Falls and Fracture in the Elderly Tuan V. Nguyen Bone and Mineral Research Program Garvan Institute of Medical Research

Overview Osteoporosis Magnitude of the problem Bone mineral density (BMD) and fracture Falls: etiology and risk factors Fracture and fall

Osteoporosis: shift in thinking Low bone mass, microarchitectural deterioration of bone tissue leading to enhanced bone fragility and a consequent increase in fracture risk (Consensus Development Conference, 1991) “ [ … ] compromised bone strength predisposing a person to an increased risk of fracture. Bone strength primarily reflects the integration of bone density and bone quality ” (NIH Consensus Development Panel on Osteoporosis JAMA 285:785-95; 2001)

Osteoporosis in risk-and-outcome view Bone Quality Bone Strength and Architecture Turnover rate Damage accumulation Degree of mineralization Properties of the collagen/mineral matrix Bone Mineral Density Osteoporosis Fracture RISK FACTOR OUTCOME

Normal vs osteoporosis

Breaking bones

Incidence of all-limb fractures

Increase in life expectancy WHO. Human Population: Fundamentals of Growth World Health, 2000.

The ageing of population Percent of population aged 65+ ABS and US Bureau of Census, 1996.

Annual fracture incidence in Australia Projected annual number of all-limb fractures in Australia aged 35+ (Sanders et al, MJA 1999)

Hip, vertebrae, and Colles fractures Fracture Hip20,70060,000 Vertebrae14,50031,700 Colles11,90023,000 Humerus7,50016,300 Pelvis4,1009,800 Projected annual number of all-limb fractures in Australia aged 35+(Sanders et al, MJA 1999)

Lifetime risk of some diseases - women Any osteoporotic fracture Hip fracture Clinical vertebral fracture Cancer (any site)* Breast cancer* Lung/bronchus* Coronary heart diseases Diabetes Mellitus *, from birth (from the age of 50)

Lifetime risk of some diseases - men Any osteoporotic fracture Hip fracture Clinical vertebral fracture Cancer (any site)* Prostate cancer* Lung/bronchus* Coronary heart diseases Diabetes Mellitus *, from birth (from the age of 50)

Consequences of fracture Reduced mortality Increased morbidity Reduced quality of life Incurred significant health care costs

Survival probability with and without fracture Source: Nguyen et al, 2005

Risk of death from hip fracture 50-year old women: Lifetime risk of mortality from: Hip Fracture: 2.8% Breast Cancer: 2.8% Endometrial Cancer: 0.7% Cummings et al. Arch Intern Med 1989; 149:

Impact of hip fractures 25% die within 6 months (*) 60% have restricted mobility (*) 25% remain functionally more dependent Cardiac (8%) and pumonary complication (4%) Transient heart attacks Non-union and avancular necrosis

Impact of vertebral fractures Symptomatic fx : Lifetime risk 1/4 women, 1/8 men Asymptomatic fx prevalence: 20-30% Back pain, functional limitation Rib-against-pelvis (RAP) syndrome Costoiliac impingement syndrome Decrease vital lung capacity

Asymptomatic vertebral fracture increases risk of subsequent fractures 300 m+w 234 No V #66 V # 29 Fx37 no fx 54 Fx 180 no fx 44%23% Pongchaiyakul C et al, J Bone Miner Res 2005

Asymptomatic vertebral fracture increases risk of death 300 m+w 234 No V #66 V # 20 deaths46 survived 25 deaths 209 survived 30%11% Pongchaiyakul C et al, J Bone Miner Res 2005

Impact of wrist fracture More common in women in their 50s Post-traumatic arthritis Account for 39% of all physical therapy sessions Reduced daily living activies Melton LJ, J Bone Miner Res 2003

Fracture Prediction

A model for assessing fracture risk Falls Quadriceps weakness Postural instability Low bone mass # Other factors (age, weight, structural factors) Interaction between BMD and fall-related factors in the prediction of hip fracture

BMD and age

Changes in BMD with age Peak bone density Puberty Menopause Osteopenia Osteoporosis Age

BMD and definition of “osteoporosis” Gaussian distribution Constant standard deviation Decrease with advancing age T-score i = (BMD i – Peak BMD) / SD Define “osteoporosis” and “osteopenia” T-score < -2.5 = “osteoporosis” -2.5 < T-scores < -1 = “osteopenia”

Prevalence of osteoporosis WomenMen

Bone mineral density (BMD) and fracture risk Source: Dubbo Osteoporosis Epidemiology Study T < 2.5 osteoporosis

14-year predictive value of BMD - women 1287women Osteoporosis 345 (27%) Non-osteoporosis 942 (73%) Fx = 137 (40%) No Fx = 208 (60%) No Fx = 751 (80%) Fx = 191 (20%) 42% Source: Dubbo Osteoporosis Epidemiology Study

