Extremely Early Appearance of Islet Autoantibodies in Genetically Susceptible Children

Table 4

Birth cohort comparison of children developing islet autoimmunity by the age of 0.50 years or by the age of 0.75 years.

	Birth cohorts				p-Value
	I	II	III	IV
	N = 2998	N = 4782	N = 3159	N = 2734
IAb^† at age ≤0.50 years, N (%)	19 (0.6%)	10 (0.2%)	15 (0.5%)	3 (0.1%)	0.016
IAb at age ≤0.50 years and confirmed positivity during follow-up, N (%)	12 (0.4%)	6 (0.1%)	6 (0.2%)	2 (0.1%)	0.018
IAb at age ≤0.75 years, N (%)	44 (1.5%)	39 (0.8%)	38 (1.2%)	15 (0.5%)	0.009
IAb at age ≤0.75 years and confirmed positivity during follow-up, N (%)	30 (1.0%)	29 (0.6%)	23 (0.7%)	13 (0.5%)	0.048

Note: The frequencies of children developing islet autoantibodies by the age of 0.50 years or by the age of 0.75 years and frequencies of those who developed confirmed islet autoantibody positivity during the follow-up. The four birth cohorts were defined according to the date of birth: I: November 1994–July 1997 and January 2003–August 2004, II: September 2004–February 2010, III: March 2010–December 2014, IV: January 2015–July 2019. Differences in the frequencies between the four cohorts were analyzed with linear-by-linear test (IBM SPSS Statistics for Windows, version 29. Armonk, NY: IBM Corp.). ^†Islet autoantibody.