No abstract

To study sudden unexplained death syndrome (SUDS) in north-east Thailand, a mailed screening questionnaire and direct retrospective interview of relatives or witnesses of the incident was carried out in four administrative districts of Khon Kaen Province, north-east Thailand. Healthy villagers, 20-49 years, who died suddenly without explanation were identified as cases. Live healthy villagers who were age- and sex-matched with the dead served as controls. The study showed that all but one case were male with a mean age of 38 +/- 8 years. The incidence of SUDS was 38 per 100,000 men 20-49 years old per year. The peak risk was at 45-49 years. About 75% of SUDS cases had an annual income per household of less than the mean per capita income in Thailand. There were more SUDS cases in the hot season than any other season. The onset was nocturnal in 84% of cases. Presence of SUDS in family members was more frequently found in cases than in controls (P < 0.001). A history of muscle soreness, malaise and recent hard labour were seen as frequently in SUDS victims as in controls. In witnessed cases, symptoms usually lasted for a few minutes prior to death. Common symptoms or signs were respiratory (groaning, choking or coughing) and muscular spasticity or paralysis. The most consistent but yet unexplained finding in this study is the association between the onset of SUDS and the rest period.

Our objective was to evaluate the oxidative stress and renal tubular cell damage in patients who have renal stones compared to normal subjects. The patients were re-evaluated after 1-months supplementation with potassium citrate. We recruited 30 patients (11 males and 19 females) diagnosed with kidney stones and scheduled for surgical stone removal the following month, and 30 healthy non-stone formers (14 males and 16 females). Two 24-h urine samples and one heparinized blood sample were collected from each subject. Plasma was separated from the erythrocytes and assayed for creatinine, potassium, sodium, calcium, magnesium, phosphate, malondialdehyde (MDA, a lipid peroxidation product) (P-MDA), protein thiol as an indicator of protein oxidation, and vitamin E. Erythrocytes were analysed for MDA (E-MDA), reduced glutathione (GSH) and cellular glutathione peroxidase (cGPx) activity. The urine was analyzed for pH, creatinine, potassium, sodium, calcium, magnesium, phosphate, oxalate, citrate, MDA (U-MDA), total protein (U-protein) and N-acetyl-beta-glucosaminidase (NAG) activity. For the stone patients, urine and blood samples were re-evaluated after supplementation with potassium citrate (60 mEq/day) for 1 month. Renal stone patients had higher plasma creatinine and lower plasma potassium, urinary pH, potassium, magnesium, phosphate and citrate than the controls. The patients had higher P-MDA, E-MDA, U-MDA, U-protein and NAG activity, but lower GSH, cGPx activity, protein thiol and vitamin E, when compared with controls. After potassium citrate supplementation, P-MDA and E-MDA decreased while plasma vitamin E, urinary NAG activity and citrate increased. Renal stone disease is associated with high oxidative stress and damage to renal tubular cells. These abnormalities are coincident with an increase in blood lipid peroxidation products and a decrease in antioxidant status. Although supplementation with potassium citrate improved urinary citrate levels and oxidative stress, it neither reduced urinary lipid peroxidation products nor remedied the damage to renal tubular cells, probably due to the existence of kidney stones.

Renal-stone disease (RSD) is common in the rural communities of northeastern Thailand. We report the biochemical composition of blood and urine in 25 healthy city dwellers (Gl), 12 healthy village dwellers (G2) and 25 village dwellers who had RSD (G3). They were male with a range of ages between 20 and 50 years and were free of renal failure, urinary infection, urinary obstruction and systemic illness. The results showed that hypocitraturia, hypokalemia and hypokaliuria were more common in the latter 2 groups. The 24-h urinary citrate excretion correlated significantly with urinary potassium in G3 cases (r = 0.704, p = 0.0002). After potassium chloride supplementation, serum and urinary potassium increased remarkably (p < 0.003 and p = 0.002, respectively), whereas urinary citrate remained unchanged. Our results suggest that the predominant abnormality in our RSD patients were hypocitraturia and potassium deficiency and that these may be related.

Background: Urolithiasis is a major health problem in the northeast part of Thailand. In this study, we examined the prevalence of renal stone disease and differences of urinary components between ston? formers and healthy control subjects in northeastern rural areas of Thailand.