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Cochrane Review on Exercise for Preventing and Treating Osteoporosis in Postmenopausal Women

Posted on: Sunday, 21 November 2004, 03:00 CST

Osteoporosis is a pathological condition characterized by the increased risk of fractures related to the reduction of bone density.1 It has been better defined as a pathological condition characterized by low bone density, alterations of the microarchitecture which lead to an increase in bone fragility and therefore an increased risk of fractures.2 The most common manifestations of osteoporosis are fractures of the femur, vertebrae and wrist.

According to the World Health Organisation's definition of osteoporosis, about 30% of the women in the postmenopausal period have osteoporosis.3, 4

The excess mortality associated with fractures of the femur is estimated at about 20%, and the cumulative risk of fractures for a woman in her 50s can reach 60%.5, 6

The value of exercise as a means of preventing the loss of bone mass has become less and less controversial. In the past 20 years numerous publications have, with varying strength, documented its usefulness. It is however necessary to define: what type of exercise is really effective, which programme, for how long, and in which manner it should be implemented.

Cochrane's revision

The aim of the revision was to determine the effectiveness of exercise on bone mass expressed in BMD in women during postmenopause. The hypothesis tested was: exercise slows down bone loss in women during menopause.

Methods

All controlled randomised studies on exercise in healthy postmenopausal women were considered. The method of randomisation had to be well defined, and studies which involved assignation, for example, according to an open list, in alteration, or based on the date of birth or number of the hospital were excluded.7 There were no restrictions of language.

The research was carried out on EMBASE and MEDLINE between 1st January 1966 and December 2003, using the following keywords: "Osteoporosis", "Exercise", "Bone mineral density", "Postmenopausal", and "Fractures". Being aware that electronic research carried out on MEDLINE was not sensitive enough to identify all the relevant randomised studies8 the work was completed using the bibliography found in articles and on Current Contents.

The quality of the studies was evaluated giving an opinion on the following levels: the bias, the method of randomisation used, the blindness, the withdrawals and the dropouts.

TABLE I.-Included studies in systematic revision.

TABLE I.-Included studies in systematic revision.

TABLE I.-Included studies in systematic revision.

TABLE I.-Included studies in systematic revision.

As stated in the objectives of the revision, the effect of exercise on bone was valued with the variation of bone density measured with single-photon (SPA), dual-photon absorptiometry (DPA), dual X-ray absorptiometry (DXA) at the beginning of the study and at yearly intervals.

All the results were converted into the percentage of bone loss per year and the difference between the percentage lost in the group with exercises and the percentage lost in the control group in this metaanalysis was considered as the measure of effect.

Each effect of the treatment was weighed with respect to the variations: in such a procedure the greatest weight was attributed to the most reliable results, that is, to the studies with the highest number of samples.

For each study a check was carried out on - other than the BMD variation - the accuracy of the measuring system of bone density, besides the adherence, that is, the percentage of the participants who completed the programme, and the attendance, that is, the average attendance per session during the period of the study (percentage of attendance of the sessions).

The data was extracted also evaluating the allocation of the subjects, the use of blindness, the percentage of those lost during the follow-up, the type of participants and the type of intervention. The methodological quality was also evaluated on this basis and gave the measure of risk of the existence of bias in assessing the results of the effects of treatment.

Statistical analysis

We estimated that the importance of the effect of treatment highlighted with a given number of participants should have been able to define the level of significance with α=0.05 and with 80% of strength (β=0.2).

TABLE II.-Accuracy in BMD measure in included studies.

TABLE III.- "Attendance" and "adherence" in included studies.

Description of the results

Ninety trials were considered and examined by 2 revisers (BS, DB), who, in an independent way, selected the studies to be included in the meta-analysis and evaluated the methodological quality. In this manner 17 studies which met the criteria for inclusion were included.9-25

There was 100% agreement between the revisers on the choices of studies to be included.