14-year predictive value of BMD - men 821 men Osteoporosis N = 90 (11%) Non-osteoporosis 731 (89%) Fx = 27 (30%) No Fx = 63 (70%) No Fx = 640 (88%) Fx = 91 (12%) 23% Source: Dubbo Osteoporosis Epidemiology Study

Fracture and BMD: summary of points BMD is the primary predictor of fracture risk Less than 50% of fractured individuals have low BMD (eg osteoporosis) BMD alone does not accurately predict fracture

Falls: etiology and risk factors

Falls The second leading cause of accidental deaths (Rivara NEJM 1997) $70 bil health care costs associated with falls and rehabilitation

Incidence of falls in the elderly Source: Dubbo Osteoporosis Epidemiology Study

Incidence of multiple falls in the elderly Source: Dubbo Osteoporosis Epidemiology Study

Why do falls occur ? Intrinsic Factors Extrinsic Factors FALLS Medical conditions Impaired vision and hearing Age related changes Medications Improper use of assistive devices Environment

Etiology of falls Accidents / environment37% Weakness, balance, gait12% Drop attack11% Dizziness or vertigo8% Orthostatic hypotension5% Acute illness, medications, vision18% Unknown8% Rubenstein et al JAGS 1988

Risk factors for falls Risk FactorOR –Sedative use28 –Cognitive Impairment 5 –Lower extremity problem 4 –Pathologic Reflex 3 –Foot Problems 2 –> 3 balance/gait problems 1.4 –>5 balance/gait problems 1.9 Tinetti NEJM 1988

A non-fracture control A hip fracture case Postural sway test Measurement of postural sway

Predictors of fall risk VariablesUnitWomenMen Age + 5y1.2(1.2,1.3)1.4(1.2,1.6) Postural sway + 60cm 2 1.2(1.1,1.4)1.3(1.1,1.5) Quadriceps strength -10kg1.3(1.1,1.5)1.3(1.1,1.5) Note: Odds ratio and 95% confidence interval Source: Dubbo Osteoporosis Epidemiology Study

Falls and Fractures

Relationship between falls and fractures 95% of hip fractures are caused by falls (Nyberg L, J Am Geriatr Soc 1996) Only 5% of falls cause fractures Falls Fx

Falls and fracture risk Source: Dubbo Osteoporosis Epidemiology Study

Fall-related factors and hip fracture risk Source: Nguyen et al, JBMR 2005

Fall-related factors and hip fracture risk BMD-and-gender-adjusted hazards ratio Source: Nguyen et al, JBMR 2005

Fall-related factors and hip fracture risk BMD-independent risk factors for hip fracture FactorCriteriaScore - Age (y)<700 > Fall in the previous 12 moNo0 Yes1 - Postural sway (tertile)(*)Low0 High1 - Quadriceps strength (tertile)(*)Low1 High0 - Prior fracture in the last 5 yNo0 Yes1 (*) gender specific ranges Source: Nguyen et al, JBMR 2005

Incidence of hip fracture by FNBMD (T-scores) and number of risk factors Source: Nguyen et al, JBMR 2005

Predictor of fractures in non-osteoporotic men and women SexRisk factor(s)PrevalencePARF WomenAge + BMD Fall + Sway MenAge + BMD Fall + Sway PARF: Population attributable risk fraction Source: Dubbo Osteoporosis Epidemiology Study

Can we prevent fracture by reducing falls?

Hip protector

Hip protectors reduced hip fracture risk Clinical trial: 1801 frail elderly individuals (age: 81 y) in Finland –78% women –63% assisted walking Fracture incidence: 2.1% vs 4.6%/yr 2.4% of falls resulted in hip fx when not wearing protector vs 0.4% when wearing protector (80% reduction in risk) Poor compliance P Kannus et al NEJM 2001

Primary prevention 301 community dwelling elders with 1+ risk factors for falling Intervention: adjustment in medications, behavioral instructions, exercise programs aimed at modifying risk factors One year follow up Tinetti et al NEJM

Primary prevention Tinetti et al NEJM

Tai Chi reduced falls Atlanta FICSIT Trial –200 community dwelling elders 70+ –Intervention: 15 weeks of education, balance training, or Tai Chi –Outcomes at 4 months: Strength, flexibility, CV endurance, composition, IADL, well being, falls Falls reduced by 47% in Tai Chi group Wolf JAGS 1996

Risk factor modifications for fracture ChangeEstimated change in fx risk Quit smoking38% Treat impaired vision50% Stop sedatives40% Hip protectors50%? Cummings et al. Unpublished data

Falls and fractures: summary Fracture, particularly hip fracture, is a serious public health problem in the elderly Although low bone mineral density is a primary predictor of fracture risk, it can not account for all fracture cases Fall is highly prevalent in the community and is a major risk of fracture

Falls and fractures: summary Risk factors for fall also contribute to fractures Preventing falls can theoretically reduce fracture incidence A preventative program is required to reduce falls and fractures

Thank you!