Association of Myeloperoxidase Gene Polymorphism With Iron Deficiency Anemia in Turkish Children.

This study was performed to investigate the gene polymorphisms of the myeloperoxidase (MPO) enzyme and to determine whether MPO gene polymorphisms influence the response to iron therapy in pediatric patients with iron deficiency anemia (IDA). In this case-control study, 50 Turkish children with IDA and 50 healthy controls were enrolled. Three MPO gene alleles were selected for genotyping in the study: GG, AG, and AA. The relationships of alleles with IDA were analyzed and compared in patients and controls. Pretreatment and posttreatment laboratory parameters and gene polymorphisms were compared in the patient group. There was a significant difference between patients with IDA and controls regarding genotype frequencies of the AA, GG, and AG alleles (P=0.005). However, the AG allele was found to be associated with variations in hemoglobin, red blood cell, hematocrit, mean corpuscular volumes, and mean corpuscular Hb concentrations levels. The frequency of AA, GG, and AG alleles of the MPO gene was potentially associated with changes in iron metabolism and the AG allele led to variations in various hemogram parameters.

Serum oxidative stress parameters and paraoxonase-1 in children and adolescents exposed to passive smoking.

BACKGROUND: Exposure to secondhand smoke is too common in many countries. The mechanism of the detrimental effects of passive smoking on childhood health, however, is poorly described. The purpose of this study was therefore to examine the effect of passive smoking on total antioxidant status (TAS), total oxidant status (TOS), and paraoxonase-1 in children compared with healthy non-passive smokers. METHODS: This study included 40 children and adolescents passively exposed to cigarette smoke (as verified on urine cotinines) and 40 age- and gender-matched healthy controls not regularly exposed to cigarette smoke. TAS, TOS, and paraoxonase-1 were all measured, and the oxidative stress index (OSI) calculated for each child to determine the degree of oxidative stress. RESULTS: Age and gender distribution were not statistically different between the two groups (P = 0.619 and 0.712, respectively). Urine cotinine/creatinine was significantly higher in the passive smoking group (127.89 ± 57.14 ng/mL) compared with the controls (5.05 ± 16.66 ng/mL; P < 0.001). TAS was not different between the two groups (P = 0.767), but TOS and OSI were significantly higher for the passive smoke-exposed children (P < 0.001), and serum paraoxonase-1 was significantly lower than in the controls (P = 0.047). CONCLUSIONS: Secondhand smoke exposure is associated with increased oxidative stress and decreased paraoxonase-1 without any change in antioxidant status.

Oxidative Stress Status in Childhood Obesity: A Potential Risk Predictor.

BACKGROUND Childhood obesity characterized by excessive fat in the body is one of the most serious health problems worldwide due to the social, medical, and physiological complications. Obesity and associated diseases are triggering factors for oxidative stress and inflammation. The aim of this study was to explore the possible association between childhood obesity and inflammatory and oxidative status. MATERIAL AND METHODS Thirty-seven obese children and 37 healthy controls selected from among children admitted to BLIND University Paediatrics Department were included in the study. Anthropometric measurements were performed using standard methods. Glucose, lipid parameters, CRP, insulin, total oxidant status (TOS), total anti-oxidant status (TAS) levels, and total thiol levels (TTL) were measured in serum. HOMA index (HOMA-IR) were calculated. The differences between the groups were evaluated statistically using the Mann-Whitney U test. RESULTS Body mass index was significantly higher in the obese group (median: 28.31(p<0.001). Glucose metabolism, insulin, and HOMA-IR levels were significantly higher in the obese group (both p<0.001). Total cholesterol, HDL cholesterol, LDL cholesterol, and triglyceride levels were significantly higher in the obese group (p<0.001). TAS (med: 2.5 µmol Trolox eq/L (1.7-3.3)) and TOS (med: 49.1 µmol H2O2 eq/L (34.5-78.8)) levels and TTL (med: 0.22 mmol/L (0.16-0.26)) were significantly higher in the obese group (p=0.001). CRP levels showed positive correlation with TOS and negative correlation with TTL levels (p=0.005, r=0.473; p=0.01, r=-0.417; respectively). TTL levels exhibited negative correlation with TOS levels (p=0.03, r=-0.347). CONCLUSIONS In conclusion, obese children were exposed to more oxidative burden than children with normal weight. Increased systemic oxidative stress induced by childhood obesity can cause development of obesity-related complications and diseases. Widely focussed studies are required on the use of oxidative parameters as early prognostic parameters in detection of obesity-related complications.

