Table 1

Characteristics of subjects in the TEDDY nested case-control study

Matching variableCase subjects, n (%)Plasma 25(OH)D concentration (nmol/L)
Childhood*Early infancy
Case subjectsControl subjectsCase subjectsControl subjects
Clinical center
 Colorado55 (14.6)50.6 ± 17.856.1 ± 15.442.6 ± 25.744.8 ± 22.6
 Georgia23 (6.1)58.3 ± 20.059.3 ± 17.051.2 ± 21.853.7 ± 21.1
 Washington35 (9.3)51.3 ± 14.656.1 ± 17.144.2 ± 18.746.7 ± 24.9
 Finland112 (29.8)43.1 ± 13.044.9 ± 13.741.1 ± 15.043.0 ± 15.8
 Germany29 (7.7)57.3 ± 23.165.0 ± 19.856.1 ± 29.964.1 ± 22.3
 Sweden122 (32.5)56.5 ± 14.659.5 ± 14.853.9 ± 20.360.4 ± 20.8
Sex
 Female167 (44.4)51.7 ± 17.054.2 ± 17.247.5 ± 21.549.8 ± 22.0
 Male209 (55.6)51.0 ± 16.755.0 ± 16.447.3 ± 21.452.2 ± 21.6
FDR/GP status
 FDR91 (24.2)47.4 ± 17.256.8 ± 17.342.5 ± 20.854.4 ± 23.3
 GP285 (75.8)52.6 ± 16.553.9 ± 16.548.9 ± 21.450.1 ± 21.2
  • Data are mean ± SD, unless otherwise stated. FDR, first-degree relative of an individual with type 1 diabetes;

  • GP, from the general population (no first-degree relative with type 1 diabetes).

  • *Average of measures from all visits prior to and including the seroconversion visit, which is the first of two consecutive visits at which the child tested positive for an autoantibody.

  • †Defined by the first 25(OH)D measure occurring before 12 months of age in 360 case subjects and their 981 control subjects.