Critical Anthropometry for Menarche

J Pediatr Adolesc Gynecol (1996) 9: 139-143

Critical Anthropometry for Menarche G.F. Gonzales , M.D. , Ph.D. , and A. Villena , M.D. Instituto de Investigaciones de la Altura, and Department of Physiological Sciences , Universidad Peruana Cayetano Heredia. Lima. Peru

Abstract. The objective of the study was to determine if any anthropometric measurements, including weight, height, and upper arm circumference, or the calculated body mass index observed at the time of menarche may be used as a threshold for menarche. The sample was randomly selected from 1133 girls aged 10-18 years from two groups, one residing in Lima, Peru, at 150 m above sea level, and the second in Cerro de Pasco, Peru, at 4340 m above sea level. For the pu中ose of this study, all girls who reached menarche at least 1 month before the study (n = 93) were considered as cases (girls at menarche)~ 88 girls without menarche at the tinle of the study were randomly matched by age and place of residence, and designated as controIs. All subjects came from the same low socioeconomic status. Body weight at menarche was 44.6 ± 5.09 kg (mean ± SD~ coefficient of variation [CV], 11.4%). Height at menarche was 15 1.6 ± 5.5 cm (CV, 3.7%). Body mass index, defined as weightJheight2 . 15 , was 18.26 ± 1.96 kg/m2 . 15 at menarche (CV, 10.7%). Upper arm circumference at menarche was 2 1.8 ± 1.6 cm (CV, 7.3%). The logistic regression analysis showed that any of the four anthropometric measurements analyzed were critical for menarche~ i.e., any of the four could be used as a threshold for menarche. Data from the present study do not support the hypothesis that there are anthropometric markers that are critical for menarche.

Key Words. Menarche-Critical anthropometry-Body Mass Index-Weight-Height 一 -Upper arm circumference-Menarche , high altitudes

Introduction Age at menarche , or age at the occurrence of the first menstruation , is an important biological indicator of sexGustavo F. Gonzales , M.D. , Ph.D. , Instituto de Investigaciones de la Altura, Universidad Peruana Cayetano Heredia, Postal Office 1843 , Lima, Peru.

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ual maturation 1 which chronologically occurs after the adolescent growth spurt. 2 Age at first menses 11lay vary according to both genetic and environmental factors .3-6 However, several studies have found that menarche occurs invariably at a critical weight , and this has raised the hypothesis that a critical level of mass , particularly threshold levels of fat mass , is required to attain menarche. 2 月 ，8 This assumption has been criticized by other authors ,9- 13 who have suggested that the association between weight and menarche is an effect of developmental age rather than a threshold effec t. 11 In addition to these concerns , different races have disparate critical weights and heights at menarche. For instance , girls in Philadelphia attained menarche at an estimated mean height of 153.5 cm and weight of 47.1 kg , whereas for Guatemalan girls , the corresponding means were 146.1 cm and 39.8 kg. 12 Frisch and Revelle 2 几 1 4 reported on white girls from Berkeley , Boston , and Denver, who had a mean height at menarche of 158.5 cm , and a weight at menarche of 47.8 kg. It has been suggested that racial differences in weights at menarche are due to the dissimilarities in height observed in adolescents from different ethnic backgrounds. 15 Because body weight results from the contribution of total body water, body fat , body muscle , and skeletal mass , it is necessary , at least, to correct the effect of height on body weight. This correction may be performed by calculating body mass index (BMI) as weigh t! heightn in which BMI may correlate well with body weight but not with heigh t. The Quetelet index defined as weight/height 2 is not useful in children and adolescents because it correlates with both weight and heigh t. 16 At this time , there are no studies relating critical BMI to menarche , despite the fact that BMI has been suggested as a marker of fa t. 17 As suggested by Ellison , lo the nature of a threshold is its invariant central tendency , i. e., it has low variance , and if there was a "critical" threshold , there would be very little variability in weight or BMI at menarche , but this is not the case. Data on critical weight and height at

