Water-loss (intracellular) dehydration assessed using urinary tests, how well do they work? Diagnostic accuracy in older people

Background: Water-loss dehydration (hypertonic, hyperosmotic or intra-cellular dehydration) is due to insufficient fluid intake and distinct from hypovolemia due to excess fluid losses. It is associated with poor health outcomes such as disability and mortality in older people. Urine specific gravity (USG), color and urine osmolality have been widely advocated for screening for dehydration in older adults. Objective: To assess the diagnostic accuracy of urinary measures to screen for water-loss dehydration in older people.Design: This was a diagnostic accuracy study of people aged ≥65years taking part in the Dehydration Recognition In our Elders (DRIE, living in long-term care) or Dietary Strategies for Healthy Ageing in Europe (NU-AGE, living in the community) studies. The reference standard was serum osmolality, index tests included USG, urine color, osmolality, cloudiness, additional dipstick measures, ability to provide a urine sample, and volume of a random urine sample. Minimum useful diagnostic accuracy was set at sensitivity and specificity ≥70% or receiver operating characteristics plot area under the curve ≥0.70. Results: DRIE participants (67% women, mean age 86 years, n=162) had more limited cognitive and functional abilities than NU-AGE participants (64% women, mean age 70 years, n=151). 19% of DRIE and 22% of NU-AGE participants were dehydrated (serum osmolality >300mOsm/kg). Neither USG nor any other potential urinary tests were usefully diagnostic for water-loss dehydration. Conclusions: Although USG, urine color and urinary osmolality have been widely advocated for screening for dehydration in older adults, we show in the largest study to date that their diagnostic accuracy is too low to be useful and these measures should not be used to indicate hydration status in older people (either alone or as part of a wider tranche of tests). There is a need to develop simple, inexpensive and non-invasive tools for the assessment of dehydration in older people

A communal catalogue reveals Earth's multiscale microbial diversity

Our growing awareness of the microbial world's importance and diversity contrasts starkly with our limited understanding of its fundamental structure. Despite recent advances in DNA sequencing, a lack of standardized protocols and common analytical frameworks impedes comparisons among studies, hindering the development of global inferences about microbial life on Earth. Here we present a meta-analysis of microbial community samples collected by hundreds of researchers for the Earth Microbiome Project. Coordinated protocols and new analytical methods, particularly the use of exact sequences instead of clustered operational taxonomic units, enable bacterial and archaeal ribosomal RNA gene sequences to be followed across multiple studies and allow us to explore patterns of diversity at an unprecedented scale. The result is both a reference database giving global context to DNA sequence data and a framework for incorporating data from future studies, fostering increasingly complete characterization of Earth's microbial diversity.Peer reviewe

A communal catalogue reveals Earth’s multiscale microbial diversity

Our growing awareness of the microbial world’s importance and diversity contrasts starkly with our limited understanding of its fundamental structure. Despite recent advances in DNA sequencing, a lack of standardized protocols and common analytical frameworks impedes comparisons among studies, hindering the development of global inferences about microbial life on Earth. Here we present a meta-analysis of microbial community samples collected by hundreds of researchers for the Earth Microbiome Project. Coordinated protocols and new analytical methods, particularly the use of exact sequences instead of clustered operational taxonomic units, enable bacterial and archaeal ribosomal RNA gene sequences to be followed across multiple studies and allow us to explore patterns of diversity at an unprecedented scale. The result is both a reference database giving global context to DNA sequence data and a framework for incorporating data from future studies, fostering increasingly complete characterization of Earth’s microbial diversity

Proceedings of the 13th annual conference of INEBRIA

CITATION: Watson, R., et al. 2016. Proceedings of the 13th annual conference of INEBRIA. Addiction Science & Clinical Practice, 11:13, doi:10.1186/s13722-016-0062-9.The original publication is available at https://ascpjournal.biomedcentral.comENGLISH SUMMARY : Meeting abstracts.https://ascpjournal.biomedcentral.com/articles/10.1186/s13722-016-0062-9Publisher's versio