Jadwiga Ambroszkiewicz

The effect of tobacco smoking during pregnancy on plasma oxidant and antioxidant status in mother and newborn.

OBJECTIVE The aim of the study was to estimate the effect of tobacco smoking during pregnancy on oxidative damage and antioxidant defence in matched samples of maternal blood and cord blood. STUDY DESIGN Healthy, pregnant women (n=140) were divided into non-smoking and smoking groups according to the concentration of cotinine in serum and urine. Oxidative damage was measured through levels of malondialdehyde (MDA) and plasma antioxidant status was evaluated by measuring concentrations of total radical trapping parameters (TRAP) and selected antioxidants (β-carotene, vitamin A, vitamin E, uric acid). Statistical analysis was done using the SAS System for Windows (SAS Institute, Cary, NC). RESULTS In the course of pregnancy the concentration of MDA increased, but to higher values in smoking women than in non-smoking ones. It was accompanied by significantly lower TRAP in the smoking group than in the controls (p<0.05). Plasma concentration of uric acid (p<0.05) and antioxidant vitamins E (p<0.01), A and β-carotene (p<0.0001) were all reduced in smokers as compared with non-smoking pregnant women especially in the third trimester. Concentration of MDA in plasma of cord blood of newborns of smoking mothers was significantly higher (p<0.01) but the antioxidant defence was lower (p<0.0001) than in non-smoking ones. It was particularly pronounced for β-carotene (32%; p<0.0001) and vitamin A (28%; p<0.001). A significant negative correlation was found between MDA and TRAP levels of maternal plasma (non-smoking and smoking: r=-0.50, p<0.0001) and cord plasma (non-smoking: r=-0.54, p=0.0057; smoking: r=-0.71, p=0.0004) in all the study subjects. Total antioxidant status positively correlated with concentrations of uric acid and vitamin E in non-smoking and smoking mothers as well as their newborns. CONCLUSION Tobacco smoke enhances lipid peroxidation and depletes antioxidant potential in the plasma of pregnant women and umbilical cord blood. Therefore smoking during pregnancy may stimulate free radical damage in the mother and the growing fetus.

A study of bone turnover markers in prepubertal children with phenylketonuria

To investigate the effect of low-phenylalanine diets onbone mineralisation status, we compared biochemicalbone formation and resorption markers in prepubertalchildren with phenylketonuria with those of age-mat-ched healthy controls.Dietary phenylalanine (Phe) restriction is the onlyknown strategy of preventing neurological impairmentand mental retardation in patients with phenylketonuria(PKU). In general, most phenylketonuric patients on alow-Phe diet can achieve normal growth and intellectualdevelopment. It is suggested, however, that this form ofdiet may influence bone metabolism, especially inchildhood and adolescence when growth and boneturnover are at their most intensive. Some authors havedescribed decreased bone mineral density and osteope-nia in patients suffering from PKU [1, 2, 3,5].Measurements of bone mineral density (BMD) reflectonly bone mineral status but not the dynamics of boneturnover. Non-invasive biochemical markers whichshow global skeletal activity have lately been developedand validated for the assessment of bone formation andbone resorption processes. Among them, osteocalcin(OC), bone alkaline phosphatase (BALP) and collagentype 1 cross-linked C-telopeptide (CTX) are consideredto be clinically useful. Recently, the novel cytokineosteoprotegerin (OPG), belonging to the tumournecrosis factor receptor family has been established asan endogenous inhibitor of osteoclastogenesis andresorption processes.Our study population consisted of 37 childrenwith PKU under surveillance at the Department ofPaediatrics at the Institute of Mother and Child inWarsaw. Patients were divided into two groups. Thosein group A (n =12; median age 4.5 years; range 3–10years) followed their therapeutic diet strictly and hadmean serum Phe concentrations close to the referencerange (189.4±64.2 lmol/l) and those in group B(n =25; median age 6.0 years; range 3–10 years) did notadhere to their diet and had increased Phe concentra-tions (649.2±140.6 lmol/l). The mean serum Pheconcentration was calculated for the last 3 years of thelife of each patient. Children with PKU were fed with anaminoacid mixture PAM, Milupa-PKU 2 or Phenyl-free. These patients have normal values for calcium andphosphate. Healthy children sent to our laboratory forroutine analytical control (n =27; median age 5.9 years;range 4–9 years) were the reference group. The wholegroup of investigated children was ethnically homoge-nous. Venous blood samples were collected after anovernight fast, centrifuged and serum levels of Phe,calcium and phosphate were determined. Remainingserum samples were frozen and collected for measure-ment of BALP, OC, CTX and OPG. Phe was assayedfluorometrically according to McCaman and Robbins;calcium and phosphate by standard procedures with aCobas Integra analyser (Roche, Switzerland). Serum OCand CTX were measured by immuno-enzymatic ELISAassays (Osteometer, Denmark). For determination ofBALP, the Alkphase-B kit from Metra Biosystems(USA) and for OPG, the kit from Biomedica (Austria)were used. The differences were evaluated by ANOVAwith Bonferroni correction. The significance was set atP <0.05.We observed lower levels of bone formation andbone resorption markers in group A than in group B,but these differences are not statistically significant(Table 1). However, OC, CTX and OPG concentrationswere significantly lower in both groups of PKU childrenin comparison to the healthy age-matched controls.There are only a few papers presenting values of boneturnover markers in PKU subjects. Perez-Duenas et al.[6] observed the same levels of OC and BALP in a groupof younger patients and significantly lower serum BALP

