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UDC 614.777:612.462.1-053.2-055.1
THE ANALYSIS OF KIDNEY FUNCTION IN BOYS OF 10-11 YEARS IN THE CONDITIONS OF CONSUMING DRINKING WATER WITH HIGH CATION CONCENTRATION
Novosibirsk State Pedagogical University, Novosibirsk 2Novosibirsk Research Institute of Hygiene, Novosibirsk
S.A. Nedovesova1, Ye.A. Tolstykh2, V.V. Turbinsky2, Ye.M. Trophimovich2, R.I. Aizman1,2
The article presents the results of study of kidney function of 10-11 years old students in conditions of consumption of drinking water with an increased content of sodium, calcium and magnesium. Analysis of the water and ion-releasing function of this contingent indicates adaptive changes in the renal response, depending on the ionic composition of drinking water, which reflects the ability of the body and mechanisms of regulation of the homeostatic functions of kidneys to adaptive reconstructions. However, prolonged intervention into the system can probably cause its stress and lead to the development of renal pathology. Key words: cations, diuresis, kidney pathology.
One of the global problems of the present time is providing the population with qualitative drinking water the content and amount of which influence the state of human health. According to the sanitary and hygienic researches performed in the FBHI "Center of hygiene and epidemiology of the Novosibirsk Oblast" of Rospotrebnadzor, by 2016 in the territory of the Novosibirsk Oblast, Vengerovsky and Kyshtovsky districts are presented as unfavorable in terms of mineralization and hardness of drinking water (Table 1).
The imbalance of chemical elements in the objects of the external environment contributes to the dis-
Materials and methods
In order to study the reaction of kidneys to the loads in the conditions of drinking water with high hardness conditioned by the content of calcium and magnesium and also with high concentration of sodium in the water of Vengerovo village, there was performed the examination of children for the evaluation of peculiarities of kidney functions and spare capacities of the system of wa-8
orders of the chemical composition of organisms and deviations in their functioning [1].
To study electrolytic homeostasis and ion-regulating kidney function under the influence of particular environmental conditions experimental researches successfully implement various salt-water exercise stress tests the diagnostic effectiveness and informative value of which is now generally acknowledged [2].
The research objective was to study the kidney function in the pupils of 10-11 years of age in the conditions of consuming drinking water with high concentration of sodium, calcium and magnesium.
ter-electrolytic balance regulation. The level of basic ions and salts in the drinking water of Verkh-Ir-men village stays within the range of maximum allowable concentration (MAC) (Table 1) which allows to determine the obtained data as control.
The study included healthy boys at the age of 10-11 (19 persons in Verkh-Irmen, 25 and 11 persons in Vengerovo and Kyshtovka respectively) with normal parameters of physical development.
Table 1
Quality indicators of drinking water in the settlements of the Novosibirsk Oblast by 2016 (mg/dm3)
№ P/P Indicators Settlements
Verkh-Irmen Vengerovo Kyshtovka
1 Sodium 61,17±6,12 224,6±22,5* 57,60±5,80
2 Potassium <0,50 <0,50 <0,50
3 Calcium 65,93±4,35 80,76±5,29* 107,82±6,99*
4 Magnesium 37,54 55,08 40,74
5 Ferrum 0,12±0,30 1,65±0,29* 3,70±0,60
6 Mineralization 493,00±59,20 1114,00±111,40 663,00±66,30
7 Total hardness 6,38±0,96 8,56±1,28 8,73±1,31
Note: * - significant differences by p< 0,05 between concentrations of ions in the villages Verkh-Irmen and Vengerovo/Kyshtovka.
The water exercise testing was performed in the morning, in the fasted state, after 10-12 hours of water deprivation (night hours). After the baseline urine sampling within the period of one hour, the examined persons drank 10ml/kg water in minimal time which did not cause any uncomfortable conditions. During two hours after the water load every hour there was collected urine to determine the concentration of basic electrolytes and osmoti-cally active substances.
The concentration of Na+ and K+ electrolytes in the urine was determined by means of flame photometry (BWB-XP FlamePhotometer, Great
Britain); the concentration of Ca2+, Mg2+ ions -by means of the biochemical analysis (analyzer "BS-200E", China). The statistical analysis of the results was conducted by means of variation statistics using the parametric t-Student test, and also standard MicrosoftOffice programs; the differences were considered significant by p<0,05.
Results and discussion
Table 2 shows the basic indexes of the diuretic kidney function in the conditions of relative rest in the morning in the fasted state (baseline) and after 1% water load.
