Table 18 Studies examining the relationship between physical activity and osteoporosis.

Robitaille et al 2008 [150]

To assess the relationship between the physician- diagnosised osteoporosis and family history and examine whether osteoporosis risk factors account for this relationship.

• n = 8,073

PA assessment: Questionnaire. Level of PA was expressed in MET (hr/wk)

Prevalence of reported osteoporosis in US women by PA level

Prevalence of osteoporosis declines with increasing PA in a dose-response manner.

• Sex: Women

• Age: ≥ 20 yrs

USA

• Characteristics: American women

• Study: NHANES (1999-2004)

G1 = 0

PA level (% prevalence)

Cross-sectional

G2 = <30

   • G1 = 11.0 (9.8-12.4)

G3 = ≥ 30

   • G2 = 7.1 (6.0-8.4)

D & B score = 10

   • G3 = 3.9 (2.8-5.4)

Muscle strengthening activities were expressed in frequency/wk Times/week

p < 0.001

PA level (age adjusted)

   • G1 = 8.9 (7.7-10.1)

G1 = 0

   • G2 = 8.4 (7.3-9.7)

G2 = <2

   • G3 = 6.2 (4.4-8.5)

G3 = ≥ 2

p < 0.01

Criteria for diagnosis of osteoporosis: Self-reported physician diagnosed

Muscle strengthening (%prevalence)

   • G1 = 8.1 (7.2-9.1)

Chi-square

   • G2 = 3.1 (1.7-5.5)

   • G3 = 7.4 (5.8-9.4)

p < 0.001

Muscle strengthening (age adjusted)

   • G1 = 7.8 (6.9-8.7)

   • G2 = 6.7 (3.8-11.8)

   • G3 = 9.5 (7.6-11.9)

p < 0.05

Keramat et al 2008 [151]

To assess risk factors for osteoporosis in postmenopausal women from selected BMD centers in Iran and India.

• Iran n = 363; 178 case, 185 control

Study period 2002 -- 2005

OR (95% CI) of osteoporosis in exercisers vs. non-exercisers. Iran (age adjusted)

Exercise was shown as protective factor in both countries and it remained significant after adjustment for age weight and height in Iran.

• India n = 354; 203 case, 151 control

PA assessment: Questionnaire. PA was categorized as exercises, other exercises (e.g., swimming, aerobics, weight training) and walking

Iran and India

• Sex: Women

   • Exercises = 0.4 (0.2-0.7)

Case control

• Age: Iran Case = 58.2 (7.1) yr; Iran Control = 55.7 (6.0) yr; India Case = 58.9 (8.1) yr; India Control = 56.4 (7.5) yr

BMD assessment: DEXA

   • Other exercises = 0.4 (0.2-0.6)

• Characteristics: Cases had BMD > 2.5 SD below average of young normal bone density in L1-L4 spine region and/or total femoral region. Controls had BMD < 1 SD below normal

Multinominal logistic regression

   • Regular Walking = 0.5 (0.3- 0.8)

D & B score = 11

Walking and other exercises were shown as protective factors in Iranian subjects.

Iran (age, weight, height adjusted)

   • Exercises = 0.4 (0.2-0.7)

   • Other exercises = 0.3 (0.2-0.6)

   • Regular Walking = 0.4 (0.2- 0.8) I

ndia (age adjusted)

   • Exercises = 0.4 (0.3-0.9)

   • Other exercises = NS

   • Regular Walking = NS

India (age, weight, height adjusted)

   • Exercises = NS

• Ethnicity: Indian and Iranian

   • Other exercises = NS

   • Regular Walking = 0.4 (0.2- 0.8)