Adult stature and age at menarche in Zapotec‐speaking communities in the Valley of Oaxaca, Mexico, in a secular perspective

Abstract

Adult stature and the age at menarche among individuals from Zapotec-speaking communities in the Valley of Oaxaca in southern Mexico are considered in a secular perspective. Four sets of observations are utilized: 1) adult stature in males and females from five rural communities; 2) age at menarche in adult women and school girls from a single rural community; 3) earlier studies of adult stature in the Valley of Oaxaca; and 4) estimated stature from long bones excavated in various archaeological sites in the Valley of Oaxaca. There were no significant differences among the five communities for stature; hence, the data were pooled for analysis and comparison. Results of linear regression of stature and stature adjusted for the estimated effects of aging after 30 years of age on year of birth indicate negligible secular changes in either sex. Comparisons with statures from earlier surveys, the earliest dates to 1899, also indicate negligible changes. When adult women are grouped according to age, there are no differences in mean ages at menarche between the older and younger women. Mean age at menarche for the total adult sample is 14.53 +/- 0.08 years, which compares favorably with the probit estimate for school girls, 14.70 +/- 0.32 years. These results thus suggest virtually no secular change in adult size and maturity of the Zapotec-speaking population in the Valley of Oaxaca over the past 80 years. Differences in stature between contemporary populations and estimated statures from long bones from several archaeological sites in Oaxaca are small, and thus suggests little secular change over the past one to two-thousand years.

Age and size at maturity in women: A norm of reaction?

“…This latter pattern is reasonable given known secular changes. People in societies with poorer growth conditions, including both current and historical societies, tend to reach puberty at a later age and attain a smaller adult height and weight (Cole, 2000;Malina, 1979;Malina et al, 1983;Roche, 1979). Models with mixed effects, however, showed an opposite, positive association of 1.42 cm/year (95% confidence interval: 0.33-2.51).…”

Socioeconomic variation in the growth status of urban school children 6–13 years in Oaxaca, Mexico, in 1972 and 2000

“…Such conditions have apparently been in place for some time in Mexico. Height of an indigenous adults showed no evidence of secular gains since the mid of 1890s (Faulhaber, 1970;Himes and Malina, 1975;Malina et al, 1983;McCullough, 1982).…”

Search for secular trends in calvarial diameters, cranial base height, indices, and capacity in South African Negro crania

“…In order to prevent confusion, this trend towards smaller size was described as a "negative" secular trend by Tobias (1975) in contrast to the "positive" secular trend when size increases and an "absent" secular trend when no systematic change was detected. A negative or absent secular trend has been described in eight non-African countries by Kenntner (1963) and in India (Vogel, 19711, Brazil (Eveleth and Tanner, 1976), Peru (Frisancho et al, 1979, and Mexico (Malina et al, 1980, 1983. Similar findings have been found in Africa (Malawi, Angola, Kenya, Uganda, and SWNNamibia) and particularly in South Africa (Tobias, 1975(Tobias, , 1978(Tobias, , 1985(Tobias, , 1986Tobias and Netscher, 1975;Price et al, 1987).…”