RESUMO
BACKGROUND: The risk for venous thromboembolism after long-haul flights represents a controversial issue. The aim of our study was to assess the incidence of venous thrombosis associated with long-haul flights in a prospective, controlled cohort study. METHODS: We included 964 passengers returning from long-haul flights (flight duration, > or =8 hours) and 1213 nontraveling control subjects. We excluded participants who were being treated with anticoagulant drugs or who used compression stockings. Main outcome measures were the incidence of ultrasonographically diagnosed thrombosis in the calf muscle and deep veins, symptomatic pulmonary embolism, and death. RESULTS: We diagnosed venous thrombotic events in 27 passengers (2.8%) and 12 controls (1.0%) (risk ratio [RR], 2.83; 95% confidence interval [CI], 1.46-5.49). Of these, 20 passengers (2.1%) and 10 controls (0.8%) presented with isolated calf muscle venous thrombosis (RR, 2.52; 95% CI, 1.20-5.26), whereas 7 passengers (0.7%) and 2 controls (0.2%) presented with deep venous thrombosis (RR, 4.40; 95% CI, 1.04-18.62). Symptomatic pulmonary embolism was diagnosed in 1 passenger with deep venous thrombosis (P =.44). All of these individuals had normal findings at baseline ultrasonography. Passengers with isolated calf muscle venous thrombosis or deep venous thrombosis had at least 1 risk factor for venous thrombosis (>45 years of age or elevated body mass index in 21 of 27 passengers). The follow-up after 4 weeks revealed no further venous thromboembolic event. CONCLUSIONS: Long-haul flights of 8 hours and longer double the risk for isolated calf muscle venous thrombosis. This translates into an increased risk for deep venous thrombosis as well. In our study, flight-associated thrombosis occurred exclusively in passengers with well-established risk factors for venous thrombosis.
Assuntos
Aeronaves , Embolia Pulmonar/epidemiologia , Viagem , Trombose Venosa/epidemiologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Estudos de Casos e Controles , Feminino , Humanos , Incidência , Masculino , Pessoa de Meia-Idade , Músculo Esquelético/irrigação sanguínea , Estudos Prospectivos , Embolia Pulmonar/etiologia , Projetos de Pesquisa , Fatores de Risco , Viés de Seleção , Síndrome , Trombose Venosa/etiologiaRESUMO
OBJECTIVE: Human urate transporter 1 (hURAT1) is a member of the organic anion transporter family (SLC22A12) that mainly regulates tubular urate reabsorption. Loss-of-function mutations result in idiopathic hypouricemia. The present case-control study was designed to analyze whether hURAT1 might also be a candidate gene for hyperuricemia with primary reduced renal urate excretion. METHODS: DNA samples from 389 individuals with reduced fractional excretion of uric acid (FEUA) (< or =6.5%) and from 263 controls (FEUA >6.5%) were sequenced. Genotype frequencies between groups were compared by Cochran-Armitage trend test. RESULTS: Significantly different genotype distributions could be demonstrated for the -788 T >A (promoter; P = 0.014), the C258T (exon 1; P = 0.006), and the C426T (exon 2; P = 0.0002) polymorphisms, but not for the T1309C (exon 8) and the +18 C >T (intron 9) polymorphisms. The strongest association with reduced FEUA was observed for the C426T polymorphism, with odds ratios (ORs) of 1.59 and 2.54 (P = 0.0002) for the CT and TT genotypes, respectively. Adjusted values for FEUA in the C426T genotype, were significantly reduced decreasing to 7.3%, 6.7%, and 6.3% in individuals with the CC, CT, and TT genotypes, respectively (P = 0.004). Haplotypes were constructed from the -788 T >A, C258T, and C426T polymorphisms. Individuals carrying at least 1 ACT haplotype (n = 349) had a significantly higher risk for reduced FEUA than individuals without any ACT haplotype (n = 303) (OR 1.39, P = 0.041). CONCLUSION: These results indicate that polymorphisms in the N-terminus of the hURAT1 gene were significantly associated with reduced renal uric acid excretion. The main regulating factor seems to be located close to the C426T polymorphism or is in strong linkage disequilibrium.
Assuntos
Proteínas de Transporte/genética , Transportadores de Ânions Orgânicos/genética , Polimorfismo Genético , Ácido Úrico/urina , População Branca , Adulto , Proteínas de Transporte/fisiologia , Estudos de Casos e Controles , Feminino , Alemanha , Haplótipos , Humanos , Masculino , Pessoa de Meia-Idade , Transportadores de Ânions Orgânicos/fisiologia , Proteínas de Transporte de Cátions OrgânicosRESUMO
OBJECTIVE: Chondromodulin-II (ChM-II) is a cartilage-derived protein involved in cartilage and bone repair. A study of Japanese patients with rheumatoid arthritis (RA) implicated an association between a 172G --> A (Val58Ile) polymorphism and radiographic damage. We analyzed ChM-II for polymorphisms and investigated the association with radiographically assessed joint destruction in German patients with RA. Possible interactions with the shared epitope (SE) were examined. METHODS: DNA samples from 204 patients with RA, 81 patients with osteoarthritis, and 116 patients with gout, serving as controls, were sequenced. Radiographic damage was assessed by modified Larsen score. Allele and genotype frequencies between groups were compared by Cochrane-Armitage trend tests. RESULTS: Five missense mutations, one silent mutation, and 5 intronic polymorphisms were found. Allele and genotype frequencies were similar in both disease groups. Larsen scores were significantly higher in RA patients carrying the 172AA (Ile/Ile) genotype (Larsen 96.8), than in RA patients with the 172GA (Val/Ile; Larsen 69.5) or 172GG (Val/Val; Larsen 54.8; p = 0.001) genotypes. Odds ratios to develop more severe radiographic joint damage (Larsen score > 90; above 75th percentile) were 4 and 15.5 for the 172GA and 172AA genotypes, respectively. Presence of a 172A allele increased the risk for enhanced radiographic damage 3-fold. SE and ChM-II 172A alleles emerged as 2 independent risk factors. A potentiated interaction of these risk alleles could not be verified. CONCLUSION: Our data indicate that ChM-II Val58Ile polymorphism is associated with radiographic progression of joint destruction, particularly in German patients with RA negative for SE.