For all of the studies the methodological quality was evaluated on the basis of the description of the modality of randomisation, of the drop out and of blinding (Table I).

The accuracy of the measuring system of bone density used varied from between 0.4% to 3% (Table II), the attendance (the average attendance per session during the period of training) from 56% to 100%, and the adherence (the percentage of the participants who completed the study) from 65% to 82% (Table III).

The accuracy of the measuring systems is obviously of fundamental importance like bias in the evaluation of the δ in the samples and in the controls. In the same manner, the registered compliance, if <70%, notably reduces the value of the results obtained in the studies.

The extreme lack of homogeneity in the physical exercise programmes which the women underwent was dealt with by subdividing the types of training into 3 big categories: those which represented mainly aerobic exercises (calistenics, fitness and muscular strengthening, exercises -with elastics or -with weights, and a little walking), muscular strengthening with machines, and walking at different speeds. The checks were always represented by the absence of the same exercise.

For each group a homogeneity test was carried out without any significant results.

The 1st group ("aerobics") represents the most numerous 9-18 with the highest number of samples (266 subjects who underwent treatment and 295 in checks). For this type of exercise, for which there nevertheless exists an extreme heterogeneity of programs, the intensity of the load and the force is described in only one study,11 and showed a efficacy at the level of the vertebral lumbar, not in the hip (Figure 1).

The 2nd group (resistance) is represented by 3 studies,14, 19, 20 with a total of 53 subjects who underwent treatment and 55 checks (Figure 2). One study 19 presents the use of only one side, in a cross-shaped manner, as a check. Eliminating in this way the bias derived from the genetic condition and the environment, but on the other hand modifying the complete efficacy of the training programme.

Figure 1.-Effectiveness of exercise in studies with aerobic exercises.

These types of exercises showed a significant effect of the strain on the bone in the vertebral lumbar, and on the hip in the limits of (p=0.04). The measurements of the 2 levels concern only 2 studies at a time, further reducing the number of samples.

The 3rd group (walking) concerns only 3 studies,21-23 consisting of 77 subjects who underwent treatment and 79 checks (Figure 3). In only one of the studies is the strain of the exercise calculate:22 this however extends itself to a somewhat short follow-up period (7 months) and does not describe the level of compliance. The significance of the efficacy was shown only at the level of the backbone, the measurement on the hip was carried out in only one study with success but only on 49 subjects and 48 checks.

From these groups we excluded the studies on programs of specific side exercises: Sinaki,24 who studied the effect of the extension exercises on spine; Revel who studied the effect of the one side hip flexion exercises.25

Discussion

The results of this revision leads to conclusions with extreme caution, given the low points in the quality score of the selected studies, the brevity of the follow-up, given also the low numbers of samples and excessive use, in the same studies, of mixed treatment (medicine and exercise). Moreover, the description of the exercise programmes being generally insufficient, it is difficult to establish the "posology" of the treatment in the study, and the results of the same exercises are often not sufficiently highlighted because the measurement of bone density is not carried out in effective specific load site.

Figure 2.-Effectiveness of exercise in studies with exercises against resistance.

Figure 3.-Effectiveness of studies using walking as exercise.

Nevertheless it is possible to reach some conclusions: knowing that, after the period of rapid loss in the first few years of postmenopause, the rate of loss returns to 1% per year, we can affirm that at this level physical exercise may be a prevention, while not compensating for the loss in the first phase of rapid bone loss. Also with all the limits due to methodology problems, this meta-analysis confirms that which has emerged in recent revisions,26, 27 or rather that the efficacy of exercise exists, but it is relatively small, and obviously, connected to its continuation in the life women.

This is the actual challenge: i\n the first place to have the elements to establish a program which is really effective and to be able to implement it, with a satisfying level of compliance in such a manner as to keep the results for life.

At the present time both exercise programmes above the stimulus threshold, site specific with individually defined loads, limited in time but repeated every 5 to 10 years, and long term programmes with greater compliance, as could be the case of speed walking, of which its efficacy has been proven, seem proposable.

