Increase in Number of Depression Symptoms Over Time is Related to Worse Cognitive Outcomes in Older Adults With Type 2 Diabetes.

OBJECTIVE: Older adults with type 2 diabetes (T2D) are at increased risk for depression, cognitive decline, and dementia compared to those without T2D. Little is known about the association of simultaneous changes in depression symptoms and cognitive decline over time. METHODS: Subjects (n=1021; mean age 71.6 [SD=4.6]; 41.2% female) were initially cognitively normal participants of the Israel Diabetes and Cognitive Decline study who underwent evaluations of depression and cognition approximately every 18 months. Cognitive tests were summarized into four cognitive domains: episodic memory, attention/working memory, executive functions, and semantic categorization. The average of the z-scores of the four domains defined global cognition. Depression symptoms were assessed using the Geriatric Depression Scale, 15-item version. We fit a random coefficients model of changes in depression and in cognitive functions, adjusting for baseline sociodemographic and cardiovascular variables. RESULTS: Higher number of depression symptoms at baseline was significantly associated with lower baseline cognitive scores in global cognition (estimate = -0.1175, SE = 0.021, DF = 1,014, t = -5.59; p < 0.001), executive functions (estimate = -0.186, SE = 0.036, DF = 1,013, t = -5.15; p = <0.001), semantic categorization (estimate = -0.155, SE = 0.029, DF = 1,008, t = -5.3; p < 0.001), and episodic memory (estimate = -0.08165, SE = 0.027, DF = 1,035, t = -2.92; p = 0.0036), but not with rate of decline in any cognitive domain. During follow-up, a larger increase in number of depression symptoms, was associated with worse cognitive outcomes in global cognition (estimate = -0.1053, SE = 0.027, DF = 1,612, t = -3.77; p = 0.0002), semantic categorization (estimate = -0.123, SE = 0.036, DF = 1,583, t = -3.36; p = 0.0008), and in episodic memory (estimate = -0.165, SE = 0.055, DF = 1,622, t = -3.02; p = 0.003), but the size of this effect was constant over time. CONCLUSION: In elderly with T2D, increase in depression symptoms over time is associated with parallel cognitive decline, indicating that the natural course of the two conditions progresses concurrently and suggesting common underlying mechanisms".

Trajectories of depression symptoms over time differ by APOE4 genotype in older adults with type 2 diabetes.

OBJECTIVES: The APOE-ε4 genotype has been associated with old-age depression, but this relationship has been rarely investigated in type 2 diabetes (T2D) older adults, who are at significantly increased risk for depression, a major contributor to T2D complications. We examined whether trajectories of depression symptoms over time differ by APOE-ε4 genotype in older adults with T2D. METHODS: Participants (n = 754 [13.1% APOE-ε4 carrier]s) were from the longitudinal Israel Diabetes and Cognitive Decline (IDCD) study. They were initially cognitively normal and underwent evaluations of depression approximately every 18 months using the 15-item version of the Geriatric Depression Scale (GDS) and the depression subscale of the Neuropsychiatric Inventory (NPI). APOE was defined as a dichotomy of ε4 carriers and non-carriers. We used Hierarchical Linear Mixed Models (HLMM) that modeled the effects of APOE status on repeated GDS and NPI-depression scores in an unadjusted model (Model 1), adjusting for demographic factors (Model 2) and additionally adjusting for cardiovascular factors and global cognition (Model 3). RESULTS: Participants' mean age was 71.37 (SD = 4.5); 38.2% female. In comparison to non-carriers, APOE-ε4 carriers had lower mean GDS scores (ß = -0.46, p = 0.018) and lower NPI-depression scores (ß = -0.170, p = 0.038) throughout all study follow period. The groups did not differ in the slope of change over time in GDS (ß = -0.005, p = 0.252) or NPI-depression (ß = -0.001, p = 0.994) scores. Additional adjustment for cardiovascular factors and global cognition did not alter these results. CONCLUSIONS: In older adults with T2D, APOE-ε4 carriers have less depressive symptoms in successive measurements suggesting they may be less susceptible to depression.

Deterioration in Motor Function Over Time in Older Adults With Type 2 Diabetes is Associated with Accelerated Cognitive Decline.

