Crystalline composition and etiologic factors of kidney stone in Thailand : update 2007.

Objective: The etiology of kidney stone is multifactorial including environmental, behavioral and genetic. Insights about predisposing causes and mineral composition are mandatory for better management of kidney stone disease. The present hospital-based study aims to explore the mineral constituents and etiologic risks of kidney stones in Thai patients from the four geographic regions of the country. Method: Two hundred and fifty six kidney stone patients from four geographic regions of Thailand, including the northeastern (n=103), the northern (n=81), the central (n=47) and the southern (n=25) were recruited in this study. Of these, 144 patients completed the food frequency questionnaire to assess the kidney stone risk. Mineral composition of stones were analyzed by Fourier transformed infrared spectrometry. Results: Kidney stone frequently affected peoples aged 40-49 years. Only 31.9 % of patients had a positive family history of renal stone. Calcium oxalate (CaOx) stone was the most prevalent type (73.8 %). Uric acid (UA) stone was found in 16.0 % commonly affected peoples aged 60-70 years. Mixed stones, notably CaOx mixed with calcium phosphate (CaP), were more prevalent than pure stones. The food frequency questionnaire data showed that 59.7 % of stone patients consumed less than two liters of water per day. Low intakes of fruits and vegetables were notably present. In contrast, high consumption of rice was observed in over 65 % of stone patients. Conclusion: CaOx mixed with CaP was the most prevalent stone type. UA stone was more likely to occur in the elderly. Kidney stone patients were found to consume less-than-adequate amounts of water, food high in carbohydrates, along with low consumtion of fruits and vegetables. These dietary habits might be risk factors in stone development among the Thai population.

Staghorn calculi in southern Thailand.

OBJECTIVE: To study the characteristics and components of staghorn calculi in southern Thailand. MATERIAL AND METHOD: 5,445 urolithiasis patients who underwent treatment in Songklanagarind Hospital between 1997 and 2000 were reviewed and 86 of them were included by the criteria of "complete staghorn" calculi. General data, laboratory data at presentation, and the component analysis was performed with infrared spectroscopy were analyzed. RESULTS: Forty-three men and 43 women were included in the present study, with a mean age of 55.5 years for men and 50.7 years for women. Uric acid was the most common component of staghorn calculi and 61.8% of the patients had hyperuricemia. Magnesium ammonium phosphate (MAP) was found in 11.6% of the calculi. A positive urine culture was found in 59.3% of the patients and the micro-organisms most frequently found were Corynebacterium sp and E. coli. CONCLUSION: There was a significant higher incidence of staghorn calculi in women in comparison with urolithiasis patients in southern Thailand, and the most common component was uric acid.

Urinary tract calculi in southern Thailand.

OBJECTIVE: To study the epidemiology of urolithiasis in Southern Thailand. DESIGN: Descriptive study. MATERIAL AND METHOD: An overview of urolithiasis in the South of Thailand was derived from 10,344 urolithiasis patients seeking treatment in 14 hospitals in southern Thailand, from January to December 2000. An epidemiological study focused on 1,452 urolithiasis patients treated at Songklanagarind Hospital during the same period. Composition of calculi was analysed with infrared spectroscopy. RESULTS: The ratio of male to female was 1.6 : 1 and the most common age group was 41 - 50 years. Ureteric calculi were more frequently found than renal calculi. ESWL was the most common treatment for upper urinary tract (UUT) calculi, while surgery was the most common treatment for lower urinary tract (LUT) calculi. The body mass index (BMI) of 48.1% was between 18.5 - 24.9. The study of the calculi composition showed that oxalate was found in most UUT, and uric acid was found in most LUT CONCLUSION: Ureteric calculi were most common in the South of Thailand. The BMI of urolithiasis patients was higher than the population average.

Prediction of upper urinary tract calculi using an artificial neural network.

OBJECTIVES: To evaluate the possibility of using an artificial neural network (ANN) in upper urinary tract calculi prediction. MATERIAL AND METHOD: Data of 168 upper urinary tract calculi patients treated in the Division of Urology, Department of Surgery, Songklanagarind Hospital from January 1997 to December 2000 were reviewed and classified into 6 catagories and 20 characteristics. 100 items were used in training and 68 in testing for an ANN designed with 3 layers: 20 nodes for an input layer, 5 nodes for a hidden layer and a node for the output. RESULTS: Output data between 0-0.38 indicate free of calculi, 0.65-1 indicate prone to have calculi, 0.38-0.65 indicate probable calculi and further need investigation. CONCLUSION: An ANN with error back-propagation training can be used in diagnosing the presence of upper urinary tract calculi. The accuracy of prediction depends on a previous history of calculi, nephrocalcinosis, 24 hour urine assay for citrate and urine culture.