Prevalência de dor crônica no Brasil, fatores associados e o papel da resposta inflamatória aguda na cronificação da dor articular após a Febre de Chikungunya

Abstract

Introduction: Brazil is a continental country, with significant regional population variability, and chronic pain (CP) prevalence data are scarce. Therefore, the first article will address the prevalence of benign chronic pain in different regions of Brazil and its associated risk factors. Still within the context of CP, an important cause of joint pain in our country is Chikungunya Fever (CHIKF). While some individuals evolve with limited symptoms after exposure to the chikungunya virus (CHIKV), others maintain chronic joint pain, these mechanisms being little known. Thus, the second article will address the role of the inflammatory response in the acute phase of CHIKF in the chronicity of joint pain. Methods: The first article searched the Ovid Medline, Embase, Web of Science and BVS Regional/Lilacs databases to identify population-based cross-sectional studies from 2005 to 2020 that reported the prevalence of benign chronic pain in Brazil (three months or longer). Risk of bias was assessed using design, sample size determination, and random selection of key questions. Pooled prevalence estimates were calculated for chronic pain in general and elderly populations. In the second article, a retrospective cohort of individuals exposed to the Chikungunya virus during the epidemic period in Rio de Janeiro (2018-2019) was analyzed. Eighty-one male and female individuals, aged 18-65 years, diagnosed with CHIKF using IgM enzyme immunoassay or Rt-PCR were included in the study. Follow-up survey was performed to see if joint pain persisted for 3 months or longer. Serum inflammatory biomarkers were evaluated in blood samples collected at the time of diagnosis. Results: In the first article, the prevalence of chronic pain in the general adult population ranged from 23.02% to 42.3% (combined estimate 35.70%, 95% Cis 30.42 to 41.17) and was described as moderate to intense. It was associated with female gender, advanced age, low education, intense professional activity, excessive alcohol consumption, smoking, central obesity, mood disorder and sedentary lifestyle. The Southeast and South regions had the highest prevalence. Prevalence in the elderly population ranged from 29.3-76.2% (pooled estimate 47.32%, 95% Cis 33.73 to 61.11). Of the 81 patients included in the second article, 27 (33.3%) developed chronic joint pain. The highest incidence of chronic joint pain was in women between the 4th and 6th decade of life, who were obese and had a low level of education. Arthritis (p=0.008) and serum levels of Interleukin 1-beta - IL-1β (p=0.0135) in the acute phase were significantly higher in the group of patients with chronic joint pain. There was a correlation between high levels of Interferon-gamma-inducible Protein 10kDa - IP-10 (p=0.041) and IL-1β (p=0.015) and the development of chronic joint pain. The high serum level of IL-10 was a protective factor for the development of chronic joint pain (p=0.038). Conclusion: Chronic pain is highly prevalent in Brazil and is associated with significant distress, disability and inadequate control. The inflammatory profile of patients in the acute phase of CHIKF may be associated with the development of chronic joint pain.