Risk factors for renal disease and urinary abnormalities in men and women: data from the World Kidney Day in the province of Ferrara, Italy

BACKGROUND

Chronic kidney disease (CKD) is a worldwide health problem due to its morbidity and mortality, and cost. World Kidney Day (WKD) has been planned to improve disease prevention. The aim of this study was to evaluate CKD risk factors and urinary abnormalities, collected on WKD along several years, in men and women.

PATIENTS AND METHODS

Between 2006 and 2012, 1980 subjects, of whom 1012 women, from general population living in Ferrara area, a town in the north-east of Italy, were investigated. For each participant age, sex, smoking, hypertensive and diabetic status, body mass index (BMI), waist circumference (WC), and blood pressure (BP) were obtained. Moreover, body shape index (BSI) was calculated. All subjects underwent dipstick urinalysis.

RESULTS

Men had higher BMI, WC, and BP than women. Women had higher prevalence of abdominal obesity and higher BSI (0.0951 ± 0.0105 vs. 0.0920 ± 0.0071 m(11/6)kg(-2/3)), while men had higher prevalence of overweight. In women, hematuria and leukocyturia were more prevalent (16.9% vs. 12.8%; OR 95%CI 1.161 (1.042-1.294); p = 0.012; 18.5% vs. 7% OR 95%CI 1.538 (1.403-1.676); p < 0.001, respectively), while glycosuria was less frequent (4.2% vs. 8.8% OR 95%CI 0.642 (0.501-0.822); p < 0.001) than in men. Frequency of proteinuria was similar in the two sexes. Venn diagrams indicate a different overlap of urinary abnormalities in the two sexes.

CONCLUSIONS

Risk factors for CKD collected during the WKD appear to be different in the two sexes, and urinary abnormalities overlap differently. Data collected during the WKD are related to sex, and women deserve greater attention.

Invasive procedure for intractable epistaxis in an old comorbid woman: a case report

Epistaxis is a condition mainly self-limiting or easily treated conservatively, although in rare cases it could become life-threatening. We discuss the case of a 73 year comorbid old woman with severe and recurrent epistaxis treated with superselective catheterism and embolization of the internal maxillary artery. The possible underlying causes, including drug related issues, are discussed.

Stroke and renal dysfunction: are we always conscious of this relationship?

Cerebrovascular disease may represent an important clinical presentation of atherosclerosis in chronic kidney disease (CKD), and atherosclerosis is frequently encountered in CKD. In fact, kidney disease is now considered a risk factor for development of cardiovascular disease. Although guidelines for primary prevention of stroke have been recently published, CKD is hardly mentioned. Based on a series of available studies, we analyzed the relationship between reduced renal function, end-stage renal disease (ESRD), and stroke. Reduced renal function and risk of stroke appear to be related to the highest risk of patients on dialysis treatment. Primary and secondary prevention of stroke should be encouraged in participants with renal dysfunction.

In-hospital mortality in patients with renal dysfunction admitted for myocardial infarction: the Emilia-Romagna region of Italy database of hospital admissions

BACKGROUND

In-hospital mortality of patients with myocardial infarction (MI) in different European populations and renal dysfunction is variable. We aimed to evaluate in-hospital mortality for MI in chronic kidney disease (CKD), in end-stage renal disease (ESRD), and in subjects admitted for MI without renal dysfunction living in the Emilia-Romagna region of Italy.

METHODS

We considered all cases of MI (first event) recorded in the database of hospital admissions of the region Emilia-Romagna of Italy, from January 1999 to December 2009. The criterion for inclusion was the presence, as a first discharge diagnosis, of acute MI (International Classification of Diseases, 9th Revision, Clinical Modification). The Charlson comorbidity index (CCI), with the exclusion of CKD, was calculated. The outcome variable was in-hospital mortality for MI, and its association with comorbidities, CKD and ESRD, was analyzed.

RESULTS

During the considered period, 88,014 cases of first MI were recorded. The percentage of patients admitted with MI and died during hospitalization were higher in patients with ESRD (38.3 %) and CKD (16.5 %) than in those without renal dysfunction (14 %) (p < 0.01). In CKD and ESRD patients, data of in-hospital mortality for MI exhibited a twofold increase in the analyzed period. In-hospital mortality for MI was independently associated with age (OR 1.077, 95 % CI 1.075-1.080, p < 0.001), CCI excluding CKD (OR 1.101, 95 % CI 1.069-1.134, p < 0.001), cerebrovascular disease (OR 1.450, 95 % CI 1.349-1.557, p < 0.001), malignancy (OR 1.234, 95 % CI 1.153-1.320, p < 0.001), and ESRD (OR 4.137, 95 % CI 3.511-4.875, p < 0.001).

