Table 1.

Summary of the Main Study Findings Regarding the Association between Race/Ethnicity and Telomere Length

Study	Sample	Tissue	Measurement of Race	Method	Major Findings
Okuda et al. 2002	86 black, 29 Hispanic, 48 white, and 5 other race female and male neonates born at two New Jersey hospitals	White blood cells, umbilical artery, and foreskin	Abstracted from medical record	Southern blot	No significant difference in TRF length among black, white, and Hispanic newborns in any tissue type examined in bivariate analysis.
Hunt et al. 2008	711 black and 1742 white women and men from the Family Heart Study, aged 30–93, and the Bogalusa Heart Study, aged 19–37	Leukocytes	Not discussed	Southern blot	Blacks had significantly longer age-adjusted telomere length than whites in both cohorts.
Diez Roux et al. 2009	279 black, 520 Hispanic, and 182 white women and men from the Multi-Ethnic Study of Atherosclerosis, aged 45–84	Leukocytes	Not discussed	PCR	Blacks and Hispanics had shorter telomere length than whites in age- and sex-adjusted models, but the difference was not statistically significant. Race/ethnic differences became significant after adjustment for income, education, smoking, physical activity, diet, and BMI.
Diaz et al. 2010	133 black, 184 white, and 8 other race women and men recruited from a health science university, aged 40–64	Leukocytes	Self-reported	PCR	Blacks had significantly longer telomere length than whites (unadjusted).
Geronimus et al. 2010	117 black and 115 white women from the Study of Women’s Health Across the Nation, aged 49–55	PBMCs	Self-reported	PCR	Blacks had shorter telomere length than whites in models adjusted for age, estradiol, PCR batch, and study site, but the difference was not statistically significant.
Fitzpatrick et al. 2011	168 black and 968 white/other women and men from the Cardiovascular Health Study, aged 65+	Leukocytes	Self-reported	Southern blot	Blacks had significantly longer telomere length than whites in age- and sex-adjusted models.
Zhu et al. 2011	319 black and 348 white female and male adolescents recruited from public high schools in Georgia, aged 14–18	Leukocytes	Self-reported	PCR	Blacks had significantly longer telomere length than whites in age- and sex-adjusted models.
Needham et al. 2012	35 black and 35 white female and male children from the Admixture Mapping for Ethnic and Racial Insulin Complex Outcomes Study, aged 7–12	Leukocytes	Not discussed	PCR	No significant difference in telomere length among blacks and whites in models adjusted for age, sex, family income, parent education, diet, physical activity, and BMI.
Adler et al. 2013	1053 black and 1546 white women and men from the Health, Aging, and Body Composition Study, aged 70–79	Leukocytes	Self-reported	PCR	Blacks had significantly longer telomere length than whites (unadjusted), but the difference was not statistically significant in models adjusted for age, sex, chronic conditions, study site, and batch.
Needham et al. 2013	986 black, 1377 Mexican-American, and 2997 white women and men from the National Health and Nutrition Survey, 1999–2002, aged 20–84	Leukocytes	Self-reported	PCR	Blacks had significantly longer telomere length than whites in models adjusted for age, age squared, sex, nativity, marital status, education, and poverty income ratio.
Rewak et al. 2014	27 black and 116 male and female newborns from the New England Family Study, aged ~41 years at follow up	Cord blood (infancy) and Leukocytes (adulthood)	Self-reported	PCR	Blacks had significantly longer telomere length than whites at birth and in adulthood, but the rate of shortening was greater for blacks than for whites. Models were adjusted for sex, study site, and age at follow-up (in longitudinal analysis).
Carty et al. 2015	667 black and 858 white women from the Women’s Health Initiative, aged 50–79	Leukocytes	Not discussed	Southern blot	Blacks had significantly longer age-adjusted telomere length than whites.
Drury et al. 2015	42 black and 24 white female and male neonates	Dried blood spots	Maternal race self-reported and assigned to child	MMq-PCR	Neonates born to black mothers had significantly longer telomere length than those born to white mothers in bivariate analysis and in models controlling for maternal age, maternal education, birth weight, sex of infant and paternal age.
Geronimus et al. 2015	239 black, Mexican, and white women and men from the Detroit Telomere Study, aged 25–64 (sample size by race/ethnicity not shown)	Leukocytes	Self-reported	PCR	No significant race differences in telomere length in age- and sex-adjusted models.