Alterations in markers of bone metabolism and adipokines following a 3-month lifestyle intervention induced weight loss in obese prepubertal children.

BACKGROUND Adipokines may influence bone metabolism in children, but this phenomenon is not well understood. Therefore, we studied the relationships between bone markers and adipokines during weight loss in obese children. MATERIALS AND METHODS We determined serum leptin, soluble leptin receptor (sOB-R), adiponectin, BALP (bone alkaline phosphatase), CTX-I (C-terminal telopeptide of type I collagen), body composition and bone mineral density (by dual-energy X-ray absorptiometry) in 100 obese prepubertal children before and after 3 months of lifestyle intervention (low-energy diet, physical activity). The control group consisted of 70 non-obese children. RESULTS Obese children had higher BALP activity by about 20% (p<0.001) and similar value of CTX-I compared with non-obese children. After weight loss (-0.96 BMI-SDS mean change), the BALP value in obese patients decreased (p<0.001), whereas CTX-I concentration was unchanged. Changes in BALP were positively correlated with changes in BMI (Body Mass Index) (r=0.352, p<0.001), but not associated with adipokine levels. Trend analysis using SDS-BMI subgroups showed that greater reduction of body mass was associated with a greater decrease of BALP (p=0.035) and leptin values (p<0.001), as well as a greater increase of sOB-R (p<0.003). CONCLUSIONS Obesity during the prepubertal period is associated with an alteration in the adipokines profile and greater whole-body bone mass as a result of increased bone formation rather than reduced bone resorption. Changes in bone metabolism during lifestyle intervention seem to be related to weight loss but not to changes in adipokines. Further studies should elucidate the influence of long-term therapy on bone mass in childhood.

ADIPOQ -11377C>G Polymorphism Increases the Risk of Adipokine Abnormalities and Child Obesity Regardless of Dietary Intake.

Objective: The aim of the present study was to verify whether selected functional single nucleotide polymorphisms in LEP, LEPR, and ADIPOQ loci are associated with the development of obesity and serum levels of the respective adipokines in prepubertal white children with obesity. Methods: Frequencies of −2548G>A LEP (rs7799039), Q223R (rs1137101) and K656N (rs8129183) LEPR, and −11377C>G (rs266729) and −11426A>G (rs16861194) ADIPOQ polymorphisms were analyzed by restriction fragment length polymorphism in 101 obese (standard deviation score [SDS]-body mass index [BMI] >2) and 67 normal-weight (SDS-BMI <−1 + 1>) children. Serum adipokine concentrations were measured using the enzyme-linked immunosorbent assay method. Results: The GC/GG genotypes of −11377C>G ADIPOQ polymorphism were associated with a higher risk of obesity (P = 0.022, odds ratio 2.08 [95% confidence interval 1.11–3.90]). Individuals carrying the GG genotype had a higher leptin/total adiponectin ratio by 25% than CC homozygotes (Ptrend = 0.05). In the multivariate linear regression model, we found differences among particular genotypes of this polymorphism in concentrations of high molecular weight (HMW) adiponectin (Ptrend = 0.043) and HMW/total adiponectin ratio (Ptrend = 0.048), with the lowest values in GG homozygotes. Positive correlations between SDS-BMI and dietary reference intake percentage were observed in individuals homozygous for allele C (r = 0.403, P = 0.01) and CG heterozygotes (r = 0.428, P = 0.004). No significant correlations between both parameters were found in the GG homozygotes. Conclusions: Among the analyzed polymorphisms, only −11377C>G ADIPOQ single nucleotide polymorphism was associated with obesity during the prepubertal period. Adipokine abnormalities coexisting with the lack of relations between SDS-BMI and dietary intake may predict a higher risk of future obesity-related disorders in obese children carrying the GG genotype than in those with other genotypes.