However, beyond these simplifications, it is necessary to remember that exercises have a wider action than what is measurable at the level of the variation in bone density, or rather they work by improving muscle mass, strength, balance and co-ordination. Therefore, unlike treatment with medicine, exercises work simultaneously on various factors,26 which really allow for a prevention of falls and therefore of fractures.

References

1. Consensus Development Conference. Prophylaxis and treatment of osteoporosis. Osteoporos Int 1991;1:114-7.

2. Consensus Development Conference. Diagnosis, prophylaxis and treatment of osteoporosis. AmJ Med 1993:94:646-50.

3. Kanis JA. Assessment of fracture risk and its application to screening for postmenopausal osteoporosis: synopsis of a WHO report. WHO Study Group. Osteoporos Int 1994;4:368-81.

4. WHO Report of a WHO Study Group. Assessment of fracture risk and its application to screening for postmenopausal osteoporosis. World Health Organ Tech Rep Ser 1994;843:1-129.

5. Cooper C. The epidemiology of fragility fractures: is there a role for bone quality? The epidemiology of fragility fractures: is there a role for bone quality? The epidemiology of fragility fractures: is there a role for bone quality? The epidemiology of fragility fractures: is there a role for bone quality? Calcif Tissue Int 1993;53 Suppl 1:523-6.

6. Cummings SR, Black DM, Rubin SM. Lifetime risks of hip, Colles', or vertebral fracture and coronary heart disease among white postmenopausal women. Arch Intern Med 1989;l49:2445-8.

7. Schulz KF, Chalmers I, Hayes RJ, Altman D. Empirical evidence of bias: dimensions of methodological quality associated with estimates of treatment effects in controlled trials. JAMA 1995;273: 408-12.

8. Dickersin K, Scherer R, Lefebvre C. Identifying relevant studies for systematic reviews. BMJ 1994;309:1286-91.

9. Bravo G, Gauthier P, Roy PM, Fayette H, Gaulin P, Peloquin I, et al. Impact of a 12 month exercise on the physical and psychological health of osteopenic women. J Am Geriatr Soc 1996;44:756-62.

10. Chow R, HarrisonJE, Notarius C. Effect of two randomised exercise programmes on bone mass of health postmenopausal women. BMJ 1997;295:1441-4.

11. Grove KA, Loncleree BR. Bone density in postmenopausal women: high impact vs low impact exercise. Med Sei Sports Exerc 1992;24:1190-4.

12. Lau EMC, Woo J, Leung PC, Swaminathan R, Leung D. The effects of calcium supplementation and exercise on bone density in elderly Chinese women. Osteoporos Int 1992;2:l68-73.

13. Lord SR, Ward JA, Williams P, Zivanovic E. The effects of a community exercise program on fracture risk factors in older women. Osteoporos Int 1996;6:36l-7.

14. Pruitt LA, Taaffe DR, Marcus R. Effects of a one year high- intensity versus low-intensity resistance training program on bone mineral density in older women. J Bone Miner Res 1995;10:1788-95.

15. Smidt GL, Lin SY, O'Dwyer KD, Blanpied PR. The effect of high- intensity trunk exercise on bone mineral density of postmenopausal women. Spine 1992;17:280-5.

16. Preisinger E, Alacamlioglu Y, PiLs K, Saradeth T, Schneider B. Therapeutic exercise in the prevention of bone loss. Am J Med Rehabil 1995;74:120-3.

17. Prince RL, Smith M, Dick IM, Price RI, Webb PG, Henderson NK et al. Prevention of postmenopausal osteoporosis: a comparative study of exercise, calcium supplementation and hormone replacement therapy. N Engl J Med 1991;325:1189-95.

18. Prince R, Devine A, Dick I, Griddle A, Kerr D, Kent N et al. The effects of calcium supplementation (milk powder or tablets) and exercise on bone density in postmenopausal women. J Bone Min Res 1995;10:1068-75.

