Scientific journal
European Journal of Natural History
ISSN 2073-4972

Peculiarities of nitrous oxide stress-reaction and metabolism among persons of youthful age with various levels of normal diastolic arterial pressure

Kuvshinov D.Y.

An increase in arterial pressure (AP) is the leading cause of death among the population of the world, strong and independent risk factor of heart-vascular diseases, and its role exceeds the contribution of smoking, hyperglycemia, dislipidemy, and obesity. This risk has two thresholds: it grows along with AP! Under physical or mental strain, in terms of stress, systolic pressure alters in larger scale than diastolic, but the latter is paid little attention to.

The research objective is to estimate the relation character between normal dualistic arterial pressure with the level of stress-activity and biochemical markers (NO) among young people.

Methods and materials. The research has been carried out upon almost healthy students of 17-21 years old of the first and the second year of medical and paediatric faculties of medical academy. All tests were carried out in laboratory conditions at morning hours (8,00 to 12 a.m.) with a regulated handwritten consent od students.

To estimate stress-reactivity (SR) we used six different methods:

  1. color test of Lusher (L.N. Sobchick, 1990);
  2. questioning of J. Taylor to reveal the anxiety level (A.B. Leonova, V.I. Medvedev, 1981);
  3. evaluation of «individual minute» (Y.O. Alyanchikova, A.G. Smirnov, 1997);
  4. iridoscopic definition of the number of iris nervous rings (E.S. Velhover and others, 1989);
  5. functional probe «Mathematic calculation» (V.I. Kiselev and pthers, 1989);
  6. automatic analysis of heart rhythm with usage of apparatus-program complex «Chronocard 2.2» to evaluate the index of regulatory systems´ tension (IRST) (R.M. Bayevskiy, 1079).

All SR parameters were estimated via ranging into high, average, and low (3, 2, and 1 point correspondingly), sum SR was calculated.

To receive an express-evaluation of physical healthiness we used a method, developed under the supervision of professor G.L. Apanasenko (1988). The degree of extra-introversion and neurotism was defined via the question list of G. Aizenk (1992).

To define the level of nitrous oxide (NO) metabolites among 123 students (60 young men and 63 women) we undertook an intake of alveolar air and its condensation until the discharge of 1,5-2 ml of fluid. Prior to that at the level of shoulder artery arterial pressure (AP) and pulse frequency (PF) were defined by a device «Omron MX-3». The estimation of sum concentration of nitrites and nitrates (CNN) - stable nitrous oxide metabolites - in the concentration of alveolar air was carried out through restoration of nitrates back to nitrite-anions under an impact of coppered cadmium under pH = 9. The concentration of nitrite-anions was defined with Griss reactive that was mixed with an equal volume of the studied probe; absorption under the wave length of 550 nm was estimated on the analyser SpectraCount (Packard, USA). CNN was defined according to the metering curve with usage of sodium nitrite (V.I. Buvaltsev and others, 2002).

Statistic processing was carried out with an applied program package «Statistika 5.5». M - selective average, and m - error of average were defined. The reliability of inner-group differences under the inspection of statistic hypothesizes in our research was defined with criterions of Mann-Witney (U-criterion), criterion of Wilcoxon. Correlation coefficient of Spirman was calculated as well.

The research results. All the studied were divided into 3 classes of normal diastolic pressure: 60-79 mm of mercury - optimal ADP, 80-84 mm of mercury - normal ADP, 85-89 mm of mercury - high normal ADP. Persons who received 3 or less points in the express-evaluation of healthiness level by G.L. Apanasenko were excluded from the further result analysis.

