Epidemiology and risk factors in urolithiasis

Stone formation in the urinary tract affects about 5-10% of the population in industrialized countries, although it is very rare in other countries such as Greenland or Japan. The high incidence and recurrence rate contribute to making the urolithiasis a serious social problem. Nowadays, urolithiasis must be considered a 'disease in evolution' for several reasons, such as epidemiological changes, evolution of the methods used for diagnosis, and the treatment and prophylaxis of the population considered 'at risk' of stone disease. Some features of stone disease have changed over the last few years due to many social, economical and cultural factors that are described here. The increased prevalence of small urinary calculi has brought about a change in clinical symptoms, with frequent episodes of renal-ureteral colic, persistent pain and hydronephrosis. Similarly, the presence of residual fragments after extracorporeal shock wave lithotripsy has induced a radical change in the management of small calculi through the use of mini-invasive surgical techniques.     

Adult urolithiasis in a population-based study in Iran: prevalence,incidence, and associated risk factors

The aim of this study was to determine the prevalence, incidence, and risk factors of adult urolithiasis in Iran. A total of 8,413 persons aged over 14 years enrolled in this cross-sectional study. They were questioned on the occurrence of urinary stones during their lifetime (prevalence) and on acute urolithiasis in 2005 (incidence) by 62 general practitioners. The subjects were randomly identified from 30 counties of Iran. Data on risk factors for urolithiasis including age, race, education, body mass index, hypertension, and current use of medication were also obtained by self-administered questionnaire. Of the 7,649 participants who provided information, 5.7% (436) [95% confidence interval (CI) 4.2–5.4], reported urinary stones. The prevalence increased from 0.9% in adults aged 15–29 years to 8.2% in those aged 60–69 years (test for trend, P = 0.001). Urolithiasis was slightly more frequent and persisted in males (6.1%) than females (5.3%) giving a male-to-female ratio of 1.15:1 [odds ratio (OR) 1.03; 95% CI 0.64–1.36; P = 0.814]. The annual incidence of urolithiasis in 2005 was 145.1. The average cumulative recurrence rate was 16% after 1 year, 32% after 5 years, and 53% after 10 years. Urinary stones were more in number among men and women who lived in south central and southwest counties, with odds increasing from west to east and from north to south. A positive association was found between urolithiasis and obesity (OR 1.74; 95% CI 1.21–2.31; P = 0.04), diuretic use (OR 1.62; 95% CI 1.18–2.70; P = 0.03), hypertension (OR 1.88; 95% CI 1.26–2.18; P = 0.04), unemployment (OR 2.10; 95% CI 1.43–2.14; P = 0.04), consumption of tea (OR 1.64; 95% CI 1.32–2.62; P = 0.03), consumption of cola (OR 1.49; 95% CI 1.23–2.19; P = 0.02), and meat consumption (OR 1.38; 95% CI 1.29–2.21; P = 0.02). This study provides a quantitative estimate of the prevalence, incidence, and main risk factors for adult urolithiasis in the Iranian population. Further studies are warranted in order to determine the incidence and prevalence of urolithiasis in different ethnic groups.     

Studies of urinary risk factors in urolithiasis

Urinary excretions of calcium, oxalate and uric acid were estimated in 160 stone-formers (male 118, female 42) and 257 healthy controls (male 207, female 50). Stone-formers were divided into two groups according to their stone analysis: calcium containing stone-formers and non-calcium stone-formers. Calcium stone-formers were divided again into those who had a single stone episode and multiple or recurrent stone episodes. Urinary calcium and oxalate showed significant increases in calcium stone-formers, while urinary uric acid increased only in male calcium stone-formers. Recurrent calcium stone-formers demonstrated significant high levels of urinary calcium excretion especially in males, whereas no difference of urinary oxalate excretion between recurrent and single stone-formers. The frequency distributions on the excretion of three subjects were estimated respectively in patients with calcium stone and in controls. Relative risks, risk curves and stone probabilities were proposed and compared. The higher excretion values of urinary calcium and oxalate closely related to higher risks of forming calcium stones. On the other hand, urinary uric acid did not have such a relation to calcium stone formation. We defined the states which urinary excretions exceeded 95% upper confidence limits of normal controls as hyperexcretions. Hypercalciuria was more than 200 mg/day in male and female, hyperoxaluria was 50 mg/day in male and 45 mg/day in female and hyperuricosuria was 850 mg/day in male and 650 mg/day in female according to our definition. Among male calcium stone-formers, hypercalciuria was found in 45.3%, hyperoxaluria in 26.4% and hyperuricosuria in 15.1%. While in female calcium stone-formers, hypercalciuria in 23.7%, hyperoxaluria in 26.3% and hyperuricosuria in 13.2%. Of the male calcium stone-formers 57.5% showed either or both hypercalciuria and hyperoxaluria, and recurrent stone-formers also demonstrated a higher incidence among them. Excretion products of urinary calcium and oxalate were calculated and compared in each group. Calcium stone-formers showed significant high values especially in male recurrent stone-formers. The estimation by combining some risk factors will provide more useful means of assessing severity of urinary calculous diseases and therapeutic effects of their various treatments.     

