Association between birth weight and insulin resistance in US adolescents: A retrospective cohort study exploring the role of concurrent body mass index

Background and aims: This study aimed to investigate the association between birth weight (BW) and abnormal HOMA-IR in US adolescents aged 12-15 years. The role of concurrent body mass index (BMI) in adolescence was also examined. Methods and results: This retrospective cohort study included 3429 participants from NHANES with data in 1999-2020. HOMA-IR >= 2.3 was considered abnormal. Participants were classified as low (LBW; <2.5 kg), normal (NBW; 2.5-4.0 kg), or high (HBW; >4.0 kg) BW. Logistic regression was used to explore the association between BW and HOMA-IR. Mediation analysis was used to examine whether BMI z-score in adolescence mediated the association between BW and HOMA-IR. Compared with those in NBW, the odds ratios (95 % CI) of abnormal HOMA-IR in LBW and HBW groups were 1.26 (0.99-1.60), and 0.62 (0.47-0.83) respectively. The association between BW and abnormal HOMA-IR was consistent in all subgroups with no significant interactions. Mediation analysis showed that BW is associated with lower risk of HOMA-IR directly, but with higher risk indirectly via BMI in adolescence. Conclusion: There was a negative linear relationship between BW and the prevalence of abnormal HOMA-IR in adolescents aged 12-15 independent of concurrent BMI. Children who were born with LBW but had high BMI in adolescence were of particularly higher risk of insulin resistance. (c) 2023 The Author(s). Published by Elsevier B.V. on behalf of The Italian Diabetes Society, the Italian Society for the Study of Atherosclerosis, the Italian Society of Human Nutrition and the Department of Clinical Medicine and Surgery, Federico II University. This is an open access article under the CC BY license.