Source of Weight regain after discontinuation

{{Infobox concept | name = Weight regain after discontinuation | subtitle = Clinical practice | image = trial-bars.svg | caption = Randomised withdrawal designs separate regain from natural variation. | Evidence design = Randomised withdrawal after a lead-in | Principal trials = STEP 4, SURMOUNT-4 | Observed pattern = Steady regain towards baseline }} '''Weight regain after discontinuation''' is the return of body weight towards its pre-treatment value when incretin therapy stops. It has been documented in randomised withdrawal trials, which are the design capable of distinguishing it from the natural course of weight in a treated population.{{r|rubino2021}} In [[STEP trial programme|STEP 4]], participants who had reached the maintenance dose during a 20-week run-in were randomised to continue or to switch to placebo. Those continuing lost further weight; those switched regained steadily over the following 48 weeks.{{r|rubino2021}} The finding is unsurprising given the mechanism. These agents act by producing a sustained pharmacological signal in the appetite-regulating system; removing the signal removes the effect, and the [[Arcuate nucleus|circuits]] return to their prior state rather than being reset by the period of treatment.{{r|drucker2018}} == What the withdrawal trials show == A randomised withdrawal design is necessary because an observational comparison of people who stop with people who continue is confounded: those who stop differ systematically, often having stopped because of intolerance or lack of response.{{r|rubino2021}} STEP 4 and SURMOUNT-4 both randomised after a lead-in on active treatment, so both groups had already lost weight and differed only in what followed. Regain in the withdrawn groups was substantial and progressive; neither trial ran long enough to establish whether weight returns fully to baseline.{{r|rubino2021}} Cardiometabolic markers moved with weight. Improvements in blood pressure, lipids and glycaemia during the lead-in reversed on withdrawal, which argues that the benefits were weight-mediated rather than persistent effects of the exposure.{{r|wilding2021}} == Interpretation == The finding is often described as showing that treatment must be lifelong. That is a stronger claim than the trials support: they show that stopping is followed by regain over the periods studied, which is a statement about what happens rather than about what must happen.{{r|rubino2021}} It is also not unique to this class. Weight regain follows cessation of essentially every weight-management intervention that is stopped, including diet and structured lifestyle programmes, and the pattern here resembles that literature rather than departing from it.{{r|wilding2021}} What the trials do establish is that any decision about duration must be made in the knowledge that the effect is contingent on continued exposure. This wiki gives no advice on such decisions.{{r|ada2024}} == Related considerations == Because the agents have long half-lives, exposure persists for weeks after the last dose, and regain begins from the point at which concentrations fall below effect rather than from the day of the last injection. See [[Missed dose]].{{r|drucker2018}} Lean and fat mass regain in different proportions from those in which they were lost, with fat mass typically regained preferentially — a pattern documented across weight-loss modalities and not specific to this class. See [[Body composition assessment]] and [[Sarcopenia]].{{r|wilding2021}} Nothing here is medical advice.{{r|ada2024}} == References == {{reflist}} <ref name="rubino2021">Rubino D, Abrahamsson N, Davies M, et al. "Effect of continued weekly subcutaneous semaglutide vs placebo on weight loss maintenance (STEP 4)." ''JAMA'' 325(14):1414–1425 (2021). PMID 33755728.</ref> <ref name="drucker2018">Drucker DJ. "Mechanisms of action and therapeutic application of glucagon-like peptide-1." ''Cell Metabolism'' 27(4):740–756 (2018). PMID 29617641.</ref> <ref name="wilding2021">Wilding JPH, Batterham RL, Calanna S, et al. "Once-weekly semaglutide in adults with overweight or obesity." ''New England Journal of Medicine'' 384(11):989–1002 (2021). PMID 33567185.</ref> <ref name="ada2024">American Diabetes Association. "Standards of Care in Diabetes." ''Diabetes Care'' 47(Suppl 1) (2024).</ref> == See also == * [[STEP trial programme]] * [[SURMOUNT trial programme]] * [[Missed dose]] * [[Body composition assessment]] * [[Sarcopenia]] {{DEFAULTSORT:Weight regain after discontinuation}} [[Category:Discontinuation and maintenance]] [[Category:Clinical practice]] [[Category:Body composition]]