This study cross-sectionally examines in the elderly population: (a) the association of type 2 diabetes with executive function (EF); (b) the effect of BMI on both type 2 diabetes and EF; (c) the association between glycaemia control and EF in type 2 diabetes. 6823 older individuals with overweight/obesity and metabolic syndrome participating in the PREDIMED-PLUS study, were assessed with a battery of cognitive tests and a medical interview. ANOVA showed a significantly worse performance on EF in type 2 diabetes vs. non-diabetic individuals. Two complementary models were displayed: (1) in the whole sample, the presence of type 2 diabetes, depressive symptoms and BMI had a direct negative effect on EF, while apnoea had an indirect negative effect; (2) in the diabetes subsample, higher illness duration was associated with worse performance in EF. Participants with type 2 diabetes and HbA1c<53 mmol/mol displayed better cognitive performance when compared to those with HbA1c≥53 mmol/mol. Our results provide a controlled comprehensive model that integrates relevant neuropsychological and physical variables in type 2 diabetes. The model suggests that, to improve treatment adherence and quality of life once diabetes has been diagnosed, cognitive decline prevention strategies need to be implemented while monitoring depressive symptoms, BMI and glycaemia control.

This project is funded by Instituto de Salud Carlos III (ISCIII), the Spanish Government Official Agency for funding biomedical research - with competitive grants for the periods 2014–2016, 2015–2017, 2017–2019 and 2018–2020, through the Fondo de Investigación para la Salud (FIS), which is co-funded by the European Regional Development Fund [grants: PI13/00673, PI13/00492, PI13/00272, PI13/01123, PI13/00462, PI13/00233, PI13/02184, PI13/00728 PI13/01090 PI13/01056, PI14/01722, PI14/00636, PI14/00618, PI14/00696, PI14/01206, PI14/01919, PI14/00853, PI14/01374, PI16/00473, PI16/00662, PI16/01873, PI16/01094, PI16/00501, PI16/00533, PI16/00381, PI16/00366, PI16/01522, PI16/01120, PI17/00764, PI17/01183, PI17/00855, PI17/01347, PI17/00525, PI17/01827, PI17/00532, PI17/00215, PI17/01441, PI17/00508, PI17/01732, PI17/00926] and the European Research Council [Advanced Research Grant 2014–2019; agreement #340918]. Additional grants: Acciones Especiales from ISCIIII, Consejería-Salud, Junta -Andalucía [PI0458/2013, PS0358/2016], Recercaixa-grant 2013 [2013ACUP00194], a SEMERGEN grant, International Nut & Dried Fruit Council – FESNAD No. 201302. Fundación Patrimonio Comunal Olivarero is providing the necessary amounts of olive oil. Nuts were initially and only partially provided by Pistachios Growers and Almond Board of California, for the pilot study. This research was also partially funded by EU-H2020 Grant (Eat2beNICE/H2020-SFS-2016–2; Ref 728018), PI14/00290 y PI17/1167(Co-funded by European Regional Development Fund, ERDF, a way to build Europe), PERIS (Generalitat de Catalunya, SLT006/17/00077), Grant PROMETEO/2017/017 (Generalitat Valenciana) and Grant FEA/SEA 2017 for Primary Care Research. We thank CERCA Programme/Generalitat de Catalunya for institutional support. ML-M is supported by a predoctoral Grant of the Ministerio de Educación, Cultura y Deporte (FPU15/02911). None of these funding sources plays any role in the design, collection, analysis, or interpretation of the data or in the decision to submit manuscripts for publication.