Table 2
The change of indicators of kidney function in the conditions of relative rest in the morning in the fasted state after 1% water load in children at the age of 10-11 in villages Verkh-Irmen (n=19), Vengerovo (n=25) and Kyshtovka (n=11).
Indicators Verkh-Irmen Vengerovo Kyshtovka
®OH 0,59=0,03 1,43=0,15^ 0,47=0,12^
V, ml/min*m2 1 nac 1,47± 0,09* 2,28=0,16*^ 1,82=0,33*
2 nac 1,67± 0,13* 2,00±0,22* 2,99=0,46*
GRF, ml/min*m2 ®OH 52,09 =2,76 113,38=15,39^ 41,55=7,00^
1 nac 43,53= 1,91* 32,21=1,97*^ 27,44=4,08*^
2 nac 36,02= 1,62* 40,41=2,25* 62,64=9,64*A^
%RH2O,% ®OH 98,82 =0,17 98,61=0,15 98,95=0,12
1 nac 96,57= 0,61* 92,39=0,65*^ 92,45=1,12*^
2 nac 95,16 =0,39 95,14=0,43* 95,10=0,55*
% water load excretion 65,62 =2,54 79,00=6,00^ 93,50=13,68^
Note: here and in the following tables significant differences by p<0,05. * - significant differences between 1, 2 hours in relation to baseline urine samples; ▲ - the significance of indicators between Verkh-Irmen and Vengerovo/Kyshtovka; • - the significance of indicators between Vengerovo and Kyshtovka.
According to the obtained data, the average indicator of the baseline diuresis in children of Vengerovo village exceeds the same parameter in Verkh-Irmen and Kyshtovka nearly two times, consequently, the background level of glomerular filtration rate in the stated group of examined by the same level of liquid reabsorption is exceeded twice. Apparently, it can be can be conditioned by the high concentration of sodium in drinking water.
In the examined children of the mentioned regions after 1% water load there was observed high output renal reaction. The exceeded reactivity of renal response in children living in the regions with high concentration of cations in drinking water appeared due to the deeper retardation of liquid reabsorption. High reactivity of renal response is also determined by the percent of liquid excretion during 2 hours, which was significantly higher than the control value both in the villages of Ven-gerovo and Kyshtovka. In consequence, in one and two hours after the water intake there was registered a significant increase of diuresis in comparison with the control group. Moreover, during one hour after the load there was observed a considerable reduction of liquid reabsorption in relation to the control and baseline values, but by the sec-
ond hour the level of reabsorption became nearly equal in all groups.
To evaluate the state of the electrolyte metabolism there was conducted the analysis of the ion urine content. Table 3 presents the basic indicators of the ion-uretic kidney function in the children of examined regions.
The background excretion of ions of calcium, magnesium, uric acid and urea in Kyshtovka nearly corresponded to the control data and did not have significant differences by slightly decreased 'excretion of sodium and potassium. However, in Ven-gerovo the baseline level of excretion for all cations several times exceeded the indicators of the examined persons both in Verkh-Irmen and Kyshtovka.
In the background of 1% water load in Ven-gerovo in relation to other regions there was registered a more expressed growth of sodium, calcium and urea excretion which can indicate the exceeded reactivity of osmoregulatory mechanisms. It should be also noted, that in the mentioned group even by the overall decrease of ionouresis after water load, the level of sodium, calcium and urea excretion was significantly higher in relation to the same values in Verkh-Irmen. The excretion of basic ions by the second hour after water load reduced like in the examined persons of Verkh-Irmen. The chil-
dren of Kyshtovka showed a two-stage reaction, namely the reduction of ion and urea excretion level during the first hour, as well as in the control group, and rapid increase during the second hour. Apparently, the content of drinking water
in these regions sensibilizated the mechanisms of regulation of ion-osmotichomeostasis, which lead to the growth of the excretion of basic cations in relation to the control group.
