WHAT’S THE PROBLEM WITH BONE DENSOMETRY?
Answer: none provided it is safely and economically measured and safely and economically corrected at all ages from small children to dotage. It is so cheap and easy to halve the fracture risk and rate in all, and thus save vast suffering, costs and especially deaths.
A spinal surgeon laments as we all do the poor correlation between dual xray bone density analysis DXA and fracture risk.
The simple answer is that bone density is not the top risk factor for fractures,
The chief risk for fractures in the aging is falls and fragility ie global health balance including agility-co-ordination, balance, and strength- muscle mass.
As this column has previously detailed, DXA is valuable for looking at risk areas in the hip or a vertebra;
but just as screening X-ray mammography overdiagnoses clinically relevant breast cancer, trunkal DXA measurement increasingly overreads bone density as we age because of false densification- vascular calcification overlying hips and spine, and progressive collapse wedging of vertebrae.
That’s why, as this column has previously referenced, QUS -quantified ultrasound – done mostly at the heelbone, has become the international gold standard for monitoring global fracture risk, since that bone measured in its long axis is generally free of overlying vascular calcification and collapse wedging. It is recommended by international bodies, many leading universities from Cape Town to Cambridge to Scotland, Japan and USA. .
There is generally good correlation between true DXA measurement at hip and spine, and heel QUS measurement.
And QUS lacks the cumulative radiation risks of DXA.
That’s why QUS bone density is increasingly recommended from childhood, for monitoring and thus simple prevention of frailty – thus avoiding the mushrooming fracture and frailty risk in later life
http://www.ncbi.nlm.nih.gov/pubmed/22878531 Osteoporos Int. 2012 Aug Quantitative ultrasound and fracture risk prediction in non-osteoporotic men and women as defined by WHO criteria.Chan ea Garvan Institute of Medical Research,Sydney, Australia.
http://www.ncbi.nlm.nih.gov/pubmed/22037972 Osteoporos Int. 2012 Jan:143-53.Quantitative ultrasound of heel and fracture risk. Moayyeri ea .University Cambridge UK. Metanalysis: 21 studies with 55,164 women and 13,742 men were included with a total follow-up of 279,124 person-years. All QUS parameters were associated with risk of different fracture: 1 SD decrease in BMD associated with almost doubling of hip fracture risk. (RR by BUA 1.69, SOS was 1.96). There was marked heterogeneity among studies on hip and any clinical fractures but no evidence of publication bias amongst them. Different validated devices predicted fracture risks with similar performance; with similar performance in men and women. This study confirms that heel QUS, using validated devices, predicts risk of different fracture outcomes in elderly men and women.
Oct 30, 2010.
FRAILTY FRACTURES- OSTEOPOROSIS- ARE ALSO COMMON- AND EASILY PREVENTED- IN AGING MEN
The just-published Champ study of osteoporosis in men over 70yrs in Australia shows the high risk for older men as well: 25% had vertebral fractures, but only 77% of the men with fractures had even osteopenia let alone osteoporosis on DXA screening. and this does not factor in the overreading by DXA at the spine and hip owing to the high prevalence of both calcinosis and vertebral collapse. And abysmally few of the men were taking realistic preventatives.
The study bears out:
that frailty, usually from aging – is the chief risk factor for non-violent fractures;
and the low sensitivity of especially DXA screening, never mind the folly of waiting for fractures or dementia or worse before doing safe lowcost (QUS bone risk) screening as one incentive to starting multipreventative supplements.
As the GIOS Project in Spain yet again confirms, simple diagnosis and safe treatment of those at risk of non-violent fractures is scandalously neglected.
And it does not require costly risky high technology – xray screening bisphosphonates or strontium ranelate..
Like doctors, men are far more resistant than even women to heeding warning to start screening and supplements early enough.
The CHAMP study again highlights the importance of asymptomatic middleaged men never mind women having periodic no-xray ultrasound quantitative bone strength scans routinely as the gold standard so as to prompt them to take the appropriate blend of the fewscore supplements effective against both frailty fractures as well as the associated lipid- diabetes- vascular -respiratory- dementia- cancer diseases.