THE 59TH ANNUAL SCIENTIFIC MEETING OF THE GERONTOLOGICAL SOCIETY OF AMERICA; DALLAS, TEXAS, NOVEMBER 16-20, 2006

More than 3000 geriatrics healthcare professionals and gerontologists attended the 59th annual meeting of the Gerontological Society of America (GSA). The conference sessions ranged from the basic science of aging and clinical geriatrics to the social and cultural issues of aging. This report presents some highlights from the meeting.

AGING RESEARCH

Research into the actual process and biological mechanisms of aging is very active. This year the annual Ibsen Longevity Award for outstanding longevity research was given to investigators who have demonstrated that aging appears to be hormonally regulated. Their research shows that the aging process in the roundworm, C. elegans, is controlled by a single gene that encodes an insulin/IGF-1 receptor. By manipulating this gene in the roundworm they have been able to extend the period of youthfulness and healthy activity of the C. elegans by six times. Their findings suggest that these hormones influence the lifespan of the animal by coordinating the expression of a wide variety of subordinate genes. These subordinate genes are important in determining stress, antioxidant, and antimicrobial responses, and other novel gene functions. All of these biologic activities work in a cumulative fashion to determine the lifespan of the animal. Some of the subordinate genes can also affect the rate of onset of age-related diseases.

Previously, researchers have shown in short-lived species (eg, mouse) that life expectancy could be significantly extended by caloric restriction of the diet. This effect was presumed to be, at least in part, due to reduced oxidative damage to tissues from the free radicals and active oxygen species generated from oxidative metabolism. At this meeting, researchers presented a study that showed significant improvement in longevity in monkeys using a 30% caloric restriction in diet. This had not been demonstrated before in such a long-lived species, nor one so closely related genetically to humans. Also significant was the finding that with just 6 months of caloric restriction in older monkeys the researchers were able to demonstrate improved immune function.

OBESITY IN THE ELDERLY

With the evidence that caloric restriction may be beneficial to health and longevity, there is increased interest in what risks may be associated with excess caloric intake and obesity in young and older persons. A symposium on “Obesity in the Elderly” discussed these issues. Clearly, studies of obesity have shown increased risk of many health problems in younger persons including diabetes, vascular disease, hypertension, degenerative joint disease, and increased mortality. Interestingly, in older adults, obesity (BMI >30) is not associated with increased mortality. Despite the increased morbidity seen in obese older persons, especially mobility problems, obesity appears to confer a protective effect when it comes to mortality. Some persons have cautioned against using restrictive dieting in older persons for fear of impairing bone and muscle metabolism, and there are very few controlled trials of weight loss dieting in older persons for reference. However, the evidence demonstrates that obesity is overwhelmingly the greatest risk factor for impaired mobility, which very likely directly contributes to bone and muscle deterioration. The potential added benefit of improved immune function with caloric restriction and the clear benefit to improved mobility would suggest that weight-loss dieting could be considered in obese older persons. However, the symposium concluded that clinical trials are needed to better define the risks and benefits before making that recommendation.

FALLS IN THE ELDERLY

Dr. Mary Tinetti, a leading authority on falls in the elderly, presented the M. Powell Lawton Award Lecture for outstanding applied clinical research benefiting the elderly. Her lecture was entitled “Falling as a Geriatric Syndrome,” and she reviewed some of the interesting epidemiology of falling and the associated risks. Falls increase with age: 30% of persons over the age of 70 fall at least once per year, and 50% of persons over the age of 80; 10% of falls result in serious injury, and falls are expensive ($24,000/ year for each person who falls). Falls are also a marker of frailty and dependency and are associated with an increased risk of nursing home placement. One fall without injury carries a 3.1 risk of nursing home placement within the year, 2 falls without injury carry a 5.5 risk, and one fall with injury has a 10.2 risk of placement.

Risk factors associated with falling include: use of sedative drugs, cognitive impairment, leg problems, positive palmar-mental reflex, vision problems, hypotension, foot problems, and balance problems. Risk factors compound the risk of falling as they accumulate: for zero factors the falling risk = 8%, for 1 factor the risk = 18%, for 2 factors the risk = 32%, for 3 factors the risk = 60%, and for 4+ factors the risk = 78%. The Frailty and Injuries: Cooperative Studies of Intervention Techniques (FICSIT) trial, which was published in 1994, demonstrated that a multi-component fall intervention including strength and balance training, medication management, and environment assessment could reduce falls by 30%, and that proved cost-effective in the highest risk (4+ risk factors) group. More than 60 randomized controlled trials since then have demonstrated similar benefit in both community and nursing home interventions. Despite the evidence and the development of fall prevention guidelines, there has been very little incorporation of these practices by clinicians caring for older persons. Dr. Tinetti described the Connecticut Collaboration for Fall Prevention project, which is a statewide program to raise fall prevention awareness among both lay and professional persons. Funders of healthcare, especially Medicaid and Medicare, are becoming aware of the potential for cost benefits of effective prevention programs. One important piece in getting physicians more actively involved will be the development of appropriate CPT and ICD-9 codes for reimbursement for fall counseling and prevention activities.

