Research on puberty of Kinh and San Diu students in Vinh Phuc and Phu Tho provinces

JOURNAL OF SCIENCE OF HNUE Chemical and Biological Sci., 2014, Vol. 59, No. 9, pp. 148-152 This paper is available online at RESEARCH ON PUBERTY OF KINH AND SAN DIU STUDENTS IN VINH PHUC AND PHU THO PROVINCES Nguyen Thi Bich Ngoc Faculty of Biology, Hanoi National University of Education Abstract. This study was designed to be a cross-sectional study of 1440 Kinh students and 718 San Diu students from 11 to 17 years of age in Vinh Phuc and Phu Tho Provinces. The study objective was to determine the age of puberty of Kinh and San Diu students in these provinces. It was found that Kinh schoolgirls reach puberty at the age of 12 years, 10 months, and San Diu schoolgirls reach puberty at the age of 13 years, 4 months. Kinh students experience their first menstrual flux earlier than San Diu students (p < 0.05). Kinh schoolboys reach puberty time at the age of 13 years, 5 months and San Diu reach puberty at the age of 14 years, 7 months. Kinh male students show signs of puberty earlier than San Diu male students (p < 0.05). Female students attain puberty at a younger age than male students (p < 0.05). Results from this study can be used as reference material and to teach about characteristic development of school age children in order to improve the quality of care, protection and education of children. Keywords: Puberty, Kinh students, San Diu students. 1. Introduction Research on human biology is fundamental and covers a large area, requiring the participation of many scientists from different fields such as medicine, biology, cybernetics, chemistry and mathematics. In recent decades, many studies on the age of puberty of Vietnamese children have been carried out, which have helped determine the age of puberty of Vietnamese young people and provide information that could lead to better education planning strategies and training of future human resources of the country [1, 6, 9]. The younger generation is the future of every nation. Vietnamese children need improved reproductive and physical health in order to attain the world. average. While some research projects have been conducted on the age of puberty of Vietnamese young people, it has not included many regions of the country [3, 7]. Children in mountainous areas are living under difficult conditions which have an adverse affect on Received November 6, 2014. Accepted December 12, 2014. Contact Nguyen Thi Bich Ngoc, e-mail address: bichngocbio@gmail.com 148 Research on puberty of Kinh and San Diu students in Vinh Phuc and Phu Tho Provinces their reproductive health development, and this is especially true for those of the ethnic minorities. This study was undertaken to determine the age at which students, 11 to 17 years old, reach puberty in Phu Tho and Vinh Phuc Provinces. The second purpose was to determine ratio of completing pubertal Kinh and San Diu pupils follow age 2. Content 2.1. Subject and method of study * Subject of study We conducted study looking at 1440 Kinh and 718 San Diu students, aged 11 to 17 years, in Phu Tho and Vinh Phuc Provinces. * Method of study - Sample research used the cross-sectional study method. - Research method to determine the attainment of puberty: interview method. - The survey data were processed using SPSS 16.0 software and Excel and statistical methods commonly used in biology [4]. 2.2. Results and discussion 2.2.1. Puberty of female pupils * The ratio of completing pubertal female pupils It was found that, at the age of 11, some female students were pubertal. Most female students in three ethnic groups attained puberty between the age of 12 and 14. All female pupils attained puberty by the age of 15. Female Kinh students attained puberty earlier than female San Diu students. Table 1. The ratio of females reaching puberty follows age and enthnicity The ratio of completing pubertal female pupils Age Kinh San Diu Numbers The ratio (%) Numbers The ratio (%) 11 90 10.70 20 4.81 12 195 23.19 68 16.35 13 276 32.81 123 29.57 14 195 23.19 145 34.86 15 85 10.11 60 14.42 16 0 0 0 0 17 0 0 0 0 Total 841 100 416 100 * Age of puberty of female students Table 2 shows that female Kinh students attain puberty at the age of 12 years and 10 months,  1 year and 3 months. For female San Diu students the age is 13 years and 4 149 Nguyen Thi Bich Ngoc months,  1 year and 8 months. Kinh students experience their first menstrual flux earlier