Acute renal failure early after heart transplantation: risk factors and clinical consequences

Gude E, Andreassen AK, Arora S, Gullestad L, Grov I, Hartmann A, Leivestad T, Fiane AE, Geiran OR, Vardal M, Simonsen S. Acute renal failure early after heart transplantation: risk factors and clinical consequences.
Clin Transplant 2010: 24: E207–E213. © 2010 John Wiley & Sons A/S. Abstract: Limited information exists about acute renal failure (ARF) early after heart transplantation (HTx). We correlated pre‐, per‐, and post‐operative patient and donor parameters to the risk of developing ARF. We also analyzed the consequences of ARF on kidney function after HTx, risk of later need for chronic dialysis or kidney transplantation, and mortality. In a retrospective study from 1983 to 2007, 145 (25%) of 585 HTx recipients developed ARF, defined as ≥26.4 micromol/L or ≥50% increase in serum creatinine from pre‐operatively to the seventh day post‐HTx and/or the need of early post‐operative dialysis. Independent risk factors for ARF were intravenous cyclosporine immediately post‐operatively (odds ratio [OR] 2.16, 95% CI 1.34–3.50, p = 0.02), donor age (OR 1.02, 95% CI 1.00–1.04, p = 0.02), and pre‐operative cardiac output (OR 1.38, 95% CI 1.12–1.71, p = 0.003). The development of ARF was a predictor for short‐term survival (≤3 months) ranging from 98% for patients who improved their creatinine after HTx vs. 79% for those in need of dialysis (p < 0.001). However, ARF did not predict subsequent end stage renal disease in need of dialysis or renal transplantation. ARF is a common complication post‐HTx. As ARF is associated with short‐term survival, post‐operative strategies of preserving renal function have the potential of reducing mortality. Of avoidable risk factors, the use of intravenous CsA should be discouraged.     

Prevalence of hypovitaminosis D in elderly women in Italy: clinical consequences and risk factors