The role of vitamin D receptor gene polymorphisms in Turkish infants with urolithiasis.

Polymorphisms in the vitamin D receptor (VDR) gene have recently been reported to be associated with urinary calculi in pediatric and adult cases, but no studies have looked at the youngest period of life. The purpose of this study was to investigate the role of VDR gene polymorphisms in infantile urolithiasis in a Turkish population. We compared a study group of 104 infants (55 girls and 49 boys, mean age 6.94 ± 3.81 months) with a control group of 96 infants (51 girls and 45 boys, mean age 7.51 ± 3.23) to evaluate their demographics and metabolic risk factors. PCR-based restriction analysis of the polymorphisms on the VDR gene (BsmI and TaqI) showed statistically significant differences between study and control groups (p = 0.001 and 0.043, respectively). In addition, the prevalence of the BsmI genotype was significantly different between the hypercalciuric and normocalciuric stone formers (p = 0.007). Allelic frequencies were similar between the urolithiasis and control groups (p > 0.05). The B allele of BsmI and the A allele of ApaI were more prevalent in the hypercalciuric stone formers than in the normocalciuric stone formers (p = 0.018 vs.0.036, respectively). These results suggest that the BsmI and TaqI VDR genotypes could be candidate genes leading to infantile urolithiasis.

Determination of early urinary renal injury markers in obese children.

BACKGROUND: Obesity is an important health issue, the prevalence of which is increasing in childhood. The aim of this study was to examine urinary renal injury markers in order to determine the renal effect of obesity and its comorbidities in a pediatric population. METHODS: Eighty-four obese children and 64 healthy control subjects were enrolled in the study. We checked their urine using N-acetyl-beta-D-glucosaminidase (NAG), neutrophil gelatinase-associated lipocalin (NGAL), kidney injury molecule-1 (KIM-1), and microalbumin as renal injury markers. Associations of renal damage markers with hypertension, an impaired glucose tolerance test, and insulin resistance were assessed. RESULTS: Obese individuals had higher urinary NAG and KIM-1 values compared to those of healthy controls (p = 0.027, p = 0.026). There was no difference in urinary NGAL between obese and lean subjects (p = 0.885). Urinary renal injury markers were not statistically different in the obese group when checked for impaired glucose tolerance, insulin resistance, and hypertension (p > 0.05). CONCLUSIONS: This study shows that urinary NAG and KIM-1 could be used as a screening method for detection of early renal damage in obese children.

The evaluation of physiological and biochemical parameters and the autonomic nervous systems of children with breath-holding spells.

AIM: The aim of this study was to investigate the physiological and biochemical parameters of children who are experiencing breath-holding spells (BHS) and to compare the function of their autonomic nervous systems with those of healthy children. PATIENTS AND METHODS: A total of 30 children (age range, 6 months-5 years) admitted for BHS were included in the study. The control group consisted of 30 age-matched and gender-matched healthy children. Each participant underwent a detailed physical examination as well as a laboratory evaluation. Echocardiography, electrocardiography (ECG), and electroencephalography were performed in the study group. The pilocarpine eye test was administered to each participant to detect autonomic dysfunction. RESULTS: No statistically significant differences were found between the groups for mean age, gender, and anthropometric measurements, nor for the biochemical parameters, including hemoglobin concentration, hematocrit, serum iron, transferrin saturation, ferritin, vitamin D, and vitamin B12 levels (p = 0.05). Compared with the control group, the study group showed significantly abnormal hypersensitivity of pupils after instillation of pilocarpine into their eyes (p = 0.01). CONCLUSION: Autonomic dysfunction existed in the children with BHS, but no correlation was found between BHS and deficiencies of iron, vitamin D, or vitamin B12.

Is oxidative stress related to childhood urolithiasis?