140

Gonzales and Villena:

menarche reported in the literature are conflicting. For instance , weight at menarche has high coefficient of variation , 14.3-169忌 ，7 ，8 ，10，14 whereas height at menarche has low coefficient of variation (CV) , as calculated from the data of Frisch and Revelle (4.1%)2几14 and Ellison (4%).10 Body fat has a CV of 33.9% , and fat/weight at menarche has a CV of 20.4% ,8 thus refuting a significant threshold relationship for menarche. Trussell 18 also gives evidence against the hypothesis that fatness triggers menarche , but recently , in a prospective study , Merzenich et al. 17 provided evidence that body weight and body fatness were , according to their data , predictors of menarche. Because controversy will continue for some time , it is important to know the behavior of different populations with respect to the relation between menarche and critical anthropometry. The Peruvian population , originally characterized by an inbreeding Quechua native people , was later mixed with the Spaniards who came to Peru during the conquest of 16th century. As a result , the Peruvian population is predominantly mestizo with two important admixture groups , one with Quechuan predominance , and the second with Spanish predominance. 19 These groups live in three different geographical conditions: 52.2% of the general population live on the coast of the Pacific Ocean; 35.7% live in highland places; and 13.1% live in the jungle. The Andean population is mainly mestizo people with Quechuan predominance , whereas lowlanders are mainly mestizo people with Spanish predominance. Despite these differences , no variations were observed in ages at menarche in girls of Quechuan or Spanish predominance. 19 However, previous studies on age at menarche revealed that girls living at high altitudes attained menarche at later ages than those living at sea level , despite ethnic , socioeconomic , and nutritional influences. 19 Therefore , these groups are excellent models to study critical anthropometric markers for menarche. The present study was designed to determine if any of the three anthropometric measurements (weight , height, and upper arm circumference) , or the calculated BMI , could be used as a critical marker for menarche in both women living at sea level and for those at high altitudes , and whether these anthroponletric measurements differ in girls who had reached menarche with respect to girls who had not , when

Materials and Methods The present study was carried out during the months of October and Noveluber, 1993 , in two urban areas of Peru, South America-one located in Lima at 150 m above sea level , and the second in Cerro de Pasco at 4340 m above sea leve l. The initial sample included 504 mestizo girls from Lima and 629 mestizo girls from Cerro de Pasco , aged 9-20 years. The subjects all at-

Anthropometry at Menarche tended public schools , and were permanently living in each place of study. In Peru , individuals attending public schools were mainly from the middle-low and low socioeconomic classes. From the total sample , girls were selected who had reached menarche no sooner than 1 month before the time of the study. These girls were defined as cases. The final sanlple of cases included 93 girls aged 11-17 years; 28 from Lima , and 65 from Cerro de Pasco. The controls were randomly selected from those girls without menarche at the time of the study. Controls were matched with cases according to age , place of residence , and ethnic background. The final sample of the controls included 88 girls aged 11-17 years. Each girl filled out a form herself, with the following data recorded: parent surnames , place of birth , time of residence in the place of study , and socioeconomic data. The age of each subject was ascertained according to date of birth. All subjects spoke Spanish , and all were studied in their classrooms. Socioeconomic status was defined according to an index score , with the following parameters taken into accoun t: location of home , type (own , rent , other) , number of persons in the home , and occupation of parents. A score was given to each of the five socioecononlic variabIes assessed , and each subject was classified as belonging to one of the following classes: middle-low , low , or very low. No differences in age at menarche among girls from these different socioeconomic subclasses were observed. Finally , data were pooled. Menarcheal age was defined as age at first shedding of the uterine lining; women were asked to answer whether or not menses began before or at the time of the study. Also , girls were asked to state the exact date of their first menses. Heights and weights were recorded to the nearest 0.1 cm and 0.1 kg , respectively. Body weight and height data were used to calculate an equation for the BMI which would correlate with body weight but not with heigh t. To such a purpose a weight /heightn index was built with an n value that did not correlate with heigh t. The selected index was weight /height2. 15, because this index correlated well with weight but not with heigh t. Upper arm circumference was measured to the nearest millimeter using a steel tape with the left arm hanging relaxed. The measurement was taken nlidway between the tip of the acromion and the olecranon process. 20 Data were entered in a database (Fox-P

Gonzales and Villena: study. CV was calculated as SD of the population -:- mean x 100. Bivariate regression analysis , analysis of variance , and logistic regression analysis were performed to test the null hypothesis that age at menarche is not significantly determined by the attainment of a critical weight , height , or fatness status. The alternative hypothesis is that age at menarche is significantly determined for any anthropometric measuremen t. The logistic regression analysis was used to determine the probability of menarche as a function of the anthropometric measurements. A difference was considered significant when p was below 0.05. The confidence interval was calculated at the 95% leve l. The power of the test was 80% with a level of significance of 59忌 ， for an anticipated odds ratio of 2.5. 2 1 An anthropometric measurement is considered critical for menarche if (1) it increases the probability to attain menarche in the logistic regression analysis , (2) it has low coefficient of variation , and (3) its value is different from that observed in girls without menarche.

