Course of body weight before and after the initiation of insulin therapy in type 2 diabetes mellitus: Retrospective inception cohort study (ZODIAC 58)

Aims The aim of this study was to explore the effect of insulin treatment initiation on weight by taking weight change prior to initiation into account. Materials and methods We performed an observational retrospective inception cohort study, concerning Dutch primary care. We identified all patients that initiated insulin treatment (n = 7967) and individually matched patients with a reference patient (n = 5213 pairs). We obtained estimated mean weight changes in the five years prior to five years post insulin therapy. We applied linear regression analysis on weight change in the first year after insulin therapy (T0 to T+1), with matched group as primary determinant adjusted for pre‐insulin weight change and additional covariates. Results Estimated mean weight increased in the five consecutive years prior to insulin therapy (−0.23 kg in year T‐5 to T‐4, 0.01 kg in year T‐4 to T‐3, 0.07 kg in year T‐3 to T‐2, 0.24 kg in year T‐2 to T‐1, and 0.46 kg in year T‐1 to T0) and continued to increase in the first year after, that is T0 to T+1, at a slightly lower rate (0.31 ± 3.9 kg). Pre‐insulin weight change had the highest explained variance and was inversely and independently associated with weight change (p
This paper is the first to specifically include weight changes prior to the initiation of insulin therapy in T2DM treated in primary care, in studying post‐insulin initiation weight change. Remarkable differences in longitudinal courses between patients that initiated insulin and their individually matched references and between post‐insulin initiation weight change strata are demonstrated.