José Luiz Nishiura

Evaluation of nephrolithiasis in autosomal dominant polycystic kidney disease patients.

BACKGROUND AND OBJECTIVES Nephrolithiasis (LIT) is more prevalent in patients with autosomal dominant polycystic kidney disease (ADPKD) than in the general population. Renal ultrasonography may underdetect renal stones because of difficulties imposed by parenchymal and/or cyst wall calcifications. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS A total of 125 patients with ADPKD underwent ultrasonography and unenhanced computed tomography (CT) scan, routine blood chemistry, and spot and 24-h urine collections. RESULTS CT scan detected calculi in 32 patients, including 20 whose previous ultrasonography revealed no calculi. The percentage of hypocitraturia was high but not statistically different between patients with ADPKD+LIT or ADPKD. Hyperuricosuria and distal renal tubular acidosis were less prevalent but also did not differ between groups, whereas hyperoxaluria was significantly higher in the former. Hypercalciuria was not detected. Renal volume was significantly higher in patients with ADPKD+LIT versus ADPKD, and a stepwise multivariate logistic regression analysis showed that a renal volume >or=500 ml was a significant predictor of LIT in patients with ADPKD and normal renal function, after adjustments for age and hypertension. CONCLUSIONS CT scan was better than ultrasonography to detect LIT in patients with ADPKD. Larger kidneys from patients with ADPKD were more prone to develop stones, irrespective of the presence of metabolic disturbances.

Ansiedade, depressão e qualidade de vida em pacientes com glomerulonefrite familiar ou doença renal policística autossômica dominante

INTRODUCTION: Psychological aspects and quality of life are often evaluated in patients under renal replacement therapy, but studies about anxiety, de>pression, and quality of life in familial renal diseases are lacking. OBJECTIVES: To evaluate the frequency of anxiety, depression, and quality of life (QOL) and their eventual associations with the main laboratory, clinical, socioeconomic, and cultural parameters in familial glomerulonephritis (GN) or autosomal dominant polycystic kidney disease (ADPKD). METHODS: Ninety adult patients (52 familial GN and 38 ADPKD) completed the questionaires of State Trait Anxiety Inventory (STAI), Beck Depression Inventory (BDI), and QOL-Short-Form SF-36, and were also submitted to a short interview. RESULTS: Moderate anxiety was detected in both groups. Depression was found in 34.6% of familial GN and 60.5% of ADPKD patients. Anxiety and depression were more associated with female gender in familial GN, and with poorer schooling in ADPKD. Patients of both groups presented two quality of life unfavorable dimensions: emotional role function and general health perception. In addition, quality of life was worse among females, unmarried, and Caucasian subjects, and those individuals with a poorer educational level. CONCLUSION: The use of these instruments allows one to appreciate the frequency and levels of anxiety, depression, and quality of life in patients with familial renal diseases that could affect their compliance to treatment. These findings can contribute to planning a better multidisciplinary assistance to such groups of patients.

Effect of calcium intake on urinary oxalate excretion in calcium stone-forming patients

Dietary calcium lowers the risk of nephrolithiasis due to a decreased absorption of dietary oxalate that is bound by intestinal calcium. The aim of the present study was to evaluate oxaluria in normocalciuric and hypercalciuric lithiasic patients under different calcium intake. Fifty patients (26 females and 24 males, 41 +/- 10 years old), whose 4-day dietary records revealed a regular low calcium intake (<or=500 mg/day), received an oral calcium load (1 g/day) for 7 days. A 24-h urine was obtained before and after load and according to the calciuria under both diets, patients were considered as normocalciuric (NC, N = 15), diet-dependent hypercalciuric (DDHC, N = 9) or diet-independent hypercalciuric (DIHC, N = 26). On regular diet, mean oxaluria was 30 +/- 14 mg/24 h for all patients. The 7-day calcium load induced a significant decrease in mean oxaluria compared to the regular diet in NC and DIHC (20 +/- 12 vs 26 +/- 7 and 27 +/- 18 vs 32 +/- 15 mg/24 h, respectively, P<0.05) but not in DDHC patients (22 +/- 10 vs 23 +/- 5 mg/24 h). The lack of an oxalate decrease among DDHC patients after the calcium load might have been due to higher calcium absorption under higher calcium supply, with a consequent lower amount of calcium left in the intestine to bind with oxalate. These data suggest that a long-lasting regular calcium consumption <500 mg was not associated with high oxaluria and that a subpopulation of hypercalciuric patients who presented a higher intestinal calcium absorption (DDHC) tended to hyperabsorb oxalate as well, so that oxaluria did not change under different calcium intake.

Caffeine intake by patients with autosomal dominant polycystic kidney disease

Because caffeine may induce cyst and kidney enlargement in autosomal dominant polycystic kidney disease (ADPKD), we evaluated caffeine intake and renal volume using renal ultrasound in ADPKD patients. Caffeine intake was estimated by the average of 24-h dietary recalls obtained on 3 nonconsecutive days in 102 ADPKD patients (68 females, 34 males; 39 ± 12 years) and compared to that of 102 healthy volunteers (74 females, 28 males; 38 ± 14 years). The awareness of the need for caffeine restriction was assessed. Clinical and laboratory data were obtained from the medical records of the patients. Mean caffeine intake was significantly lower in ADPKD patients versus controls (86 vs 134 mg/day), and 63% of the ADPKD patients had been previously aware of caffeine restriction. Caffeine intake did not correlate with renal volume in ADPKD patients. There were no significant differences between the renal volumes of patients in the highest and lowest tertiles of caffeine consumption. Finally, age-adjusted multiple linear regression revealed that renal volume was associated with hypertension, chronic kidney disease stage 3 and the time since diagnosis, but not with caffeine intake. The present small cross-sectional study indicated a low level of caffeine consumption by ADPKD patients when compared to healthy volunteers, which was most likely due to prior awareness of the need for caffeine restriction. Within the range of caffeine intake observed by ADPKD patients in this study (0-471 mg/day), the renal volume was not directly associated with caffeine intake.

