Low birthweight is associated with an increased risk of LADA and type 2 diabetes: results from a Swedish case–control study

Abstract

Aims/hypothesis: Our aim was to investigate the association between birthweight and latent autoimmune diabetes in adults (LADA), a common diabetes form with features of both type 1 and type 2 diabetes. Methods: We used data from the Epidemiological Study of Risk Factors for LADA and Type 2 Diabetes (ESTRID), a Swedish population-based study. Eligible for the analysis were 134 incident LADA cases (glutamic acid decarboxylase antibody [GADA] positive), 350 incident type 2 diabetes cases (GADA negative) and 603 randomly selected controls. We present ORs and 95% CIs for LADA and type 2 diabetes in relation to birthweight, adjusted for sex, age, BMI and family history of diabetes. Results: Low birthweight increased the risk of LADA as well as the risk of type 2 diabetes; OR per kg reduction was estimated as 1.52 (95% CI 1.12, 2.08) and 1.58 (1.23, 2.04), respectively. The OR for participants weighing <3 kg compared with ≥4 kg at birth was estimated as 2.38 (1.23, 4.60) for LADA and 2.37 (1.37, 4.10) for type 2 diabetes. A combination of low birthweight (<3 kg) and current overweight (BMI ≥ 25) further augmented the risk: LADA, OR 3.26 (1.69, 6.29); and type 2 diabetes, OR 39.93 (19.27, 82.71). Family history of diabetes had little impact on these estimates. Conclusions/interpretation: Our results suggest that low birthweight may be a risk factor for LADA of the same strength as for type 2 diabetes. These findings support LADA, despite its autoimmune component, having an aetiology that includes factors related to type 2 diabetes.