In order to evaluate the prevalence, risk factors, and clinical consequences of hypovitaminosis D in elderly Italian women a multicenter study of 43 osteoporosis centers from all regions of Italy was carried out. Study population included 700 women aged 60–80 years in whom blood was taken for 25-hydroxyvitamin D (25OHD) and parathyroid hormone (PTH) measurements. All subjects were also questioned to assess the prevalence of several risk factors for hypovitaminosis D, osteoporotic fractures and activities of daily living (ADL). Values of 25OHD lower than 5 ng/ml were found in 27% of the women and lower than 12 ng/ml in 76%. 25OHD and PTH levels were negatively correlated (r=–0.38, after logarithmic transformation of both variables). 25OHD levels significantly declined with advancing age and number of pregnancies and were positively correlated with educational level (years spent at school), dairy calcium intake, and days spent on holiday by the sea. In a multivariate model including all these variables, the only one that remained significant was the level of education. The lowest age-adjusted 25OH D levels were found in smokers or in women living in central Italy as compared with those living in northern or southern Italy. The mean (±SD) age-adjusted 25OH D values were significantly lower in women who sustained a hip fracture (7.1±2.2 versus 11.0±9.9). Women with low 25OHD levels (<12 ng/ml) had worse scores for ADL and mobility ADL (move outdoors, use stairs, walk at least 400 m, carry a heavy object). Vitamin D deficiency is extremely common among elderly Italian women. Women with lower educational level, living in central Italy, smokers or with lower intake of dairy products are at greater risk. Hypovitaminosis D is associated with worsening of the ability to perform activities of daily living and higher hip fracture prevalence. This finding should lead to an urgent population-based strategy to remedy this condition.Local participants in the study (name and Italian town of study site): S. Adami, Verona; M. Bevilacqua, Milano; E.M. Bibolotti, Piombino; F. Cantini, Prato; S. Coaccioli, Terni; R. Conca, Milano; D. Costi, Parma; G. D'Avola, Catania; O. Di Munno, Pisa; M. Ferraris, Vercelli; P. Filipponi, Perugia; C.M. Francucci, Ancona; G. Gandolini, Milano; S. Gatto, Napoli; P. Gigliotti, Cosenza; T. Gismondi, Bari; S. Gnudi, Bologna; E. Grimaldi, Trieste; G. Isaia, Torino; G. La Montagna, Napoli; G. Lojacono, Bari; R.V. Lovato; F. Luparelli, Taranto; U. Martorana, Palermo; A. Mathieu, Cagliari; D. Maugeri, Catania; S. Minisola, Roma; S. Miozzi, Roma; G. Occhipinti, Livorno; R. Pellerito, Torino; D. Policicchio, Avellino; M. Portigliatti Barbos, Torino; G.B. Rini, Palermo; G. Rosa, Napoli; D. Schinella, Pordenone; M. Sfrappini, Tronto; P. Simonetta, Reggio Calabria; L. Sinigaglia, Milano; S. Stisi, Benevento; A. Tarroni, Rimini; F. Trotta, Ferrara; F. Versace, Savona     

Assessment of risk factors of pediatric urolithiasis in Egypt

Objective

Pediatric urolithiasis is a significant medical problem, which has seen an increasing incidence in developing countries. The main objective of the present study was to investigate the clinical characteristics and the most important risk factors that contribute to stone formation in Egyptian children.

Patients and methods

This prospective study was carried out at the outpatient clinics of Cairo university children’s hospital as well as October 6 University hospitals, between November 2008 and March 2012. One hundred and fifty children (100 males, 50 females; mean age 3.5 years; range, 1-14 years) suffering from urinary stones were included. The mean follow-up duration; 33.1 months. All patients underwent detailed medical and family histories, dietary habits and physical examination, including Growth percentiles. Laboratory investigations were performed including: complete urine analysis and culture and sensitivity tests, urine collection in 24-h to quantity urinary volume, pH, calcium, uric acid, magnesium, creatinine, oxalate and citrate. Blood samples were obtained to measure (serum creatinine, calcium, phosphorus, uric acid level, and alkaline phosphatase and electrolyte levels, in addition to pH and pCO₂ values). Radio-sonographic investigation of the abdomen and pelvis was also performed.

Results

The commonest presentations were abdominal pain in 42 children (28%) and gross hematuria in 35 patients (23%). Urinary tract infection was the most common risk factor, 60 patients (40%) had UTI, 70% of them had recurrent infections. Genito-urinary abnormalities, as a risk factor, were detected in 38 children (25%), with vesico-uretheral refux being the commonest abnormality (18/38). Metabolic risk factors were detected in 34 children (23%) with hypercalciuria and hyperoxaluria being the commonest metabolic abnormalities. Treatments used were, ESWL in 69 patients (46%), endoscopic interventions in 40 children (27%) and open surgery in 15 children (10%). The remaining 26 children (17%) were managed conservatively.

Conclusions

treatment of pediatric urolithiasis requires stone removal besides a thorough metabolic and environmental evaluation of all patients on an individual basis, entailing the treatment of metabolic abnormalities. Children with a positive family history should be followed up cautiously to avoid stone recurrence.     

Reduction of the urinary risk factors of urolithiasis with magnesium and tartrate mixture: a new treatment

Magnesium and tartrate each reduce calcium oxalate crystal formation in urine. Since the effects are additive, a palatable mixture of magnesium and tartrate salts was devised and fed to 6 healthy volunteers. There were no side effects. There was a moderate fall in urinary calcium, moderate rises in urinary magnesium, tartrate and citrate, and no change in urinary oxalate. Hence there are good grounds for supposing that this mixture could be used to prevent urinary stone recurrence.     