CONCLUSIONS

As for the Emilia-Romagna region of Italy, in-hospital mortality for MI is increasing over the last years, and mortality seems to be related with patients' comorbidities and presence of advanced stages of CKD.

Low molecular weight heparins and glomerular filtration rate: a report to be considered

Venous thromboembolism is a common condition and low molecular weight heparins (LMWHs) are widely used for its treatment. Chronic kidney disease (CKD) is also a frequent disease especially in subjects with comorbidities admitted to internal medicine wards. LMWHs are eliminated by the kidney and their half-life is increased in renal impairment. Based on a series of available studies we analyzed the relationship between treatment with LMWHs and different degrees of renal impairment including end-stage renal disease (ESRD). In order to reduce haemorrhagic risk, the LMWH dose should be reduced in CKD, even if reducing LMWH dose could impair drug effectiveness. Further studies relating glomerular filtration rate to LMWH effectiveness and side effects are required.

Evidence-based statin prescription for cardiovascular protection in renal impairment

Dyslipidemia is a well-known risk factor for cardiovascular disease in the general population, and the cardioprotective role of statins is well established. However, although cardiovascular disease is the major cause of morbidity and mortality in chronic kidney disease (CKD), the role of statin therapy is still under investigation. In CKD the atherosclerotic burden is high and pathophysiology of dyslipidemia is complex; however, the majority of large-scale statin trials excluded patients with CKD. Statins could have different effects in the different stages of CKD. Two large trials involving haemodialysis patients showed unfavourable results, whereas in renal transplant subjects as well as in early CKD subjects, statins reduced cardiovascular risk. The studies involving early CKD patients are post-hoc analyses of large trials and they showed that statins are more effective in secondary than in primary prevention. The aim of this study was to evaluate the effectiveness of statins for prevention of cardiovascular events by calculating the number of patients needed to be treated in different interventional trials. We conclude that dyslipidemia is a modifiable cardiovascular risk and statins appear to be an effective treatment especially in the early stages of CKD. Patients on renal replacement therapy could obtain an advantage from this treatment; however, the patient's clinical prognosis should be taken into account when evaluating treatment.

Relationship between N-terminal pro-B-type natriuretic peptide plasma levels and renal function evaluated with different formulae in older adult subjects admitted because of dyspnea

BACKGROUND

N-terminal pro-B-type natriuretic peptide (NT-proBNP) plasma levels are associated with congestive heart failure severity, and are an important diagnostic tool for assessing patients with acute dyspnea. Reduced renal function increases NT-proBNP concentrations, and therefore it might be a confounding factor in chronic kidney disease (CKD) patients.

OBJECTIVE

The aim of the present study was to relate NT-proBNP plasma levels to different stages of renal function assessed with different methods in older adult subjects admitted because of dyspnea.

METHODS

NT-proBNP plasma levels (Roche Diagnostic, Mannheim, Germany) were measured in 134 older adult patients (age: 80 ± 6 years) admitted to hospital because of dyspnea. Anthropometrics, anamnesis, and biochemical data were collected. Glomerular filtration rate (GFR) was evaluated with different equations, the 4 variables MDRD equations (GFR(MDRD186), GFR(MDRD175)), Mayo Clinic Quadratic formula (GFR(MAYO)), and the new CKD-EPI formula (GFR(CKD-EPI)). Patients were classified into the five K/DOQI stages of CKD and median NT-proBNP values were calculated evaluating their relationship with GFR.

RESULTS

Median NT-proBNP values were better stratified into the five K/DOQI stages by GFR(MAYO) (stage 1 (n = 10) 1,640 pg/ml vs. stage 2 (n = 61) 2,371 pg/ml vs. stage 3 (n = 42) 3,815 pg/ml vs. stage 4 (n = 18) 6,320 pg/ml vs. stage 5 (n = 3) 7,256 pg/ml, p = 0.017). However, similar results were obtained with the other formulae. NT-proBNP was negatively correlated with GFR as evaluated with all the different formulae (r -0.25 to -0.29; all p < 0.01). Multiple regression analysis confirmed the independent association between LnNT-proBNP and GFR.

