Table 3

Factors potentially affecting change in cartilage volume over 4.5 years

Factor

Univariate analysis

Multivariate analysis^a

Regression coefficient

p

Regression coefficient

95% CI

p

Medial cartilage

Initial age^b

1.6

0.84

3.7

- 10.9 to 18.2

0.62

Gender^c

28.3

0.08

12.6

- 29 to 54

0.55

Height^d

1.11

0.20

-

-

-

Weight^e

- 0.65

0.90

-

-

-

Body mass index^f

- 1.68

0.34

1.1

- 2.3 to 4.6

0.53

Initial cartilage volume^g

41.2

0.15

18.3

- 19.4 to 56.1

0.34

Bone size^h

4.61

0.03

3.4

- 1.8 to 8.6

0.21

WOMAC painⁱ

- 6.7

<0.001

- 7.1

- 10.8 to - 3.4

<0.001

Lateral cartilage

Initial age^b

3.7

0.63

4.0

- 11.2 to 19.3

0.61

Gender^c

22.9

0.15

7.2

- 36.3 to 50.7

0.75

Height^d

1.2

0.14

-

-

-

Weight^e

1.9

0.72

-

-

-

Body mass index^f

- 0.8

0.65

0.2

- 3.4 to 3.9

0.90

Initial cartilage volume^g

- 1.2

0.93

- 23.6

- 63.2 to 16.0

0.24

Bone size^h

3.6

0.07

2.9

- 2.6 to 8.4

0.29

WOMAC painⁱ

- 1.6

0.40

- 1.7

- 5.5 to 2.2

0.40

BMI, body mass index; CI, confidence interval; WOMAC, Western Ontario and McMaster University Osteoarthritis Index. ^aMultivariate analysis with age, gender, BMI, initial cartilage volume, bone size and initial pain (WOMAC) score in regression equation; ^bdifference in rate of loss of cartilage volume per 10-year difference in age; ^cdifference in rate of loss of cartilage volume for males compared with females; ^ddifference in rate of loss of cartilage volume per centimetre difference in height; ^edifference in rate of loss of cartilage volume per 10 kg difference in weight; ^fdifference in rate of loss of cartilage volume per unit increase in BMI; ^gdifference in rate of loss of cartilage volume per 1,000 mm³ increase in initial cartilage volume; ^hdifference in rate of loss of cartilage volume per 100 mm² increase in bone area; ⁱdifference in rate of loss of cartilage volume per 10-unit increase in baseline WOMAC pain score.

Wluka et al. Arthritis Research & Therapy 2006 8:R90   doi:10.1186/ar1962