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OJHAS: Vol. 4, Issue
2: (2005 Apr-Jun) |
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| Menarchial Age of Secondary School Girls in Urban and Rural Areas of Rivers State,
Nigeria
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Ikaraoha CI, Dept. of Chemical Pathology, School of Clinical Medicine, Igbinedion
University, Okada, Edo State. Nigeria
Mbadiwe INC, Department of Internal Medicine, UNTH Enugu, Nigeria
Igwe CU, Department of Medical Laboratory Sciences, College of Medicine, Ambrose Alli
University, Epkoma, Edo State, Nigeria
Allagua DO, Department of Preventive and Social Medicine, University of Portharcourt,
Rivers State, Nigeria
Mezie O, Department of Preventive and Social Medicine, University of Portharcourt,
Rivers State, Nigeria
Iwo GTO, Department of Preventive and Social Medicine, University of Portharcourt,
Rivers State, Nigeria
Ofori PI, Department of Preventive and Social Medicine, University of Portharcourt,
Rivers State, Nigeria |
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Address For Correspondence |
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C.I. Ikaraoha, Dept. of Chemical Pathology, School of Clinical Medicine,
College of Health Science, Igbinedion University, Okada,
P.M.B. 0006, Benin City, Edo State, Nigeria.
E-mail: iykeikaraoha@yahoo.com
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| Ikaraoha
CI, Mbadiwe INC, Igwe CU, Allagua DO, Mezie O, Iwo GTO, Ofori PI.
Menarchial Age of Secondary School Girls in Urban and Rural Areas of Rivers State,
Nigeria.
Online J Health Allied Scs. 2005;2:4 |
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Submitted: Feb 2,
2005; Accepted: Jun 27, 2005; Published:
Aug 23, 2005 |
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| Abstract: |
The menarchial age of 859 secondary school girls consisting of 508 from urban
and 351 from rural area of Rivers State, Nigeria were determined, using questionnaires
and interview method. Data collation revealed that 69.2% (243) of the rural population
were menstruating, while 70.1% (356) of the urban population were menstruating.
Mean ages of menarche were 13.19±1.32 years and 14.22±1.47 years
for urban and rural areas respectively .A statistically significant lower mean
menarchial age was observed in urban area girls, compared to their rural counterparts.
Girls from families of high socio-economic class has significantly lower mean
menarchial age in both urban and rural area. The mean age of menarche was significantly
higher in girls involved in vigorous sporting activity in rural areas compared
to their non-sporting counterparts.
Urban school girls attain menarche earlier than those in rural area. High socio-economic
class and vigorous sporting activity can be predisposing factors to low and
high age of menarche respectively. There is need for redefinition of high socio-economic
class in Nigeria.
Key Words:
Menarchial age, School Girls, Urban, Rural, Sports, Socio-economic class |
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Menarche is the onset of menstruation. It is one of the major events within
the complex changes of puberty in girls. Menarche is believed to be influenced
by many factors including socio-economic class1,2 and sports.3 Other factors
attributed to influence menarchial age includes rate of physical growth. It
has been observed that girls with faster physical growth and that were relatively
overweight had faster onset of menarche.4 Genetic factors have been suggested
to influence menarchial age. HLA linked genes have been noted to play important
role in determining the age of menarche.5 However there is no significant association
between the age of menarche and genetic markers such as ABO blood group, Rhesus
factor, haptoglobulins, esterase D and phosphoglucomutase.6 Information on
the age
of menarche is well documented in Nigeria, Europe and American girls. But most
of the information in Nigeria was focused on the urban areas of northern and
western Nigeria. There is still paucity of information on the menarchial age
of Nigerian girls in rural areas, especially Rivers state, the eastern region
of Nigeria where the quality of life depends much on the earning power of the
citizens. This study is designed to bridge this gap in knowledge.
Study Area
By simple random sampling method, four secondary schools were selected. Two
were from the urban area (Portharcourt), and other two from rural area (Etche). The
two schools selected for each group consisted of one co-education school and
another
girls-only school respectively.
Subjects
This included all students from junior secondary I to senior secondary II of
the selected schools, since the senior secondary III girls had graduated out
as at the time of the study.
Method of data collation:
Using the retrospective method, about 900 questionnaires were distributed, according
to the population proportion of the four schools. Of this, 41 were not properly
answered, so we had 508 and 351 properly answered questionnaires from urban
and rural schools respectively. The questionnaire was verbally interpreted in
simple language and properly explained to avoid any form of misunderstanding
and to facilitate accurate response by the subjects. The questionnaires were
retrieved immediately after completion to minimise interpersonal communication
amongst the subjects and to prevent the influence of peers on individual responses.
Ethical consideration:
The authorities of the secondary schools and the girls concerned were informed
and educated on the study to be carried out. Also, informed consent was obtained
from all the girls and the school authorities before the study was carried out.
Statistical Analysis:
Means, standard deviations and simple percentage were determined. Z-score was
used to test for significance level, since the sample size was large. In all
cases a 5% level of error was assumed and 95% level of confidence accommodated
with a critical value of 1.96 on a two-tailed distribution or a critical value
of 1.64 on a one-tailed distribution.
