Age at menarche is used as both a marker of maturational timing and as
a population-based indicator of general socioeconomic and nutritional
well being. The presence of continuing secular trend in earlier menar
chial age among industrial or non-industrial populations and the fact
that populations in North America, Europe and parts of the Pacific Rim
have experienced marked deceleration of this trend over the past 20 y
ears, have strengthened the view that these populations are experienci
ng improvement in health. Few studies have addressed the consequences
of secular trend in body size or decreasing age at menarche from the p
erspective of long- term effects on adult health outcomes, specificall
y with respect to risk factors of chronic diseases. To this end, data
on age at menarche, weight, and triceps and subscapular skinfolds are
presented for 1578 women born between 1890 and 1950 from the Tecumseh
Community Health Surveys. In Tecumseh, secular trend in menarche was a
ccompanied by a doubling of the frequency of women attaining menarche
younger than age 12. Age-specific normalized Z-scores of weight and su
bcutaneous skinfolds show that early menarche women are significantly
heavier and fatter throughout adulthood, placing them at higher risk f
or obesity-related chronic diseases. Moreover, teenage sons and daught
ers of early menarche Tecumseh women were heavier and showed increased
skinfolds. Higher relative life-time risk for breast cancer and other
estrogen-mediated cancers are implicated from these results.