BACKGROUND: Urolithiasis is a common condition in pediatric populations in Turkey. The role of oxidative stress in renal stone formation in pediatric patients has not been reported to date. The aim of this study was to assess oxidative stress in childhood urolithiasis. METHODS: Seventy-four children diagnosed with urolithiasis and 72 healthy control subjects were enrolled in the study. Kidney stone formers were evaluated by analysis of metabolic conditions related to urolithiasis, such as hypercalciuria, hyperoxaluria, hypocitraturia and hyperuricosuria. Urine total antioxidant status (TAS), and total oxidant status (TOS) were measured, and oxidative stress index (OSI) was calculated as an indicator of the degree of oxidative stress. RESULTS: Among the stone formers, metabolic analyses revealed that 30 % had hypercalciuria, 45 % had hypocitraturia, 6 % had hyperoxaluria and 40 % had hyperuricosuria. Elevated levels of the renal tubular damage marker urinary N-acetyl- beta-D-glucosaminidase (NAG) was elevated in 25 % of the patient group, but microalbuminuria was not detected. Total oxidant status and total antioxidant status were significantly higher in stone formers than in the controls (p = 0.023 and 0.004, respectively). In addition, urinary NAG was significantly correlated with TOS (r = 0.427, p = 0.019). CONCLUSIONS: The results of this study show that oxidative stress may play an important role in the pathogenesis of pediatric stone formers.

Serum paraoxonase 1 activity and oxidative stress in pediatric patients with pulmonary tuberculosis.

OBJECTIVES: The aim of this study was to determine the oxidative stress and paraoxonase 1 (PON1) levels in children with pulmonary tuberculosis (TB) compared to healthy controls, and to examine the association of demographical with oxidative stress. SUBJECTS AND METHODS: Forty children diagnosed with pulmonary TB and 40 age- and gender-matched healthy controls were enrolled in the study. Serum total antioxidant status (TAS), total oxidant status (TOS) and PON1 levels were measured. The oxidative stress index (OSI) was calculated to indicate the degree of oxidative stress. RESULTS: The TAS levels were lower (1.73 ± 0.5 vs. 2.54 ± 1.2 µmol Trolox Eq/l) while TOS levels were significantly higher (26.9 ± 14.4 vs. 13.4 ± 7.7 µmol H2O2 Eq/l) in the TB group than in the controls (p < 0.001). The OSI was significantly higher in the TB group than in the controls (21.2 ± 5.1 vs. 6.5 ± 4.9 units, p = 0.006). Serum PON1 levels were significantly lower in the TB group than in the controls (14.2 ± 13.2 vs. 28.4 ± 17.3 U/l, p < 0.001). The lower PON1 levels correlated with TAS and OSI levels but not with anthropometric parameters (r = 0.264, p = 0.018 and r = -0.255, p = 0.023, respectively). CONCLUSION: The TOS and OSI levels were higher and the TAS and PON1 levels were lower in pediatric patients with pulmonary TB when compared to healthy controls. This indicates greater oxidative stress in the patients.

Characteristic features of migraine in schoolchildren and adolescents and its relationship with autonomic nervous system disorders.

OBJECTIVE: The studies about autonomic nervous system (ANS) disorders in adult migraineurs show conflicting results with limited data on ANS function in childhood and adolescence. This study aimed to investigate ANS function in childhood migraine. PATIENTS AND METHODS: The migraine and control groups consisted of 35 migraineurs and 30 healthy children, respectively. In both groups, heart rate interval variation (RRIV) and sympathetic skin response (SSR) were used as noninvasive ANS function tests. RESULTS: No significant differences in age and gender distribution were found between the study and control groups. A family history of migraine was seen in 65% patients in the study group and 20% in the control group. The duration, quality, frequency, and location of pain were variable; only 14.1% of the patients had sensory and visual aural symptoms. There was neither a significant difference in RRIV and SSR between migraine and control groups (p > 0.05) nor in heart rate responses to deep breathing (p = 0.83). The mean amplitude of SSR in children with migraine was smaller than that in the control group, but it did not reach a level of statistical significance. CONCLUSIONS: In children with migraine, our results demonstrate no abnormal ANS function related to either the sympathetic or the parasympathetic nervous system.

The clinical and biochemical presentation of vitamin D deficiency and insufficiency in children and adolescents.

