Table 2

Association between insulin resistance (HOMA-IR) and gait speed in men and women

Models with HOMA-IR as a continuous variable

Men

Women

β*

(SE)

P value

β*

(SE)

P value

Model 1

-0.035 (0.013)

0.007

-0.018 (0.013)

0.172

Model 2

-0.033 (0.013)

0.010

-0.014 (0.013)

0.289

Model 3

-0.040 (0.013)

0.003

-0.011 (0.013)

0.377

Model 4

-0.042 (0.012)

0.001

-0.012 (0.013)

0.364

Models with HOMA-IR by increasing quartiles

Men

Women

Quartile comparison

β†

(SE)

P value

P for trend

Quartile comparison

β†

(SE)

P value

P for trend

Model 1

Q2 v.s. Q1

-0.013 (0.026)

0.616

0.035

Q2 v.s. Q1

0.049 (0.027)

0.072

0.446

Q3 v.s. Q1

-0.043 (0.029)

0.141

Q3 v.s. Q1

-0.032 (0.031)

0.304

Q4 v.s. Q1

-0.066 (0.033)

0.046

Q4 v.s. Q1

-0.001 (0.035)

0.987

Model 2

Q2 v.s. Q1

-0.010 (0.026)

0.711

0.056

Q2 v.s. Q1

0.052 (0.027)

0.057

0.521

Q3 v.s. Q1

-0.039 (0.029)

0.177

Q3 v.s. Q1

-0.025 (0.030)

0.403

Q4 v.s. Q1

-0.058 (0.033)

0.078

Q4 v.s. Q1

0.004 (0.033)

0.905

Model 3

Q2 v.s. Q1

-0.015 (0.027)

0.567

0.024

Q2 v.s. Q1

0.055 (0.025)

0.042

0.700

Q3 v.s. Q1

-0.046 (0.030)

0.120

Q3 v.s. Q1

-0.020 (0.030)

0.504

Q4 v.s. Q1

-0.072 (0.033)

0.030

Q4 v.s. Q1

0.013 (0.033)

0.702

Model 4

Q2 v.s. Q1

-0.006 (0.026)

0.786

0.019

Q2 v.s. Q1

0.051 (0.026)

0.054

0.663

Q3 v.s. Q1

-0.039 (0.028)

0.167

Q3 v.s. Q1

-0.018 (0.030)

0.556

Q4 v.s. Q1

-0.072 (0.032)

0.024

Q4 v.s. Q1

0.008 (0.033)

0.807

Adjusted covariates:

Model 1 = Age, race, body mass index categories, smoking status, alcohol consumption, and use of walking devices

Model 2 = Model 1 + co-morbidities (hypertension, chronic lung disease, heart disease, and arthritis)

Model 3 = Model 2 + markers of nutrition and cardiovascular risk (natural-log-transformed levels of folate, vitamin B₁₂, total cholesterol, homocysteine and C-reactive protein).

Model 4 = Model 3 + peak leg strength

* Parameter estimates (β) can be interpreted as differences in mean gait speed (m/sec) for each increment of one standard deviation in the log transformed HOMA-IR among men (or women).

† Parameter estimates (β) can be interpreted as differences in mean gait speed (m/sec) compared male (or female) subjects in the 2^nd, 3^rd, and 4^th quartiles of HOMA-IR to those in the lowest quartile.

Abbreviations: homeostasis model assessment of insulin resistance, HOMA-IR; SE, standard error.

The cut-off values HOMA-IR quartiles among the men were: quartile 1 (<1.80), quartile 2 (1.80-2.51), quartile 3 (2.52-3.69), and quartile 4 (>3.69); while among the women the cut-off values were: quartile 1 (<1.48), quartile 2 (1.48-2.28), quartile 3 (2.29-3.52), and quartile 4 (>3.52).

Kuo et al. BMC Geriatrics 2009 9:49   doi:10.1186/1471-2318-9-49