Exercise Program Improves Osteoporosis

(May 25, 2004)

An exercise program is beneficial for osteoporosis and can be sustained, according to the results of a controlled trial published in the May 24 issue of the Archives of Internal Medicine.

"There is growing evidence that exercise prevents at least some of the negative consequences associated with menopause, such as bone loss, increased risk of coronary heart disease, or chronic diseases, (e.g. diabetes)," write Wolfgang Kemmler, PhD, from the University of Erlangen in Germany, and colleagues. "Here we determine the effects of intense exercise on physical fitness, bone mineral density (BMD), back pain, and blood lipids in early postmenopausal women."

In this study, 50 early postmenopausal women participated in an exercise program that lasted 26 months and consisted of two supervised group training sessions, each lasting 60 to 70 minutes, per week, and two unsupervised home training sessions, each lasting 25 minutes, per week. Average age was 55 years, and these women were not taking any medications and had no diseases affecting bone metabolism.

The control group consisted of 33 women, average age about 55 years, who did not take part in an exercise program. The women in both groups received calcium and cholecalciferol and were evaluated for physical fitness, BMD, and blood lipid levels at study enrollment and at termination.

After 26 months, strength improved in the exercise group. Measurements of BMD remained relatively stable in the exercise group but decreased in the control group. Compared with the control group, the exercise group reported less pain and had slightly reduced cholesterol levels.

Specific improvements from baseline in the exercise group compared with the control group included isometric strength of trunk extensors (36.5% vs. 1.7%), trunk flexors (39.3% vs. -0.4%), maximum oxygen consumption (+0.7% vs. -2.3%), quantitative computed tomography (QCT) L1-L3 trabecular region of interest (+0.4% vs. -6.6%), QCT L1-L3 cortical region of interest (+3.1% vs. -1.7%], total hip (dual-energy x-ray absorptiometry [DXA], -0.3% vs. -1.7%]), total cholesterol levels (-5.0% vs. +4.1%) and triglyceride levels (-14.2% vs. +23.2%).

Study limitations include nonrandomized design and possible bias related to different levels of motivation or other variables in nonrandomized exercise studies.

"In this study we showed that a long-term multipurpose exercise program with emphasis on bone density not only offsets bone loss but also improves physical fitness and lower back pain and reduces some coronary heart disease risk factors in early postmenopausal women," the authors write. "To show a significant impact on bone density, the exercise intensity (strain magnitude) must be higher than the minimum effective strain threshold of bone. Therefore, our program not only promotes high-strain rates but also unusual strain distributions through a variety of movements during running, gaming, aerobics, jumping, and resistance and stretching sequences."

Henning Ber-Sanofi Synthelabo in Berlin, Germany, supplied the calcium and cholecalciferol for all study participants, and Thera-Band GmbH in Hadamer, Germany supplied Therabands. The Uni-Bund Erlangen also helped support this study. The authors report no relevant financial interests.

In an accompanying editorial, Daniel Mazanec, MD, from the Cleveland Clinic Foundation in Ohio, notes that osteoporosis is highly prevalent but treatable in older women. However, both screening and treatments are underused. In a primary care health plan, only 49% of 1,500 women aged 40 to 69 years reported that a healthcare provider had discussed osteoporosis with them, and fewer than one third of women defined as "high risk" for osteoporosis had BMD testing.

"Over the past 15 years, several pharmacologic agents have been shown to reduce fracture risk in osteoporotic patients," Dr. Mazanec writes. "Despite clearly meeting the tenets for a condition meriting aggressive screening and treatment, osteoporosis remains underrecognized and undertreated."

Arch Intern Med. 2004;161:1047-1048, 1084-1091

Learning Objectives
Upon completion of this activity, participants will be able to:
List the benefits of general exercise on strength and endurance and bone density in early postmenopausal women with osteopenia.
Describe the benefits of exercise on back pain and lipid levels in early postmenopausal women with osteopenia.

Clinical Context

Using World Health Organization (WHO) criteria, up to 50% of women older than 50 years in the U.S. have osteopenia. In asymptomatic women older than 50 years, the prevalence of osteoporosis is 7.2%, and the prevalence of osteopenia is 40%, according to a study by Siris and colleagues published in the Dec. 12, 2001, issue of The Journal of the American Medical Association. The lifetime risk of hip fractures is 17.5% for U.S. women, and the mortality rate is 24% for hip fractures within one year. For women older than 65 years, the age-adjusted mortality rate for vertebral compression fractures is 23%. The U.S. Preventive Services Task Force recommends BMD screening in all women older than 65 years and for those older than 60 years at high risk.

