Later puberty onset among chronically undernourished adolescents living in a Karachi slum, Pakistan

Abstract

The timing of puberty onset, an important pubertal milestone, is frequently used to evaluate the general health of a population with an important impact on future health. Despite increased global attention to adolescent research, there is currently little interest in scientific research dedicated to puberty. Most recently, Deardorff et al 1 stress the importance of puberty research in understudied populations including diverse ethnic groups, boys and sexual minority youth. Research on puberty among children who reside in lowresource settings is sparse. Here, puberty is thought to be delayed due to adverse living conditions but little current research exists. A delay in pubertal timing may be protective for breast and testicular cancer, and it may also have lasting negative consequences like poor psychosocial functioning, poor academic performance, low bone mineral density, short stature and metabolic disorders. 2 Abstract Aim: To assess factors associated with the timing of puberty onset (Tanner Stage Breast 2/Genital 2) among adolescents living in an urban slum in Karachi, Pakistan.Methods: Girls enrolled at 8-10 years (n = 1009) and boys 9-11 years (n = 863) were followed every 6 months from 2006 to 2010. Parametric survival analysis for interval-censored data was used to estimate median age at puberty onset and assess the association between exposures and timing of puberty onset. Results:The overall median age at Tanner Stage Breast 2 (AAB2) was 10.1 years (95% ). Stunting delayed AAB2 1 year and AAG2 about 6 months when compared to non-stunted peers. In the multivariable model, after adjusting for age at enrolment, stunting, thinness and vitamin A deficiency (VAD) were significantly associated with delayed AAB2, while stunting and anaemia were significantly associated with delayed AAG2. Conclusion:Among adolescents living in the Karachi slum, stunting and highly prevalent anaemia delayed AAG2, while stunting, thinness and VAD delayed AAG2.Parental and household factors were not significantly associated with the timing of puberty onset. K E Y W O R D SBMI, height, micronutrients, puberty onset, undernutrition S U PP O RTI N G I N FO R M ATI O NAdditional supporting information may be found online in the Supporting Information section.

Anemia and associated factors among adolescent girls and boys at 10-14 years in rural western China

“…However, we could not provide evidence for the causality between puberty development and anemia due to the cross-sectional design. Based on a cohort study in Pakistan, Campisi and colleagues reported that anemia and stunting in childhood can delay the adolescent puberty onset [41]. We hypothesized that among female adolescents, those who had puberty onset may have better nutrition status and lower risk of anemia, on the other hand the onset of puberty among those with better nutritional status was associated with regular blood loss and higher risk of anemia, which potentially resulted in the null associations between puberty development and anemia among females.…”

Prevalence and associated factors of anemia among adolescent girls and boys at 10-14 years in rural western China

“…However, we could not provide evidence for the causality between puberty development and anemia due to the cross-sectional design. Based on a cohort study in Pakistan, Campisi and colleagues reported that anemia and stunting in childhood can delay the adolescent puberty onset [37]. We hypothesized that among female adolescents, those who had puberty onset may have better nutrition status and lower risk of anemia, on the other hand the onset of puberty among those with better nutritional status was associated with regular blood loss and risk of anemia, which potentially resulted in the null associations between puberty development and anemia among females.…”

Prevalence and Associated Factors of Anemia Among Adolescent Girls and Boys at 10-14 Years in Rural Western China

“…However, we could not provide evidence for the causality between puberty development and anemia due to the cross-sectional design. Based on a cohort study in Pakistan, Campisi and colleagues reported that anemia and stunting in childhood could delay the adolescent puberty onset [34]. We hypothesized that among female adolescents, those who had puberty onset would have better nutrition status and lower risk of anemia, but the onset of puberty was associated with regular blood loss and higher risk of anemia, consequently resulting in the null associations between puberty development and anemia.…”