CONCLUSION

NT-proBNP plasma levels progressively increase with worsening of renal function, and appear to be related to the five K/DOQI stages of CKD. For this purpose, GFR assessed with the GFR(MAYO) formula appears to better stratify NT-proBNP in older adult subjects. Renal function should be considered when interpreting NT-proBNP levels in older adult patients admitted for dyspnoea.

Estimation of renal function in patients with eating disorders

BACKGROUND

Renal function could be evaluated with different equations such as Cockcroft-Gault formula (C-G), Mayo Clinic Quadratic (MAYO) and four MDRD variables. Clinical application of different formulae in conditions with severe energy restriction or in obese subjects is still a matter of investigation.

METHOD

Renal function of 55 anorexia nervosa (AN) and 44 bulimia nervosa (BN) patients was evaluated with C-G formula for creatinine clearance calculation, and glomerular filtration rate (GFR) was estimated with MAYO and MDRD equations.

RESULTS

BN group was older and had higher weight, body mass index (BMI), body surface area than AN subjects; however, their mean BMI was in the normal range. AN group had better renal function than BN one when it was evaluated with MAYO and MDRD; on the contrary, it was worse when it was calculated with C-G. The results obtained from the three formulae were poorly correlated and Bland-Altman analysis confirmed that the results of the three formulae were not in agreement.

DISCUSSION

C-G is inaccurate when it is applied to obese or cachectic subjects. MDRD underestimates renal function in normal-high GFR. MAYO seems to be a good alternative to the other equations leading to correct classification of patients; therefore, it should be used to diagnose eating disorder subjects as renal insufficient.

Risk factors for metabolic syndrome in stable Italian renal transplant patients

BACKGROUND

The prevalence of metabolic syndrome (MS) in renal transplant recipients (RTR) is still under investigation.

METHODS

We performed a cross-sectional study of 107 stable RTR who were diagnosed as having MS defined by the Adult Treatment Panel III of the National Cholesterol Education Program (NCEP-ATP III) criteria. Anthropometric, clinical and biochemical data were collected.

RESULTS

Mean age of the patients studied was 55 ± 11 years (72 male, 35 female), dialysis duration before transplantation 30 ± 31 months, time since transplantation 42 ± 13 months. Mean serum creatinine was 1.68 ± 0.64 mg/dl; creatinine clearance by Cockcroft-Gault formula 53 ± 20 ml/min, glomerular filtration rate by 4-variable MDRD formula 48 ± 18 ml/min/1.73 m(2). Thirty-seven patients (34.5%) had MS. The MS patients had higher weight (76 ± 13 vs. 68 ± 12 kg, p = 0.0033), body mass index (BMI) (26 ± 4 vs. 24 ± 3 kg/m(2), p = 0.0025), waist circumference (101 ± 11 vs. 90 ± 11 cm, p < 0.0001), prevalence of BMI >25 k/m(2) (57 vs. 34%, p = 0.0254), prevalence of diabetes mellitus before transplantation (8 vs. 0%, p = 0.0157), glycaemia (104 ± 31 vs. 87 ± 11 mg/dl, p = 0.0002), and triglyceridaemia (225 ± 105 vs. 112 ± 35 mg/dl, p < 0.0001). They also showed lower levels of high-density lipoprotein cholesterol (48 ± 15 vs. 68 ± 17 mg/dl, p < 0.0001). Multiple logistic regression analysis showed that only BMI was independently associated with MS (OR 1.21, 95% CI 1.06-1.37, p = 0.0037).

CONCLUSIONS

MS according to NCEP-ATP III criteria appears to be present in about one-third of RTR, and even small increases in BMI above 25 kg/m(2) may determine the presence of MS in these patients. Therefore the preventive value of lifestyle modifications is very important for such patients, in order to strictly maintain body fat accumulation within the normal range.

Elevated NT-proBNP levels should be interpreted in elderly patients presenting with dyspnea

BACKGROUND

B-type natriuretic peptide (BNP) assay is a useful tool in order to diagnose dyspnea due to congestive heart failure (CHF). On the other hand many other diseases could affect BNP levels. The aim of this study was to investigate a group of elderly patients admitted to an Internal Medicine unit because of dyspnea.

