ARE THERE LONG-TERM HEALTH CONSEQUENCES OF SECULAR TREND IN EARLY MENARCHE

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.