重庆地区尿石症危险因素的研究

目的　探讨尿石症患者的发病年龄、发病诱因及发病季节等因素与家族史的关系。　方法　采用问卷调查形式对 36 0例有家族史和 12 0 0例无家族史尿石症患者及 10 0 0例正常对照组进行调查。　结果　① 36 0例有家族史尿石症者中 ,一级亲属和二级亲属的患病率分别为 10 .71% (14 7/1372 )、1.6 8% (5 4 / 32 14 ) ;而对照组一级亲属和二级亲属的患病率分别为 0 .6 6 % (2 3/ 3480 )、0 .12 % (9/7345 )。②有家族史尿石症者中 ,男性平均发病年龄 (2 6 .35岁 ) ,女性 (36 .4岁 ) ,两组比较差异有显著性意义 (t=1.75 ,P <0 .0 5 )。有家族史男性发病年龄 (2 6 .35岁 )早于无家族史男性 (2 9.31岁 ,t =2 .2 15 ,P <0 .0 5 ) ,女性患者有家族史者平均发病年龄 34.9岁 ,无家族史者平均发病年龄 35 .2岁 ,二者比较差异无显著性意义 (t=0 .739,P >0 .0 5 )。③发病诱因、发病季节在有家族史和无家族史间无统计学意义 ,但环境因素两组比较差异均有显著性意义 (χ2 =0 .2 3,P <0 .0 5 )。　结论　尿石症是一种多因素的且可能与遗传因素有关的疾病。     

拉萨地区尿结石发病情况及危险因素的调查研究

目的:通过单中心调查,研究拉萨地区尿结石的发病情况及其危险因素,为本地区尿结石的诊治及预防提供科学依据。方法:对我院确诊为尿结石的362例患者进行问卷调查,对调查因素进行统计分析。结果:362例患者中,尿结石患者男女比例为3.36∶1(279/83),高发年龄段为20~39岁,且以上尿路结石为主;饮水少、高脂肪、高蛋白、高食盐、饮酒是本地区引发尿结石的危险因素。结论:减少饮酒和动物蛋白脂肪的摄入,限制钠盐日摄入量,并合理增加饮水,对本地区泌尿系结石的防治有积极意义。     

Analysis of the urinary risk factors of urolithiasis in healthy children

Since incidence of idiopathic calcium oxalate urolithiasis in children was very low, a study was made to analyze the risk factors of calcium oxalate stone in male volunteers without any episode of urolithiasis. They were divided into four groups, group I: eight years old, group II: 11 years old, group III: 18 to 24 years old, group IV: 41 to 45 years old. Inhibitory activities of urine were significantly higher in groups of children than in groups of adults. However, inhibitory activities of filtered urine, extracted through filters with conserved limit of 25000 of molecular weight, were reduced significantly. Therefore, it was suggested that materials with molecular weight over 25000 participated in the inhibitory activities. Furthermore, the activities of filtered urine of group I were still higher than those of the non-filtered urine in groups of adults. Accordingly it was considered that substances less than 25000 of molecular weight also participated in the inhibitory activities in children. An analysis of uric acid, citrate, magnesium and uronic acid in urine revealed that magnesium excretion volume and magnesium concentration ratio to creatinine were higher in children than in adults. Magnesium seemed to boost the inhibitory activities in children. In the measurement of crystalloid materials, the concentration of calcium was significantly lower in children groups than in groups of adults. It seemed that calcium also takes part in reduction of incidence of urinary stone in children.     

Results of medical treatment and metabolic risk factors in children with urolithiasis

Data on conservative treatment in children with urolithiasis are limited. The aim of the study was to determine the metabolic etiology and results of conservative treatment in children with urolithiasis. We evaluated the clinical presentation and metabolic features of 112 children with urolithiasis. The mean age at diagnosis of urolithiasis was 3.9 (range 0.1–18) years, and follow-up duration was 16.7 (range 1–36) months. The most common presenting symptoms were flank or abdominal pain and restlessness (25%). Urine analysis revealed metabolic abnormalities in 92% of cases, including hypocitraturia (42%), hyperoxaluria (32.1%), hypercalcuria (25%), hyperuricosuria (9.8%), and cystinuria (2.7%). Patients who had metabolic risk factors were treated according to underlying metabolic abnormalities. About half of these patients were stone free or stones were diminished in size. These results showed that early recognition and treatment of urinary metabolic abnormalities will reduce the number of invasive procedures and renal damage in children with urolithiasis.     