PATIENTS AND METHODS

NT-proBNP was assessed in 132 consecutive patients aged 80±6 years because of dyspnea. History data, anthropometric, clinical and biochemical parameters were collected. Renal function was assessed by the CKD-EPI formula. Diagnosis of pulmonary disease such as infections and chronic obstructive disease was considered and was analyzed as a single parameter. Statistical analysis was carried out dividing patients with high NT-proBNP from those with normal NT-proBNP according to the Januzzi cut-off.

RESULTS

NT-proBNP was higher than the normal reference values in 68.7% of patients and its levels increased in the 5 different stages of chronic kidney disease. Subjects with high NT-proBNP had lower haemoglobin levels (11.6±2.1 vs 12.8±1.9 g/dl, p=0.003), higher prevalence of atrial fibrillation (54.3 vs 25%, p=0.001), and lower prevalence of pulmonary diseases (29.7 vs 57.5%, p=0.005). Logistic regression analysis showed that NT-proBNP levels were independently associated with haemoglobin (OR 1.307 95% CI 1.072-1.593, p=0.008) and pulmonary diseases (OR 3.069 95% CI 1.385-6.801, p=0.006).

CONCLUSIONS

A disease different from CHF appears to affect NT-proBNP plasma levels. Therefore, determination of its levels does not seem to help clinicians in the definition of dyspnea in elderly people with different comorbidities.

Detection of urinary abnormalities in a community from northern Italy based on the World Kidney Day screening program

BACKGROUND

Chronic kidney disease (CKD) is a worldwide health problem, and promotion of the World Kidney Day has improved general population education and awareness of renal illnesses aimed at ameliorating disease prevention. The Kidney Day was also an opportunity for us to investigate risk factors for CKD in an Italian population.

PATIENTS AND METHODS

A total of 1,341 subjects from the general population living in the area of Ferrara, a town in the northeast of Italy, aged 50-70 years, were investigated. From each participant age, sex, smoking status, current antihypertensive medications, hypercholesterolemic and diabetic status, body mass index (BMI), waist circumference and blood pressure (BP) were obtained. All subjects underwent dipstick urinalysis for the evaluation of proteinuria, hematuria and leukocyturia.

RESULTS

Fifteen percent of patients were diabetics, and 20% were smokers. Mean BMI was 26.9 ± 4.3 kg/m(2), mean systolic BP was 133.7 ± 18.7 mmHg and mean diastolic BP 78.1 ± 9.9 mmHg. A total of 828 participants were not taking any antihypertensive drugs. In 24% of subjects, we found proteinuria, in 18% hematuria and in 16% leukocyturia. Proteinuria was significantly associated with age and diabetes, hematuria was associated with age, female sex and smoking status, and leukocyturia was associated with age and female sex.

CONCLUSIONS

Urinary abnormalities are common in general population, and in many cases, various abnormalities overlap. These abnormalities could be associated with cardiovascular risk factors. We believe that our initiative, based on the experience of the World Kidney Day, could increase the awareness of general practitioners and general population of the risks of renal conditions.

Pulmonary hypertension in dialysis patients: a cross-sectional italian study

Introduction. Pulmonary hypertension (PHT) is an independent predictor of mortality. The aim of this study was to relate pulmonary arterial pressure (PAP) to the cardiovascular status of dialysis patients. Methods. 27 peritoneal dialysis (PD) and 29 haemodialysis (HD) patients (60 ± 13 years, 37 males, dialysis vintage was 40 ± 48 months) had PAP measured by echocardiography. Clinical and laboratory data of the patients were recorded. Results. PHT (PAP > 35 mmHg) was detected in 22 patients (39%; PAP 42 ± 6 mmHg) and was diagnosed in 18.5% of PD patients and 58.6% of HD patients (P = .0021). The group of subjects with PH had higher dialysis vintage (63 ± 60 versus 27 ± 32 months, P = .016), interdialytic weight gain (2.1 ± 1 versus 1.3 ± 0.9 Kg, P = .016), lower diastolic blood pressure (73 ± 12 versus 80 ± 8 mmHg, P = .01) and ejection fraction (54 ± 13 versus 60 ± 7%, P = .021) than the patients with normal PAP. PAP was correlated positively with diastolic left ventricular volume (r = 0.32, P = .013) and negatively with ejection fraction (r = −0.54, P < .0001). PHT was independently associated with dialysis vintage (OR 1.022, 95% CI 1.002–1.041, P = .029) and diastolic blood pressure (OR 0.861, 95% CI 0.766–0.967, P = .011). Conclusions. PHT is frequent in dialysis patients, it appears to be a late complication of HD treatment, mainly related to cardiac performance and cardiovascular disease history.

