Long-term effects of socioeconomic status on the incidence of decreased glomerular filtration rate in a Southeast Asian cohort.

BACKGROUND: There is limited information on the role of low socioeconomic status (SES) in the development of new chronic kidney disease (CKD) in the general population, especially from developing countries. This study will test the hypothesis that low SES increases the risk of incidence of decreased glomerular filtration rate (GFR, used as an estimate for CKD) in a Thai worker cohort. METHOD: In this prospective, longitudinal observational study, we evaluated the association of income and educational attainment on incident decreased GFR (iGFR <60 mL/min/1.73 m2) over a 27-year period in employees of Electricity Generating Authority of Thailand. In 1985, subjects participated in a health survey and were re-examined in 1997, 2002, 2007 and 2012. Education was classified into three categories: low, 0-8th grade; medium, 9-12th grade; and high, >12th grade. Income was categorised as follows: low <10 000 Thai Baht (THB)/month; medium, 10 000-20 000 THB/month; and high, >20 000 THB/month. HRs of iGFR<60 mL/min/1.73 m2 were estimated using Cox interval-censored models with high income or education as the reference groups after adjustments for clinical risk factors. RESULTS: Participants (n=3334) were followed for 23 (15, 27) years. When evaluated separately, both education and income were risk factors for iGFR<60 mL/min/1.73 m2 (adjusted HR education: medium-1.26 (95% CI 1.13 to1.42) and low-1.57 (95% CI 1.36 to 1.81) and adjusted HR income: medium-1.21 (95% CI 0.97 to 1.50) and low-1.47 (95% CI 1.18 to 1.82)). When both income and education were included together, low and medium education remained independently associated with iGFR<60 mL/min/1.73 m2. CONCLUSIONS: Low education was independently associated with increased risk of decreased GFR in a Thai worker population. Strategies to identify risk factors among low SES may be useful to prevent early CKD.

Vitamin D Receptor Gene Polymorphism and Smoking in the Risk of Chronic Periodontitis.

BACKGROUND: Polymorphisms of the vitamin D receptor (VDR) gene have been implicated in susceptibility to infections and bone-related diseases. However, their relationship with periodontal disease remains unclear. This cross-sectional study investigates whether susceptibility to chronic periodontitis (CP) in a Thai population is associated with VDR polymorphisms. METHODS: Genomic DNA was obtained from 1,460 participants, aged 39 to 66 years. Genotyping of VDR polymorphisms (FokI, BsmI, ApaI, and TaqI) was performed using real-time polymerase chain reaction. Participants were categorized into three groups: 1) no/mild; 2) moderate; and 3) severe CP. Multinomial logistic regression was used to determine degree of association between VDR polymorphisms and periodontal status adjusted for known confounders. RESULTS: The CC+CT genotypes of FokI polymorphism were associated with severe CP with an odds ratio (OR) of 1.9 (95% confidence interval [CI]: 1.3 to 2.8). Compared with genotype-negative (TT) non-smokers, positivity for the risk genotypes (CC+CT) alone and current smoking alone were associated with severe CP with ORs of 1.8 (95% CI: 1.1 to 3.2) and 2.5 (95% CI: 1.0 to 6.2), respectively. The combination of being genotype positive and smoking further increased the OR to 9.6 (95% CI: 4.5 to 20.4). This combined effect was 3.7 times (95% CI: 1.2 to 11.1) greater than expected from the sum of their individual effects, indicating a synergistic interaction. No significant association was observed between other polymorphisms and CP. CONCLUSION: FokI CC+CT genotypes were associated with increased susceptibility to severe CP, which was aggravated further when combined with smoking.

Streptococcus suis infection: clinical features and diagnostic pitfalls.

Eight cases of Streptococcus suis (S. suis) infection between 1993-1999 were retrospectively studied. There were 6 cases of meningitis and 2 cases of endocarditis. Acute meningitis with early sensorineural hearing loss was the characteristic feature and the most common presentation of S. suis infection. S. suis endocarditis is a rare presentation in Thailand. This organism was often mistaken for Streptococcus pneumoniae or Streptococcus viridans. In this study, this was true in five cases in whom S. suis was identified later. However, the rapid diagnosis of S. suis meningitis may rely on Gram stain of the CSF in the setting of acute meningitis with hearing loss. These cases were treated with intravenous penicillin or ampicillin with a mean duration of 4 weeks. This treatment was very effective and there was no relapse among these patients.