Hypovitaminosis D in Tunisian osteoporotic postmenopausal women and the relationship with bone fractures.

AIM: The purpose of this study is to evaluate the frequency of hypovitaminosis D in Tunisian osteoporotic women and to search an eventual association between vitamin D status and the fracture risk. METHODS: A transverse descriptive study enrolled 134 osteoporotic menopausal women aged 50 years or more. We measured calcium, phosphorus, albumin, alkaline phosphatase, creatinine and 25 hydroxyvitamin D [25 (OH) vit D]. Bone mineral density (BMD) was measured for all and osteoporotic women were defined for a T-score of -2,5 or less in the spine, hip or femoral neck. Two groups were defined: G1 with fracture and G2 without fracture. We used SPSS 10.5, chi-2 tests and a statistical significance level of p<0,05. RESULTS: Women in G1 (n= 102) were more aged than those in G2 (n= 32) and their menopause was more ancient. Hypovitaminosis D was found in 45,2% of all women, respectively in 50,98% of G1 and 25% of G2. The mean level of vitamin D was more important in G2 (27,5 + 15,1 vs 21,3 + 12,8 ng/ml; p=0,002). BMD in femoral and lumbar were statistically lower when fractures are present (p<0,001). CONCLUSION: Our study shows that women with hypovitaminosis D (vit D < 20 ng/ml) are prone to osteoporotic fractures. All fracture in community in menopausal women, should be assessed with BMD and screening for 25 (OH) vit D. Increasing life expectancy in our country suggests that this public health problem will grow in the years to come, pointing out the importance of better management of osteoporosis and hypovitaminosis D to prevent fractures.

[Recurrent urinary lithiasis revealing hereditary xanthinuria]. / Lithiases urinaires récidivantes révélant une xanthinurie héréditaire.

INTRODUCTION: Hereditary xanthinuria, due to a purine metabolism disorder, is a rare cause of urinary lithiasis in children. CASE: We report the case of a child aged 3 and a half years, who presented recurrent urinary lithiasis that led to destruction of the right kidney. Infrared spectrophotometric analysis of the calculus concluded that it was composed of 100% xanthine. Laboratory tests showed hypouricemia and hypouricosuria with elevated urinary excretion of oxypurines. These findings led to a diagnosis of hereditary xanthinuria. CONCLUSION: Early diagnosis of this rare disease is essential to avoid its complications. Metabolic causes must be sought in children with lithiasis.