Table 1 Effects of zidovudine on soleus muscle histology, serum parameters, mtDNA, mitochondrial function, and muscle fiber-type characteristics

Soleus muscle fiber diameter (median μm)

58.3 (IQR 54.2, 62.3)

41.1 (IQR 37.5, 47.1)

<0.001

Serum creatine kinase (U/L)

724 ± 480

548 ± 257

0.3

Serum creatinine (mg/L)

3.6 ± 0.34

3.1 ± 0.11

<0.001

Serum glucose (mg/L)

1,760 ± 100

1,680 ± 220

0.055

Serum resting lactate (mM)

4.5 ± 1.8

5.0 ± 1.6

0.9

Serum alanine aminotransferase (U/L)

66 ± 8

56 ± 7

0.1

Serum aspartate aminotransferase (U/L)

125 ± 35

101 ± 13

0.09

mtDNA copy number (mean copies/myonucleus)

559 ± 46

399 ± 78

<0.001

NADH DH (μmoles min^-1 g muscle protein^-1 )

684 ± 254

474 ± 236

0.042

COX (μmoles min^-1 g muscle protein^-1 )

28 ± 8

18 ± 9

0.026

SDH (μmoles min^-1 g muscle protein^-1 )

36 ± 6

35 ± 10

0.7

NADH DH/SDH-ratio (% of control mean)

100 ± 28

72 ± 20

0.027

COX/SDH-ratio (% of control mean)

100 ± 27

67 ± 26

0.016

Single-fiber soleus muscle

Control

Zidovudine

p-value

Fiber type

Fast

Slow

Fast

Slow

Fast

Slow

Fiber-type proportion (% of all fibers)

5.2 ± 3.0

94.8 ± 3.0

13.3 ± 5.1

86.7 ± 5.1

<0.001

<0.001

Fiber diameter (mean μm)

54.8 ± 5.8

65.5 ± 10.6

37.3 ± 9.3

51.8 ± 6.2

<0.001

0.006

mtDNA copy number (mean copies/myonucleus)

617 ± 91

683 ± 94

384 ± 91

206 ± 97

<0.001

<0.001