OBJECTIVE: Type 2 diabetes (T2D) is associated with motor impairments and a higher dementia risk. The relationships of motor decline with cognitive decline in T2D older adults has rarely been studied. Using data from the Israel Diabetes and Cognitive Decline study (N = 892), we examined associations of decline in motor function with cognitive decline over a 54-month period. METHODS: Motor function measures were strength (handgrip) and gait speed (time to walk 3 m). Participants completed a neuropsychologic battery of 13 tests transformed into z-scores, summarized into 4 cognitive domains: episodic memory, attention/working memory, executive functions, and language/semantic categorization. The average of the 4 domains' z-scores defined global cognition. Motor and cognitive functions were assessed in 18-months intervals. A random coefficients model delineated longitudinal relationships of cognitive decline with baseline and change from baseline in motor function, adjusting for sociodemographic, cardiovascular, and T2D-related covariates. RESULTS: Slower baseline gait speed levels were significantly associated with more rapid decline in global cognition (P = .004), language/semantic categorization (P = .006) and episodic memory (P = .029). Greater decline over time in gait speed was associated with an accelerated rate of decline in global cognition (P = .050), attention/working memory (P = .047) and language/semantic categorization (P<.001). Baseline strength levels were not associated with cognitive decline but the rate of declining strength was associated with an accelerated decline in executive functions (P = .025) and language/semantic categorization (P = .006). CONCLUSION: In T2D older adults, the rate of decline in motor function, beyond baseline levels, was associated with accelerated cognitive decline, suggesting that cognitive and motor decline share common neuropathologic mechanisms in T2D.

Mobility data shows effectiveness of control strategies for COVID-19 in remote, sparse and diffuse populations.

Data that is collected at the individual-level from mobile phones is typically aggregated to the population-level for privacy reasons. If we are interested in answering questions regarding the mean, or working with groups appropriately modeled by a continuum, then this data is immediately informative. However, coupling such data regarding a population to a model that requires information at the individual-level raises a number of complexities. This is the case if we aim to characterize human mobility and simulate the spatial and geographical spread of a disease by dealing in discrete, absolute numbers. In this work, we highlight the hurdles faced and outline how they can be overcome to effectively leverage the specific dataset: Google COVID-19 Aggregated Mobility Research Dataset (GAMRD). Using a case study of Western Australia, which has many sparsely populated regions with incomplete data, we firstly demonstrate how to overcome these challenges to approximate absolute flow of people around a transport network from the aggregated data. Overlaying this evolving mobility network with a compartmental model for disease that incorporated vaccination status we run simulations and draw meaningful conclusions about the spread of COVID-19 throughout the state without de-anonymizing the data. We can see that towns in the Pilbara region are highly vulnerable to an outbreak originating in Perth. Further, we show that regional restrictions on travel are not enough to stop the spread of the virus from reaching regional Western Australia. The methods explained in this paper can be therefore used to analyze disease outbreaks in similarly sparse populations. We demonstrate that using this data appropriately can be used to inform public health policies and have an impact in pandemic responses.

Vitamin E Intake Is Associated with Lower Brain Volume in Haptoglobin 1-1 Elderly with Type 2 Diabetes.

BACKGROUNDS: The efficacy of vitamin E in prevention of diabetes-related complications differs by Haptoglobin (Hp) genotype. OBJECTIVE: To examine the role of Hp genotype in the relationship of vitamin E intake with brain volume in cognitively normal elderly patients with type 2 diabetes. METHODS: Brain volumes for the superior, middle, and inferior frontal gyri and for the middle temporal gyrus were generated from structural T1 MRI in 181 study participants (Hp 1-1: n = 24, Hp 2-1: n = 77, Hp 2-2: n = 80). Daily vitamin E intake was assessed using the Food Frequency Questionnaire. Analyses of covariance, controlling for demographic and cardiovascular variables was used to evaluate whether the association of daily vitamin E intake with brain volume was modified by Hp genotype. RESULTS: Average age was 70.8 (SD = 4.2) with 40% females, and mean Mini-Mental State Examination score of 28.17 (SD = 1.90). A significant interaction was found between vitamin E intake and Hp genotype in inferior frontal gyrus' volume; p = 0.0108. For every 1 microgram increase in vitamin E intake, the volume of the inferior frontal gyrus decreased by 0.955% for Hp 1-1 (p = 0.0348), increased by 0.429% for Hp 2-1 (p = 0.0457), and by 0.077% for Hp 2-2 (p = 0.6318). There were no significant interactions between vitamin E intake and Hp genotype for the middle (p = 0.6011) and superior (p = 0.2025) frontal gyri or for the middle temporal gyrus (p = 0.503). CONCLUSIONS: The effect of dietary vitamin E on the brain may differ by Hp genotype. Studies examining the impact of vitamin E on brain-related outcomes should consider Hp genotype.