Secular change in height, sitting height and leg length in rural Oaxaca, southern Mexico: 1968-2000

OBJECTIVE: To evaluate secular changes in height, sitting height and estimated leg length between 1968 and 2000 in residents in a rural Zapotec-speaking community in Oaxaca, southern Mexico. MATERIALS AND METHODS: Height and sitting height were measured in school children 6-13 years (1968; 1978, 2000), in adolescents 13-17 years (1978, 2002) and adults 19-29 years (1978, 2000). Leg length was estimated as height minus sitting height. The sitting height/ height ratio was calculated. Subjects were grouped by sex into four age categories: 6-9, 10-13, 13-17 and 19-29 years for analysis. The Preece-Baines Model I growth curve was fitted to cross-sectional means for 1978 and 2000. RESULTS: There were no differences between children 6-9 and 10-13 years in 1968 and 1978 with the exception of the sitting height ratio in girls 6-9 years. Children of both sexes 6-13 years and adolescent boys 13-17 years were significantly larger in the three dimensions in 2000 compared to 1978; adolescent girls differed only in height and sitting height. Adult males in 2000 were significantly taller with longer legs than those in 1978, but the samples did not differ in sitting height and the ratio. Adult females in 1978 and 2000 did not differ significantly in the three dimensions. Rates of secular change in height and sitting height between 1978 and 2000 were reasonably similar in the three age groups of male children and adolescents, but the rate for estimated leg length was highest in 10-13-year-old boys. Secular gains were smaller in adult males, but were proportionally greater in estimated leg length. Girls 6-9 and 10-13 years experienced greater secular gains in height, sitting height and estimated leg length than adolescent and young adult females, while secular gains and rates decreased from adolescent girls to young adult women. Ages of peak velocity for height, sitting height and estimated leg length declined in boys, while only ages of peak velocity for height and estimated leg length declined in girls. CONCLUSIONS: There are major secular increases in height, sitting height and estimated leg length of children and adolescents of both sexes since 1978. Secular gains in height are of similar magnitude in boys and girls 6-13 years, but are greater in adolescent and young adult males than females. The secular increase in height of young adults of both sexes is smaller than that among adolescents. Estimated leg length accounts for about 60% of the secular increase in height in children of both sexes. Estimated leg length and sitting height contribute equally to the secular increase in height in adolescent boys, whereas estimated leg length accounts for about 70% of the secular increase in height in young adult males. Sitting height contributes about two-thirds of the secular increase in height in adolescent and young adult females.     

Overweight and obesity in a rural Amerindian population in Oaxaca, Southern Mexico, 1968-2000.

The purpose of this study was to evaluate secular change in the prevalence of overweight and obesity in a rural Zapotec Indian community in southern Mexico between 1968 and 2000. Cross-sectional surveys of children 6-13 years, adolescents 13-17 years, and adults 19 years of age and older resident in a rural community in Oaxaca were conducted in 1968/1971, 1978, and 2000. Individuals present in the 1968, 1978, and 2000 surveys provided a small longitudinal component. Height and weight were measured; the BMI was calculated. International criteria for overweight and obesity were used. Overweight and obesity were virtually absent in school children 6-13 years in 1968 and 1978 and in adolescents in 1978. Small proportions of children (boys, 5%; girls, 8%) and adolescents (boys, 3%; girls, 15%) were overweight in 2000; two children (1%) and no adolescents were obese. Among adults, 7% of males and 19% of females were overweight and <1% of males and 4% of females were obese in 1971/1978, but 46% of males and 47% of females were overweight; and 5% of males and 14% of females were obese in 2000. The trends for children, adolescents, and adults were confirmed in the longitudinal subsamples. In conclusion, overweight and obesity are not presently a major problem in children and adolescents in this rural Zapotec community. Overweight, in particular, and to a lesser extent obesity have increased in prevalence among adults since the late 1970s. The results suggest adulthood as a critical period for onset of overweight and obesity in this sample.     

Secular trend in the age at menarche in Haiti

Trends in age at menarche of 10,563 pregnant Haitian women enrolled in a longitudinal study of maternal mortality are examined. Mean recalled age at menarche for adult women in the sample was 15.37 years. However, there was a clear decline in mean menarcheal ages from the oldest to the youngest women, with a mean rate of decline for adult women of 0.36 years per decade. Mean menarcheal age was higher in each age group of rural women than for women in the metropolitan Port-au-Prince area; the rate of decline for adult rural women (0.37 years per decade) was nonsignificantly higher than that for adult metropolitan women (0.30 years per decade). The data suggest a secular decline in age at menarche in Haiti, as well as a continuing disparity between metropolitan and rural women. A declining age at menarche has important implications for fertility and reproductive health in Haiti, and may reflect a gradual improvement in health and nutritional status. © 1995 Wiley-Liss, Inc.     