EQUIL 93: a tool for experimental and clinical urolithiasis

An extensively updated version of the EQUIL software is described. The former version, designated EQUIL2, is widely used to study urolithiasis and related areas of biomineralization. In this report, we discuss recent enhancements which give EQUIL93 an expanded scope of application. This program has been frequently used in studies of the physicochemical processes underlying stone salt crystallization, especially crystal growth and nucleation, but it has also been employed as an aid for in vivo research and as an evaluator of therapeutic measures. We illustrate several new applications, including some outside the urologic realm, and we discuss how the enhanced software can be helpful in stone risk assessments.     

Postcardiopulmonary bypass hypoxemia: a prospective study on incidence, risk factors, and clinical significance

OBJECTIVE: To evaluate the clinical significance of low arterial oxygen tension-inspired oxygen concentration (PaO2-FIO2) ratio, as a measure of hypoxemia, in the early period after cardiac surgery with cardiopulmonary bypass (CPB); and to evaluate the preoperative, intraoperative, and postoperative factors contributing to the development of hypoxemia within the first 24 hours after cardiac surgery with CPB. DESIGN: Prospective observational study. SETTING: University hospital. PARTICIPANTS: Patients who underwent elective or emergency cardiac surgery with CPB (n = 466). INTERVENTIONS: Preoperative clinical and laboratory data were recorded, as were intraoperative and postoperative data regarding the PaO2-FIO2 ratio, fluid and drug therapy, and chest radiograph. Data analysis evaluated hypoxemia as depicted by the PaO2-FIO2 ratios at 1, 6, and 12 hours after surgery. Thereafter, the effect of the PaO2-FIO2 ratios on time to extubation, lung injury, and length of hospital stay was evaluated. The risk factors were analyzed in 3 separate periods: preoperative, intraoperative, and postoperative. Univariate and multivariate analyses were performed on each period separately. All data were analyzed in 2 consecutive steps: univariate analysis and multivariate analysis. MEASUREMENTS AND MAIN RESULTS: PaO2-FIO2 ratios after CPB were significantly lower compared with baseline values. Six patients (1.32%) met the clinical criteria compatible with acute lung injury. All 6 patients had prompt recovery. Significant risk factors for hypoxemia were age, obesity, reduced cardiac function, previous myocardial infarction, emergency surgery, baseline chest radiograph with alveolar edema, high creatinine level, prolonged CPB time, decreased baseline PaO2-FIO2, use of dopamine after discontinuation of CPB, coronary artery bypass grafting, use of left internal mammary artery, higher pump flow requirement during CPB, increased level of hemoglobin or total protein content, persistent hypothermia 2 and 6 hours after surgery, requirement for reexploration, event requiring reintubation, and chest radiograph with alveolar edema 1 hour after surgery. Six hours after surgery, a lower PaO2-FIO2 ratio correlated significantly with time to extubation and lung injury. CONCLUSIONS: This study shows that despite improvements in the technique of CPB, hypoxemia depicted by low PaO2-FIO2 ratios is common in patients after CPB. It is short lived, however, and has minimal effect on the postoperative clinical course of these patients.     

Recurrent varicose veins: incidence, risk factors and groin anatomy.

OBJECTIVES: To investigate the recurrence rate after sapheno-femoral junction (SFJ) ligation and great saphenous vein (GSV) stripping for varicose veins (VV), to evaluate risk factors for recurrence and to classify the anatomy of the recurrence in the groin. Design. Clinical follow-up study. METHODS: Eighty-nine consecutive patients with 100 operated legs were re-examined clinically and with duplex after 6-10 years. Fourteen groins were re-explored, 13 after varicography. The anatomy in the groin was classified according to the Edinburgh system. The original medical records were examined to check for risk factors which could lead to a recurrence. RESULTS: Fifty-seven legs had incompetent veins in the groin according to duplex. In 54 of them, it was possible to define whether the incompetent veins emanated from the former SFJ. Varicography and operative findings correlated well to duplex. The main difficulty was to distinguish neovascularization from residual branches. No significant risk factor for recurrence was found in the medical records. CONCLUSIONS: Recurrence of VV after SFJ ligation is common irrespective of perioperative difficulties or the surgeon's experience. The anatomy of recurrence in the groin is difficult to classify according to the Edinburgh system mainly because neovascularization is difficult to verify.     

