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Augustin AD, Charlett A, Weller C, Dobbs SM, Taylor D, Bjarnason I, Dobbs RJ. Quantifying rigidity of Parkinson's disease in relation to laxative treatment: a service evaluation. Br J Clin Pharmacol 2016; 82:441-50. [PMID: 27062674 PMCID: PMC4972160 DOI: 10.1111/bcp.12967] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2015] [Revised: 03/28/2016] [Accepted: 04/04/2016] [Indexed: 12/13/2022] Open
Abstract
Aim To estimate whether laxatives prescribed for constipation in Parkinson's disease (PD) could moderate rigidity. Constipation predates diagnosis of PD by decades. Deposition of misfolded protein may begin in the gut, driven by dysbiosis. Successive antimicrobial exposures are associated with cumulative increase in rigidity, and rigidity has biological gradients on circulating leukocyte‐subset counts. Methods Retrospective service evaluation, in a gut/brain axis clinic, yielded an interrupted time series, relating maintenance laxative and other medication to rigidity, in consecutive outpatients identified by inclusion and exclusion criteria. Objective assessment of rigidity was used to bring greater sensitivity to change, validated against subjective gold standard (UPDRS). Results There were 1493 measurements of torque required to extend (flexor rigidity) and flex (extensor rigidity) the forearm in 79 PD patients over 374 person‐years. Both were strongly associated with UPDRS (P < 0.001 and P = 0.008, respectively). Before exhibition of laxative, flexor rigidity increased by 6% (95% CI 1, 10) per year, plateauing at −2% (−4, 1) per year after, with no shift at initiation. Change in slope was significant (P = 0.002), and manifest in those naïve to antiparkinsonian medication. The change was replicated for individual laxative classes (bulk, osmotic, enterokinetic). There was no temporal change in extensor rigidity. Limited experience with a quanylate cyclase‐C receptor agonist (17 patients, 6 person‐years) indicated a large and significant step down in flexor and extensor rigidity, of 19% (1, 34) and 16% (6, 24) respectively (P = 0.04 and <0.001). Conclusions Maintenance laxative usage was associated with apparent stemming of the temporal increase in rigidity in PD, adding to indicative evidence of a continuing role of gastrointestinal dysbiosis in pathogenesis.
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Affiliation(s)
- Aisha D Augustin
- Institute of Pharmaceutical Science, King's College London, London, SE1 9NH, UK.,The Maudsley Hospital, London, SE5 8AZ, UK
| | - André Charlett
- Institute of Pharmaceutical Science, King's College London, London, SE1 9NH, UK.,Statistics Unit, Centre for Infectious Disease Surveillance and Control, Public Health England, London, NW9 5EQ, UK
| | - Clive Weller
- Institute of Pharmaceutical Science, King's College London, London, SE1 9NH, UK
| | - Sylvia M Dobbs
- Institute of Pharmaceutical Science, King's College London, London, SE1 9NH, UK.,The Maudsley Hospital, London, SE5 8AZ, UK.,Department of Gastroenterology, King's College Hospital, London, SE5 9RS, UK
| | - David Taylor
- Institute of Pharmaceutical Science, King's College London, London, SE1 9NH, UK.,The Maudsley Hospital, London, SE5 8AZ, UK
| | - Ingvar Bjarnason
- Department of Gastroenterology, King's College Hospital, London, SE5 9RS, UK
| | - R John Dobbs
- Institute of Pharmaceutical Science, King's College London, London, SE1 9NH, UK.,The Maudsley Hospital, London, SE5 8AZ, UK.,Department of Gastroenterology, King's College Hospital, London, SE5 9RS, UK
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