Diet, body size and menarche in a multiethnic cohort

Abstract

Summary A multiethnic cohort of 1378 Southern California school girls aged 8-13 years was followed for 4 years to evaluate factors predicting age at menarche, a risk factor for breast cancer. Height and weight were measured and dietary intake was assessed using a semiquantitative food frequency questionnaire. Of 939 girls providing data on menarcheal status, 767 were premenarcheal at the start of the study; 679 girls provided acceptable dietary data and were included in the analyses. Cox proportional hazards models were used to assess the relationship between diet, body size, ethnicity and age at menarche. Hispanic, Asian/Pacific Island and African-American girls were more likely to experience early menarche than non-Hispanic white girls. Tall (> 148.6 cm) versus short (< 135.9 cm) girls experienced earlier menarche (relative hazard (RH) = 2.9, 95% confidence interval (CI) 2.1-4.1) as did those with high Quetelet's index (QI, kg m -2 ) (> 20.7) versus low QI (< 16.1) (RH = 2.2, 95% CI 1.7-2.9). Of all the dietary variables analysed, only energy intake was related to age at menarche. High versus low energy intake (> 12 013 kJ vs < 7004 kJ) was associated with a delay in menarche (RH = 0.7, 95% CI 0.5-0.9); this finding was limited to a subset of heavy Hispanic girls who appeared to underreport their dietary intake.

Longitudinal changes in risk variables underlying metabolic Syndrome X from childhood to young adulthood in female subjects with a history of early menarche: The Bogalusa Heart Study

“…16,38 Further, it has been found that the ethnic differences in menarcheal age and Tanner stages of puberty remained even after adjusting for current adiposity and social and economic factors. 39 As in previous studies, 36,[40][41][42][43] the study cohort with early menarche was taller even before the onset of menarche and continued to be so until the postmenarcheal age of 18 y. Age at peak height velocity, an indication of maximal bone growth and skeletal maturation, is known to precede the onset of menarche, probably reflecting the prepubertal stimulation by growth hormone.…”

Diet throughout childhood and age at menarche in a contemporary cohort of British girls

“…A large retrospective study of UK vegetarians in the 1990s found no difference in AAM between life-long vegetarians and those becoming vegetarian as adults (48) . Several other later studies which measured protein intake around the time of menarche found little evidence of an association (10)(11)(12)(13)(14)(15) .…”

Breast cancer among young African-American women

“…Evaluation of factors predicting age at menarche showed that Asian/Pacific Islander, Hispanic, and African-American ethnicity predicted earlier age at menarche, even after controlling for other factors. 23,27,28 Early oral contraceptive use has a modest effect on breast cancer risk in young women. 29,30 Another study showed that there was an odds ratio of 2.39 for Her-2/neu-positive versus Her-2/neu-negative tumors in women younger than 45 years who had taken oral contraceptives.…”