Age at menarche in Peruvian girls at sea level and at high altitude: Effect of ethnic background and socioeconomic status

Gonzáles, Gustavo F.; Villena, Arturo; Ubilluz, Milward

doi:10.1002/(sici)1520-6300(1996)8:4<457::aid-ajhb5>3.0.co;2-v

Cited by 24 publications

(15 citation statements)

References 12 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Other factors such as nutrition (Simodon et al, 1997), seasonality (Boldsen, 1992), physical activity (Malina, 1983), and altitude (Gonzales et al, 1996) also have shown a significant effect on age at menarche. In a recent review of published studies on the variability of age at menarche throughout the world, Thomas et al (2001) found that the factors that best explained the variation in age at menarche were adult illiteracy rate and vegetable caloric consumption.…”

supporting

confidence: 84%

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

Silva

Padez

2005

American J Hum Biol

View full text Add to dashboard Cite

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 ¼ 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 AE 1.76 years. The retrospective method was applied to recall data of the 77 post-menarcheal adolescents, yielding an average of 13.06 AE 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 ¼ 4.371, P ¼ 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.

show abstract

supporting

confidence: 84%

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

Silva

Padez

2005

American J Hum Biol

View full text Add to dashboard Cite

show abstract

“…Only subjects who had not yet reached sexual maturation (boys) or menarche (girls) were enrolled into the study. Sexual maturation is delayed in this population, as has been observed for other high-altitude populations in the region (Gonzales et al, 1996;Greksa, 1990).…”

Section: Subjectssupporting

confidence: 77%

Regression‐based prediction of net energy expenditure in children performing activities at high altitude

Sarton-Miller

Holman

Spielvogel

2003

American J Hum Biol

View full text Add to dashboard Cite

We developed a simple, non-invasive, and affordable method for estimating net energy expenditure (EE) in children performing activities at high altitude. A regression-based method predicts net oxygen consumption (VO(2)) from net heart rate (HR) along with several covariates. The method is atypical in that, the "net" measures are taken as the difference between exercise and resting VO(2) (DeltaVO(2)) and the difference between exercise and resting HR (DeltaHR); DeltaVO(2) partially corrects for resting metabolic rate and for posture, and DeltaHR controls for inter-individual variation in physiology and for posture. Twenty children between 8 and 13 years of age, born and raised in La Paz, Bolivia (altitude 3,600m), made up the reference sample. Anthropometric measures were taken, and VO(2) was assessed while the children performed graded exercise tests on a cycle ergometer. A repeated-measures prediction equation was developed, and maximum likelihood estimates of parameters were found from 75 observations on 20 children. The final model included the variables DeltaHR, DeltaHR(2), weight, and sex. The effectiveness of the method was established using leave-one-out cross-validation, yielding a prediction error rate of 0.126 for a mean DeltaVO(2) of 0.693 (SD 0.315). The correlation between the predicted and measured DeltaVO(2) was r = 0.917, suggesting that a useful prediction equation can be produced using paired VO(2) and HR measurements on a relatively small reference sample. The resulting prediction equation can be used for estimating EE from HR in free-living children performing habitual activities in the Bolivian Andes.

show abstract

“…This could be related to the delayed presentation of adrenarche and delayed onset of puberty observed in girls living at high altitude compared with those living at sea level (Góñez et al 1993, Gonzales et al 1996. Early age at adrenopause could also be related to the early onset of menopause observed at high altitude (Gonzales & Villena 1997).…”

Section: Discussionmentioning

confidence: 99%

Adrenopause or decline of serum adrenal androgens with age in women living at sea level or at high altitude

Gonzales¹,

Góñez²,

Villena³

2002

Journal of Endocrinology

View full text Add to dashboard Cite

The present study aimed to determine adrenopause or reduction of serum adrenal androgens with age at high altitude and at sea level. It was a cross-sectional study performed in 210 women resident at high altitude (4340 m) and 123 women living in Lima (150 m), aged 20-70 years. Fasting early morning blood samples were obtained. Serum dehydroepiandrosterone (DHEA), DHEA sulphate (DHEAS), androstenedione, testosterone and estradiol were measured by radioimmunoassay. Serum testosterone concentrations were greater in women living at high altitude than in those resident at sea level. Serum concentrations of DHEA, DHEAS and androstenedione were lower in women living at high altitude than in those living at sea level. The DHEAS/DHEA ratio was significantly greater, and the androstenedione/testosterone ratio was lower in samples from women living at high altitude. Among women older than 50 years of age, a greater decline in serum concentrations of DHEA was observed in those living at high altitude than in those living at sea level. Among women 60-70 years of age, serum concentrations of DHEA at high altitude were 46·9% of those in women of the same age living at sea level. Decay of DHEAS at sea level and at high altitude occurred from the age of 40 years. The decline was faster at high altitude than at sea level, and in women aged 60-70 years serum values of DHEAS at high altitude were 56% of those at sea level. In the same age group, serum concentrations of androstenedione among those native to high altitudes were 27·34% of the value at sea level. At sea level, serum testosterone concentrations did not change with age from 20 to 70 years. In women aged 20-39 years and 50-59 years, serum testosterone concentrations were greater at high altitude than at sea level (P<0·05). In those aged 60-70 years, the concentrations were similar in those living at sea level and at high altitude. At sea level and at high altitude, the serum testosterone/estradiol ratio increased with age (P<0·0034 and P<0·0001 respectively). This ratio increased at an earlier age among those living at high altitude (40-49 years) than among those living at sea level (50-59 years). Multivariate analysis showed that altitude (P<0·0001) and greater chronological age (P<0·001) were associated with lower serum DHEAS concentrations. DHEAS was related to chronological age (P<0·0001). Low serum androstenedione concentrations were related to living at high altitude at birth and greater chronological age (P<0·0001). In conclusion, adrenopause is attained earlier and is of greater magnitude at high altitude than at sea level.

show abstract

Age at menarche in Peruvian girls at sea level and at high altitude: Effect of ethnic background and socioeconomic status

Cited by 24 publications

References 12 publications

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

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

Regression‐based prediction of net energy expenditure in children performing activities at high altitude

Adrenopause or decline of serum adrenal androgens with age in women living at sea level or at high altitude

Contact Info

Product

Resources

About