than do San Diu students (p < 0.05). Table 2. Age of female attainment of puberty Enthric Numbers Puberty age of female pupils P Kinh (1) 841 12 years 10 months  1 year 3 months p (1 - 2) < 0.05 San Diu (2) 416 13 years 4 months  1 year 8 months Changes in morphology are closely associated with the attainment of puberty. From the study, it can be seen that female students in Phu Tho and Vinh Phuc Provinces attain puberty when they are from 12 years and 10 months to 13 years and 4 months old. The age of first menstruation of Kinh students is earlier than that of San Diu students. In our opinion, in addition to genetic factors and gender, Kinh people attain puberty earlier because they have a better diet, they read books and newspapers, they watchTV, they use the Internet and they take part in Kinh-oriented community activities [6]. 2.2.2. Puberty of male students *The ratio of male students who have attained puberty Our research shows that no male student of the 11 to 12 year age group showed signs of puberty. Male students began to show signs of puberty at the age of 13 and 100% of the male students show signs of puberty by the age of 17. Table 3. The ratio of males reaching puberty follows age and enthnicity The ratio of completing pubertal male pupils Age Kinh San Diu Numbers The ratio (%) Numbers The ratio (%) 11 0 0 0 0 12 0 0 0 0 13 105 17.53 42 13.91 14 211 35.23 99 32.78 15 186 31.05 112 37.09 16 93 15.53 41 13.58 17 4 0.66 8 2.65 Total 599 100 302 100 * Age of male attainment of puberty The age at which male Kinh students show signs of puberty (13 years 5 months old  1 year 2 months old) is earlier than that of male San Diu students (14 years 7 months old  1 year 4 months old) with p < 0.05. Male Kinh students show signs of puberty earlier than do male San Diu students (p < 0.05) (see Table 4). 150 Research on puberty of Kinh and San Diu students in Vinh Phuc and Phu Tho Provinces Table 4. Age of puberty of male students Enthric Numbers The puberty age of male pupils P Kinh (1) 599 13 years 5 months  1 year 2 months P (1 - 2) < 0.05 San Diu (2) 302 14 years 7 months  1 year 4 months Puberty is attained by male students when they are from 14 years 2 months old to 14 years 7 months old. Kinh students show signs of puberty earlier than San Diu students for the same reasons given for female students. Puberty is reached by female students earlier than male students by about 1 - 2 years old (p < 0.05). This difference is probably influenced by genetic factors and the less prosperous living conditions of the ethnic group students. Table 5. The age of puberty of female students in others studies Year Author Subjects Areas The age of puberty of female students 1975 Biological constant of Vietnamese people City 14 years  1 year 2 months Rural 15 years  3 year 4 months 1991 Dao Huy Khue Students Ha Tay 13 years 8 months  1 year 8 months 2009 Do Hong Cuong Students Thai Hoa Binh 13 years 4 months  6 months Kinh Hoa Binh 13 years 4 months  7 months 2012 Nguyen Thi Bich Ngoc Students Kinh 12 years 10 months  1 year 3 months San Diu 13 years 4 months  1 year 8 months The age of puberty of Kinh and San Diu students that we found is earlier than that of the "Biological constant of Vietnamese people” of 1975 and also earlier than that of students in Hanoi, Thai Binh and Ha Tay Provinces in some studies done between 1978 – 1990, and that of students in Hoa Binh Province (Table 5&6) [2, 5, 8]. Table 6. The age of puberty of male students in others studies Year Author Subjects Areas The age of puberty of male students 2009 Do Hong Cuong Students Muong Hoa Binh 14 years  7 months Kinh Hoa Binh 13 years 11 months  10 months 2012 Nguyen Thi Bich Ngoc Students Kinh 13 years 5 months  1 year 2 months San Diu 14 years 7 months  1 year 4 months 151 Nguyen Thi Bich Ngoc 3. Conclusion The age at which Kinh students have their first menstrual flow (12 years and 10 months) is earlier than that of San Diu students (13 years 4 months). Male Kinh male students show signs of puberty (13 years 5 months) earlier than do San Diu male pupils (14 years 7 months). Puberty of female Kinh and San Diu students arrives earlier than it does for male students by 1 - 2 years. REFERENCES [1] Department of Pediatrics, Hanoi Medical University, 1995. Development characteristics of sexual maturity and development in children. Medical Publishing House, Hanoi. [2] Do Hong Cuong, 2008. 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