title: Experimental pain phenotyping in community-dwelling individuals with knee osteoarthritis.
abstract: Pain among individuals with knee osteoarthritis (OA) is associated with significant disability in older adults, and recent evidence demonstrates enhanced experimental pain sensitivity. Although previous research showed considerable heterogeneity in the OA clinical pain presentation, less is known regarding the variability in responses to experimental pain. The present study included individuals with knee OA (n = 292) who participated in the Understanding Pain and Limitations in Osteoarthritic Disease study and completed demographic and psychological questionnaires followed by a multimodal quantitative sensory testing (QST) session. Quantitative sensory testing measures were subjected to variable reduction procedures to derive pain sensitivity index scores, which in turn were entered into a cluster analysis. Five clusters were significantly different across all pain sensitivity index variables (P < 0.001) and were characterized by: (1) low pain sensitivity to pressure pain (N = 39); (2) average pain sensitivity across most modalities (N = 88); (3) high temporal summation of punctate pain (N = 38); (4) high cold pain sensitivity (N = 80); and (5) high sensitivity to heat pain and temporal summation of heat pain (N = 41). Clusters differed significantly by race, gender, somatic reactivity, and catastrophizing (P < 0.05). Our findings support the notion that there are distinct subgroups or phenotypes based on experimental pain sensitivity in community-dwelling older adults with knee OA, expanding previous findings of similar cluster characterizations in healthy adults. Future research is needed to further understand the pathophysiological mechanisms underlying pain within these subgroups, which may be of added value in tailoring effective treatments for people with OA.
authors.affiliation: Pain Research and Intervention Center of Excellence (PRICE), University of Florida, Gainesville, FL, USA.
authors.forename: Josue S
authors.initials: JS
authors.lastname: Cardoso
authors.affiliation: Pain Research and Intervention Center of Excellence (PRICE), University of Florida, Gainesville, FL, USA.|Department of Community Dentistry and Behavioral Science, University of Florida, Gainesville, FL, USA.
authors.forename: Joseph L
authors.initials: JL
authors.lastname: Riley
authors.affiliation: Pain Research and Intervention Center of Excellence (PRICE), University of Florida, Gainesville, FL, USA.|Departments of Biobehavioral Nursing Science and.
authors.forename: Toni
authors.initials: T
authors.lastname: Glover
authors.affiliation: Pain Research and Intervention Center of Excellence (PRICE), University of Florida, Gainesville, FL, USA.|Aging and Geriatric Research, University of Florida, Gainesville, FL, USA.
authors.forename: Kimberly T
authors.initials: KT
authors.lastname: Sibille
authors.affiliation: Pain Research and Intervention Center of Excellence (PRICE), University of Florida, Gainesville, FL, USA.|Department of Community Dentistry and Behavioral Science, University of Florida, Gainesville, FL, USA.
authors.forename: Emily J
authors.initials: EJ
authors.lastname: Bartley
authors.affiliation: Department of Psychology, University of Alabama at Birmingham, Birmingham, AL, USA.
authors.forename: Burel R
authors.initials: BR
authors.lastname: Goodin
authors.affiliation: Department of Psychology, University of Alabama at Birmingham, Birmingham, AL, USA.
authors.forename: Hailey W
authors.initials: HW
authors.lastname: Bulls
authors.affiliation: Department of Psychology, University of Alabama at Birmingham, Birmingham, AL, USA.
authors.forename: Matthew
authors.initials: M
authors.lastname: Herbert
authors.affiliation: Division of Clinical Immunology and Rheumatology, University of Alabama at Birmingham, Birmingham, AL, USA.
authors.forename: Adriana S
authors.initials: AS
authors.lastname: Addison
authors.affiliation: Pain Research and Intervention Center of Excellence (PRICE), University of Florida, Gainesville, FL, USA.|Department of Medicine, University of Florida, Gainesville, FL, USA.
authors.forename: Roland
authors.initials: R
authors.lastname: Staud
authors.affiliation: Departments of Biostatistics and.
authors.forename: David T
authors.initials: DT
authors.lastname: Redden
authors.affiliation: Division of Clinical Immunology and Rheumatology, University of Alabama at Birmingham, Birmingham, AL, USA.|Medicine and Rheumatology, University of Alabama at Birmingham, Birmingham, AL, USA.
authors.forename: Laurence A
authors.initials: LA
authors.lastname: Bradley
authors.affiliation: Pain Research and Intervention Center of Excellence (PRICE), University of Florida, Gainesville, FL, USA.|Department of Community Dentistry and Behavioral Science, University of Florida, Gainesville, FL, USA.
authors.forename: Roger B
authors.initials: RB
authors.lastname: Fillingim
authors.affiliation: Pain Research and Intervention Center of Excellence (PRICE), University of Florida, Gainesville, FL, USA.|Department of Community Dentistry and Behavioral Science, University of Florida, Gainesville, FL, USA.|Aging and Geriatric Research, University of Florida, Gainesville, FL, USA.
authors.forename: Yenisel
authors.initials: Y
authors.lastname: Cruz-Almeida
mesh_terms: D058443:Catastrophization; D005260:Female; D006801:Humans; D057187:Independent Living; D008297:Male; D008875:Middle Aged; D020370:Osteoarthritis, Knee / Q000150:complications*; D010146:Pain / Q000150:complications*; D010147:Pain Measurement; D017288:Pain Threshold / Q000502:physiology*; D010641:Phenotype; D025341:Principal Component Analysis; D018709:Statistics, Nonparametric; D011795:Surveys and Questionnaires