Relationship between major adverse cardiac events and angiographic findings in dialysis patients

BACKGROUND

In dialysis patients, coronary angiography (CA) predicts major adverse coronary events (MACE) better than non-invasive tests. The aim of this study was to investigate in such patients the relationship between coronary atherosclerotic damage shown by angiography and MACE, during an average follow-up period of more than 5 years.

PATIENTS AND METHODS

Coronary angiography was performed in 63 dialysis patients (mean age 56 ± 12 years, 49 men); 37 subjects awaiting kidney transplantation had no history of cardiac disease, whereas the remaining 26 patients had clinical evidence of coronary artery disease (CAD). During a follow-up period of 62 ± 20 months (range 12-109), all the MACE were recorded. Statistical analysis was carried out by dividing the patients into two groups, those who had MACE (MACE group) and those who were free of cardiac events (FCE group). Severe CAD on CA was defined as luminal stenosis ≥ 75% in at least one vessel. Logistic regression analysis and Cox regression analysis were carried out in order to evaluate which variable was associated with MACE.

RESULTS

At the end of follow-up, 17 subjects had MACE and severe CAD was shown in the epicardial arteries of 31 patients (49%). Compared to the FCE group, the MACE group had older age (65 ± 10 vs 53 ± 11 years, P = 0.002), lower diastolic blood pressure (79 ± 7 vs 85 ± 7 mmHg, P = 0.0037), higher prevalence of CAD (82 vs 30%, P = 0.0002) and cerebrovascular disease (41 vs 15%, P = 0.0278). Coronary artery damage was higher in the MACE group than in the FCE group. Logistic and Cox regression analyses showed that age was the only variable independently associated with MACE (OR 1.109 95% CI 1.022-1.204, P = 0.0133, hazard ratio 1.066 95% CI 1.010-1.125, P = 0.02, respectively). After removal of age from the model, MACE were independently associated with haemodynamic stenosis of coronary arteries (OR 7.429 95% CI 1.829-30.173, P = 0.005, hazard ratio 5.992 95% CI 1.655-21.698, P = 0.006, respectively). Event-free survival was much better in the 37 renal transplant candidates with no history of CAD than in the 26 patients who had clinical evidence of CAD.

CONCLUSIONS

This observational study confirms that in dialysis patients coronary atherosclerotic damage shown by angiography is strongly related to MACE and that age and severe CAD are major risk factors for MACE.

Posterior reversible encephalopathy syndrome in an 87-year-old woman with Escherichia coli bloodstream infection

We present the case of an 87-year-old woman with history of hypertension, hypercholesterolemia, ischemic heart diseases, urinary tract infections, and cerebrovascular disease who experienced a transient clinical picture characterized by confusion, lethargy, and acute renal dysfunction in the course of urinary tract infection with Escherichia coli bacteremia. Escherichia coli bloodstream infection was associated with brain computed tomography (CT) and magnetic resonance imaging (MRI) patterns in which the lesion distribution was consistent with posterior reversible encephalopathy syndrome (PRES). Diagnosis of PRES was confirmed by demonstration of vasogenic edema on apparent diffusion coefficient (ADC) maps and near-complete resolution of clinical manifestations at discharge.