AIM: To evaluate the clinical and biochemical findings of the children and adolescents with vitamin D deficiency and insufficiency in order to determine the clinical and biochemical presentation differences between age groups. METHODS: This retrospective study included a review of medical reports of 543 patients (aged between 1-17 years) who were referred to our hospital between October 2011 and May 2012 with symptoms related to vitamin D deficiency or insufficiency. The patients were divided into four groups by age: 1-3 years (Group 1), 4-6 years (Group 2), 7-11 years (Group 3) and 12-17 years (Group 4). Patients diagnosed with vitamin D deficiency or insufficiency were evaluated as to their clinical and biochemical findings. RESULTS: Gender distribution were not statistically different between the four groups. The mean ages of Groups 1-4 were 1.9±0.7, 5.1±0.9, 8.9±1.3, 13.1±1.1, respectively. Major complaints on admission were muscle weakness (91%), low weight gain (failure to thrive) (89%), head deformity (frontal bossing) (35.6%), bone deformity (enlargement of wrist and ankles) (29.7%) for Group 1. Muscle weakness (76%) and low weight gain (failure to thrive) (68%) for Group 2. Leg and chest pain were the major symptoms in Group 3 (57% and 28%, respectively) and in Group 4 (26% and 55%, respectively) as well as high rates of obesity (31% and 63%). The biochemical findings of vitamin D deficiency mostly appeared in the first group who developed vitamin D deficiency due to the lack of vitamin D supplementation. However, in older children, the majority of the patients had low 25 hydroxyvitamin D (25 OHD) values without evidence of biochemical findings of osteomalacia. CONCLUSION: Depending on the degree of deficiency and insufficiency, and the age of the patients, the clinical and biochemical findings varied widely. Children under the age of 3 who either never received vitamin D supplementation or who had been receiving supplementation that was stopped too early were at a greater risk for developing clinically and biochemically proved vitamin D deficiency. In older children, low vitamin D levels mostly resulted in subtle complaints without abnormal biochemical findings.

Skin temperature measurement using an infrared thermometer on patients who have been exposed to cold.

BACKGROUND: The aim of this study was to determine if the skin temperature of febrile children is affected by the child's exposure to cold outdoor temperatures immediately prior to the taking of that temperature. METHODS: A total of 150 febrile and non-febrile children (aged 3-10 years) who had walked to the hospital's pediatric emergency department and were thus exposed to outside cold weather were enrolled in the study. Using infrared thermometry, forehead and chest skin temperatures were simultaneously measured every 2 min during the first 14 min after presentation. Temperatures were recorded and differences between the two measurements were calculated. RESULTS: By the fifth evaluation (10 min from the first reading), skin temperatures from forehead and chest had equalized. CONCLUSION: Determination of fever from the body parts that had been exposed to cold environmental conditions may cause contradictory results if taken while the child is still chilled from exposure to the cold. For accuracy, children should be acclimated to the indoor temperature before taking body temperature readings. Acclimation takes at least 10 min after coming in from cold weather outside.

Investigation of irisin's role in pubertal onset physiology in female rats.

OBJECTIVE: The timing of pubertal development is closely related to metabolic status and energy reserves. It is thought that irisin, which is involved in the regulation of energy metabolism and is shown to be present in the hypothalamo-pituitary-gonadal (HPG) axis, may play a role in this process. In our study, we aimed to investigate the effect of irisin administration on pubertal development and HPG axis in rats. DESIGN-METHODS: 36 female rats were included in the study were divided into 3 groups: 100 ng/kg/day irisin treatment group (irisin-100), 50 ng/kg/day irisin treatment group (irisin-50), and control group. On the 38th day, serum samples were taken to determine levels of luteinizing hormone (LH) and follicle stimulating hormone (FSH), estradiol and irisin. Brain hypothalamus samples were taken to determine levels of pulsatile gonadotropin-releasing hormone (GnRH), kisspeptin, neurokinin-B, dynorphin (Dyn), and makorin ring finger protein-3 (MKRN3). RESULTS: Vaginal opening and estrus were seen firstly in the irisin-100 group. At the end of the study, the highest rate of vaginal patency was found in the irisin-100 group. Hypothalamic protein expression levels of GnRH, NKB and Kiss1 in homogenates; serum FSH, LH, and estradiol levels were the highest in the irisin-100 group, followed by the irisin-50 and control groups, respectively. Ovarian sizes were significantly greater in the irisin-100 group compared to the other groups. The hypothalamic protein expression levels of MKRN3 and Dyn were the lowest in the irisin-100 group. CONCLUSIONS: In this experimental study, irisin triggered the onset of puberty in a dose-dependent manner. Irisin administration caused the excitatory system to dominate in the hypothalamic GnRH pulse generator.

Assessment of motor development using the Alberta Infant Motor Scale in full-term infants.