Genetic diversity of HLA system in two populations from Oaxaca,Mexico: Oaxaca city and rural Oaxaca

We studied HLA class I (HLA-A, -B) and class II (HLA-DRB1, -DQB1) alleles by PCR-SSP based typing in 636 Mexicans from the state of Oaxaca living in the city of Oaxaca (N = 151) and rural communities (N = 485), to obtain information regarding allelic and haplotypic frequencies. We found that the 13 most frequent haplotypes in Oaxaca are all of putative Native American origin. Admixture estimates revealed that the main genetic components in the state of Oaxaca are Native American (73.12 ± 2.77% by ML; 61.52% of Native American haplotypes) and European (17.36 ± 2.07% by ML; 20.69% of European haplotypes), and a relatively high African genetic component (9.52 ± 0.88% by ML; 8.94% of African haplotypes).     

Secular change in menarche in women in Madrid

The age at menarche was estimated by recollection in 1617 women between the ages of 18 and 60 in Madrid and a nearby suburb, Pinto. The population of Pinto is working-class and the Madrid group, taken from residential neighbourhoods , belongs to the upper middle class. In both groups we found a diminution in average age at menarche, from 14.04 to 13.02 years in Madrid and from 14.55 to 13.16 years from about 1935 to about 1965 in Pinto. These changes have been more intense in the group which is less well-off economically, where living conditions have varied much more drastically.     

Age of menarche in Oaxaca,Mexico, schoolgirls,with comparative data for other areas of Mexico

Status quo menarcheal information was collected for a mixed urban colonia and rural sample of 315 girls in the Valley of Oaxaca, Mexico. Comparative status quo data for girls from four major urban centres in Mexico and for a rural sample were also analysed. Median age at menarche (estimated by probit analysis) for Oaxaca girls was 14·27±0·20 years, about 0·5 year later than that for the rural sample from Tampico-Altamira, Tamaulipas (13·79±0·20 years), and approximately 1·5 years later than that for girls from the four urban centres in Mexico (12·55±0·10, 12·61±0·08, 12·75±0·10, 12·76±0·07 years). The timing of menarche in Oaxaca girls is similar to that for rural Mayans in Guatemala. Ages at menarche for urban Mexican girls are somewhat lower than those for girls of North-west European ancestry and of North American girls of European ancestry.     

Age of menarche in Oaxaca, Mexico, schoolgirls, with comparative data for other areas of Mexico

Status quo menarcheal information was collected for a mixed urban colonia and rural sample of 315 girls in the Valley of Oaxaca, Mexico. Comparative status quo data for girls from four major urban centres in Mexico, and for a rural sample were also analysed. Median age at menarche (estimated by probit analysis) for Oaxaca girls was 14.27 +/- 0.20 years, about 0.5 year later than that for the rural sample from Tampico-Altamira, Tamaulipas (13.79 +/- 0.20 years), and approximately 1.5 years later than that for girls from the four urban centres in Mexico (12.55 +/- 0.10, 12.61 +/- 0.08, 12.75 +/- 0.10, 12.76 +/- 0.07 years). The timing of menarche in Oaxaca girls is similar to that for rural Mayans in Guatemala. Ages at menarche for urban Mexican girls are somewhat lower than those for girls of North-west European ancestry and of North American girls of European ancestry.     

