RESUMO
BACKGROUND: Fibromyalgia (FM) is a chronic pain syndrome characterized by generalized skeletal muscle chronic pain. Its etiology is not well defined, because there are several factors that may trigger it such as physical and/or emotional stresses, or a genetic susceptibility, involving serotonergic, dopaminergic and catecholaminergic paths. The objective of this study was to investigate the association between the strength of the lower limb, genetic polymorphism of the serotonin receptor gene HTR2A in women with fibromyalgia. METHODS: In this observational study of case-control type 48 women were evaluated who belonged to the group with FM (52 ± 12 years) and 100 women in the control group (58 ± 11 years). Socio demographic and anthropometric data were collected and peripheral blood samples for DNA extraction; genotypic analyzes were performed by means of PCR in real time by TaqMan® system. The lower limb muscle strength was assessed through the test of sitting down and standing up for 30 s. The chi-square test or Fischer Exact was used for possible associations among the variables; the t-test for independent samples was used to compare the averages among the groups; the value of significance adopted was 5%. RESULTS: There was an association between the polymorphism of the HTR2A gene with FM, demonstrating that carriers of the genotype GG have 24.39 times more likely to develop the syndrome (IC95% 5.15-115.47; p = 0.01). It was observed an association between FM and the test to sit and stand up demonstrating that women with fibromyalgia have lower limb muscle strength (p = 0.01). The study showed that the white race has 3.84 times more likely to develop FM (p = 0.01). CONCLUSION: The results of this study suggest that women of Caucasian ethnicity with GG genotype or G allele presented greater risk of developing fibromyalgia and that these patients have lower limb muscle strength compared to the control group.
Assuntos
Fibromialgia/genética , Força Muscular/genética , Polimorfismo Genético , Receptor 5-HT2A de Serotonina/genética , Estudos de Casos e Controles , Distribuição de Qui-Quadrado , Feminino , Fibromialgia/etnologia , Fibromialgia/fisiopatologia , Humanos , Extremidade Inferior/fisiopatologia , Pessoa de Meia-Idade , Reação em Cadeia da Polimerase em Tempo Real , Postura Sentada , Posição Ortostática , População BrancaRESUMO
BACKGROUND: Osteoarthritis (OA) is a major musculoskeletal disease with high prevalence in the elderly. The study of genetic polymorphisms of inflammatory mediators involved in OA may contribute to the elucidation of the complex pathophysiology of this disease and identification of susceptibility individuals. AIM: This study aimed to evaluate the association between polymorphism at tumor necrosis factor alpha gene (SNP - 308 G/A TNFA) with presence, severity and functional status of osteoarthritis in elderly. METHODS: This study was characterized as case-control and encompassed 257 physically independent elderly (Mean Age: 68.55 ± 5.2; Minimum age: 60 and Maximum age: 82) were recruited. After this selection, the groups were divided in: 92 elderly individuals with osteoarthritis (case group) and 165 without the disease (control group). METHODS: The individuals were genotyped by the TaqMan real-time PCR system. The subjects were classified based on the degree of radiological impairment according to the criteria of Kellgren-Laurence and regarding functional impairment using the WOMAC and LEQUESNE questionnaires. RESULTS: TNFA gene polymorphic individuals (subjects harboring allele A) are more affected by OA (χ2 = 8.7, p = 0.003), once they have major radiological lesion both in hip (Fisher-Freeman-Halton Test = 3.9, p = 0.04) and knee (Fisher-Freeman-Halton Test = 4.0, p = 0.04) as well as worse functional status assessed by the Lequesne questionnaire (Mann-Whitney, p = 0.04). At the multivariate analysis, after adjustment for age, gender, body mass index, the presence of rare allele for TNFA (allele A) increases the susceptibility to OA development [OR: 1.87 (95% CI: 1.1-3.2)]. CONCLUSION: We conclude that the SNP - 308 G/A of TNFA gene may affect osteoarthritis susceptibility, severity and functional status of individuals with osteoarthritis.