19. Kerr D, Morton A, Dick I, Prince R. Exercise effects on bone mass in postmenopausal women arc site specific and load-dependent. J Bone Miner Res 1996;11:218-25.

20. Nelson ME, fiatarone MA, Morganti CM, Trice I, Greenberg RA, Evans WJ. Effects of high intensity strength training on multiple risk factors for osteoporotic fractures. JAMA 1994;272:1909-14.

21. Ebrahim S, Thompson PW, Baskaran V, Evans K. Randomized placebo-controlled trial of brisk walking in the prevention of post- menopausal osteoporosis. Age Ageing 1997;26:253-60.

22. Hatori M, Hasegawa A, Adachi H, Shinozaki A, Hayashi R, Okano H el al. The effect of walking at the anaerobic thresold level on vertebral bone loss in postmenopausal women. Calcif Tissue Int 1994;52:4ll-4.

23. Martin D, Notelovitz M. Effects of aerobic training on bone mineral density of postmenopausal women. J Hone Miner Res 1993:8:931- 6.

24. Sinaki M, Wahner HW, Offord KP, Hodgson SF. Efficacy of non loading exercises in prevention of bone vertebral loss in post- menopasusal women: a controlled trial. Mayo Clin Proc 1989; 64:762- 9.

25. Revel M, Mayoux-Benhamou MA, Kabourdin JP, Baghcri E, Roux C. One-year psoas training can prevent lumbar bone loss in post- menopausal women: a randomised copntrollecl trial. Calcif Tissue Int 1993;53:307-11.

26. Berard A, Bravo G, Gauthier P. Meta-analysis of the effectiveness of physical activity for the prevention of bone loss in post-menopausal women. Osteoporos Int 1997;7:331-7.

27. Wolff I, van Croonenborg JJ, Kemper HC, Kostense PJ, Twisk JW. The effect of exercise training programs on bone mass: a metaanalysis of published controlled trials in pre- and postmenopausal women. Osteoporos Int 1999;9:I-12.

Published data only

Bravo 1996 {published data only}

Bravo G, Gauthier P, Roy PM, Payette H, Gaulin P, Harvey M et al. Impact of a 12-month exercise program on the physical and psychological health of osteopenic women, J Am Geriatr Soc 1996;44:756-62.

Chow 1987 {published data only}

Chow R, HarrisonJE, Notarius C. Effect of two randomised exercise programmes on bone mass of health poslmenopausal women. BM) 1987;295:l441-4.

Ebrahim 1997 {published data only}

Ebrahim S, Thompson PW, Baskaran V, Evans K. Randomized placebo- controlled trial of brisk walking in the prevention of postmenopausal osteoporosis. Age Ageing 1997;26:253-60.

Grove 1992 {published data only}

Grove KA, Londeree BR. Bone density in postmenopausal women: high impact vs low impact exercise. Med Sei Sports Exerc 1992;24: 1190- 4.

Hatori 1993 {published data only}

Hatori M, Hasegawa A, Adachi H, Shinozaki A, Hayashi R, Okano H et al. The effects of walking at the anaerobic threshold level on vertebral bone loss in postmenopausal women. Calcif Tissue Int 1993:52:411-4.

Kerr 1996 {published data only}

Kerr D, Mortem A, Dick I, Prince R. Exercise effects on bone mass in postmenopausal women are site-specific and load-dependent. J Bone Miner Res 1996;! 1:218-25.

Lau 1992 {published data only}

Lau EMC, Woo J, Leung PC, Swaminathan R, Leung D. The effects of calcium supplementation and exercise on bone density in elderly Chinese women. Osteoporos Inl 1992;2:l68-73.

Lord 1996 {published data only}

Lord SR, Ward JA, Williams P, Zivanovic K. The effects of a community exercise program on fracture risk factors in older women. Osteoporos Int 1996;6:36l-7.