Results Weight at menarche was 44.6 ± 5.09 kg (mean ± SD) , height at menarche was 151.59 ± 5.54 cm , BMI at n1enarche was 18.26 ± 1.95 kg/m 2 . 15 , and upper arm circumference at menarche was 21.8 ± 1.60 cm. The CVs at the time of menarche were 3.7% for height , 7.3% for upper arm circumference , 10.7% for BMI , and 11.4% for weigh t. The CVs at a time before menarche were 3.9~ for height , 10.8% for upper arm circumference , 11.9% for BMI , and 14.7% for weigh t. The probability for attaining menarche was not predicted by any of the four anthropometric parameters in the model; in the absence (Table 1), or in the presence (Table 2) of age. At each chronological age , the means of body weight , BMI and upper arm circumference of girls without menarche were not significantly different with respect to girls at the time of menarche. These findings were observed among all ages from 11 to 17 years of age (Table 3). Height was similar in girls without menarche and in girls at the time of menarche at all ages except at 13 and 14 Table 1. Logistic Regression Analysis for the Probability of Menarche as a Function of Anthropometric Variables Independent Variable

Odds Ratio

Standard E叮or

Z

Weight Height BMI UAC

0.66 1.42 3.30 0.81

0.28 0.37 3 .45 0.10

一0 . 9 7

1.34 1.14 一1. 66

p>

[司

0.33 0.18 0.25 0.10

959毛CI

0.28- 1.53 0.85-2.36 0 .42-25.57 0.64-1.04

CI , Confidence interval; BMI , body mass index; UAC , upper arm circumference; log likelihood， 一117.64;χ2 = 14.05; p> X2 = 0.007; pseudo R2 = 0.056; Hosmer-Lemeshow X2 = 6.99; p > X2 = 0.54.

Anthropometry at Menarche

141

Table 2. Logistic Regression Analysis for the Probability of Menarche as a Function of Anthropometric Variables and Age Independent Variable

Odds Ratio

Standard Error

Age Weight Height BMI UAC

0.97 0.66 1.42 3.28 0.82

0.14 0.28 0.37 3.42 0.10

Z

p>[月

959毛CI

一0 . 2 2

0.82 0.34 0.18 0.26 0.11

0.73- 1.28 0.29- 1.53 0.85-2.36 0 .42-25.28 0.64-1.05

-0.96 1.34 1.14 一1. 60

CI , confidence interval; BMI , body mass index; UAC , upper arm circumference; log likelihood， 一117.62;χ2 = 14.10; p> χ2 = 0.015; pseudo R 2 = 0.056; Hosmer-Lemeshow X2 = 6.77; p> χ2 = 0.56.

years (Table 3) in which height was higher in girls with menarche (p == 0.01).

Discussion A critical anthropometric marker for menarche should be a measurement with low variance and low percentage of change at age of menarche. For any chronological age , its value is different from that observed in girls from the san1e chronological age but without menarche. We have analyzed whether any of four anthropometric variables (weight , height , BMI , or upper arm circumference) is critical for menarche Data from the present study demonstrate that none of the four anthropometric measurements met the criteria of being critical for menarche. The CV was higher for all anthropometric variables except heigh t. This is in accordance with findings from Ellison , 10 , 11 who found that menarcheal age is significantly synchronized with the attainment of an appropriate skeletal maturity , and that this synchronization has a greater determining effect upon menarcheal age than do synchronizations with weight or fatness. The present study showed a considerable variability in body weight at menarche , with a CV of 11.4% , similar to that obtained by other authors? , 14 Higher values of CV were also observed for BMI at the time of menarche. The CV of height at menarche was 3.6% , suggesting that height is a good factor to use as a marker for menarche. However , this could be an al1ifact rather than a real effect on age at menarche. In fact , the calculated CV of height at ages 11-17 years in those girls without menarche was also low (3.8%) , suggesting that low variance for height in adolescents is a common feature observed independently of the presence or absence of menses. However , when absolute numbers are calculated from this low CV , it is observed that menarche is attained with a high range of height ranging from 139 to 169 cm; this interval (30 cm) is too elevated to be considered as a threshold for height at menarche. This broad range is without biological significance because it includes all ranges of heights which is typical of adolescent ages.

