Use of urinary concentrations in mg/dl in relation to absolute values in 24-hour samples for the evaluation of lithogenic factors in stone forming patients. / Uso de las concentraciones urinarias en mg/dl en relación a los valores absolutos en 24 h para la evaluación de factores litogénicos en pacientes litiásicos.

OBJECTIVE: The aim of this study is to analyze urine concentrations (mg/dl) of different lithogenic factors in a sample of 24 h as a predictor of these changes rather than absolute values depend on the volume of diuresis. METHODS: A total of 131 patients from the North Almeria Health Management Area (Spain) with urinary calstone disease in whom a metabolic study was indicated were included from June 2014 to May 2015. The concentrations of calcium, oxalate, uric acid, citrate and magnesium were measured in the urine, and the calcium/citrate ratio was calculated. The classifications used were: hypercalciuria (>260mg/24h), hyperuricosuria (>750mg/24h), hyperoxaluria (>40mg/24h), hypocitraturia (<320mg/24h) and hypomagnesuria (<35mg/24h). The statistical analysis was performed using SPSS 17.0. RESULTS: A cut-off point of 12.55mg/dl, with a sensitivity of 90% and a specificity of 85% and a relative risk (RR) of 51.2 (13.9-188.4), was estimated for urinary calcium. For oxalate the cut-off point was 1.86mg/dl, with a sensitivity of 91% and a specificity of 84% with an estimated RR of 67.2 (8.3-540.6). As regards the uric acid concentration in urine, a cut-off point of 31.2mg/dl was estimated, with a sensitivity of 85% and a specificity of 70% and a RR of 12 (3.8-37.6). For citrate the cut-off point was 18.8mg/dl, with a sensitivity and specificity of 82% and 74%, respectively, with a RR of 13.7 (4.4- 42.6). The cut-off point for magnesium was 2.26mg/dl with a sensitivity of 95% and specificity of 78%, with a RR of 67.6 (11.4-398.3). CONCLUSION: The determination of urine concentrations, instead of absolute values, depends to a large extent on urine output, appears to be useful when estimating classic metabolic alterations and should be taken into account in the evaluation of patients with urinary stone disease.

Treatment with hydrochlorothiazide and alendronate in patients with stones and bone mineral density loss. Evolution of bone metabolism and calciuria with medical treatment. / Tratamiento con hidroclorotiazida y alendronato en pacientes con litiasis y pérdida de densidad mineral ósea. Evolución de la calciuria y metabolismo óseo en el tratamiento médico.

OBJECTIVES: Treatment of calcium stones is based on diet and pharmacological measures such as the use of thiazides and other drugs. The aim of this study is to assess the effect of alendronate on hydrochlorothiazide on urinary calcium and bone mineral density in patients with calcium stones. METHODS: Prospective observational study involving 77 patients with relapsing calcium stones divided into 2 groups according to treatment received. Group 1: 36 patients treated with alendronate 70 mg/week; Group 2: 41 patients treated with hydrochlorothiazide 50 mg/day. All patients receive diet recommendations and fluid intake. Studied and analyzed among other variables were bone mineral density, bone turnover markers and calciuria before and after 2 years of treatment. Statistical study with SPSS 17.0, statistical significance p<0.05. RESULTS: No statistically significant differences in the distribution by sex or age of the patients between groups. In group 1 statistically a significant decrease was observed in the Β-crosslaps and improvement in bone mineral density, along with decreased urinary calcium after 2 years of treatment. In Group 2 statistically significant decrease in urinary calcium and fasting calcium/creatinine was seen, along with improvement in bone mineral density after 2 years of treatment. In group 1, there is a more obvious and significant improvement in bone mineral density compared to 2 and Β-crosslaps decrease. However, in group 2 the decrease in urinary calcium and calcium/creatinine was more significant than in group 1. CONCLUSION: Treatment with thiazide decrease calciuria and produces an improvement in bone mineral density, although not in the same range as treatment with alendronate.

Calcium and phosphorus metabolism and lithogenic factors in patients with osteoporotic fracture.

OBJECTIVES: To demonstrate the attendance of mineral metabolism disorders and lithogenic factors in patients' urine with osteoporotic fracture without previously known stones MATERIAL AND METHODS: 67 patients with osteoporotic fractures surgically treated in trauma service are included. The area of the fracture site, fracture mechanism and the presence of osteoporosis were the factors taken into account to diagnose osteoporotic fracture. Mineral metabolism, calciuria, oxaluria, uricosuria and citraturia in 24hours urine were analyzed. The presence of abnormal calcium and phosphorus metabolism was proved comparing hypercalciuria patients with normocalciuria ones. RESULTS: 12 men and 55 women with mean age 68.8±14.5 years old were included. Mean Body Mass Index (BMI) was 27.4±4.1kg/m2. 42% of patients showed hypercalciuria, 34% hyperoxaluria, 34% hypocitraturia and 7% hyperuricosuria. Statistically significant differences were observed only in fasting calcium/creatinine ratio (0.17 vs. 0.08; P<.0001) when comparing patients with hypercalciuria with those with normocalciuria. CONCLUSIONS: Patients with osteoporotic fractures show different lithogenic factors in urine, mainly hypercalciuria, always in fasting conditions.