Martin 1993 {published data only}

Martin D, Notelovitz M. Effects of aerobic training on bone mineral density of postmenopausal women. J Bone Miner Res 1993;8:931- 6.

Mayoux-Benhamou 1997 {published data only}

Mayoux-Benhamou MA, Bagheri F, Roux C, Auleley GR, Rabourdin JP, Revel M. Effect of psoas training on postmenopausal lumbar bone loss: a 3-year follow-up study. Calcif Tissue Int 1997;60:348-53.

Nelson 1994 {published data only}

Nelson ME, Fialarone MA, Morganti CM, Trice I1 Greenberg RA, Evans WJ. Effects of high-intensity strength training on multiple risk factors for osteoporotic fractures. JAMA 1994;272:1909-14.

Preisinger 1995 {published data only}

Preisinger E, Alacamlioglu Y, PiIs K, Saradeth T, Schneider B. Therapeutic exercise in the prevention of bone loss. AmJ Phys Med Rehabil 1995;74:120-3.

Prince 1991 {published data only}

Prince RL, Smith M, Dick IM, Price KI, Webb PG, Henderson NK et al. Prevention of postmenopausal osteoporosis: a comparative study of exercise, calcium supplementation, and hormone-replacement therapy. N Engl J Med 1991;325:1189-95.

Prince 1995 {published data only}

Prince R, Devine A, Dick I, Griddle A, Kerr D, Kent N et al. The effects of calcium supplementation (milk powder or tablets) and exercise on bone density in postmenopausal women. J Bone Miner Res 1995;10:1068-75.

Pruitt 1996 {published data only}

Pruitt LA, Taaffe, Marcus R. Effects of a one-year high- intensity versus low-intensity resistance training program on bone mineral density in older women. J Bone Miner Res 1996;10:1788-95.

Revel 1993 {published data only}

Revel M, Mayoux-Benhamou MA, Rabourdin JP, Bagheri f, Roux C. One- year psoas training can prevent lumbar bone loss in postmenopausal women: a randomized controlled trial. Calcif Tissue Intl993;53:307- 11.

Sinaki 1989 {published data only}

Sinaki M, Wanner HW, Offord KI', Hodgson SK. Efficacy of nonloading exercises in prevention of vertebral bone loss in postmenopausal women: a controll trial. Mayo Clin Proc 1989;64: 702- 9.

Smidt 1992 {published data only}

Smidt GL, Lin SY, O'Dwyer KD, Blanpied PR. The effect of high- intensity trunk exercise on bone mineral density of postmenopausal women. Spine 1992;l7:280-5.

References to studies excluded from this review

Heinonen 1996

Heinonen A, Kannus P, Sievanen H, Oja P1 Pasanen M, Rinne M et al. Randomised controlled trial of effect of high-impact exercise on selected risk factors for osteoporotic fra\ctures. Lancet 1996;348:1343-7.

Kohrt 1995

Kohrt WM, Snead DU, Slatopolsky E, Birgc S. Additive effects of weight-bearing exercise and estrogen on bone mineral density in older women. J Bone Miner Res 1995:10:1303-11.

Kriska 1980

Kriska AM, Bayles C, Cauley JA, La porte KE, Sandler RB, Pambianco G. A randomized exercise trial in older women: increased activity over two years and the factors associated with compliance. Med Sei Sports Exerc 1986;18:557-62.

Leichter 1989

Leichter I, Simkin A, Margulies JY, Bivas Λ, Sleinberg R, Giladi M el al. Gain in mass density of bone following strenuous physical activity. J Orthop Res 1989;7:86-90.

Lohman 1995

Lohman T, Going S, Pamenter R, Hall M, Boyden T, Houtkooper L el al. Effects of resistance training on regional and total bone mineral density in premenopausal women: a randomized prospective study. J Bone Miner Res 1995;10:1015-24.

