Apathy is a frequently reported neuropsychiatric symptom in Parkinson's disease (PD), but its prevalence and clinical correlates are debated. We aimed to address these issues by conducting a systematic review and meta-analysis. Embase, Medline/PubMed, and PsychINFO databases were searched for relevant studies. Data were extracted by two independent observers, using predefined extraction forms tailored specifically to the research question. From 1,702 titles and abstracts, 23 studies were selected. Meta-analysis showed a prevalence of apathy in PD of 39.8% (n = 5,388, 905% CI 34.6-45.0%). Apathy was associated with higher age (3.3 years, 95% CI = 1.7-4.9), lower mean Mini-Mental State Evaluation (MMSE) score (-1.4 points, 95% CI = -2.1 to -0.8), an increased risk of co-morbid depression (relative risk [RR] = 2.3, 95% CI = 1.9-2.8), higher Unified Parkinson's Disease Rating Scale (UPDRS) motor score (6.5 points, 95% CI = 2.6-10.3), and more severe disability (Hedges-G = 0.5, 95% CI = 0.3-0.6). Half of the patients with apathy had concomitant depression (57.2%, 95% CI = 49.4-64.9%), and this estimate was similar after exclusion of patients with cognitive impairment (52.5%, 95% CI = 42.2%-62.8%). In conclusion, we found that apathy affects almost 40% of patients with PD. Several factors influence reported prevalence rates, contributing to the considerable heterogeneity in study results. Half of patients with apathy do not suffer from concomitant depression or cognitive impairment, confirming its status as a separate clinical syndrome in PD. The pervasiveness of apathy in PD warrants research into its treatment, although different underlying pathophysiological mechanisms may require different treatment strategies. Treatment of apathy could improve patient quality of life, reduce caregiver burden, alleviate disability by increasing motivation for self-care, and reduce cognitive impairment by improving executive functioning.

SummaryDespite advances in our understanding of the mechanisms underlying the progression of chronic kidney disease and the development of fibrosis, only limited efficacious therapies exist. The calcium binding protein S100A8/A9 is a damage‐associated molecular pattern which can activate Toll‐like receptor (TLR)‐4 or receptor for advanced glycation end‐products (RAGE). Activation of these receptors is involved in the progression of renal fibrosis; however, the role of S100A8/A9 herein remains unknown. Therefore, we analysed S100A8/A9 expression in patients and mice with obstructive nephropathy and subjected wild‐type and S100A9 knock‐out mice lacking the heterodimer S100A8/A9 to unilateral ureteral obstruction (UUO). We found profound S100A8/A9 expression in granulocytes that infiltrated human and murine kidney, together with enhanced renal expression over time, following UUO. S100A9 KO mice were protected from UUO‐induced renal fibrosis, independently of leucocyte infiltration and inflammation. Loss of S100A8/A9 protected tubular epithelial cells from UUO‐induced apoptosis and critical epithelial–mesenchymal transition steps. In‐vitro studies revealed S100A8/A9 as a novel mediator of epithelial cell injury through loss of cell polarity, cell cycle arrest and subsequent cell death. In conclusion, we demonstrate that S100A8/A9 mediates renal damage and fibrosis, presumably through loss of tubular epithelial cell contacts and irreversible damage. Suppression of S100A8/A9 could be a therapeutic strategy to halt renal fibrosis in patients with chronic kidney disease.

Objectives: To systematically review and synthesize the evidence on differential associations between antihypertensive medication (AHM) classes and the risk of incident dementia. Design: Systematic review and random effects frequentist network meta-analysis. Embase, MEDLINE, and the Cochrane library were searched from origin to December 2019. Setting and participants: Randomized controlled trials (RCTs) and prospective cohort studies that compared associations of different AHM classes with incident all-cause dementia and/or Alzheimer's disease over at least 1 year of follow-up. Measures: All cause dementia and/or Alzheimer's disease. Results: Fifteen observational studies and 7 RCTs were included. Data on AHM classes were available for 649,790 participants and dementia occurred in 19,600 (3.02%). Network meta-analysis showed that in observational studies, treatment with either calcium channel blockers (CCBs) or angiotensin II receptor blockers (ARBs) was associated with lower dementia risks than treatment with other antihypertensives: CCBs vs angiotensin converting enzyme inhibitors (ACE inhibitors) (HR¼0.84, 95% CI 0.74-0.95), beta blockers (HR¼0.83, 95% CI 0.73-0.95) and diuretics (HR¼0.89, 95% CI 0.78-1.01) and ARBs vs ACE inhibitors (HR¼0.88, 95% CI 0.81-0.97), beta blockers (HR¼0.87, 95% CI 0.77-0.99), and diuretics (HR¼0.93, 95% CI 0.83-1.05). There were insufficient RCTs to create a robust network based on randomized data alone. Conclusions and Implications: Recommending CCBs or ARBs as preferred first-line antihypertensive treatment may significantly reduce the risk of dementia. If corroborated in a randomized setting, these findings reflect a low-cost and scalable opportunity to reduce dementia incidence worldwide.