C telopeptides of type I collagen inpostmenopausal women: an experience in a Tunisian clinical laboratory

The purpose of study was to evaluate the interest of C-telopeptides of type I collagen [CTX] in the diagnosis of osteoporosis in postmenopausal women and to define its cut-off value. A transverse descriptive study enrolled postmenopausal women: 139 osteoporotic [G1] and 39 non osteoporotic [G2]. The 2 groups were defined by bone density measurement. The followmg markers were measured: serum alkaline phosphatase [ALP] bone alkaline phosphatase [bone ALP], serum C-terminal telopeptide of type I collagen [CTX]. Statistical analyses were performed using SPSS 10, 5. The corresponding estimation of sensitivity and specificity of CTX have been presented as receiver Operating Curve [ROC]. There was no difference in the measurement of ALP and bone ALP in the 2 groups but CTX was statistically higher in G1 compared to G2 [p<0.001]. The percentage of osteoporotic women [G1] with CTX values>0.500 ng/ml was higher than that of non osteoporotic women [G2]. We have established a ROC curve to find the cut-off value of CTX that enables the distinction between osteoporotic women with high level of bone remodelling, and non osteoporotic women. The cut-off value of CTX 0.55 pg/mi was the best; it associated best sensitivity and specificity. The total increase and significance for CTX was greater in the group of osteoporotic women and appeared therefore to be a good bone turnover marker in the diagnosis of osteoporosis in comparison with ALP and bone ALP. The cut-off value of CTX 0.55 pg/mi may improve the sensitivity and specificity of prediction of future fractures

[Variation of biochemical parametrs of the first morning urine during month of Ramadan]

The purpose of this study is to evaluate the effect of fluid and diet restriction in fasting on biochemical factors of stone formation. Our study concerns 90 patients divided in three groups: healthy fasting patient [G1], healthy non fasting patient [G2] and non fasting patient with calcium lithiasis [G3]. The promotors [oxalate calcium, uric. acid, phosphates] and inhibitors [citrate, magnesium] are statistically significant between G1,G2 and G3,G2. Supersaturation of urine with oxalate, uric acid and brushite are the same for [G1] and [G3] and higher than [G2]. Crystalluria is more important in lithiasis subjects compared with healthy non fasting patients [58% vs 11,4%]. Oxalate monohydrate [Whewellite] and uric crystal don't exist in the healthy non fasting people but reached 4% and 12% respectively in the lithiasis patient. The crystalluria profile is the same in the healthy fasting patients and calcium lithiasis patients. However healthy patients have equilibria between promotors and inhibitors of crystal formation which minimize the risk of crystalluria and subsequent stone formation