Biochemical markers of bone metabolism in children with cow's milk allergy

Introduction Patients with cows milk allergy (CMA) and following a cow milk protein-free diet for a long time are potentially at risk of developing bone abnormalities. To assess the balance between bone formation and resorption processes, we determined serum concentrations of osteocalcin (OC), bone alkaline phosphatase (BALP), C-terminal telopeptide of type I collagen (CTX), fetuin-A, osteoprotegerin (OPG) and receptor activator of nuclear factor κB ligand (RANKL) in children with CMA. Material and methods The study included 50 prepubertal children with diagnosed cows milk allergy, who were under systematic medical and nutritional care at the Institute of Mother and Child and 40 healthy counterparts as a control group. The concentrations of bone metabolism markers were determined by immunoenzymatic assays. Results The diets of all investigated children were correct in terms of phosphorus and magnesium contents but deficient in terms of calcium and vitamin D. Serum OC and CTX as well as fetuin-A concentrations were similar in both studied groups. The BALP activity was significantly (p < 0.05) higher in children with cows milk allergy than in the controls. Serum OPG concentration was comparable in both groups, but the RANKL level was higher (p < 0.05) in CMA children than in healthy ones. Hence, the ratio of OPG/RANKL was lower in children with CMA. Conclusions Our study demonstrates slight disturbances in the profile of bone metabolism markers in growing children with CMA. The increase in RANKL level and decrease in OPG/RANKL ratio may contribute to intensification of bone resorption in these patients.

The pregnancy-associated plasma protein A and insulin-like growth factor system in response to cigarette smoking

Objective: Maternal smoking during pregnancy is associated with a reduction in birth size but the mechanism by which this occurs still remains unclear. The purpose of this study was to evaluate the effect of tobacco smoking on concentrations of pregnancy-associated plasma protein A (PAPP-A), insulin-like growth factor I (IGF-I), II (IGF-II) and binding proteins BP-3 and BP-4 in pregnant women and correlations between these parameters. Methods: Sixty healthy pregnant women were divided into smoking and tobacco-abstinent group according to results of serum cotinine concentration. The current smokers were defined as those who had smoked five or more cigarettes per day during pregnancy. Results: The mean serum concentrations of PAPP-A, IGF-I and IGF–II were significantly lower in smoking than in non-smoking pregnant women (p < 0.01). The level of PAPP-A correlated positively with the IGF-II concentration in both studied group (non-smoking: r = 0.54; p < 0.001; smoking: r = 0.40; p < 0.05). In tobacco-abstinent group negative correlation between IGF-II and IGFBP-4 concentrations was found (r = −0.35; p < 0.05). Conclusion: Tobacco smoking during pregnancy decreases the pregnancy-associated plasma protein A and insulin growth factors I and II levels. The correlation between PAPP-A and IGF-II may suggest function of this protein as a protease and regulator in the IGF system.

Complementary Effects of Genetic Variations in LEPR on Body Composition and Soluble Leptin Receptor Concentration after 3-Month Lifestyle Intervention in Prepubertal Obese Children

In obese individuals, weight loss might be affected by variants of the adipokine-encoding genes. We verified whether selected functional single nucleotide polymorphisms in LEP, LEPR and ADIPOQ are associated with changes in serum levels of the respective adipokines and weight loss in 100 prepubertal obese (SDS-BMI > 2) Caucasian children undergoing lifestyle intervention. Frequencies of the -2548G > A LEP, Q223R LEPR, K656N LEPR, -11377C > G and -11426A > G ADIPOQ polymorphisms were analyzed by restriction fragment length polymorphism. Serum adipokine and soluble leptin receptor (sOB-R) concentrations were measured using the ELISA method. Among the analyzed polymorphisms, only LEPR polymorphisms were associated with changes of SDS-BMI or sOB-R concentrations in children after therapy. Carriers of the wild-type K665N and at least one minor Q223R allele had the greatest likelihood of losing weight (OR = 5.09, p = 0.006), an increase in sOB-R (ptrend = 0.022) and decrease in SDS-BMI correlated with the decrease of fat mass (p < 0.001). In contrast, carrying of the wild-type Q223R and at least one minor K665N allele were associated with a decrease in sOB-R concentrations and a decrease in SDS-BMI correlated with a decrease in fat-free mass (p = 0.002). We suggest that the combination of different LEPR variants, not a single variant, might determine predisposition to weight loss in the prepubertal period.

