Table 3

Biomechanical, neurobehavioral, and inflammatory changes with diet-induced obesity

Bivariate (r)

Multivariate (β, r²)

Parameter

Diet

Percentage body fat

Knee OA

Diet (β)

Percentage body fat (β)

Knee OA (β)

Whole model (r²)

Biomechanical

Dark phase locomotion (m)

0.25

0.26

0.14

-

-

-

0.05

Velocity (cm/s)

-0.42*

-0.40

0.01

1.02

-0.11

0.14

0.21

Prompted velocity (cm/s)

-0.26

-0.19

0.09

-

-

-

0.09

Stride frequency (Hz)

-0.34

-0.37

0.08

-

-

-

0.22

Prompted stride frequency (Hz)

-0.31

-0.29

0.03

-

-

-

0.11

Rotarod latency to fall (s)

-0.71***

-0.83***

-0.33

-18.7

-10.1**

0.55

0.70***^a

Forelimb grip strength (g)

-0.70***

-0.54*

-0.16

15.6**

0.73

-0.15

0.50**^a

Hind limb grip strength (g)

-0.45*

-0.46*

-0.26

-

-

-

0.21

Neurobehavioral

Hotplate withdrawal latency (s)

-0.63**

-0.55**

-0.31

2.24

0.076

-0.106

0.43*

Tail-flick withdrawal latency (s)

-0.02

-0.01

-0.13

-

-

-

0.02

Time in open areas (%total)^b

-0.47*

-0.46**

0.01

2.56

-0.18

0.18

0.43*

Time freezing (%total)^b

0.46*

0.32

0.33

-14.06*

-1.16

0.95

0.35*

Stretch attends^b

-0.66***

-0.60**

-0.20

4.85

-0.03

-0.03

0.51**^a

Open-closed transitions^b

-0.18

-0.17

0.32

-

-

-

0.23

Time immobile^c (s)

-0.56**

-0.44

-0.30

63.1*

4.0

-3.34

0.37

Inflammatory

IL-1α

-0.08

-0.09

-0.49*

18.8

3.0

-8.2*

0.27

IL-1 receptor antagonist

-0.05

-0.07

-0.18

-

-

-

0.03

IL-12

0.18

0.17

0.19

-

-

-

0.06

Keratinocyte-derived cytokine

0.17

0.17

-0.21

-

-

-

0.12

IFNγ-induced protein

0.10

-0.01

0.06

-

-

-

0.08

MIP-1α

0.24

0.39

0.17

-

-

-

0.22

Leptin

0.84***

0.95***

0.53**

-1.9

2.9***

1.1*

0.93***^a

Adiponectin

-0.19

-0.02

-0.40

2694*

324*

-274**

0.42*

Inflammatory concentrations were measured in serum, and time points for comparisons are described in the text. MIP-1α, macrophage inflammatory protein-1; OA, osteoarthritis. ^aP < 0.05 controlling for 5% false discovery rate correction of multivariate whole-model analyses. ^bZero-maze behavioral test. ^cTail suspension test. *P < 0.05, **P < 0.01, ***P < 0.001 using bivariate and multivariate generalized linear modeling. P values less than 0.05 shown in bold.

Griffin et al. Arthritis Research & Therapy 2010 12:R130   doi:10.1186/ar3068