The Alberta Infant Motor Scale (AIMS) is a well-known, norm-referenced scale that evaluates the gross motor development of children from birth to 18 months. The aim of the study was to compare the Canadian norms with the AIMS scores of a Turkish sample of infants, and to investigate whether the current reference values of the AIMS are representative for Turkish full-term infants. The study was conducted with 411 Turkish infants of both sexes (195 girls and 216 boys), born with gestational age 38 weeks and older, weighing ≥2500 g at birth. Motor performance of all the cases at different ages were assessed with the AIMS which was used by a physiotherapist. The mean AIMS scores of Turkish infants were compared with the norm values of the original AIMS established in a Canadian sample of infants. The results showed no statistically significant differences between the AIMS scores of Turkish and Canadian infants during the first 18 months of life except at 0- < 1 and 2- < 3 months of age. The AIMS scores were significantly lower in Turkish infants than in Canadian infants at 0- < 1 (p=0.025) and 2- < 3 (p=0.042) months of age. In conclusion, the AIMS can be used in Turkish children to assess gross motor development, especially after 4 months of age. However, this paper was presented as a preliminary study to compare AIMS results between Turkish and Canadian infants, and further studies are needed to realize the Turkish validation of AIMS.

Serum catalase, thiol and myeloperoxidase levels in children passively exposed to cigarette smoke.

BACKGROUND: Free radicals found in cigarette smoke can harm all tissues and cellular structures in the human body. Passive smoking increases free radical production, leads to the depletion of antioxidants and increases oxidative stress which causes lipid peroxidation. Many studies have been conducted to determine the effects of passive smoking on antioxidant enzymes and lipid levels in adults, but pediatric studies on this topic are few. In our study, we compared the levels of antioxidants, oxidants, total and LDL cholesterol in children exposed to passive cigarette smoking with a healthy control group that was not exposed to passive smoking. METHODS: A total of 41 children (4-17 years of age, 24 girls and 17 boys) exposed to passive smoking and 18 healthy girls and 12 healthy boys were included in this study. Secondhand smoking was confirmed via measurement of the cotinine/creatinine ratio. Various sociodemographic characteristics of patients were recorded. The levels of catalase, thiol, myeloperoxidase were measured to determine the antioxidant and oxidant levels in children, while the levels of total cholesterol and LDL cholesterol were measured to determine the alterations in lipid profile. RESULTS: The groups were similar in regard to demographic characteristics. Myeloperoxidase levels were significantly higher in the passive cigarette smoking group compared to the non-exposure group; however, catalase and thiol levels were similar. In regard to lipid profile, the levels of total cholesterol and LDL cholesterol were also similar in those with and without exposure to passive smoking. CONCLUSIONS: Our findings suggest that the effects of passive smoking initially influence oxidants (MPO), but not antioxidants (thiol and catalase). However, it is apparent that passive smoking adversely affects oxidative balance in children and this may lead to the development of various diseases which could cause significant morbidity and mortality.

Risk factors for childhood obesity: Do the birth weight, type of delivery, and mother's overweight have an implication on current weight status?

BACKGROUND: The aim of this study was to identify risk factors, including the type of delivery, breastfeeding and its duration, birth weight, the timing of solid food introduction, the mother's education level at birth, and smoking status during pregnancy, that are associated with obesity in children living in Istanbul. METHODS: This study involving 4990 healthy children aged 2-14 years, at an outpatient clinic in a tertiary care hospital from June 2012 to July 2014. RESULTS: The overall rates of overweight and obesity in children were 13.1% and 7.8%, respectively. Results demonstrated that 44.5% of children were delivered by caesarean section. In all age groups, 7.8% of children delivered by caesarean section were obese compared with 7.9% of children born vaginally. No significant association between caesarean section delivery and obesity in childhood was found in our study [odds ratio (OR)=0.98, 95% confidence interval (CI)=0.64-2.87, P=0.454]. There was also no association between duration of breastfeeding and the introduction of solid foods before 4 months or after 6 months of age and childhood obesity (OR=0.95, 95% CI=0.69-1.3, P=0.771; OR=0.99, 95% CI=0.64-1.53, P=0.261). Regression analyses revealed that children with birth weights greater than 3801 g or those with maternal body mass index (BMI) equal to or greater than 30 had an increased risk of being obese or overweight (OR=1.78, 95% CI=1.19-2.65; OR=3.95, 95% CI=1.94-5.81). CONCLUSIONS: This study demonstrated that increased birth weight and maternal BMI are significant risk factors for obesity in children living in Istanbul, Turkey. No relation between caesarean section delivery and childhood obesity was found in this study.

Cathelicidin (LL-37) and human ß2-defensin levels of children with post-infectious bronchiolitis obliterans.