von Kanel et al. 2015	161 black and 180 white South African teachers from the Sympathetic Activity and Ambulatory Blood Pressure in Africans study, aged 23–66	Leukocytes	Not discussed	PCR	Blacks had significantly shorter telomere length than whites in bivariate analysis and in models controlling for age, sex, years having lived in area, HIV infection, hypertension, BMI, C-reactive protein, and alcohol abuse.
Fatctor-Litvak et al. 2016	Female and male neonates born to 45 black, 140 Hispanic, 273 white, and 32 other race mothers enrolled in the NuMoM2b study	Cord blood	Maternal race self-reported	Southern blots	Infants born to black mothers had significantly longer telomere length than those born to white mothers in bivariate analysis and in models controlling for parents’ telomere length, parents’ age, maternal race, and infant sex.
Hamad et al. 2016	1599 Black, 1110 Hispanic, 9034 white, and 191 other race women and men from the Health and Retirement Study, aged 50+	Saliva	Self-reported	PCR	Blacks and Hispanics had longer telomere length than whites in bivariate analysis. Blacks had longer telomere length than whites in models adjusted for age, sex, education, and assets. After adjusting for genetic structure, the race difference was no longer statistically significant.
Hansen et al. 2016	100 East African, 90 European, and 97 African American women and men, mean age ~43 years	Leukocytes	Not discussed	Southern blots	Africans had longer telomere length than African Americans and Europeans in age- and sex-adjusted models.
Lynch et al. 2016	142 black, 679 Hispanic, and 689 white women and men from three medical centers, aged 38–63	Leukocytes	Not discussed	Southern blots	Blacks and Hispanics had longer telomere length than whites in models controlling for age, gender, cancer status, DNA extraction method, and study site.
Raymond et al. 2016	101 black and 104 white African women and men with rheumatoid arthritis, mean age ~ 57 years	Leukocytes	Not discussed	PCR	Blacks had longer telomere length than whites (unadjusted), but the association was no longer significant after adjusting for age and gender.
Walton et al. 2016	128 Asian, 73 black, 88 white and 44 mixed/other female and male children from the London-based Exploration of Health and Lungs in the Environment study, aged 8–9	Saliva	Self-reported and genetic ancestry analysis using random SNPs	MMq-PCR	Blacks had longer telomere length than Asians and whites in models adjusted for sex, BMI, environmental tobacco, and area-level deprivation. African ancestry was associated with longer telomere length in sex-adjusted models.
Weber et al. 2016	38 black and 38 white full-term male neonates from the Hormones in Umbilical Cord Blood study	Cord blood	Not discussed	PCR	No significant race difference in telomere length before or after adjusting for maternal age and parity, neonate birthweight and placental weight, and steroid and peptide hormones.
Jones et al. 2017	34 black and 12 white pregnant women recruited in New Orleans, aged 18–41	Placental tissue (amnion, chorion, villus, umbilical cord)	Self-reported	MMq-PCR	Samples from black mothers had shorter telomere length than samples from white mothers in bivariate analysis, and the association was stronger after controlling for infant sex, maternal education and age at conception, gestational age, and duration to sample collection. The greatest difference was for chorionic telomere length.
Needham et al. 2017	Female and male neonates born in Michigan to 63 black, 67 Hispanic, and 65 white mothers	Dried blood spots	Maternal race self-reported	PCR	Infants born to black mothers had significantly longer telomere length than those born to Hispanic or white mothers in bivariate analysis and in models controlling for maternal characteristics (education, receipt of public assistance, marital status, age, obstetric complications, and infection), infant sex, gestational age, and year of birth. In models stratified by receipt of public assistance, the race difference was only significant among those who did not receive public assistance.
Weber et al. 2018	22 black and 33 white maternal-neonate pairs from the Expanded Hormones in Umbilical Cord Blood study, mothers aged 18+	Leukocytes (mothers) and cord blood (neonates)	Self-reported	PCR	No significant race difference in telomere length among mothers or neonates in maternal age- and plate-adjusted models.

PBMCs=peripheral blood mononuclear cells, PCR=polymerase chain reaction, TRF=terminal restriction fragment, BMI=body mass index, MMq-PCR=monochrome multiplex quantitative real-time PCR, SNP=single nucleotide polymorphism.

Note: p-value <0.05 considered statistically significant.