142

Gonzales and Villena:

Anthropometry at Menarche

Table 3. Anthropometric Values for Girls with and without Menarche at the Time of the Study With Menarche

SD

44222 22lll AU 司3 AU

2

- OO

20.3

cv 司/吋 L

- 司3

4.2

ζJ

σb

I ­

吋/

52.。

OO

AU

15.0 18.0 17.8 18.4 16.9

可4 J

-』

Mean

-

E

AY

AY

E

tI

AY

AU

0.0

42534-o 33.5 12.0 42.6 9.5 40.9 6.8 43.7 7.1 4 1.8 3.7

cv

/O

tI

155.0

SD

tI

A

6 .4 3.6 7.2 4 .4 5.9

Mean

句L

tI

••••

144.5 149.1 146.8 149.3 152.6

cv

而/且 吋/

A

SD

司3

••••

A

Mean

k

Weight (kg)

正U

A且 可A 斗 T AU

4 •••

Height (em)

岫2 盯

cv

AU

23.5

SD 戶、 J

A

18.3 2 1.1 2 1.0 22 .4 2 1.4

AW J

A

••••

Mean

吋/且呵呵〕吋/扭吋/蚵吋 L

-4

A

司、U AY

•••

4 •••

司、U AY

•••

cv '、 J

48.。

44l214 16.4 18.3 17.8 18.6 17.7 19.3 19.2

•••

••

SD

勻/缸 吋/』 吋/蚵 吋/缸 吋/且

5.5 6.1 4.8 5.4 4.6 7.1 0.0

Mean

tI

40.7 43.5 43.2 46.3 43.1 49.6

cv

ζJ

σb

SD

Ai川

1 1.7 2.5 5.4* 5.6* 5.0 4.3

Mean

且

152.6 149 .4 150.9 152.7 15 1.0 154.6 153.0

cv

且

SD

A且可A且可呵呵 U 司3

司/AU

，EE且

ζU句/

0.3 2.0 1.3 1.6 1.8 1.5 0.0

司/OO

且

I

U A且 T ζJ

A-EEl--EA--E

•••

20.7 2 1.4 2 1.2 22.2 2 1.5 22.9 22.5

Mean

4EEl--E 且

••

cv

Upper Arm Circumference (em)

14J''Y••

k ,

Weight (kg)

Height (em)

。。吋 L

-4

SD

1IAY4U

117且可

•••

Mean

E』

Age

Without Menarche

叫叮

Upper Arm Circumference (em)

*p , 0.01 with respect to values in girls without menarche. One-way analysis of variance. BMI, Body mass index kg/m2 . 15 ; SD, standard deviation; CV, coefficient of variation (0/0).

BMI is a calculation of weight for height ,2 , 15 in which the index correlates with weight but not with heigh t. Despite this correction for height , however , the CV for BMI at menarche was 10.82% with individual values 2 15 ranging from 13.04 to 23.09 kg/m . , still too high to consider BMI as a threshold for menarche. If we observe individual data from BMI of those girls aged 11-17 years in which menarche has not been reached , values for BMI ranged from 13.80 to 26.79. It is evident that BMI of girls without menarche are included in the same range as girls with menarche. Previous studies have reported that despite the variability in age at menarche among populations ,22 ,23 body weight or fat at menarche should be the same. 2 ,7 ,8 ,14 In the present study , we have effectively demonstrated that weight and BMI are not predictive for menarche , suggesting that they could not be considered as thresholds for menarche. Similarly , they do not meet the complete criteria for threshold , because body weight and BMI have high variances and the means of weight or BMI at the time of menarche were not different from those in girls without menarche. 扎10 st authors take into account the relationship between body weight and height , and age at menarche , but they do not analyze weight and height in those girls without menarche， 的it was designed in the present study. In this case , anthropometric values were almost the same in those girls with and without menarche , rejecting the hypothesis that there is an anthropometric marker for menarche. Acknowledgments. This study was supported in part by a Long Institutional Development Grant from the World Health Organization , Special Programme of Research , Development , and Research Training in Human Reproduction. References 1. Danker-Hopfe H , Malina RM: Estimation of mean ages at menarche: methodological considerations. Acta Med Auxol 1992; 24: 173