Associations between IGF-I, IGF-binding proteins and bone turnover markers in prepubertal obese children.

Abstract Objective: To assess the relationships between components of the growth hormone axis, body composition, and bone markers in obese children. Methods: We determined the levels of bone alkaline phosphatase (BALP), C-terminal telopeptide of type I collagen (CTX-I), insulin-like growth factor-I (IGF-I), and IGF-binding proteins (IGFBPs) by immunoenzymatic methods, and body composition by dual-energy X-ray absorptiometry in 45 obese and 20 non-obese children. Results: IGF-I and functional IGFBP-3 levels, IGF-I/total IGFBP-3, and functional IGFBP-3/total IGFBP-3 molar ratios were significantly higher in obese patients than in controls. Multivariate regression analysis in obese patients showed significant associations of BALP with IGF-I (p=0.047) and percent of body fat mass (p=0.002). Conclusion: The relationship of IGF-I and functional IGFBP-3 to BALP may support the concept of IGF-I influence on accelerated bone formation process in obesity. Moreover, IGF-I and percentage of body fat mass may be significant predictors of BALP in obese during the prepubertal period.

The effect of weight loss on body composition, serum bone markers, and adipokines in prepubertal obese children after 1-year intervention

ABSTRACT Purpose/Aim: The influence of weight loss on bone turnover and bone quality in childhood remains controversial, but it may implicate interactions between adiposity and bone metabolism. Therefore, we studied the relationships between bone markers and adipokines during weight loss in obese children. Materials and Methods: We determined serum leptin, soluble leptin receptor, adiponectin, bone alkaline phosphatase (BALP), C-terminal telopeptide of type I collagen (CTX-I), osteocalcin (OC), carboxylated-OC (Gla-OC), undercarboxylated-OC (Glu-OC), sclerostin, body composition, and bone mineral density (BMD) in 40 obese prepubertal children before and after therapy. The control group, matched for sex and age, consisted of 40 non-obese children. Results: We found that values of the total body less head-bone mineral content (TBLH-BMC) and TBLH-BMD were significantly increased, but TBLH-BMD Z-score was decreased by 25% (p = 0.002) in obese children with weight loss after therapy. We observed increases of CTX-I to OC ratio (p = 0.009), and Gla-OC concentrations (p = 0.049). Changes in TBLH-BMD Z-score in patients were positively correlated with changes in BMI Z-score (p = 0.001), percentage of fat mass (p = 0.004), and BALP activity (p = 0.01). Changes in BALP activity were negatively correlated (p < 0.001) with changes in adiponectin concentrations, while changes in sclerostin levels were positively correlated (p = 0.001) with leptin changes. Conclusions: We suggest that alterations in adipokines metabolism were associated with a lower rate of bone mineral accrual as a result of decreased bone formation rather than increased bone resorption. The lower rate of bone mass accrual in weight losing children may be an effect of reduced BALP levels related to increase in adiponectin levels.

Total Oxidant and Antioxidant Status in Prepubertal Children with Obesity

Aims Obesity is accompanied by the formation of oxygen free radicals, whose intensified activity without effective defense mechanisms can lead to oxidative stress and related complications. We evaluated the presence of oxidative stress in obese prepubertal children. Methods The study included 83 healthy children aged 2–10 years (62 with obesity and 21 nonobese controls). Total oxidant capacity (TOC), total antioxidant capacity (TAC), oxidized low-density lipoprotein (ox-LDL), lipid parameters, glucose, and C-reactive protein (CRP) were measured in serum. Oxidative stress index (OSI) was calculated. Results Serum TOC concentration was significantly higher (p < 0.05) and TAC concentration was lower (p < 0.05) in obese children. OSI was higher (p < 0.01) in obese subjects compared with controls. CRP levels were normal in all children, but median CRP value was higher (p < 0.01) and HDL cholesterol levels were lower (p < 0.05) in the obese group. We found a significant negative correlation between TAC and ox-LDL concentrations (r = −0.27, p < 0.05) in obese children. Furthermore, obesity duration was positively correlated with TOC level (r = 0.32, p < 0.05) in this group. Conclusions Obesity-related oxidative stress already occurs in prepubescence. Early obesity diagnosis and the necessary therapeutic activity implementation is a vital strategy for the prophylaxis of free radical damage and related multiorgan complications.