Diabetes and dementia in older people: a Best Clinical Practice Statement by a multidisciplinary National Expert Working Group

Both dementia and diabetes mellitus are long‐term disabling conditions and each may be a co‐morbidity of the other. Type 2 diabetes is associated with a 1.5‐ to 2‐fold higher risk of dementia. Diabetes also may occur for the first time in many individuals with mental ill health, including cognitive impairment and dementia, and this may complicate management and lead to difficulties in self‐care. Case finding is often poor for cognitive impairment in medical settings and for diabetes in mental health settings and this needs to be addressed in the development of care pathways for both conditions. Many other deficiencies in quality care (both for dementia and diabetes) currently exist, but we hope that this Best Clinical Practice Statement will provide a platform for further work in this area. We have outlined the key steps in an integrated care pathway for both elements of this clinical relationship, produced guidance on identifying each condition, dealt with the potentially hazardous issue of hypoglycaemia, and have outlined important competencies required of healthcare workers in both medical/diabetes and mental health settings to enhance clinical care.     

Cerebral energy metabolism and the brain's functional network architecture: an integrative review

Recent functional magnetic resonance imaging (fMRI) studies have emphasized the contributions of synchronized activity in distributed brain networks to cognitive processes in both health and disease. The brain''s ‘functional connectivity'' is typically estimated from correlations in the activity time series of anatomically remote areas, and postulated to reflect information flow between neuronal populations. Although the topological properties of functional brain networks have been studied extensively, considerably less is known regarding the neurophysiological and biochemical factors underlying the temporal coordination of large neuronal ensembles. In this review, we highlight the critical contributions of high-frequency electrical oscillations in the γ-band (30 to 100 Hz) to the emergence of functional brain networks. After describing the neurobiological substrates of γ-band dynamics, we specifically discuss the elevated energy requirements of high-frequency neural oscillations, which represent a mechanistic link between the functional connectivity of brain regions and their respective metabolic demands. Experimental evidence is presented for the high oxygen and glucose consumption, and strong mitochondrial performance required to support rhythmic cortical activity in the γ-band. Finally, the implications of mitochondrial impairments and deficits in glucose metabolism for cognition and behavior are discussed in the context of neuropsychiatric and neurodegenerative syndromes characterized by large-scale changes in the organization of functional brain networks.