Background: Dementia with Lewy bodies (DLBs) often presents with neuropsychiatric symptoms (NPSs), yet the role of hyperglycemia, a common cause of delirium in older adults, as a contributing factor remains under-recognized. This article aims to explore the relationship between hyperglycemia and NPSs.

Methods: We report the case of a 71-year-old male with DLBs and type 2 diabetes mellitus (T2DM) who experienced worsening NPSs closely associated with periods of hyperglycemia. Initial pharmacological and nonpharmacological interventions were insufficient, prompting adjustments to insulin therapy and dietary modifications to stabilize blood glucose levels.

Results: Improved glycemic control resulted in a clinically significant reduction in NPSs.

Conclusions: This case suggests a potential link between hyperglycemia and NPSs in DLB patients, emphasizing the importance of maintaining glycemic control in managing NPSs. Although the exact mechanisms remain incompletely understood, adopting a holistic framework for brain health could offer a comprehensive approach to cognitive care. Further studies are needed to elucidate the biological pathways involved, validate these findings in larger populations, and develop evidence-based clinical guidelines.