Decline in age at menarche among Spanish women born from 1925 to 1962

<p>Abstract</p> <p>Background</p> <p>While the timing of reproductive events varies across populations, a downward trend in age at menarche has nevertheless been reported in most of the developed world over the past century. Given the impact of change in age at menarche on health conditions, this study sought to examine secular trends in age at menarche among women living in Navarre (Northern Spain) who participated in a population-based breast cancer screening programme.</p> <p>Methods</p> <p>The study was based on 110545 women born from 1925 to 1962. Trends were tested using a linear regression model, in which year of birth was entered continuously as the predictor and age at menarche (years) as the response variable, using size of town and region of birth as covariates.</p> <p>Results</p> <p>Among women born in Navarre between 1925 and 1962, age at menarche declined steadily from an average of 13.72 years in the 1925-1929 birth-cohorts to 12.83 years in the 1958-1962 birth-cohorts. Controlling for size of town or city of birth, age at menarche declined by an average of 0.132 years every 5 years over the period 1925-1962. This decline was greater in women born in rural versus urban settings. Trends were also different among regions of birth.</p> <p>Conclusion</p> <p>We report a population-based study showing a downward trend in age of onset of menarche among Spanish women born in the period 1925-1962, something that is more pronounced among women born in rural settings and varies geographically.</p

Long-term consequences of early linear growth retardation (stunting) in Swedish children

Linear growth retardation (stunting) is prevalent (10-80%) in developing countries. It takes place between 6 and 18 mo of age and can be characterized by the delayed onset of the childhood phase of growth. The objective of this work was to study the existence of stunting in early life and, when present, its lifelong effects on final height in a normal healthy population in a developed country. A total of 2432 children with longitudinal height data from birth to adulthood were analyzed. The series represents a normal healthy population-based sample of full-term children born around 1974 in Goteborg, Sweden. We found the incidence of stunting to be about 10% as indicated by delayed onset of the childhood phase of growth (> 12 mo of age): 14% in boys and 8% in girls. In a multiple linear regression model, final height was described by length at 6 mo of age, age at onset of the childhood phase of growth, and age at peak height velocity during puberty. All three measures contributed significantly (p < 0.05) to final height with a total R2 of 0.33. A final height difference of 5.0 cm could be explained by abnormal onset of the childhood phase of growth in this normal population. The timing of the childhood onset of growth did not correlate with the timing of puberty. For the first time, we can conclude that stunting in early life is not only a problem in developing countries. Its importance on final height achieved is clearly shown, even after controlling for the timing of puberty.link_to_subscribed_fulltex

The ovine Booroola fecundity gene (FecB) is linked to markers from a region of human chromosome 4q

The autosomal Booroola fecundity gene (FecB) mutation in sheep increases ovulation rate and litter size, with associated effects on ovarian physiology and hormone profiles. Analysis of segregation in twelve families (379 female progeny) identified linkage between the mutation, two microsatellite markers (OarAE101 and OarHH55, Zmax &gt; 9.0) and epidermal growth factor (EGF) from human chromosome 4q25 (Zmax &gt; 3.0). The marker OarAE101 was linked to secreted phosphoprotein 1 (SPP1, which maps to chromosome 4q21-23 in man) in the test pedigrees and independent families (Zmax &gt; 9.7). The identification of linkage between the FecB mutation and markers from human chromosome 4q is an important step towards further understanding the control of ovulation rates in mammals