Mbarki Mohamed, Jabrane Jawad, Oussama Abdelkhalek, Daudon Michel
Laboratoire de Spectrochimie Appliquée et Environnement, Unite d'Urolithiase, Faculté des Sciences, Béni-Mellal, Maroc.
Prog Urol. 2005 Jun;15(3):420-5; discussion 425-6.
The incidence of diabetes, particularly non-insulin-dependent diabetes, is on the increase in industrialized and developing countries. The prevalence of renal stones in the diabetic population was recently estimated to be 21%, i.e. more than twice the prevalence of stones in the general population. Other studies have emphasized the high frequency of uric acid stones in this particular population. The present study was designed to verify whether diabetic patients present a particular type of crystalluria predisposing them to a high frequency of uric acid stones than other types of stones, which could allow detection of this risk and the proposal of therapeutic measures to prevent these stones.
The first morning urine of 208 diabetic patients was examined by polarized light microscopy to detect and identify crystalluria. Patients were distributed into 3 age-groups: less than 40 years, 40 to 59.9 years and 60 years or more. The results are expressed as the predominant crystalline species.
The overall frequency of crystalluria was 29.8%, i.e. about one half that observed in calcium stones. However, the crystallogenic profile was very unusual, as 61.3% of cases of crystalluria consisted of purine. Uric acid crystalluria was twice as frequent in women than in men (66% vs 33.3%, p < 0.05). The mean pH of the urine of diabetic subjects was 5.5, i.e. significantly more acidic than that of normal subjects or patients with calcium stones. pH was negatively correlated with the patient's age, decreasing from 5.54 in patients younger than 40 to 5.3 in patients over the age of 60 (p < 0.05). The mean pH of crystalluric urine was significantly more acidic than that of crystal-free urine (pH 5.2 +/- 0.46 vs 5.5 +/- 0.67, p < 0.01).
Diabetic patients have an acidic urinary pH which tends to decrease with age, predisposing to uric acid crystalluria, which is particularly frequent in women. The high prevalence of uric acid crystalluria and the high proportion of uric acid stones reported in diabetic women suggest that women are at greater risk than men of developing uric acid stones in the context of diabetes. The study of crystalluria could be useful to detect this risk and to propose preventive measures. Complementary studies are necessary to identify factors accounting for the increased risk of uric acid stones in diabetic women and to verify whether good glycaemic control can reduce the crystallogenic risk.
在工业化国家和发展中国家，糖尿病尤其是非胰岛素依赖型糖尿病的发病率正在上升。最近估计糖尿病患者中肾结石的患病率为21%，即比普通人群中结石的患病率高出两倍多。其他研究强调了这一特定人群中尿酸结石的高发生率。本研究旨在验证糖尿病患者是否存在一种特殊类型的结晶尿，使其比其他类型结石更易患尿酸结石，这有助于检测这种风险并提出预防这些结石的治疗措施。
对208例糖尿病患者的晨尿进行偏振光显微镜检查，以检测和识别结晶尿。患者分为3个年龄组：小于40岁、40至59.9岁和60岁及以上。结果以主要结晶种类表示。
结晶尿的总体发生率为29.8%，即约为钙结石患者中观察到的发生率的一半。然而，结晶形成特征非常不寻常，因为61.3%的结晶尿病例由嘌呤组成。女性尿酸结晶尿的发生率是男性的两倍（66%对33.3%，p<0.05）。糖尿病患者尿液的平均pH值为5.5，即明显比正常受试者或钙结石患者的尿液更酸。pH值与患者年龄呈负相关，从40岁以下患者的5.54降至60岁以上患者的5.3（p<0.05）。结晶尿的平均pH值明显比无结晶尿的尿液更酸（pH 5.2±0.46对5.5±0.67，p<0.01）。
糖尿病患者尿液pH值呈酸性，且随年龄增长有降低趋势，易患尿酸结晶尿，在女性中尤为常见。糖尿病女性中尿酸结晶尿的高发生率和尿酸结石的高比例表明，在糖尿病背景下，女性比男性患尿酸结石的风险更大。对结晶尿的研究可能有助于检测这种风险并提出预防措施。需要进行补充研究以确定导致糖尿病女性尿酸结石风险增加的因素，并验证良好的血糖控制是否可以降低结晶形成风险。