Post-transplant hyperglycaemia: a study of risk factors.

BACKGROUND: Post-transplant diabetes mellitus (PTDM) has several identifiable pre- and post-transplant risk factors. The link to nutritional status pre-transplant has not been explored previously. This study was conducted to identify risk factors for the development of PTDM, with emphasis on pre-transplant nutritional status and glucose tolerance. METHODS: Non-diabetic adult end-stage renal failure patients awaiting renal transplantation were studied prospectively. Their nutritional status was assessed as body mass index (BMI), serum albumin, and the evolution of these parameters over time prior to transplantation. An oral glucose tolerance test (OGTT) was performed pre- and serially post-transplant until 6 months. Pre- and post-transplant risk factors such as age, nutritional status, glucose tolerance parameters and immunosuppression were related to the development of PTDM or impaired glucose tolerance (IGT) post-transplant. RESULTS: The mean age of 174 patients studied over a 2-year period was 32.9 +/- 9.7 years. The mean post-transplant follow-up was 25.6 +/- 12.8 months. The mean BMI at recruitment was 18.3 +/- 2.4 kg/m(2). The rate of increase in BMI pre-transplant showed an inverse correlation with the baseline BMI (r = -0.34, P = 0.000) and formed an independent marker of nutritional status. PTDM developed in 21.4% patients and 24.1% had IGT. On univariate and multivariate analyses, the factors significantly associated with the development of PTDM were greater age, more rapid increase in dry weight after starting haemodialysis (HD), elevated pre-transplant OGTT responses and cyclosporin (CsA) and prednisolone doses early post-transplant. Additionally, on multivariate analysis, higher CsA trough level > 300 ng/ml at 3 months increased the risk for the development of PTDM. Of patients who developed PTDM, 57% had impairment of glucose tolerance pre-transplant (> 140 mg/dl at 2 h). Patients with a 1-h glucose value greater than the 50th percentile on pre-transplant OGTT had a 3.9-fold greater risk for the development of PTDM (P = 0.05, 95% CI = 1.03-11.1). In those patients with higher 1-h glucose (> 50th percentile) who also gained in dry weight rapidly pre-transplant, the risk increased to 5.3 (P = 0.02). Of 76 patients with abnormal OGTT early post-transplant, only 68% continued to have PTDM or IGT post-transplant, the remainder reverting to normal glucose tolerance. CONCLUSIONS: Persistent abnormal glucose tolerance after transplantation was seen in 45% of the patients. Pre-transplant factors including greater age, abnormal glucose tolerance parameters, and rapid gain in dry weight on HD, along with higher prednisolone and CsA doses early post-transplant were the important factors associated with the development of PTDM. Identification of patients with pre-transplant risks might allow modification of post-transplant immunosuppression with non-diabetogenic agents.     

Incidence of shoulder pain after neck dissection: a clinical explorative study for risk factors.

BACKGROUND: It is the purpose of this study to determine the incidence of shoulder pain and restricted range of motion of the shoulder after neck dissection, and to identify risk factors for the development of shoulder pain and restricted range of motion. METHODS: Clinical patients who underwent a neck dissection completed a questionnaire assessing shoulder pain. The intensity of pain was assessed using a visual analog scale (100 mm). Range of motion of the shoulder was measured. Information about reconstructive surgery and side and type of neck dissection was retrieved from the medical records. RESULTS: Of the patients (n = 177, mean age 60.3 years [SD, 11.9]) 70% experienced pain in the shoulder. Forward flexion and abduction of the operated side was severely reduced compared to the non-operated side, 21 degrees and 47 degrees, respectively. Non-selective neck dissection was a risk factor for the development of shoulder pain (9.6 mm) and a restricted shoulder abduction (55 degrees ). Reconstruction was risk factor for a restricted forward flexion of the shoulder (24.5 degrees ). CONCLUSIONS: Shoulder pain after neck dissection is clinically present in 70% of the patients. Non-selective neck dissection is a risk factor for shoulder pain and a restricted abduction. Reconstruction is a risk factor for a restricted forward flexion of the shoulder.