Marginal structural model to evaluate the joint effect of socioeconomic exposures on the risk of developing end-stage renal disease in patients with type 1 diabetes: a longitudinal study based on data from the Swedish Childhood Diabetes Study Group

The role of socioeconomic factors on discontinuation of insulin during pregnancy—methodological challenges from a Swedish register-based study

Aim

Continuous use of antidiabetic medication, especially insulin, is crucial for diabetes management. In pregnancy, adherence to medication is generally low and may also be associated with lower socioeconomic status. However, little is known about discontinuation of insulin in pregnant women and the potential role of socioeconomic factors. Therefore, this study aims to measure the associations between socioeconomic factors and insulin discontinuation during pregnancy in women using insulin prior to the start of pregnancy in Sweden.

Subjects and methods

This cohort study identified pregnancies recorded in the Swedish Medical Birth Register from 2006 to 2016 in women receiving insulin prior to the start of pregnancy (N = 6029). Discontinuation of insulin was defined as not receiving a refill within 120 days from the previous refill. Associations between discontinuation and socioeconomic factors were investigated via logistic regression. Sensitivity analyses were performed using different definitions of discontinuation.

Results

Women discontinued insulin use in 34.2% of pregnancies. The odds ratios (ORs) of discontinuation of insulin were 1.17 [95% confidence interval (CI): 1.01–1.37] for women with lower household disposable incomes and 1.14 (95% CI: 1.01–1.29) for women with lower educational levels. When testing a change in the maximum refill gap from 91 days to 180 days, women with lower educational levels and those born in non-Nordic countries showed greater associations with discontinuation.

Conclusion

The definition of discontinuation affects the level of association of socioeconomic factors with discontinuation. Nevertheless, discontinuation of insulin is common in Sweden, especially in the lower socioeconomic groups. The socioeconomic inequality in insulin use behavior is worth noting.

Helminths protect against type 1 diabetes: effects and mechanisms

Type 1 diabetes (T1D) is an autoimmune disease in which cells of the immune system destroy pancreatic β cells, which secrete insulin. The high prevalence of T1D in developed societies may be explained by environmental changes, including lower exposure to helminths. Indeed, infection by helminths such as Schistosoma, Filaria, and Heligmosomoides polygyrus and their by-products has been reported to ameliorate or prevent the development of T1D in human and animal models. Helminths can trigger distinct immune regulatory pathways, often involving adaptive immune cells that include T helper 2 (Th2) cells and regulatory T cells (Tregs) and innate immune cells that include dendritic cells, macrophages, and invariant natural killer T cells, which may act synergistically to induce Tregs in a Toll-like receptor-dependent manner. Cytokines such as interleukin (IL)-4, IL-10, and transforming growth factor (TGF)-β also play an important role in protection from T1D. Herein, we provide a comprehensive review of the effects and mechanisms underlying protection against T1D by helminths.