Lee Sang-Cheol, Kim Yong-June, Kim Tae-Hwan, Yun Seok-Joong, Lee Nam Kyu, Kim Wun-Jae
Department of Urology, Chungbuk National University College of Medicine, Cheongju, South Korea.
J Urol. 2008 Feb;179(2):570-4. doi: 10.1016/j.juro.2007.09.040. Epub 2007 Dec 21.
Recent studies have suggested an increased prevalence of urolithiasis and recurrence associated with obesity. We assessed the influence of obesity on stone risk factors as well as on stone recurrence.
A database of patient history, body mass index, and serum and urine chemistry was analyzed for 704 consecutive stone formers (467 first time stone formers and 247 recurrent stone formers). Obesity was defined as body mass index greater than 25 kg/m(2). The effect of obesity on stone risk factors and recurrence were stratified according to stone episodes. Of these, 163 (23.2%) patients who had been followed for more than 36 months (median 54, range 5 to 148) were included in recurrence analysis.
Obesity was significantly associated with stone episodes (p = 0.043). Obese stone formers excreted increased amounts of sodium, calcium, uric acid and citrate, while the urinary pH in a 24-hour urine sample was decreased compared to nonobese stone formers (p <0.05, respectively). Stone analysis revealed that uric acid stone was significantly more commonly found in the obese patients (p = 0.046). Multivariate Cox regression model stratified by stone episodes revealed that obesity (HR 2.572, 95% CI 1.376-4.807, p = 0.003) was the only strong predictor of stone recurrence in first time stone formers. No association between obesity and stone recurrence was detected in recurrent stone formers. Kaplan-Meier curves showed identical results.
This study reveals that obesity is associated with metabolic alterations and urinary stone recurrence. Weight control may be considered one of the preventive modalities against recurrent stone formation, especially in first time stone formers.
近期研究表明，肥胖与尿石症患病率及复发率增加有关。我们评估了肥胖对结石危险因素以及结石复发的影响。
分析了704例连续性结石患者（467例初发结石患者和247例复发结石患者）的病史、体重指数以及血清和尿液化学指标数据库。肥胖定义为体重指数大于25kg/m²。根据结石发作情况对肥胖对结石危险因素和复发的影响进行分层。其中，163例（23.2%）随访时间超过36个月（中位数54个月，范围5至148个月）的患者纳入复发分析。
肥胖与结石发作显著相关（p = 0.043）。肥胖结石患者钠、钙、尿酸和枸橼酸盐排泄量增加，而24小时尿液样本中的尿pH值与非肥胖结石患者相比降低（p均<0.05）。结石分析显示，尿酸结石在肥胖患者中显著更常见（p = 0.046）。按结石发作情况分层的多变量Cox回归模型显示，肥胖（HR 2.572，95%CI 1.376 - 4.807，p = 0.003）是初发结石患者结石复发的唯一强预测因素。在复发结石患者中未检测到肥胖与结石复发之间的关联。Kaplan-Meier曲线显示了相同的结果。
本研究表明，肥胖与代谢改变和尿路结石复发有关。控制体重可被视为预防结石复发的措施之一，尤其是在初发结石患者中。