SARCOPENIA

The Health, Aging and Body Composition Study (Health ABC) is a 7-year prospective observational study of 3075 community-dwelling older persons ages 70-79 years that now has accumulated 5 years worth of data. The study group reported on some of its findings regarding the causes and consequences of sarcopenia in older adults. Low levels of testosterone have been thought to be associated with loss of muscle mass and decline in strength and physical performance in older men. The study reported that men with low testosterone levels did not have a significantly greater loss of strength using a grip test than did men with high levels of testosterone. Thus, they cautioned against testosterone supplementation in older men in an attempt to improve strength and function. Muscle mass was measured using DXA (dual beam x-ray absorptiometry), and it was noted that the muscle strength decreased almost fourfold greater (3.5%/year) than the apparent decrease in muscle mass (< 1%). The researchers noted that there was a fatty infiltration into the muscle tissue that was associated with decreased muscle quality and performance. They concluded that fat infiltration into muscle may have an important role in age-related changes in muscle strength and quality. Another interesting finding from the study was the observation that persons in the highest tertile for levels of the inflammatory markers IL-6, CRP, and TNF showed a greater loss of muscle mass (P < .0001) and decreased strength (P = .02). This suggests that inflammation may accelerate sarcopenia in old age.

OSTEOARTHRITIS

A symposium on osteoarthritis (OA) reviewed the current state of understanding and management of this disease. The prevalence of OA increases with age, and by age 65, over 2/3 of persons will have radiographic evidence of OA in at least one joint. OA is the leading cause of disability in the United States and accounts for an enormous amount of impairment in older persons. There is no cure for OA, and there are no disease-modifying agents available to date; however, use of the neutraceutical glucosamine, often in combination with chondroitin, has shown some promise in improving symptoms. A small randomized, controlled trial (N=20, for 6 months) of glucosamine with chondroitin sulfate in persons with OA of the knee demonstrated significantly improved gait velocity (P = .023), knee joint extension (P =.021), and reduction of joint pain at the second month (P = .049), third month (P = .002), and fifth month (P = .015). While treatment was for 6 months, benefits persisted in the treated group as compared to the control group out to 9 months (P = .023).

The most important intervention for persons with OA is to remain physically active. Physical inactivity accelerates the disability and the dependency caused by OA. One important treatment modality that has been shown to be safe and effective in reducing the pain and disability of OA is acupuncture. Pain management is often a difficult problem, especially with the risks and side effects associated with nonsteroidal anti-inflammatory medications. Acupuncture has been underutilized for pain control in OA, and the presenter recommended that it be incorporated as a first-line therapy for these patients.

OSTEOPOROSIS

Osteoporosis (OP) is another major health problem of the elderly, with an estimated 1.5 million OP-related fractures per year. An interesting Finnish study of monozygotic female twins (ages 63-72 years) who were discordant for hormone replacement therapy (HRT) was presented. Using assessment with quantitative computed tomography, investigators showed that the twin who received HRT had significantly greater bone mineral density and greater bone volume, and stronger bones. The bone-bending strength was determined to be 22% greater in HRT users. The study showed benefits to both cortical and trabecular bone and convincingly reaffirmed that HRT can be helpful in preventing OP in women.

Bisphosphonates have become the standard treatment for persons with OP, but that class of drugs has a significant rate of bothersome side effects and some inconvenient restrictions when dosed orally. Two equivalency studies, one comparing the frequency and the other the route (intravenous vs oral) of dosing the bisphosphonate ibandronate (IB) were presented. The MOBILE (Monthly Oral iBandronate In LadiEs) was a 2-year randomized trial of 1609 women (ages 55-80 years) with evidence of OP by bone mineral density (BMD) testing with T-scores between -2.5 and -5.0. The treatment of 2.5 mg IB daily was compared to the treatment of 150 mg monthly, both given orally. The monthly regimen proved superior in improving BMD (P < .05) and the gastrointestinal side-effect rates were identical, 7.8% for each treatment. The Dosing IntraVenous Administration (DIVA) study was a 2-year randomized double-blind, double-dummy trial in 1358 women ages 55-80 with BMD evidence of OP comparing daily oral dosing of IB with intravenous dosing every 2 or every 3 months. The three treatment arms were 2.5 mg IB daily versus 2 mg IB intravenously every 2 months versus 3 mg IB intravenously every 3 months. All three treatment arms received the dummy form of dosing of the other oral or intravenous regimens. All treatments improved BMD, but the intravenous treatments were superior (P < .001), and side effects and tolerability were felt to be similar between groups. The researchers concluded that intermittent intravenous IB therapy was effective and may be a useful alternative for persons unsuited for oral therapy.

NEUROPLASTICITY AFTER STROKE

There has been increased interest of late in long-term recovery of motor function after stroke. A recent article in JAMA (Nov 1, 2006) on the EXtremity Constraint Induced Therapy Evaluation (EXCITE) study described significant clinical improvement in functional recovery of motor function by intensive focus on continued use of the affected limb. This study was in persons whose average age was under age 65 and who were within 3 to 9 months of their stroke. It has generally been held that this neuroplasticity is greater in younger persons, and neurological retraining may be limited to a post-stroke or injury period of 6 months to 1 year. A small pilot study (N = 20) presented at this meeting lends optimism to the possibilities of neurological recovery in older persons, even at time periods greater than 1 year post-stroke. Using specific behavioral procedures and operant conditioning-based biofeedback, investigators reported that they were able to demonstrate “large” changes in motor neuron recruitment in all muscle groups where the procedures were applied, resulting in clinically significant functional improvement. What is perhaps most impressive is that all subjects were older than age 70 years, had had their stroke more than 1 year previously, and had reached a plateau in functional recovery. In addition, assistive robotics have been developed that can aid the patient or physical therapist in retraining the functions in a stroke-afflicted extremity.

Meeting Abstracts Abstracts for the entire meeting can be found in the journal of the Gerontological Society of America, The Gerontologist; Special Issue 1, vol 46: October 2006.