Influence of genetic polymorphisms on mechanical pain sensitivity and endogenous pain modulation of trigeminal and spinal areas

Abstract

Background: Previous evidence indicates significant association between genetic polymorphisms and phenotypes related to pain sensitivity in patients with temporomandibular disorders (TMD). Despite the important advances in cataloguing diverse factors such as sleep disorders, anxiety and depression, the interrelated mechanisms of painful TMD aetiopathogenesis still need investigation.Objectives: This case-control study aimed to evaluate the influence of genetic polymorphisms (rs6296, rs6295, rs1799971, rs4680, rs4633, rs4818) and psychosocial factors on the mechanical pain sensitivity and endogenous pain modulation in women with painful TMD and asymptomatic controls. Methods:We evaluated six independent variables: anxiety levels, depression, stress, sleep quality, pain catastrophising and genetic polymorphisms, and four dependent variables: mechanical pain threshold (MPT), pressure pain threshold (PPT), wind-up ratio (WUR) and conditioned pain modulation (CPM) collected at masseter (trigeminal) and hand (spinal) areas in a sample of 95 painful TMD patients and 85 controls. A regression model was used to test the possible effect of the independent variables on dependent variables. Results:The regression model was significant for MPT (F 11,168 = 9.772; R 2 = .390).Painful TMD diagnoses and sleep quality were associated with trigeminal MPT (B coefficient = −.499; and B coefficient = −.211, respectively). WUR was associated with rs6295 and rs6746030, respectively, for the spinal and the trigeminal area. Conclusion:Genetic polymorphisms had a slight contribution to endogenous pain modulation as indicated by the significant association with WUR but did not contribute to mechanical pain sensitivity. On the other hand, the presence of painful TMD and the sleep quality contributed significantly to mechanical pain sensitivity.

Influence of Psychometric and Sleep Quality Features on Painful Mechanical Sensitivity and Pain Modulation in Patients with Temporomandibular Disorders

“…This cross-sectional study constitutes a secondary analysis of data [17]. The study was submitted and approved by the Research Ethics Committee of the Bauru School of Dentistry, University of São Paulo (CAAE 63551122.7.0000.5417).…”

“…Moreover, increased sensitivity to nociceptive stimuli is a commonly observed in chronic pain conditions [16]. In patients with painful TMD, sensory abnormalities, particularly heightened mechanical painful sensitivity, have been detected through quantitative sensory tests [17,18]. Indeed, QST is widely accepted tool for investigating somatosensory alterations [19][20][21].…”

Influência de agrupamentos psicossociais na sensibilidade mecânica dolorosa e na modulação da dor de pacientes com Disfunção Temporomandibular

“…Além disso, o aumento da sensibilidade à estímulos nociceptivos é uma característica frequente na dor crônica (22)(23)(24). Nesse sentido, tem sido verificado que anormalidades sensoriais são frequentemente detectadas em pacientes com DTM dolorosa (S. F. , incluindo o aumento da sensibilidade dolorosa mecânica mensurada por meio dos testes quantitativos sensoriais (S. F. Soares et al, 2023). Os testes quantitativos sensoriais (QST) são uma ferramenta amplamente aceita para investigar alterações somatossensoriais (Costa et al, 2019;Cruz-Almeida & Fillingim, 2014;Weaver et al, 2022), através de testes psicofísicos padronizados que garantem a confiabilidade e consistência na mensuração (Costa et al, 2019).…”