TY - JOUR A1 - Tanoey, Justine A1 - Baechle, Christina A1 - Brenner, Hermann A1 - Deckert, Andreas A1 - Fricke, Julia A1 - Günther, Kathrin A1 - Karch, André A1 - Keil, Thomas A1 - Kluttig, Alexander A1 - Leitzmann, Michael A1 - Mikolajczyk, Rafael A1 - Obi, Nadia A1 - Pischon, Tobias A1 - Schikowski, Tamara A1 - Schipf, Sabine M. A1 - Schulze, Matthias B. A1 - Sedlmeier, Anja A1 - Moreno Velásquez, Ilais A1 - Weber, Katharina S. A1 - Völzke, Henry A1 - Ahrens, Wolfgang A1 - Gastell, Sylvia A1 - Holleczek, Bernd A1 - Jöckel, Karl-Heinz A1 - Katzke, Verena A1 - Lieb, Wolfgang A1 - Michels, Karin B. A1 - Schmidt, Börge A1 - Teismann, Henning A1 - Becher, Heiko T1 - Birth order, Caesarean section, or daycare attendance in relation to child- and adult-onset type 1 diabetes: results from the German National Cohort JF - International Journal of Environmental Research and Public Health N2 - (1) Background: Global incidence of type 1 diabetes (T1D) is rising and nearly half occurred in adults. However, it is unclear if certain early-life childhood T1D risk factors were also associated with adult-onset T1D. This study aimed to assess associations between birth order, delivery mode or daycare attendance and type 1 diabetes (T1D) risk in a population-based cohort and whether these were similar for childhood- and adult-onset T1D (cut-off age 15); (2) Methods: Data were obtained from the German National Cohort (NAKO Gesundheitsstudie) baseline assessment. Self-reported diabetes was classified as T1D if: diagnosis age ≤ 40 years and has been receiving insulin treatment since less than one year after diagnosis. Cox regression was applied for T1D risk analysis; (3) Results: Analyses included 101,411 participants (100 childhood- and 271 adult-onset T1D cases). Compared to “only-children”, HRs for second- or later-born individuals were 0.70 (95% CI = 0.50–0.96) and 0.65 (95% CI = 0.45–0.94), respectively, regardless of parental diabetes, migration background, birth year and perinatal factors. In further analyses, higher birth order reduced T1D risk in children and adults born in recent decades. Caesarean section and daycare attendance showed no clear associations with T1D risk; (4) Conclusions: Birth order should be considered in both children and adults’ T1D risk assessment for early detection. KW - perinatal KW - adult-onset KW - late-onset KW - autoimmune KW - delivery mode KW - sex KW - offspring KW - NAKO Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-286216 SN - 1660-4601 VL - 19 IS - 17 ER -