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- Danaei, Goodarz, et al.
(författare)
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Effects of diabetes definition on global surveillance of diabetes prevalence and diagnosis: a pooled analysis of 96 population-based studies with 331288 participants
- 2015
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Ingår i: The Lancet Diabetes & Endocrinology. - 2213-8595 .- 2213-8587. ; 3:8, s. 624-637
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Tidskriftsartikel (refereegranskat)abstract
- Background Diabetes has been defined on the basis of different biomarkers, including fasting plasma glucose (FPG), 2-h plasma glucose in an oral glucose tolerance test (2hOGTT), and HbA(1c). We assessed the effect of different diagnostic definitions on both the population prevalence of diabetes and the classification of previously undiagnosed individuals as having diabetes versus not having diabetes in a pooled analysis of data from population-based health examination surveys in different regions. Methods We used data from 96 population-based health examination surveys that had measured at least two of the biomarkers used for defining diabetes. Diabetes was defined using HbA(1c) (HbA(1c) >= 6 . 5% or history of diabetes diagnosis or using insulin or oral hypoglycaemic drugs) compared with either FPG only or FPG-or-2hOGTT definitions (FPG >= 7 . 0 mmol/L or 2hOGTT >= 11 . 1 mmol/L or history of diabetes or using insulin or oral hypoglycaemic drugs). We calculated diabetes prevalence, taking into account complex survey design and survey sample weights. We compared the prevalences of diabetes using different definitions graphically and by regression analyses. We calculated sensitivity and specificity of diabetes diagnosis based on HbA1c compared with diagnosis based on glucose among previously undiagnosed individuals (ie, excluding those with history of diabetes or using insulin or oral hypoglycaemic drugs). We calculated sensitivity and specificity in each survey, and then pooled results using a random-effects model. We assessed the sources of heterogeneity of sensitivity by meta-regressions for study characteristics selected a priori. Findings Population prevalence of diabetes based on FPG- or-2hOGTT was correlated with prevalence based on FPG alone (r= 0 . 98), but was higher by 2-6 percentage points at different prevalence levels. Prevalence based on HbA(1c) was lower than prevalence based on FPG in 42 . 8% of age-sex-survey groups and higher in another 41 . 6%; in the other 15 . 6%, the two definitions provided similar prevalence estimates. The variation across studies in the relation between glucose-based and HbA(1c)-based prevalences was partly related to participants' age, followed by natural logarithm of per person gross domestic product, the year of survey, mean BMI, and whether the survey population was national, subnational, or from specific communities. Diabetes defined as HbA(1c) 6 . 5% or more had a pooled sensitivity of 52 . 8% (95% CI 51 . 3-54 . 3%) and a pooled specificity of 99 . 74% (99 . 71-99 . 78%) compared with FPG 7 . 0 mmol/L or more for diagnosing previously undiagnosed participants; sensitivity compared with diabetes defined based on FPG-or-2hOGTT was 30 . 5% (28 . 7-32 . 3%). None of the preselected study-level characteristics explained the heterogeneity in the sensitivity of HbA(1c) versus FPG. Interpretation Different biomarkers and definitions for diabetes can provide different estimates of population prevalence of diabetes, and differentially identify people without previous diagnosis as having diabetes. Using an HbA(1c)-based definition alone in health surveys will not identify a substantial proportion of previously undiagnosed people who would be considered as having diabetes using a glucose-based test.
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| 2. |
- Naseri, Narges, et al.
(författare)
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IPN Hydrogels Based on Nanocellulose for Soft Tissue Engineering
- 2015
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Konferensbidrag (refereegranskat)abstract
- In tissue engineering, development of materials, which positively interact with tissues, is very important.1 In this regard, hydrogels composed of three-dimensional polymeric networks, have become more attractive materials due to their ability to absorb high water content and swells without losing their structural integrity.2 Furthermore, hydrogels need to provide physico-mechanical support for cell growth, proliferation and new tissue formation.3 However, their low mechanical properties have found one drawback4 and therefore in this study, cellulose nanocrystals (CNCBE) isolated from bioethanol residue were used as reinforcement or functional additive. The objective of this work was to develop double-crosslinked Interpenetrating Polymeric Networks (IPNs) of nanocellulose-based hydrogels on alginate and gelatin and investigate the effect of IPN processing route on physico-chemical properties of the produced hydrogels as well as their potential in soft tissue engineering. Fully bio-based porous IPN scaffolds were processed through two freeze-drying steps and crosslinked using calcium chloride and genipin. The second freeze-drying was performed to induce more pores in the structure. The morphology studies showed highly porous structure (90-97% porosity), which is beneficial for cell attachment and growth, but resulted in lower mechanical performances under compression. Addition of CNCBE and crosslinking decreased the moisture uptake while increased the compression modulus. Furthermore, the development of extracellular matrix (ECM) is expected to improve the mechanical performances after implantation.AcknowledgementsFinancial support from VINNOVA (No. 2011-02071) under MNT-ERANET project, n-POSSCOG is acknowledged. References1. Silva, S. S.; Motta, A.; Rodrigues, M. T.; Pinheiro, A. F.; Gomes, M. E.; Mano, J. F.; Reis, R. L.; Migliaresi, C. Biomacromolecules 2008, 9, 2764-2774.2. Dragan, E. S.; Perju, M. M.; Dinu, M. V. Carbohydr. Polym. 2012, 88, 270-281.3. Drury, J. L.; Mooney, D. J. Biomaterials 2003, 24, 4337-4351.4. Matricardi, P.; Di Meo, C.; Coviello, T.; Hennink, W. E.; Alhaique, F. Adv. Drug Deliv. Rev. 2013, 65, 1172-1187.
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