Systematic Review Estimating the Burden of Dementia in the Latin America and Caribbean Region: A Bayesian Approach.

Background: The global burden of dementia has increasingly shifted to low- and middle-income regions that lack essential data for monitoring epidemiological progression, and policy and planning support. Drawing upon data that have emerged since the last known estimates published in 2015, this study aims to update dementia estimates in the Latin America and Caribbean (LAC) region for the years 2020, 2030, and 2050 through the application of a recently validated Bayesian approach for disease estimates useful when data sources are scarce. Methods: A comprehensive parallel systematic review of PubMed, EMBASE, PsycINFO, Global Health, and LILACS was conducted to identify prospective population-based epidemiological studies on dementia published in English from 2013 to 2018 in LAC. English and non-English data cited by a recent review on dementia estimates in LAC were also examined for additional data. A Bayesian normal-normal hierarchical model (NNHM) was developed to estimate age-specific and age-adjusted dementia prevalence in people aged 60+. Using age-specific population projections from the UN, the total number of people affected by dementia for the years 2020, 2030, and 2050 were estimated. Results: 1,414 studies were identified, of which only 7 met the inclusion criteria. The studies had 7,684 participants and 1,191 dementia cases. The age-standardized prevalence of all forms of dementia in LAC was 8% (95% CI: 5-11.5%) in people aged 60+. The estimated prevalence varied with age, increasing from 2.5% (95% CI: 0.08-4.0%) in the 60-69 age group, to 9.4% (95% CI: 5.4-13.2%) in the 70-79 age group and 28.9% (95% CI: 20.3-37.2%) in the ≥80 age group. The number of people age 60 and older living with dementia in LAC in 2020 was estimated at 6.86 (95% CI: 4.3-9.8) million, 9.94 (95% CI: 6.16-14.15) million in 2030, and 19.33 (95% CI: 12.3-13.6) million in 2050. Conclusion: We project an upward disease trajectory for dementia in LAC countries. The projection is likely an underestimation of the true dementia burden given the underrepresentation of rural and socio-economically deprived populations. More research is urgently needed to improve the accuracy of disease estimates, guide clinicians to improve evaluations for earlier recognition of dementia, and support the development of effective policies for improving dementia prevention, diagnosis and clinical management in LAC's diverse and aging communities.

The gut microbiome in sickle cell disease: Characterization and potential implications.

BACKGROUND: Sickle Cell Disease (SCD) is an inherited blood disorder that leads to hemolytic anemia, pain, organ damage and early mortality. It is characterized by polymerized deoxygenated hemoglobin, rigid sickle red blood cells and vaso-occlusive crises (VOC). Recurrent hypoxia-reperfusion injury in the gut of SCD patients could increase tissue injury, permeability, and bacterial translocation. In this context, the gut microbiome, a major player in health and disease, might have significant impact. This study sought to characterize the gut microbiome in SCD. METHODS: Stool and saliva samples were collected from healthy controls (n = 14) and SCD subjects (n = 14). Stool samples were also collected from humanized SCD murine models including Berk, Townes and corresponding control mice. Amplified 16S rDNA was used for bacterial composition analysis using Next Generation Sequencing (NGS). Pairwise group analyses established differential bacterial groups at many taxonomy levels. Bacterial group abundance and differentials were established using DeSeq software. RESULTS: A major dysbiosis was observed in SCD patients. The Firmicutes/Bacteroidetes ratio was lower in these patients. The following bacterial families were more abundant in SCD patients: Acetobacteraceae, Acidaminococcaceae, Candidatus Saccharibacteria, Peptostreptococcaceae, Bifidobacteriaceae, Veillonellaceae, Actinomycetaceae, Clostridiales, Bacteroidacbactereae and Fusobacteriaceae. This dysbiosis translated into 420 different operational taxonomic units (OTUs). Townes SCD mice also displayed gut microbiome dysbiosis as seen in human SCD. CONCLUSION: A major dysbiosis was observed in SCD patients for bacteria that are known strong pro-inflammatory triggers. The Townes mouse showed dysbiosis as well and might serve as a good model to study gut microbiome modulation and its impact on SCD pathophysiology.

Colorectal Cancer in Young African Americans: Is It Time to Revisit Guidelines and Prevention?

BACKGROUND & AIMS: Previous studies have suggested an increase in the incidence of colorectal cancer (CRC) in young adults (younger than 50 years). Among older people, African Americans have disproportionally higher CRC incidence and mortality. We assessed whether this CRC disparity also applies to CRC diagnosed among young people. METHODS: Using the Surveillance, Epidemiology, and End Results cancer registries, a population-based cancer registry covering 25.6 % of the United States' African American population, we identified patients diagnosed with CRC between the years of 2000-2012. The age-adjusted rates for non-Hispanic whites (NHW), African Americans, and Asian-Pacific Islanders (API) were calculated for the age categories 20-24, 25-29, 30-34, 35-39, and 40-44. RESULTS: CRC age-adjusted incidence is increasing among all three racial groups and was higher for African Americans compared to NHW and API across all years 2000-2012 (P < 0.001). Stage IV CRC was higher in African Americans compared with NHW, while there was higher stage III CRC in API compared with NHWs. CONCLUSION: CRC incidence is increasing among the young in all racial groups under study. This increase in frequency of CRC is true among young African American adults who display highly advanced tumors in comparison with other races. While the present attention to screening seems to have decreased CRC prevalence in individuals older than 50, special attention needs to be addressed to young African American adults as well, to counter the observed trend, as they have the highest incidence of CRC among young population groups by race/ethnicity.