INTRODUCTION: The antimicrobial peptides (AMPs) human ß-defensins and cathelicidin (LL-37) are key factors in innate and adaptive immune responses of the respiratory tract and play an important role in many respiratory diseases. No data are available in the literature about the levels of these AMPs in paediatric patients with post-infectious bronchiolitis obliterans (BO). This study aimed to determine human ß-defensin 2 (hBD2) and LL-37 levels and compare between post-infectious BO patients and the control group. METHOD: The patients diagnosed with post-infectious BO between September 2012 and 2013 and age- and-gender matched healthy controls were enrolled in this multi-center study. Serum hBD2 and LL37 levels were determined with the enzyme-linked immunosorbent assay method. RESULTS: Sixty-three post-infectious BO patients and 65 healthy children (median age 73 ± 55 and 78.74 ± 36.32 months, respectively) were enrolled in the study. The mean of hBD2 levels in patients and the control group were 1.06 ± 0.24 and 0.67 ± 0.72 ng/mL, respectively (P < 0.001). The mean of LL-37 levels in patients and the control group were 72.13 ± 29.06 and 50.10 ± 21.98 ng/mL, respectively (P < 0.001). No correlation was found between these AMPs levels and chronological age, age at the time of diagnosis, gender, Z-scores of weight and length, hospitalization numbers, the disease history before diagnosis and 25-OH D vitamin levels. CONCLUSION: This is the first study to demonstrate the higher levels of serum hBD2 and LL-37 levels in paediatric post-infectious BO patients. These AMPs may have important roles in the immune systems and pathogenesis of these patients.

The relation of urinary bisphenol A with kisspeptin in girls diagnosed with central precocious puberty and premature thelarche.

BACKGROUND: Bisphenol A (BPA) is known as an endocrine disruptor and it is supposed to have a role on the development of central precocious puberty (CPP). Kisspeptin, a hypothalamic peptide, is a neuromodulator of gonadotropin releasing hormone and it has an important role on regulation of the onset of puberty. The BPA levels in girls with CPP and premature thelarche (PT) and its relation with kisspeptin levels were investigated. METHODS: Twenty-eight girls with CPP, 28 girls with PT and 22 prepubertal girls as a control group were enrolled to the study. Urinary BPA and serum kisspeptin levels were compared in the groups. Bivariate correlations were performed to evaluate the relations of BPA with kisspeptin and estradiol. RESULTS: There was no statistical difference between groups regarding BPA levels. Serum kisspeptin levels were higher in CPP group than controls [306.56 (interquartile range (IQR), 175.63-504.66) vs. 157.62 (IQR, 55.61-285.00) p: 0.008]. There were no correlations between BPA and kisspeptin levels (r: 0.088, p: 0.391) and between BPA and estradiol (r: -0.171, p: 0.144). CONCLUSIONS: The BPA levels did not differentiate between groups and it seems that the exposed amount of BPA in daily life did not affect kisspeptin levels in girls with CPP and PT.

Renal tubular function and urinary N-acetyl-ß-d-glucosaminidase and kidney injury molecule-1 levels in asthmatic children.

BACKGROUND: Asthma is a chronic inflammatory disorder of the airways which results in chronic hypoxia. Chronic hypoxia and inflammation can affect renal tubular function. OBJECTIVES: The aim of this study was to investigate renal tubular function and early kidney injury molecules such as urinary N-acetyl-betaglucosaminidase (NAG) and kidney injury molecule-1 (KIM-1) excretion in children with asthma. METHODS: Enrolled in the study were 73 children diagnosed with asthma and 65 healthy age- and gender-matched control subjects. Urine pH, sodium, phosphorus, potassium, microalbumin, creatinine, NAG, KIM-1, and serum creatinine, sodium, phosphorus were evaluated. The diagnosis of asthma and classification of mild or moderate were done according to the Global Initiative for Asthma guidelines. RESULTS: Serum sodium, phosphorus, creatinine, and urinary microalbumin were within normal levels in the both groups. Urinary pH, sodium, potassium, phosphorus, microalbumin, and KIM-1 excretions were similar between the control and study groups. Tubular phosphorus reabsorption was within normal limits in two groups. Urine NAG was elevated in the study group (P = 0.001). Urinary KIM-1 and NAG levels were positively correlated (r = 0.837; P = 0.001). When children with mild and moderate asthma were compared, all of the parameters were similar (P >0.05). CONCLUSIONS: This study showed that chronic asthma can lead to subtle renal impacts. We suggest that in children with asthma, urinary NAG level is a more valuable parameter to show degree of renal tubular injury than markers such as microalbumin and KIM-1. Chronic hypoxy and inflammation probably contributes to these subclinical renal effects.