[Unexpected cause of acute renal failure in an 85-year-old woman]

Acute postinfectious glomerulonephritis (APIGN) is usually diagnosed in young people, while in elderly people rapidly progressive forms appear to be the most important glomerular disease causing acute renal failure. We report on a 85-year-old woman with acute renal failure due to APIGN. An 85-year-old woman with a history of hypertension and cerebrovascular disease was hospitalized because of diarrhea and syncope associated with atrial fibrillation. She was found to have left lower lobe pneumonia. Serum creatinine was over 2 mg/dL. Fluids were given, without improvement in renal function but leading to volume overload instead. Within a few days serum creatinine reached a level of 5.4 mg/dL with reduction of urine output despite administration of diuretics. The patient developed hematuria and purpura of the feet. Serum IgA was high and the urine sediment showed casts. Methylprednisolone 125 mg i.v. was given for three days followed by prednisone 50 mg daily. The patient's clinical condition gradually improved and serum creatinine decreased to 1.9 mg/dL. Renal biopsy showed APIGN. During hospitalization, three major complications occurred: hemodynamic instability due to atrial fibrillation, Clostridium difficile colitis and urinary tract infections due to Enterococcus faecalis and Candida tropicans, all successfully treated. APIGN should be taken into account as a cause of acute renal failure in hospitalized elderly patients with many comorbidities.

Pseudostenosis of axillary vein due to adduction of the upper limb

Axillary vein stenosis is a well-documented complication in hemodialysis (HD) patients, but in adipose or athletic subjects, pseudostenosis of the axillary vein can be detected. We report a case of pseudostenosis in a fit dialysis patient who underwent phlebography of the right upper limb, performed to create a new vascular access (VA). The investigation demonstrated that the axillary vein appeared sharpened with a reduced lumen. Based on this exam, angioplasty of the right axillary vein was planned. The new phlebographic study, performed abducting the arm, demonstrated that the previously marked stenosis of the axillary vein disappeared. Our case illustrates how the reduction of the axillary vein lumen was secondary to ""muscular print"" and was present only if the arm was adducted. In uremic patients, the squeezing of the vascular nervous bundle of the upper limb is possible in fit patients at the time of phlebography, an examination that should be performed with the arm both in adduction and abduction.

The relationship between carotid and coronary atherosclerotic damage in dialysis patients

BACKGROUND

Data relating carotid ultrasound (CU) to atherosclerotic damage evaluated by coronary angiography in hemodialysis patients are scarce.

METHODS

We carried out a cross-sectional study in 33 uremic subjects (age 55 +/- 12 years, 22 male, 7 diabetic), who have been on dialysis for 41 +/- 48 months (range 2-192). Twenty-two underwent a coronary angiography in order to complete clinical evaluation for inclusion on the kidney transplantation waiting list, and 11 because of coronary artery disease (CAD); Gensini's score was calculated. Intima-media thickness (IMT) and presence of plaques were related to the degree of coronary stenosis and to cardiovascular risk factors. Patients were divided into two groups depending on mean IMT (group 1 IM <or= 0.9 mm, n=18; group 2 IMT>0.9 mm, n=15).

RESULTS

Group 2 was older (60 +/- 8 vs 50 +/- 12 year, p=0.01), had higher frequency of CAD (53 vs 16%, p=0.02) and had higher prevalence of coronary artery stenosis >or= 75% in the right (60 vs 22%, p=0.02), left anterior descending (46 vs 16%, p=0.06) and left circumflex coronary arteriers (60 vs 11%, p=0.05) than group 1. IMT was not related to the degree of CAD evaluated by Gensini's score. IMT sensibility and specificity in detecting the presence of hemodynamically significant coronary stenosis were 64% and 68%, respectively. Coronary narrowing was correlated with the degree of stenosis of common, internal and external carotid arteries (Spearman's rank correlation coefficient). During two years of follow-up, six major cardiac events were recorded and they were related to Gensini's score.

CONCLUSIONS

In uremic patients, ultrasonographic evaluation of carotid arteries is a simple, noninvasive examination that could be a helpful tool in detecting coronary atherosclerotic damage, but IMT does not appear to add more information regarding risk stratification of CAD.

Displacement of the inferior vena cava as a factor limiting catheter performance in long-term hemodialysis patients

We report a case of a lady affected by autosomal dominant polycystic kidney disease who had been on hemodialyis for 24 years. She has exhausted all options for arterious-venous fistula. The presence of an acquired anatomical abnormality was an obstacle in order to get appropriate blood flow from standard tunnelled femoral catheters. The enlarged right kidney was pushing the inferior vena cava to the left side of the abdomen, and the abnormality was demonstrated by phlebography. Only after placing a cuffed catheter 53 cm long in her left femoral vein we could dialyze efficiently. Venography is mandatory before placing a cuffed catheter especially in uremic patients with long history of access failure, because it saves costs.