Table 1.
Sample characteristics
| Cohorta | Sample size | Smoking statusb | Sex | Age (years) | BMI | Ethnicityc | |||
|---|---|---|---|---|---|---|---|---|---|
| S (n) | F (n) | NS (n) | F (%) | M (%) | |||||
| Discovery stage | |||||||||
| TwinsUK | 407 | 23 | 237 | 147 | 100 | 0 | 64 ± 8 | 26.8 ± 5.0 | White British |
| NSHD | 236 | 23 | 75 | 138 | 60 | 40 | 63 ± 0.5 | 27.9 ± 4.7 | White British |
| NCDS1 | 235 | 53 | 118 | 64 | 53 | 47 | 45 | 25.6 ± 4.3 | White British |
| NCDS2 | 294 | 125 | 87 | 82 | 51 | 49 | 45 | 25.8 ± 4.3 | White British |
| BCS70 | 235 | 45 | 126 | 64 | 57 | 43 | 46 | 26.6 ± 5.0 | White British |
| Replication stage | |||||||||
| SHS | 2325 | 893 | 648 | 748 | 59 | 41 | 55 ± 6 | 29.6 ± 3.0 | American Indian |
| GENOA | 1100 | 179 | 255 | 666 | 71 | 29 | 56 ± 10 | 31 ± 6.6 | African-American |
aCohort abbreviations: TwinsUK: https://twinsuk.ac.uk/, NSHD: MRC National Survey of Health and Development, NCDS: National Child Development Study (NCDS1 = selected to minimize data missingness, but not selected for specific exposures and trait outcomes. NCDS2 = selected for extremes of child and adulthood adversity), BCS70: 1970 British Cohort Study, SHS: Strong Heart Study. GENOA: Genetic Epidemiology Network of Arteriopathy
bSmoking status, age and BMI are obtained at the date of blood draw for DNA methylation profiling. Smoking status (S = smoker, F = former smoker, NS = never smoker) is determined through questionnaires
cParticipants from the UK population cohorts are predominantly “White British.” NCDS2 includes one individual who did not identify as “White British” (“Mixed”). BCS70 includes three individuals who did not identify as “White British” (one “White Other”, one “White and Asian” and one “Other Ethnic Group”)