The Impact of Type 2 Diabetes on Peripheral and Cerebral Haemodynamic Responses to Active Stand

Abstract Background Whilst Type 2 Diabetes Mellitus (T2DM) is an established risk factor for cognitive impairment, the underlying mechanisms remain poorly explored. One potential mechanism may be through effects of T2DM on cerebral perfusion. The current study hypothesised that T2DM is associated with altered peripheral and central haemodynamic responses to orthostasis, which may in turn be associated with cognitive impairment in T2DM. Methods A novel use of function-on-scalar regression; which allows the entire haemodynamic response curve to be modelled; was employed to assess the association between T2DM and haemodynamic responses to orthostasis. Logistic regression was used to assess the relationship between tissue saturation index (TSI), T2DM and cognitive impairment. All analyses used cross-sectional data from wave 3 of The Irish Longitudinal Study on Ageing (TILDA). Results Of 2,984 older adults (aged 64.3 ± 8.0; 55% female), 189 (6.3%) had T2DM. T2DM was associated with many features that are indicative of autonomic dysfunction including a blunted peak heart rate and lower diastolic blood pressure. T2DM was associated with reduced Tissue Saturation Index (TSI) and also with greater odds of impaired performance on the Montreal Cognitive Assessment (OR: 1.62, CI (1.07,2.56); p=0.019). Greater TSI was associated with lower odds of impaired performance (OR: 0.90, CI (0.81-0.99); p = 0.047). Conclusions T2DM was associated with impaired peripheral and cerebral haemodynamic responses to active stand. Both T2DM and reduced cerebral perfusion were associated with impaired cognitive performance. Altered cerebral perfusion may represent an important mechanism linking T2DM and adverse brain health outcomes in older adults.