Table 1

Description of 45 monozygotic twin pairs discordant for chronic impairing fatigue.

Variable

Affected twins

Unaffected co-twins

Statistical comparison


Met criteria for chronic fatigue syndrome

32/45, 71%

0/45, 0%

By design

Met criteria for idiopathic chronic fatigue

13/45, 29%

0/45, 0%

By design

Female sex

40/45, 89%

40/45, 89%

Identical by design

Median age at evaluation, IQR

51, 39-59 years

51, 39-59 years

Identical by design

Median body mass index, IQR

25, 22-30 kg/m2

24, 22-31 kg/m2

Paired t44 = 0.1, p = 0.91

Median SF-36 physical function, IQR

41, 27-48

48, 39-52

Paired t44 = 3.1, p = 0.003

Median SF-36 mental function, IQR

39, 29-48

51, 39-56

Paired t44 = 4.7, p = 3 × 10-5

Median current fatigue by VAS, IQR

69, 49-77

19, 10-51

Paired t43 = -7.2, p = 6 × 10-9


Abbreviations: IQR = inter-quartile range, VAS = visual analogue scale (0-100).

Sullivan et al. BMC Microbiology 2011 11:2   doi:10.1186/1471-2180-11-2

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