Clinical bottom line
Pancreatic delta cells, which secrete somatostatin, play a critical modulatory role in islet hormone regulation, influencing both insulin and glucagon secretion. Emerging therapies targeting delta cell function or somatostatin signaling represent a novel avenue for diabetes management, aiming to restore islet hormone balance and improve glycemic control. Current evidence remains preliminary and largely preclinical, but these approaches hold promise as adjuncts or alternatives to existing therapies, particularly for patients with dysregulated islet hormone dynamics. Clinicians should be aware of this evolving field while recognizing that clinical validation and safety data are still needed before routine implementation.
What the evidence shows
Delta cells constitute approximately 5–10% of pancreatic islet cells and secrete somatostatin, a potent paracrine inhibitor of both insulin and glucagon secretion. This regulatory role is crucial for maintaining glucose homeostasis. Dysfunction or altered delta cell activity has been implicated in the pathophysiology of both type 1 and type 2 diabetes, contributing to impaired insulin and glucagon secretion dynamics (Fernández Díaz et al., 2023).
Recent preclinical studies have explored therapeutic strategies aimed at modulating delta cell function or somatostatin receptor signaling to improve islet hormone secretion profiles. For example, selective somatostatin receptor antagonists have been shown in animal models to enhance insulin secretion and reduce hyperglycemia by attenuating somatostatin-mediated inhibition of beta cells. Conversely, somatostatin analogs with modified receptor specificity are being investigated for their potential to suppress inappropriate glucagon secretion in diabetes (Fernández Díaz et al., 2023).
Additionally, genetic and molecular studies highlight the interplay between delta cells and beta cell survival and function. Dysregulation of insulin-degrading enzyme (IDE) activity, which affects beta cell function, may be influenced by delta cell signaling pathways, suggesting a complex network that could be therapeutically targeted (Fernández Díaz et al., 2023). While direct clinical trials targeting delta cells are lacking, these mechanistic insights provide a rationale for future translational research.
Caveats and uncertainty
The majority of evidence regarding delta cell-targeted therapies remains preclinical or mechanistic. There is a lack of robust clinical trial data demonstrating efficacy and safety in humans. The complexity of islet cell interactions and the pleiotropic effects of somatostatin signaling pose challenges in selectively modulating delta cell function without unintended consequences, such as dysregulated glucagon secretion or gastrointestinal side effects.
Moreover, heterogeneity in delta cell function among individuals with diabetes and across diabetes subtypes is not fully understood, complicating patient selection for potential therapies. The long-term effects of altering somatostatin pathways on islet cell health and systemic metabolism are also unknown.
Given these uncertainties, current clinical guidelines do not incorporate delta cell-targeted therapies, and their use remains investigational.
How this may change practice
If ongoing and future clinical studies validate the safety and efficacy of delta cell-targeted therapies, these agents could complement existing diabetes treatments by addressing islet hormone dysregulation more holistically. Such therapies might be particularly beneficial in patients with persistent hyperglucagonemia or impaired insulin secretion despite standard care.
Clinicians should monitor emerging data from early-phase trials and mechanistic studies to understand potential indications, contraindications, and integration with current regimens, including incretin-based therapies and insulin. Awareness of this novel therapeutic axis may also inform personalized approaches to diabetes management as the field evolves.