TimingofPubertalMilestonesinLow-and Middle-IncomeCountries:ASystematicReviewand Meta-Analysis

Abstract

Despite increasing global attention to adolescent health in low- and middle-income countries (LMICs), limited literature exists on the timing of pubertaldevelopmentinthesesettings.Thisstudyaimedtodeterminetheageatmenarche(AAM)andageofpubertyonset[femaleTannerStage Breast 2 (B2) and male Tanner Stage Genital 2 (G2)] among healthy adolescents living in LMICs. It also aimed to explore the impact of nutritional status on pubertal timing in this population. MEDLINE, Embase, Cochrane CENTRAL, Web of Science, Scopus, and grey literature databases were searched.Observationalstudiesandcontrolarmsofrandomizedcontrolledtrials(RCTs)withhealthyparticipantsfromLMICsborninorafter1998 wereincluded.Pooledestimateswith95%CIswerecalculatedbyrandom-effectsmeta-analysesusingtheDerSimonianandLairdinversevariance methodforeachpubertalmilestoneandbyBMIcategorysubgroups.Twenty-sevenstudieswereincludedinthemeta-analysis,representing90,188 adolescents (78.3% female). Pooled mean estimates for AAM for normal, thin, and overweight BMI groupings were 12.3 y (95% CI: 12.1, 12.5), 12.4 y (95% CI: 12.2, 12.6), and 12.1 y (95% CI: 11.7, 12.5), respectively. For Tanner Stage B2, pooled mean age estimates for normal, thin, and overweight BMI groupings were 10.4 y (95% CI: 9.2, 11.6), 10.2 y (95% CI: 9.3, 11.4), and 8.4 y (95% CI: 6.8, 10.0), respectively. Finally, for Tanner Stage G2, pooled mean estimates for normal, thin, and overweight BMI groupings were 11.0 y (95% CI: 10.3, 11.7), 11.3 y (95% CI: 9.8, 12.9), and 10.3y(95%CI:10.0,10.6),respectively.Dataonthetimingofpubertalmilestoneshastraditionallycomefromhigh-incomesettings.Inthissystematic review of contemporary data from adolescents in LMICs, AAM, as well as age at pubertal onset, were similar to those reported from high-income settings