Early childhood determinants of age at menarche in rural guatemala

The influence of early childhood determinants on age at menarche was investigated in a sample of Guatemalan women who participated as children in a nutrition intervention study conducted from 1969 to 1977. Age at menarche was retrospectively estimated in 1991 and 1992. Mean age at menarche was 13.7 (±1.3) years. Data on linear growth, diarrhea and respiratory illnesses, and energy intake from supplementation as well as home sources were available between birth and 7 years of age. Socioeconomic status (SES) data were collected in 1975. Four hundred and ninety-seven women who had reached menarche by 1992 were grouped into three categories of stunting based on their height-for-age z-scores (none, >−2.0; moderate, −2.0 SD to −3.0 SD; severe, <−3.0 SD relative to National Center for Health Statistics reference data) at 3 years of age. About 78% of the sample was moderately or severely stunted at 3 years of age. The group that was severely stunted in childhood reached menarche at 14.1 ± 1.4 years, significantly later than those who were moderately stunted (13.7 ± 1.2 years) or not stunted (13.5 ± 1.3 years). Using multiple linear regression methods, stunting was a significant predictor of age at menarche. Average energy intake (kcal/d) from home diet was associated with earlier menarche independent of preschool growth status. Percent time ill with diarrhea was positively associated with age at menarche. When the effects of diet, supplement, percent time ill with diarrhea and respiratory illnesses, and SES were taken into account, the independent influence of stunting on age at menarche persisted and remained significant. © 1996 Wiley-Liss, Inc.     

Secular trends in age at menarche among Caboclo populations from Pará, Amazonia, Brazil: 1930-1980.

The present study is part of a large research project on growth, development, nutrition, and health of Caboclo populations from the Brazilian Amazon. The aim of this paper is to analyze the age of menarche in adolescents (N=164) and adult women (219) in the studied populations. Caboclo are admixed rural, peasant groups that live along the Amazon river and its tributaries, and there are few previous studies about them. Probit analysis of the status quo data yielded a median age at menarche of 12.29+/-1.76 years. The retrospective method was applied to recall data of the 77 post-menarcheal adolescents, yielding an average of 13.06+/-1.27 years. Number of children in the family did not show any statistical influence on age at menarche in any age group. In adult women, age at menarche decreased from 14.50 in those born in 1930 to 12.88 for those born in 1980 (F=4.371, P=0.001). The downward trend found was, on average, 0.237 year per decade in the study period. The median age at menarche in the adolescents (12.29 years) is one of the lowest values found for Central and South American populations. In the ecological context, a low age at menarche could be an adaptive advantage because it provides a greater chance for reproduction at a young age in an environment where, until recently, life expectancy was low. As has been reported for other developing countries, the change found in age at menarche in the women born from the 1930s to the 1980s is likely to be related to changes in health and nutritional factors that occurred in Brazil because this country experienced significant improvement in living standards related to education, vaccination, and health conditions, which, although not equally, reached all regions after the 1960s.     

Nutritional status and age at menarche in a rural area of Bangladesh

The age at menarche and its association with nutritional status in a rural area of Bangladesh was determined. A cross-sectional study was conducted in four villages of Rupganj Thana of Narayanganj district. Data was collected through October to December 1996 using a pre-tested structured questionnaire interview schedule, and nutritional status was measured by weight, height, body mass index (BMI) and physical examination. Data were obtained on 436 adolescent girls aged 10-17 years. Among them, 165 (37.8%) girls had commenced menarche. The mean age at menarche as determined by retrospective recall was 13 years SD 0.89 (n = 165). The median age at menarche determined by the status quo method was 13.0. Among the adolescents 60.1% were thin (BMI < 5th centile WHO recommended reference) and 48.2% were stunted (< 3rd centile NCHS/WHO). The mean weight and BMI were significantly higher among the menstruating girls of 13, 14 and 15 years (p < 0.01) than non-menstruating girls. The mean height was found to be significantly higher at 11-14 years among the menstruating girls (p < 0.05). A lower prevalence of angular stomatitis was found among the menstruating adolescent girls compared with the non-menstruating girls, 36.4% versus 46.5%, although this was statistically non-significant (odds ratio = 0.66, 95% CI 0.43-1.00). For glossitis, no significant difference was found. Among the menstruating girls 12.1% were suffering from menorrhagia and 31.5% from dysmenorrhoea. We conclude that the age of menarche among this rural Bangladeshi community is not as delayed as expected. Not surprisingly, menarche is associated with better nutritional status. The surveyed population had extremely high rates of undernutrition which suggests that adolescents in this and similar situations require specific intervention programmes to improve their nutritional status.     