Tradução, adaptação cultural e aplicação de um questionário de dor para pacientes com doença renal policística

INTRODUCTION: Pain is a common symptom in patients with autosomal dominant polycystic kidney disease (ADPKD), affecting around 60% of cases. OBJECTIVE: Translate a pain questionnaire developed and validated for ADPKD in USA into Portuguese and to perform its cultural adaptation and apply it. METHOD: The cultural adaptation performed by a panel of experts resulted in small changes consisting of words substitution by synonyms or deletion of terms not commonly used in our culture in 12 out of the 46 questions posed, to solve patients difficulties in understanding the questionnaire. RESULTS: There has been equivalence between the adapted form of the instrument with the back-translation. The final form of the questionnaire applied in 97 patients with ADPKD (64F/33M, 35 ± 12 years) showed that 65 (67%) had isolated or associated pain in multiple locations , more often at lumbar region (77%), followed by abdominal (66%), headache (15%) and chest (4%). The questionnaire revealed that after family history, pain was the second factor contributing to the diagnosis of ADPKD in this population (55% and 22% of cases, respectively). DISCUSSION: Clinical and laboratory data from medical records showed that patients referring pain had renal volume and size of the largest cyst significantly higher than those without pain. CONCLUSION: We conclude that the use of a specific pain questionnaire for ADPKD population provided a better characterization of this symptom, as well as its relationship with the associated complications that commonly occur in this setting.

Exercise Capacity in Polycystic Kidney Disease

BACKGROUND Reports about exercise performance in autosomal dominant polycystic kidney disease (ADPKD) are scarce. We aimed to evaluate exercise capacity and levels of nitric oxide and asymmetric dimethylarginine (ADMA) in normotensive patients with ADPKD. STUDY DESIGN Prospective controlled cohort study. SETTING & PARTICIPANTS 26 patients with ADPKD and 30 non-ADPKD control participants (estimated glomerular filtration rate>60 mL/min/1.73 m2, aged 19-39 years, and blood pressure [BP]<140/85 mmHg). We excluded smokers, obese people, and individuals with associated diseases. PREDICTOR ADPKD versus control. OUTCOMES Exercise capacity and nitric oxide and ADMA levels in response to exercise. MEASUREMENTS Cardiopulmonary exercise testing and serum and urinary nitric oxide, plasma ADMA, and BP levels before and after exercise. RESULTS Mean basal systolic and diastolic BP, estimated glomerular filtration rate, and age did not differ between the ADPKD and control groups (116±12 vs. 110±11 mmHg, 76±11 vs 71±9 mmHg, 113±17 vs. 112±9.6 mL/min/1.73 m2, and 30±8 vs. 28.9±7.3 years, respectively). Peak oxygen uptake and anaerobic threshold were significantly lower in the ADPKD group than in controls (22.2±3.3 vs. 31±4.8 mL/kg/min [P<0.001] and 743.6±221 vs. 957.4±301 L/min [P=0.01], respectively). Postexercise serum and urinary nitric oxide levels in patients with ADPKD were not significantly different from baseline (45±5.1 vs. 48.3±4.6 μmol/L and 34.7±6.5 vs. 39.8±6.8 μmol/mg of creatinine, respectively), contrasting with increased postexercise values in controls (63.1±1.9 vs. 53.9±3.1 μmol/L [P=0.01] and 61.4±10.6 vs. 38.7±5.6 μmol/mg of creatinine [P=0.01], respectively). Similarly, whereas postexercise ADMA level did not change in the ADPKD group compared to those at rest (0.47±0.04 vs. 0.45±0.02 μmol/L [P=0.6]), it decreased in controls (0.39±0.02 vs. 0.47±0.02 μmol/L [P=0.006]), as expected. A negative correlation between nitric oxide and ADMA levels after exercise was found in only the control group (r = -0.60; P<0.01). LIMITATIONS Absence of measurements of flow-mediated dilatation and oxidative status. CONCLUSIONS We found lower aerobic capacity in young normotensive patients with ADPKD with preserved kidney function and inadequate responses of nitric oxide and ADMA levels to acute exercise, suggesting the presence of early endothelial dysfunction in this disease.

Pain determinants of pain in autosomal dominant polycystic kidney disease

Pain is the most common symptom reported by ADPKD patients, afflicting approximately 60% of cases and may result from renal hemorrhage, calculi, urinary tract infections, cyst rupture, or due to stretching of the capsule or traction of the renal pedicle. We have recently investigated pain patterns in AD-PKD patients using a translated version of a pain questionnaire specific for AD-PKD population. The questionnaire revealed that 67% patients with ADPKD exhibited some type of pain. The findings of that study emphasized that pain appeared early in the course of ADPKD, when patients still exhibited preserved renal function. In the present study, a multivariate logistic regression analysis disclosed that renal volume (9-fold increased risk) and nephrolithiasis (4-fold increased risk) were the most important determinant factors for pain in ADPKD patients with preserved renal function, after adjustments for the presence of hypertension and duration of the disease.