Matrix metalloproteinases are associated with brain atrophy in cognitively unimpaired individuals.

Matrix metalloproteinases (MMPs) and their tissue inhibitors (TIMPs) have been linked to age-related neurodegeneration and Alzheimer's disease (AD), but their role in normal aging is poorly understood. We used linear mixed models to determine if baseline or rate of yearly change in cerebrospinal fluid (CSF) levels of MMP-2; MMP-3; MMP-10; TIMP-123 (composite of TIMP-1, TIMP-2, and TIMP-3); or TIMP-4 predicted changes in bilateral entorhinal cortex thickness, hippocampal volume, or lateral ventricle volume in cognitively unimpaired individuals. We also assessed effects on the CSF AD biomarkers amyloid-ß42 and phosphorylated tau181. Low baseline levels of MMP-3 predicted larger ventricle volumes and more entorhinal cortex thinning. Increased CSF MMP-2 levels over time predicted more entorhinal thinning, hippocampal atrophy, and ventricular expansion, while increased TIMP-123 over time predicted ventricular expansion. No MMP/TIMPs predicted changes in CSF AD biomarkers. Notably, we show for the first time that longitudinal increases in MMP-2 and TIMP-123 levels may predict age-associated brain atrophy. In conclusion, MMPs and TIMPs may play a role in brain atrophy in cognitively unimpaired aging.

Longitudinal trajectories of functional recovery after hip fracture.

BACKGROUND: There is limited evidence regarding predictors of functional trajectories after hip fracture. We aimed to identify groups with different trajectories of functional recovery the first year after hip fracture, and to determine predictors for belonging to such groups. METHODS: This longitudinal study combined data from two large randomized controlled trials including patients with hip fracture. Participants were assessed at baseline, four and 12 months. We used the Nottingham Extended Activities of Daily Living (NEADL) as a measure of instrumental ADL (iADL) and Barthel Index for personal ADL (pADL). A growth mixture model was estimated to identify groups of patients following distinct trajectories of functioning. Baseline characteristics potentially predicting group-belonging were assessed by multiple nominal regression. RESULTS: Among 726 participants (mean age 83.0; 74.7% women), we identified four groups of patients following distinct ADL trajectories. None of the groups regained their pre-fracture ADL. For one of the groups identified in both ADL outcomes, a steep decline in function was shown the first four months after surgery, and none of the groups showed functional recovery between four and 12 months after surgery. CONCLUSIONS: No groups regained their pre-fracture ADL. Some of the patients with relatively high pre-fracture function, had a steep ADL decline. For this group there is a potential for recovery, but more knowledge and research is needed in this group. These findings could be useful in uncovering groups of patients with different functioning after a hip fracture, and aid in discharge planning.

Orthogeriatrics prevents functional decline in hip fracture patients: report from two randomized controlled trials.

BACKGROUND: The incidence of hip fractures are expected to increase in the following years. Hip fracture patients have in addition to their fracture often complex medical problems, which constitute a substantial burden on society and health care systems. It is thus important to optimize the treatment of these patients to reduce negative outcomes. The aim of this study was to assess the effect of comprehensive orthogeriatric care (CGC) on basic and instrumental activities of daily living (B-ADL and I-ADL). METHODS: This study is based on two randomized controlled trials; the Oslo Orthogeriatric Trial and the Trondheim Hip Fracture Trial. The two studies were planned in concert, and data were pooled and analyzed using linear mixed models. I-ADL function was assessed by the Nottingham Extended ADL Scale (NEADL) and B-ADL by the Barthel ADL (BADL) at four and twelve months after surgery. RESULTS: Seven hundred twenty-six patients were included in the combined database, of which 365 patients received OC and 361 patients received CGC. For the primary endpoint, I-ADL at four months was better in the CGC group, with a between-group difference of 3.56 points (95 % CI 0.93 to 6.20, p = 0.008). The between-group difference at 12 months was 4.28 points (95 % CI 1.57 to 7.00, p = 0.002). For B-ADL, between-group difference scores were only statistically significant at 12 months. When excluding the patients living at a nursing home at admission, both I-ADL and B-ADL function was significantly better in the CGC group compared to the OC group at all time points. CONCLUSIONS: Merged data of two randomized controlled trials showed that admitting hip fracture patients to an orthogeriatric care unit directly from the emergency department had a positive effect on ADL up to twelve months after surgery.

CSF sTREM2 and Tau Work Together in Predicting Increased Temporal Lobe Atrophy in Older Adults.

Neuroinflammation may be a key factor in brain atrophy in aging and age-related neurodegenerative disease. The objective of this study was to test the association between microglial expression of soluble Triggering Receptor Expressed on Myeloid Cells 2 (sTREM2), as a measure of neuroinflammation, and brain atrophy in cognitively unimpaired older adults. Brain magnetic resonance imagings (MRIs) and cerebrospinal fluid (CSF) sTREM2, total tau (t-tau), phosphorylated181 tau (p-tau), and Aß42 were analyzed in 115 cognitively unimpaired older adults, classified according to the A/T/(N)-framework. MRIs were repeated after 2 (n = 95) and 4 (n = 62) years. High baseline sTREM2 was associated with accelerated cortical thinning in the temporal cortex of the left hemisphere, as well as bilateral hippocampal atrophy, independently of age, Aß42, and tau. sTREM2-related atrophy only marginally increased with biomarker positivity across the AD continuum (A-T- #x2292; A+T- #x2292; A+T+) but was significantly stronger in participants with a high level of p-tau (T+). sTREM2-related cortical thinning correlated significantly with areas of high microglial-specific gene expression in the Allen Human Brain Atlas. In conclusion, increased CSF sTREM2 was associated with accelerated cortical and hippocampal atrophy in cognitively unimpaired older participants, particularly in individuals with tau pathology. This suggests a link between neuroinflammation, neurodegeneration, and amyloid-independent tauopathy.