Effects of obesity on human sexual development

Abstract

Puberty is a period of physical and psychological maturation, with long-term effects on health. During the 20(th) century, a secular trend towards earlier puberty occurred in association with improvements in nutrition. The worldwide pandemic of childhood obesity has renewed interest in the relationship between body composition in childhood and the timing and tempo of puberty. Limited evidence suggests that earlier puberty is associated with a tendency towards central fat deposition; therefore, pubertal status needs to be carefully considered in the categorization of childhood and adolescent overweight and obesity. In the other direction, rapid early weight gain is associated with advanced puberty in both sexes, and a clear association exists between increasing BMI and earlier pubertal development in girls. Evidence in boys is less clear, with the majority of studies showing obesity to be associated with earlier puberty and voice break, although a subgroup of boys with obesity exhibits late puberty, perhaps as a variation of constitutional delay in growth and puberty. The possible mechanisms linking adiposity with pubertal timing are numerous, but leptin, adipocytokines and gut peptides are central players. Other possible mediators include genetic variation and environmental factors such as endocrine disrupting chemicals. This Review presents current evidence on this topic, highlighting inconsistencies and opportunities for future research.

MANAGEMENT OF ENDOCRINE DISEASE: Long-term outcomes of the treatment of central precocious puberty

“…Several studies reported an association between overweight and early/precocious puberty (5, 33) suggesting the involvement of various environmental, genetic, and biochemical factors (5,7,17,34,35) to explain this association. However, what remains to be clarified is whether it is the high BMI that results in precocious pubertal development or is it the latter that promotes the weight gain (33,35).…”

Study of lipid metabolism-related genes as candidate genes of sexual precocity in Nellore cattle

“…Nellore heifers that are heavier at 12 and 18 months go into first heat at a younger age (Alencar et al, 1987). Recent studies in humans have shown that girls with a relatively higher body mass index are more likely to menstruate early (Kaplowitz, 2008;Wagner et al, 2012). In addition to the correlation of weight gain with sexual precocity, adipose tissue has been identified as the main site of metabolism of steroid hormones (Siiteri, 1987), a factor related to the onset of reproductive activity.…”

Age at spermarche: 15‐year trend and its association with body mass index in Chinese school‐aged boys

“…However, the studies analyzing association between BMI and spermarche in boys are scare. Although previous studies have used different variables, such as voice break, age at onset of pubertal growth spurt and at peak height velocity, pubic hair development, testicular volume, and penis length to assess male puberty (9)(10)(11)(12)(13), the findings of association between BMI and those variables are controversial (9). Some studies in Europe report that estimated mean age at onset of puberty, such as age at onset of pubertal growth spurt and at peak height velocity, age of initial 4 appearance of pubic hair, and age at attainment of testicular volume above 3 ml has declined with the coincident increase in BMI (10-13), whereas among US boys a negative association has been found between boys' testicular volume and BMI (14) and higher BMI in earlier childhood may be associated with later onset of puberty which is measured by Tanner genitalia staging in a longitudinal study (15).…”