Table 3
Iono-uretic kidney function in children of 10-11 years of the villages Verkh-Irmen (n=19), Vengerovo (n=25) and Kyshtovka (n=11) in the conditions of relative rest in the morning in the fasted state after 1% water load (M±m)
Indicators Verkh-Irmen Vengerovo Kyshtovka
UNa V, mkM/min*m2 Фон 98,67±6,28 242,80±32,92А 37,98±4,57А*
1 час 50,15±6,56* 62,37±7,44* 49,91±11,94
2 час 40,78±4,67* 63,58±9,51*А 95,61±16,84* А
UK V, mkmol/min*m2 Фон 45,94±2,42 90,59±13,03А 34,26±6,20А*
1 час 47,16±4,48 35,83±3,39* 24,21±4,94А*
2 час 38,80±3,47 41,80±4,02* 73,58±16,80* А*
UCaV, mkM/min*m2 Фон 0,50±0,03 3,69±0,53А 0,48±0,12*
1 час 0,26±0,03* 0,62±0,15* А 0,32±0,20
2 час 0,13±0,04* 0,50±0,15* А 0,55±0,24А
UMgV, mkmol/min*m2 Фон 1,26±0,08 2,77±0,32А 1,09±0,26*
1 час 0,83±0,04* 0,68±0,09* 0,71±0,13
2 час 0,66±0,08* 0,98±0,17* А 1,85±0,54А
UUa V, mkmol/min*m2 Фон 1020,2±44,9 3081,4±392,0А 939,6±254,6*
1 час 1272,8±56,8* 1173,7±76,9* 1074,0±149,5
2 час 982,4±71,3 1401,1±157,0* А 2380,9±376,0* А*
UureaV, mkM/min*m2 Фон 90,3±4,4 1210,2±157,3А 86,1±18,0*
1 час 112,7±6,1* 394,1±51,1*А 91,3±17,8*
2 час 92,1±7,5 135,4±11,7* А 161,7±18,2* А*
EF Na, % Фон 1,46±0,10 1,56±0,16 0,81±0,16А*
1 час 0,83±0,09* 1,42±0,17А 0,42±0,19А*
2 час 0,81±0,07* 1,07±0,13* 0,38±0,15А*
EF K, % Фон 23,88±1,40 19,59±2,45 21,66±2,85
1 час 26,36±2,55 27,46±2,30* 22,57±3,88
2 час 26,25±2,31 25,30±2,20* 26,75±4,23
EFCa, % Фон 0,37±0,03 1,47±0,25А 1,03±0,19А
1 час 0,19±0,03* 0,84±0,23* А 1,18±0,18А
2 час 0,16±0,06* 0,51±0,16*А 1,17±0,23 А*
EFMg, % Фон 2,63±0,11 2,85±0,22 2,70±0,33
1 час 1,96±0,10* 2,48±0,35 3,11±0,58А
2 час 2,07±0,28* 2,60±0,38 2,96±0,60
EFUrea, % Фон 39,51±1,19 241,97±12,17А 44,76±2,57*
1 час 56,56±2,31* 263,00±29,12А 71,85±5,27* А*
2 час 56,57±4,34* 73,30±3,64* А 62,26±4,81**
Due to lower reabsorption the background level of the excreted calcium and urea fraction in the villages of Vengerovo and Kyshtovka is higher than the control values which can be conditioned by the elevated calcium level in drinking
water. The excreted sodium fraction in the examined children in Kyshtovka is also exceeding the control values by a significant level of its reduction in Kyshtovka.
After 1% water load the examined children of Vengerovo and Kyshtovka retained the lowered level of reabsorption of calcium, magnesium and urea ions in comparison with the data of Verkh-Irmen, which was indicated by the increase of the excreted fraction amount, while in Vengerovo - also by a significant increase of the excreted sodium fraction. The excreted potassium fraction after the water load did not differ significantly from the control values.
Conclusion
Thus, the analysis of the water and ion-releasing kidney function in children living in the districts with various concentration of sodium, calcium and magnesium in drinking water indicates the adaptive changes of kidney reaction depending on the ion content of drinking water, which reflects the possibility of the organism and mechanisms of homeostatic kidney function regulation to adaptive changes. However, long-term influence on the system can, apparently, cause its tension and lead to the development of kidney pathology [3].
References
Agadzhanyan N.A., Skalny A.V. Chemical elements in the environment and ecological portrait of human. Moscow, 2001.
Orekhov K.V., Aizman R.I., Velikanova L.K., Terner A.Ya., Finkinshtein Ya.D., Trofi-movich Ye.M. Age aspects of research of water-salt metabolism and kidney function in human by means of water and water-salt functional samples. Methodological recommendations. Approved by the Ministry of Health of the USSR 28.12.83, №11-14/22-6.
You-Lin Tain, Chiening Hsu Developmental Or-iginsof Chronic Kidney Disease: Should We Focuson Early Life. International Journal of Molecular Sciences. 2017; 2 (18): 381.
Contacts:
Corresponding author - Turbinsky Viktor Vladisla-vovich, Doctor of Medical Sciences, Associate Professor, Director of Novosibirsk Research Institute of Hygiene of Rospotrebnadzor, Novosibirsk. 630108, Novosibirsk, Parkhomenko Ulitsa, 7. Tel.: (383) 3433401. Email: ngi@niig.su
