and Higher in Fiber May Lower Risk for Chronic Disease in Adulthood
Study shows dietary intervention in adolescence benefits glycemic control and blood pressure long-term
A recent study has found that a childhood behavioral intervention to lower dietary intake of total fat and saturated fat and increase consumption of foods that are good sources of dietary fiber resulted in significantly lower fasting plasma glucose levels and lower systolic blood pressure when study participants were re-evaluated in young adulthood. The study was accepted for publication in The Endocrine Society’s Journal of Clinical Endocrinology and Metabolism (JCEM).
A Western dietary pattern high in total fat and saturated fatty acids and refined grains is associated with an increased risk of the metabolic syndrome, a cluster of metabolic abnormalities that include abdominal obesity, low levels of high-density lipoprotein cholesterol (sometimes considered “good cholesterol”), higher levels of triglycerides and blood glucose, and elevated blood pressure. This study evaluated the long-term effects of a dietary intervention to reduce fat and increase fiber intake during childhood on components of the metabolic syndrome in young adult women.
“This research is important because it suggests that modest reductions in total fat and saturated fat intake and increased consumption of dietary fiber during childhood and adolescence may have beneficial effects later in life by decreasing risk of chronic diseases such as diabetes and heart disease,” said Joanne Dorgan, PhD, of Fox Chase Cancer Center in Philadelphia, PA and lead author of the study.
In this study, researchers evaluated 230 women between the ages of 25 and 29 years, who nine years before the current study participated in the Dietary Intervention Study in Children (DISC). DISC was a randomized controlled clinical trial of a reduced-fat dietary intervention that strived to limit fat intake to 28 percent of daily caloric intake and increase dietary fiber intake by encouraging consumption of fruits, vegetables and whole grains. The current study was conducted among females who had participated in the DISC trial to determine the longer-term effects of the DISC intervention.
Researchers measured body composition of study participants using whole body dual-energy x-ray absorptiometry (DXA) scans. Blood pressure was measured using automatic blood pressure monitors and blood samples were analyzed to assess levels of plasma glucose, cholesterol and triglycerides.
“Few participants in our follow-up study met the criteria for metabolic syndrome, however the intervention group had statistically significant lower mean systolic blood pressure and fasting plasma glucose levels compared to the control group,” said Dorgan. “Significant differences at the follow-up visit, but not earlier, suggest that adolescent diet may have long-term effects on age-related changes in blood pressure and glycemic control that begin to become apparent in young adulthood. Longer follow-up studies of DISC participants are needed to determine if the differences found in this study persist or widen with increasing age.”
Other researchers working on the study include: Lea Liu of Clinical Trials & Surveys Corporation in Owings Mills, MD; Bruce Barton of the University of Massachusetts in Shrewsbury; Snehal Deshmukh of Fox Chase Cancer Center; Linda Snetselaar of the University of Iowa in Iowa City; Linda Van Horn of Northwestern University in Chicago, IL; Victor Stevens of Kaiser Permanente Center for Health Research in Portland, OR; Alan Robson of Children’s Hospital in New Orleans, LA; Norman Lasser of the New Jersey Medical School in Newark; John Himes of the University of Minnesota in Minneapolis; John Shepherd of the University of California San Francisco; Ray Pourfarzib of LipoScience Inc. in Raleigh, NC; Kelley Pettee Gabriel of the University of Texas in Austin; Andrea Kriska of the University of Pittsburgh in PA; and Peter Kwiterovich, Jr. of Johns Hopkins Hospital in Baltimore, MD.
The article, “Adolescent Diet and Metabolic Syndrome in Young Women: Results of the Dietary Intervention Study in Children (DISC) Follow-Up Study,” appears in the December 2011 issue of JCEM.
3. New Patient Guide Explains How Continuous Glucose Monitoring Works and Who Should Use It
The Hormone Foundation’s new Patient Guide to Continuous Glucose Monitoring is a companion piece to The Endocrine Society’s recently released clinical practice guideline on the same topic. The guide explains the two main uses of a continuous glucose monitoring (CGM) system: short-term use by patients with type 1 or type 2 diabetes to help clinicians make any needed treatment adjustments, and “real time,” long-term use to help type 1 patients manage their diabetes day-to-day. The guide describes how the sensor, transmitter, and monitor work and the need for blood glucose testing several times daily to calibrate the system. It presents the pros—including potentially better glucose control—and cons of CGM and offers recommendations for who should and should not use a CGM system.
The Patient Guide can be found online at:
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Founded in 1916, The Endocrine Society is the world's oldest, largest, and most active organization devoted to research on hormones and the clinical practice of endocrinology. Today, The Endocrine Society's membership consists of over 14,000 scientists, physicians, educators, nurses and students in more than 100 countries. Together, these members represent all basic, applied, and clinical interests in endocrinology. The Endocrine Society is based in Chevy Chase, Md. To learn more about the Society, and the field of endocrinology, visit our web site at www.endo-society.org.