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Variation in serum urate levels in the absence of gout and urate lowering therapy

BACKGROUND: Previous studies have noted significant variation in serum urate (sUA) levels, and it is unknown how this influences the accuracy of hyperuricemia classification based on single data points. Despite this known variability, hyperuricemic patients are often used as a control group in gout...

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Autores principales: Shaffer, Andrew, Rahn, Elizabeth, Saag, Kenneth, Mudano, Amy, Gaffo, Angelo
Formato: Online Artículo Texto
Lenguaje:English
Publicado: BioMed Central 2021
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8425059/
https://www.ncbi.nlm.nih.gov/pubmed/34493347
http://dx.doi.org/10.1186/s41927-021-00202-6
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author Shaffer, Andrew
Rahn, Elizabeth
Saag, Kenneth
Mudano, Amy
Gaffo, Angelo
author_facet Shaffer, Andrew
Rahn, Elizabeth
Saag, Kenneth
Mudano, Amy
Gaffo, Angelo
author_sort Shaffer, Andrew
collection PubMed
description BACKGROUND: Previous studies have noted significant variation in serum urate (sUA) levels, and it is unknown how this influences the accuracy of hyperuricemia classification based on single data points. Despite this known variability, hyperuricemic patients are often used as a control group in gout studies. Our objective was to determine the accuracy of hyperuricemia classifications based on single data points versus multiple data points given the degree of variability observed with serial measurements of sUA. METHODS: Data was analyzed from a cross-over clinical trial of urate-lowering therapy in young adults without a gout diagnosis. In the control phase, sUA levels used for this analysis were collected at 2–4 week intervals. Mean coefficient of variation for sUA was determined, as were rates of conversion between normouricemia (sUA ≤6.8 mg/dL) and hyperuricemia (sUA > 6.8 mg/dL). RESULTS: Mean study participant (n = 85) age was 27.8 ± 7.0 years, with 39% female participants and 41% African-American participants. Mean sUA coefficient of variation was 8.5% ± 4.9% (1 to 23%). There was no significant difference in variation between men and women, or between participants initially normouricemic and those who were initially hyperuricemic. Among those initially normouricemic (n = 72), 21% converted to hyperuricemia during at least one subsequent measurement. The subgroup with initial sUA < 6.0 (n = 54) was much less likely to have future values in the range of hyperuricemia compared to the group with screening sUA values between 6.0–6.8 (n = 18) (7% vs 39%, p = 0.0037). Of the participants initially hyperuricemic (n = 13), 46% were later normouricemic during at least one measurement. CONCLUSION: Single sUA measurements were unreliable in hyperuricemia classification due to spontaneous variation. Knowing this, if a single measurement must be used in classification, it is worth noting that those with an sUA of < 6.0 mg/dL were less likely to demonstrate future hyperuricemic measurements and this could be considered a safer threshold to rule out intermittent hyperuricemia based on a single measurement point. TRIAL REGISTRATION: Data from parent study ClinicalTrials.gov Identifier: NCT02038179.
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spelling pubmed-84250592021-09-10 Variation in serum urate levels in the absence of gout and urate lowering therapy Shaffer, Andrew Rahn, Elizabeth Saag, Kenneth Mudano, Amy Gaffo, Angelo BMC Rheumatol Research BACKGROUND: Previous studies have noted significant variation in serum urate (sUA) levels, and it is unknown how this influences the accuracy of hyperuricemia classification based on single data points. Despite this known variability, hyperuricemic patients are often used as a control group in gout studies. Our objective was to determine the accuracy of hyperuricemia classifications based on single data points versus multiple data points given the degree of variability observed with serial measurements of sUA. METHODS: Data was analyzed from a cross-over clinical trial of urate-lowering therapy in young adults without a gout diagnosis. In the control phase, sUA levels used for this analysis were collected at 2–4 week intervals. Mean coefficient of variation for sUA was determined, as were rates of conversion between normouricemia (sUA ≤6.8 mg/dL) and hyperuricemia (sUA > 6.8 mg/dL). RESULTS: Mean study participant (n = 85) age was 27.8 ± 7.0 years, with 39% female participants and 41% African-American participants. Mean sUA coefficient of variation was 8.5% ± 4.9% (1 to 23%). There was no significant difference in variation between men and women, or between participants initially normouricemic and those who were initially hyperuricemic. Among those initially normouricemic (n = 72), 21% converted to hyperuricemia during at least one subsequent measurement. The subgroup with initial sUA < 6.0 (n = 54) was much less likely to have future values in the range of hyperuricemia compared to the group with screening sUA values between 6.0–6.8 (n = 18) (7% vs 39%, p = 0.0037). Of the participants initially hyperuricemic (n = 13), 46% were later normouricemic during at least one measurement. CONCLUSION: Single sUA measurements were unreliable in hyperuricemia classification due to spontaneous variation. Knowing this, if a single measurement must be used in classification, it is worth noting that those with an sUA of < 6.0 mg/dL were less likely to demonstrate future hyperuricemic measurements and this could be considered a safer threshold to rule out intermittent hyperuricemia based on a single measurement point. TRIAL REGISTRATION: Data from parent study ClinicalTrials.gov Identifier: NCT02038179. BioMed Central 2021-09-08 /pmc/articles/PMC8425059/ /pubmed/34493347 http://dx.doi.org/10.1186/s41927-021-00202-6 Text en © The Author(s) 2021 https://creativecommons.org/licenses/by/4.0/Open AccessThis article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article's Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article's Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/ (https://creativecommons.org/licenses/by/4.0/) . The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/ (https://creativecommons.org/publicdomain/zero/1.0/) ) applies to the data made available in this article, unless otherwise stated in a credit line to the data.
spellingShingle Research
Shaffer, Andrew
Rahn, Elizabeth
Saag, Kenneth
Mudano, Amy
Gaffo, Angelo
Variation in serum urate levels in the absence of gout and urate lowering therapy
title Variation in serum urate levels in the absence of gout and urate lowering therapy
title_full Variation in serum urate levels in the absence of gout and urate lowering therapy
title_fullStr Variation in serum urate levels in the absence of gout and urate lowering therapy
title_full_unstemmed Variation in serum urate levels in the absence of gout and urate lowering therapy
title_short Variation in serum urate levels in the absence of gout and urate lowering therapy
title_sort variation in serum urate levels in the absence of gout and urate lowering therapy
topic Research
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8425059/
https://www.ncbi.nlm.nih.gov/pubmed/34493347
http://dx.doi.org/10.1186/s41927-021-00202-6
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