2. Frisch RE , Revelle R: Height and weight at menarche and a hypothesis of critical body weight and adolescent events. Science 1970; 169:397 3. Bogin B , Mac Vean RB: Ethnic and secular influences on the size and maturity of seven year old children living in Guatemala city. Am J Phys Anthropol 1982; 59:393 4. Frisancho AR: Human growth and developn1ent among high-altitude populations. In: The Biology of High Altitude Peoples. Edited by Bake r. Cambridge , Cambridge University Press , 1977, p 117 5. Frisancho AR , Guire K , Babler vv九 et al: Nutritional influence of childhood development and genetic control of adolescent growth of Quechuas and mestizos from the Peruvian lowlands. Am J Phys Anthropol 1980; 52:367 6. Roche AF: Secular trends in stature , weight , and maturation. Monogr Soc Res Child Dev Serial No 179, 1979, P 1 7. Frisch RE , Revelle R: Height and weight at menarche and a hypothesis of menarche. Arch Dis Child 1971; 46:695 8. Frisch RE , Revelle R , Cook S: Components of weight at n1enarche and the initiation of the adolescent growth spurt in girls: estimated total water , lean body weight and fa t. Hum BioI 1973; 45:469 9. Billewicz vv習 ， Fellowes HM , Hytten CA: Comments on the critical metabolic mass and the age of menarche. Ann Hum BioI 1976; 3:51 10. Ellison PT: Threshold hypotheses , developmental age , and menstrual function. Am J Phys Anthropol 1981; 54:337 11. Ellison PT: Skeletal growth , fatness , and menarcheal age: a comparison of two hypotheses. Hum BioI 1982; 54:269 12. Johnston FE , Malina RM , Galbraith MA: Height , weight and age at menarche and the" critical weigh t" hypothesis. Science 1971; 174:1148 13. Johnston FE , Roche AF , Schell LM , Wettenhall HNB: Critical weight at menarche: critique of a hypothesis. Am J Dis Child 1975; 129:19 14. Frisch RE , Revelle R: The height and weight of girls and boys at the time of the initiation of the adolescent growth spurt in height and weight and the relationship to menarche. Hum BioI 1971; 43: 140 15. Meredith HV: Findings from Asia , Australia , Europe and North America on secular change in mean height of children , youth and young adults. Am J Phys Anthropol 1976; 44:315

Gonzales and Villena: 16. Cronk CE , Roche AF , Kent R , et al: Longitudinal trends and continuity in weight/stature 2 from 3 months to 18 years. Hum BioI 1982; 54:729 17. Merzenich H , Boeing H ， 嗎T ahrendorf J: Dietary fat and sports activity as determinants for age at menarche. Am J Epidemiol 1993; 138:217 18. Trussell J: Statistical flaws in evidence for the Frisch hypothesis that fatness triggers menarche. Hum BioI 1980; 52:711 19. Gonzales GF , Ortiz I: Age at menarche at sea level and high altitude in Peruvian women of different ethnic background. Am J Hum BioI 1994; 6:637

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20. Martorell R , Yarbrough C , Lechtig A , et al: Upper arn1 anthropometric indicators of nutritional status. Am J Clin Nutr 1976; 29:46 2 1. Iλ;vanga SK , Lemeshow S: Sample size determination in health studies: a practice manual. World Health Organization , Geneva , 1991 , 80 pp 22. Eveleth PB: Differences between populations in body shape of children and adolescents. Am J Phys Anthropol 1978; 49:373 23. Frisch RE , McArthur JW: Menstrual cycles: fatness as a determinant of minimum weight for height necessary for their maintenance or onse t. Science 1974; 185:949