Nutritional status and age at menarche in a rural area of Bangladesh

The age at menarche and its association with nutritional status in a rural area of Bangladesh was determined. A cross-sectional study was conducted in four villages of Rupganj Thana of Narayanganj district. Data was collected through October to December 1996 using a pre-tested structured questionnaire interview schedule, and nutritional status was measured by weight, height, body mass index (BMI) and physical examination. Data were obtained on 436 adolescent girls aged 10-17 years. Among them, 165 (37.8%) girls had commenced menarche. The mean age at menarche as determined by retrospective recall was 13 years SD 0.89 (n=165). The median age at menarche determined by the status quo method was 13.0. Among the adolescents 60.1% were thin (BMI&lt; 5th centile WHO recommended reference) and 48.2% were stunted (&lt; 3rd centile NCHS/WHO). The mean weight and BMI were significantly higher among the menstruating girls of 13, 14 and 15 years (p &lt; 0.01) than non-menstruating girls. The mean height was found to be significantly higher at 11-14 years among the menstruating girls (p &lt; 0.05). A lower prevalence of angular stomatitis was found among the menstruating adolescent girls compared with the non-menstruating girls, 36.4% versus 46.5%, although this was statistically non-significant (odds ratio=0.66, 95% CI 0.43-1.00). For glossitis, no significant difference was found. Among the menstruating girls 12.1% were suffering from menorrhagia and 31.5% from dysmenorrhoea. We conclude that the age of menarche among this rural Bangladeshi community is not as delayed as expected. Not surprisingly, menarche is associated with better nutritional status. The surveyed population had extremely high rates of undernutrition which suggests that adolescents in this and similar situations require specific intervention programmes to improve their nutritional status.     

Secular trend in age at menarche for women born between 1920 and 1979 in Rio de Janeiro, Brazil

PRIMARY OBJECTIVE: This article presents data on the secular trend in age at menarche for 1955 women from 16 to 76 years of age born between 1920 and 1979 and studied under the Nutrition and Health Survey conducted in the municipality of Rio de Janeiro, Brazil, in 1996. METHODS AND PROCEDURES: Age at menarche was defined by the retrospective method. Women were grouped according to decade of birth, and the trend was estimated using simple linear regression between age at menarche and year of birth for the following specific periods: 1920-1940, 1920-1960, 1960-1979 and 1920-1979. MAIN OUTCOMES AND RESULTS: Mean age at menarche decreased from 13.07 to 12.40 years when comparing the group of women born in the 1920s with the 1970s birth cohort, corresponding to a mean rate of -0.0123 years per year (p < 0.001). The downward trend was -0.0120 years per year (p > 0.05) for the 1920s, 30s and 40s, -0.0093 years per year (p < 0.05) for the period from 1920 to 1960, and -0.0224 years per year (p < 0.01) for the 1960s/70s. CONCLUSIONS: The results suggest a secular trend in age at menarche. The literature points to such environmental variables as improved living conditions and expanded access to health services. Within this context, age at menarche could be used as a marker for social development.     

Age at menarche in rural France

Data upon age at menarche have been collected among 254 schoolgirls of a relatively endogamous rural population in central France. The median age at menarche estimated by probits was 13·05±0·18, SD1·42. This accords well with results obtained from urban samples in the years 1965–68. Both rural and urban samples give a median age 0·5 year earlier than data from a national survey performed in 1950.     

SHORT REPORT: Secular trend in age at menarche for women born between 1920 and 1979 in Rio de Janeiro,Brazil

Primary objective: This article presents data on the secular trend in age at menarche for 1955 women from 16 to 76 years of age born between 1920 and 1979 and studied under the Nutrition and Health Survey conducted in the municipality of Rio de Janeiro, Brazil, in 1996.

Methods and procedures: Age at menarche was defined by the retrospective method. Women were grouped according to decade of birth, and the trend was estimated using simple linear regression between age at menarche and year of birth for the following specific periods: 1920-1940, 1920-1960, 1960-1979 and 1920-1979.

Main outcomes and results: Mean age at menarche decreased from 13.07 to 12.40 years when comparing the group of women born in the 1920s with the 1970s birth cohort, corresponding to a mean rate of -0.0123 years per year (p &lt; 0.001). The downward trend was -0.0120 years per year (p &gt; 0.05) for the 1920s, 30s and 40s, -0.0093 years per year (p &lt; 0.05) for the period from 1920 to 1960, and -0.0224 years per year (p &lt; 0.01) for the 1960s/70s.

Conclusions: The results suggest a secular trend in age at menarche. The literature points to such environmental variables as improved living conditions and expanded access to health services. Within this context, age at menarche could be used as a marker for social development.     

The age at menarche in Somalia

The mean age at menarche calculated by the recollected-age method for 524 Somalian girls, all over 16 years of age, was 14·78±0·07 years. The subjects, gathered from schools and other communities in the capital and from the Catholic Missions in Benadir and Upper and Lower Giuba, originated from all the regions of the country. Regions showed a significant difference in menarcheal age.