There was a statistically significant lower mean menarchial age in urban school
girls compared to the rural school girls (Z-score =10.22, Table 1). In both
urban and rural areas, school girls from high socio-economic class had significantly
lower mean menarchial age compared to their counterparts from low socio-economic
class (Z score = 13.89 and 7.68, respectively, Table 2). In the rural area,
school girls involved in vigorous sport activity had a higher age of menarche
compared to girls in non-sporting activity (Z = 9.75, Table 3)
Table 1: Mean menarchial age in urban and rural secondary school girls
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Urban |
Rural |
Z = score |
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Menarchial
age (years) |
13.19 ±
1.32 |
14.22 ±
1.47 |
10.22* |
Values are mean ± S D
*Statistically significant
Table 2: Mean menarchial age (years) of high, middle and low socio-economic class school
girls in the urban and rural areas
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High |
Middle |
Low |
High Vs
Low Z – score |
Middle Vs
Low Z
-score |
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Urban area |
13.06±1.35
(n =218) |
13.08±1.27
(n =87) |
13.70±1.18
(n =51) |
18.89* |
7.29* |
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Rural area |
13.98±1.46
(n =61) |
14.10±1.59
(n =49) |
14.38±1.42
(n -133) |
7.68* |
-1.54NS |
Values are Mean ± SD
*Significant
NS = Not significant
Table 3: Relationship between menarchial age
(years) and sporting activity
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Sporting |
Non-
sporting |
Z-score |
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Urban |
13.10 ± 1.27 (n = 284) |
12.98 ± 1.40 (n = 224) |
-1.12 Ns |
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Rural |
14.61 ± 1.34
(n = 211) |
14.09 ± 1.57 (n = 140) |
9.75* |
Values are Mean ± SD
Data from the present study shows a statistically significant lower mean menarchial
age (13.89 ± 1.37 years) for urban secondary school girls than the mean
value for the rural school girls (14.22 ± 1.47 years). This is consistent
with the observation of Lin et al7, that urban Chinese girls had a lower menarchial age than their rural counterparts. A number of factors may have
contributed to this difference. Socio-economic factor was investigated in this
study and it was observed that school girls from a high socio-economic class
had a statistically significant lower mean age of menarche compared to those
in low Socio-economic class. Ikechebelu8 had earlier noted lower age of menarche
in girls of high socio-economic status than those of low socio-economic class.
It seems that the socio-economic status affects menarchial age, and this may account
for the significant difference in menarchial age between urban and rural school
girls, since 56.6% (133) of the rural school girls were within the low socio-economic
group while only 14% of the urban school girls were of low socio-economic group.
The question of a proper definition of socio-economic status in Nigeria however
arises, considering that there is little or no difference in menarchial age
between girls in the middle and high socio-economic groups. In fact, in one
of the schools studied, we discovered that girls in the middle class had a lower
mean menarchial age than girls in the high social class. This clearly is a reflection
of the discrepancy between social class and earning power in Nigeria today.
Most Business men are placed within the middle class because of their educational
attainment. They are generally richer and have more assets and therefore a better
standard of living than the professionals (the so-called elites) who are classified
as the high social class. This is reflected in the mean menarchial age of their
daughters. It therefore implies that the classification of socio-economic status
in the developed world, where educational attainment is almost concomitant with
social well being, may not be applicable in Nigeria. Therefore, we suggest a
redefinition of socio-economic status in Nigeria, based on earning power and
assets such as cars and landed property, which better reflect the standard of
living.
In this study there was similarity in the mean menarchial age of urban school
girls involved in vigorous sports and those not involved. While in rural area,
there was a significantly higher mean age of menarche for girls involved in
active sports than those not involved. This corroborates an earlier report that
active sports increase the age of menarche.9 This may be due to the release
of androgen hormones (aldosterone) in sporting girls which is likely to delay
menarche. Perhaps the similarity in the mean menarchial age of the urban school
girls involved in vigorous sporting activity and those not involved in vigorous
sporting is because most of the urban girls are in high socio-economic class.
They are better nourished and therefore have a better ability to cope with the strenuous
effect of vigorous sporting activity on the body physiology. This may also contribute
to the generally lower mean menarchial age of girls in urban area.
In conclusion, urban school girls had a lower mean age of menarche than rural school girls.
Low menarchial age can be a reflection of high socio-economic status, while
vigorous sports tend to increase menarchial age. There is need for redefinition
of socio-economic status in Nigeria.
- Abioye-kuteyi EA, Ojofetimi EO, Anina OI, Kio F, Aluko Y, Mosuro O. The
Influence of socio-economic and nutritional status on menarche in Nigeria school
girls. Nutri Health.1997;11:186-95.
- Dare FO, Oguniyi SO, Makinde OO. Biosocial Factors affecting Menarche in
mixed Nigerian population. Cent Afri J Med.1992;77-81
- Toriola AL, Mathur DN. Mentrual dysfunction in Nigerian Athlethes.
Br J Obstet Gynaecol 1986;93: 979-85.
- Samsudin L. The age of menarche as related to physical growth of junior high
school girls in Jakarta. Paediatr- Indones.1990;30: 254-60.
- Diegton CM, Sykes H, Walker DT. Rheumatoid Arthritis, HLA identity and
age of menarche. Ann Rheum- Dis. 1993;52:322-6.
- Valenzuela C, Avendano A, Hueta J, Wells P, Gana R. Age of menarche and
genetic blood markers. Rev. Med Chil.1990;118:736-8.'
- Lin WS, Chen AC, Su JZ, Zhu FC, Xing WH, Li JY, Ye GS. The menarche of
Chinese girls. An Hum.Biol. 1992;502-12.
- Ikechebelu JI. The age of menarche in Nigerian
school girls, its relationship
to socio- economic status with comments on the secular trends. Orient J Med
1991;1:182-5.
- Stager JM, Hatler LK. Menarche in Athlethes: The influence of genetic and
pre-pubertal training. Med Sci Sports Exerc.1988;29:269-73.
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