Table 1 Parameters of stress-reactivity and CNN among young men with different levels of normal ADP

Indexes

Persons with optimal ADP

Persons with normal ADP

Persons with high
normal ADP

p

n = 44

n = 10

n = 5

ADP,mm of mercury

70,11 ± 0,74

82,20 ± 0,47

87,60 ± 0,93

 

Average AP, mm of mercury

128,61 ± 1,72

134,00 ± 3,01

131,00 ± 3,83

 

Cardiac rate

70,57 ± 1,51

76,40 ± 2,43

76,00 ± 2,92

 

Height, cm

178,55 ± 1,13

180,6 ± 1,59

178,8 ± 2,85

 

Body mass , kg

69,97 ± 1,52

70,50 ± 1,86

76,40 ± 6,73

*

Introversion, points

12,40 ± 0,47

12,60 ± 1,03

11,80 ± 1,62

 

Neurotism, points

7,68 ± 0,72

7,30 ± 1,36

5,00 ± 0,89

*

IRST, point

117,59 ± 11,32

122,30 ± 22,78

145,60 ± 35,01

*

Sun heart rate, points

9,24 ± 0,24

9,89 ± 0,42

9,20 ± 0,37

 

CNN, mcM/l

n = 42

7,44 ± 0,94

n = 10

5,38 ± 0,83

n = 4

3,76 ± 0,61

*

 

Table 2 Parameters of stress-reactivity and CNN among young women with different levels of normal ADP

Indexes

Persons with optimal ADP

Persons with normal ADP

Persons with high normal ADP

p

n = 90

n = 18

n = 5

ADP,mm of mercury

72,55 ± 0,5

82,00 ± 0,41

88,00 ± 0,68

 

Average AP, mm of mercury

116,96 ± 0,98

124,00 ± 2,05

124,00 ± 2,37

 

Cardiac rate

75,99 ± 0,92

82,42 ± 3,14

77,67 ± 3,62

*

Height, cm

165,78 ± 0,59

162 ± 1,56

166,83 ± 2,94

 

Body mass , kg

54,64 ± 0,7

54,14 ± 1,67

56,51 ± 1,77

 

Introversion, points

11,94 ± 0,35

10,61 ± 0,78

11,83 ± 0,79

 

Neurotism, points

9,06 ± 0,47

11,83 ± 1,08

9,33 ± 1,56

*

IRST, point

118,83 ± 9,66

155,64 ± 29,98

105,9 ± 40,22

*

Sun heart rate, points

9,47 ± 0,19

11,21 ± 0,46

10,00 ± 0,63

 

CNN, mcM/l

n = 42

8,24 ± 0,58

n = 10

7,96 ± 2,42

n = 3

7,24 ± 1,20

 

The majority of young men (44 persons) had an optimal arterial diastolic pressure (ADP), those with optimal ADP also had the lowest body mass. According to the sum HR groups differed insignificantly, and the level of neurotism was even lower among persons with normal ADP. The comparison of NO metabolites concentration in the condensate of the inhaled air showed us that the highest concentration of it have persons with optimal ADP, and the lowest - those with high normal ADP. Diastolic pressure correlated with CNN among the young men with optimal ADP (r = -0,38, р = 0,0144), and among those with high normal pressure - with IRST (r = 0,79, р = 0,0327).

The results´ analysis among the young women showed us that the majority of the studied has an optimal ADP level. Differences in height and mass were unreliable, a trend towards body mass growth was observed among the patients with high normal ADP. Persons with high normal pressure had higher indexes of neurotism, stress-reactivity, including high IRST parameters. Differences in CNN carries a character of trend - the highest concentration was observed among the patients with optimal ADP.

According to the described data we can suppose that for young men humoral factors, particularly nitrous oxide production are more important in the process of dualistic pressure regulation, while for women stress prevails the stress factor. Besides, young women with normal pressure, obviously, form even higher risk group than persons with high normal pressure. However, additional research is required for more detailed answer to this question.

The work was carried out with a support of grant of President of Russian Federation MD - 4145.2011.7

 


The work was submitted to international scientific conference «Fundamental and applied research in medicine», (Russia) Sochi, 22-25 September, 2011, came to the editorial office on 28.07.2011.