Long-term studies (two years) on postmenopausal women, such as one reported by Heikkinen in Maturitas in March 1997, have shown improved BMD, muscle strength, and lipid metabolism. Vuori and colleagues, in the June 2001 issue of Medical Science and Sports Exercise, also showed a dose-related response for physical activity and back pain in women with osteoporosis and osteoarthritis.

This open study of self-selected postmenopausal women with osteopenia examined the feasibility and effects of 26 months of a general exercise program on BMD, strength and endurance, pain, and cardiovascular risk.

Study Highlights

137 women aged 48 to 60 years recruited by letter and telephone were asked to select either a general exercise program (n = 86) or no exercise (usual lifestyle; n = 51). Of the original respondents, 71 and 40 in each group qualified, and they were followed for 26 months.
Inclusion criteria were 1 to 8 years after menopause and osteopenia at the lumbar spine or hip by WHO criteria using DXA measurement.

Exclusion criteria were known osteoporotic fractures, disease or use of medication affecting bone metabolism, athletic activity, cardiovascular disease, and low exercise capacity.
All women received calcium and cholecalciferol supplements according to their nutritional intake.
The exercise program consisted of 4 sessions per week: 2 supervised group sessions (both isometric and graduated high-intensity and high-impact aerobic components) lasting 60 to 70 minutes and 2 unsupervised home sessions (isometric and graded rope skipping with increasing intensity at 12 week intervals) of 25 minutes each. Individuals used training logs, and attendance and compliance were monitored.

Nutritional analysis and anthropometric data, including body mass index (BMI), waist-hip ratio, and body composition were determined 2 months before and 26 months after the start of the program.
Primary outcomes were program adherence, isometric strength and endurance measured by maximum oxygen uptake, maximum carbon dioxide output and ventilation, and BMD and serum markers of bone turnover such as osteocalcin.
Secondary outcomes were pain at skeletal sites and blood lipid levels.

The 71 women in the exercise group averaged attendance of 79% for group exercise sessions and 61% for home exercise sessions. 50 and 33 women, respectively, completed the program as prescribed and were included in the analysis. Thus, analysis was not by "intention to treat." Withdrawal was primarily due to nonadherence to program.
Women had a mean age of 55 years, BMI of 25 kg/m2, waist-hip ratio of 0.8, and parity of 2. 52%, had low physical activity at baseline, 15% had a positive family history of osteoporosis, 10% had previously used oral steroids for more than 6 months, and 8% to 12% were smokers. Mean calcium intake was 1,100 mg per day, and average coffee intake was 800 mL per day.

Anthropometric measurements and lifestyle parameters remained unchanged in both groups over 26 months.
Physical fitness improved significantly in all measured parameters in the exercise group.
Isometric strength in trunk extensors improved by 36.5% compared with 1.7% in the no exercise group, and in trunk flexors improvement was 39.3% in the exercise group compared with -0.4% in the no exercise group (P < .001 for both comparisons).

Maximum oxygen consumption improved by 12.4% in the exercise group compared with -2.3% in the no exercise group.

Lumbar spine BMD was stable and improved by 0.7% in the exercise group compared with a deterioration of -2.3% in the no exercise group.

Measures of bone turnover did not show significant changes in either group.
There were significant differences in lipids between the groups, with reductions in total cholesterol and triglyceride levels and an increase in high-density lipoprotein cholesterol (compared with baseline) in the exercise group and no change in the no exercise group (P < .05 for all comparisons).

Pain intensity (graded from 1 as "very weak/very seldom" to 7 as "very heavy/very often") in the exercise group decreased significantly at the cervical and thoracic spine with no changes for main joints.
Both groups had improvements in vasomotor symptoms over 26 months with no significant differences between them.

Pearls for Practice
A general exercise program for otherwise sedentary women in early postmenopause with osteopenia is feasible.
Four exercise sessions per week for 26 months improves exercise capacity and strength, BMD, lipid levels, and back pain in women with osteopenia.