Mayoux-Benhamou 1995

Mayoux-Benhamou MA, Rabourdin JP, Bagheri F, Roux C, Revel M. Effet de l'exercice physique sur la densit osseuse lombaire chez la femme mnopause. Ann Readaptation Med Phys 1995:38:117-24.

Nelson 1991

Nelson ME, Fisher EC, Dilmanian EA, Dallal GE, Evans WJ. A 1- year walking program and increased dietary calcium in postmenopausal women: effects on bone. Am J Clin Nutr 1991;53:1304-11.

Notelovitx 1991

Notelovitz M, Martin D, Tesar R, Khan FY, Probart C, Fields C et al. Estrogen therapy and variable-resistance weight training increase bone mineral in surgically menopausal women. J Bone Miner Res 1991;6:583-4.

Pruitt 1992

Pruitt LA, Jackson RD, Battels RL, Lehnhard HL. Weight-training effects on bone mineral density in early postmenopausal women. J Bone Miner Res 1992;7:179-85.

Rikli 1990

Rikli RE, McManis BG. Effects of exercise on bone mineral content in postmenopausal women. Res Q Exerc Sport 1990;6l:243-9.

White 1984

White MK, Martin RB, Yeater RA, Butcher RL, Radin EL. The effects of exercise on the bones of postmenopausal women. Int Orthop 1984;7:209-14.

Additional references

Berard 1997

Berard A, Bravo G, Gauthier P. Meta-analysis of the effectiveness of physical activity for the prevention of bone loss in postmenopausal women. Osteoporos Int 1997;7:331-7.

Chamberlain 1982

Chamberlain MA, Care G, Harfield B. Physiotherapy in osteoarthritis of the knees. A controlled trial of hospital ferais home exercises. Int Rehabil Med 1982;4:101-6.

Kovar PA, Allegrante JP, Mackenzie CR, Peterson MG, Gutin B, Charlson ME. Supervised fitness walking in patients with osteoarthritis of the knee. Ann Intern Med 1992;ll6:529-34.

Kreindler 1989

Kreindler H. Effects of three exercise protocols on strength of persons with osteoarthritis of the knee. Top Geriatr Rehabil 1989;4: 32-9.

Lankhosrt 1982

Lankhorst GJ, van de Stadt RJ, van der Korst JK, Hinlopen- Bonrath E, Griffione FM, de Boer W. Relationship of isometric knee extension torque and functional variables in osteoarthritis of the knee. Scand J Rehabil Med 1982;14:7-10.

Minor 1989

Minor MA, Hewett JE, Webel RR, Anderson SK, Kay DR. Efficacy of physical conditioning exercise in patients with rheumatoid arthritis and osteoarthritis. Arthritis Rheum 1989;32:1396-405.

Peterson 1993

Peterson MG, Kovar-Toledano PA, Otis JC, Allegrante JP, Mackenzie CR, Gutin B et al. Effect of walking program on gait characteristics in patients with osteoarthritis. Arthritis Care Res 1993;6:11-6.

B. SHEA 1, D. BONAIUTI 2, R. IOVINE 3, S. NEGRINI 4 5, V. ROBINSON 1, H. C. KEMPER 1, G. WELLS 1, P. TUGWELL 1, A. CRANNEY 1

1 Institute of Population Health University of Ottawa, Ottawa, Canada

2 Unit of Physical Medicine and Rehabilitation San Gerardo Hospital, Monza, Italy

3 Unit of Functional Rehabilitation, Civil Hospital Giovanni Persiceto, Bologna, Italy

4 ISICO (Italian Scientific Spine Institute), Milan, Italy

5 Unit of Functional Rehabilitation, Don Gnocchi Foundation, Milan, Italy

Address reprint requests to: B. Shea, Institute of Population Health, University of Ottawa, 1 Stewart Street, Ottawa, Ontario, Canada, K1N 6N5. E-mail: bevshea@uottawa.ca

Copyright Edizioni Minerva Medica Sep 2004

Source: Europa Medicophysica

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