Table 3.

Estimated mean differences in plasma IGF-I levels associated with IGF-I SNP variants relative to estimated mean IGF-I levels for reference genotypes (italicized) based on linear regression models for premenopausal Caucasian and African American women

IGF-I SNP*IGF-I locationCaucasians
African Americans
LD blockDiplotype group (position)MAF (%)Genotypen§Mean differences or means, ng/mL (95% CI)LD blockDiplotype group (position)MAF (%)Genotypen§Mean differences or means, ng/mL (95% CI)
rs35767UpstreamOutside1 (1)16.0AG, AA1165 (−7 to 18)11 (1)40.8AA99−1 (−19 to 17)
AG264−2 (−16 to 11)
GG280171 (164-177)GG205166 (156-176)
rs5742612Upstream3.9AG, GG3021 (−1 to 42)3.3AG, GG355 (−20 to 31)
AA368171 (165-177)AA536164 (158-171)
rs5742614Intron 11.8CG1418 (−14 to 49)11 (2)11.5CG, CC1248 (−6 to 23)
GG385172 (166-178)GG444163 (156-170)
rs3729846Exon 200.8CT933 (−16 to 82)
CC399172 (166-178)CC557164 (158-170)
rs12821878Intron 212 (1)22.7AA210 (−26 to 27)Outside1 (3)5.8AG, AA64−15 (−34 to 5)
AG1395 (−8 to 17)
GG237171 (163-178)GG505167 (160-173)
rs10860869Intron 2129.1TT31−5 (−28 to 17)Outside2 (1)32.3TT5911 (−10 to 32)
AT1706 (−6 to 18)AT24912 (−1 to 25)
AA196170 (162-179)AA262158 (149-167)
rs1019731Intron 212 (2)12.3AC, AA9310 (−4 to 23)3.4AC39−10 (−34 to 14)
CC304170 (164-177)CC528165 (159-172)
rs7956547Intron 212 (3)27.3CC29−5 (−28 to 18)22 (2)26.2CC438 (−16 to 32)
CT1602 (−10 to 14)CT21010 (−3 to 23)
TT209172 (164-180)TT314160 (152-168)
rs5742626Intron 20.5CT4−3 (−61 to 54)22 (3)7.2CT, CC78−8 (−26 to 9)
TT394172 (166-178)TT491166 (159-173)
rs17880975Intron 20.1AG1−78 (−193 to 37)2.3AG268 (−21 to 38)
GG395173 (167-178)GG540165 (158-171)
rs2033178Intron 223 (1)6.2AG, AA475 (−13 to 22)4.7AG, AA50−24 (−46 to −3)
GG349172 (166-178)GG513167 (161-174)
rs17884646Intron 20TT397172 (166-178)0TT570165 (159-171)
rs5742657Intron 22.2AG, GG1718 (−11 to 46)212.1AG, GG1283 (−11 to 18)
AA383171 (166-177)AA440164 (157-170)
rs5742663Intron 20.1GT112 (−103 to 127)211.6GT, GG1238 (−6 to 23)
TT396172 (167-178)TT444163 (156-170)
rs11829586Intron 22.3AG1816 (−12 to 43)211.5AG, AA1217 (−8 to 22)
GG380172 (166-178)GG445163 (156-170)
rs4764884Intron 2225.7TT25−16 (−40 to 8)22 (4)23.7TT3410 (−16 to 36)
CT1530 (−12 to 12)CT2005 (−8 to 18)
CC218173 (165-181)CC333162 (154-170)
rs5742683Intron 20.1AG112 (−102 to 127)210.6AG, GG1135 (−11 to 20)
AA396172 (166-178)AA454164 (157-171)
rs17884626Exon 301.0CT1113 (−31 to 57)
CC399172 (167-178)CC559164 (158-171)
rs5009837Intron 3230.3TT36−6 (−27 to 15)Outside2 (5)41.3TT1058 (−9 to 26)
CT1676 (−6 to 18)CT26010 (−3 to 24)
CC192170 (162-178)CC203158 (148-168)
rs17727841Intron 323 (2)19.1CC15−4 (−35 to 27)4.7CG, CC4923 (1-44)
CG123−4 (−17 to 8)
GG261174 (167-181)GG520163 (156-169)
rs4764883Intron 3230.9CC37−8 (−29 to 12)345.8TT132−12 (−29 to 5)
CT1674 (−8 to 17)CT248−11 (−25 to 3)
TT186171 (163-179)CC180173 (162-183)
rs9308315Intron 3228.2AA28−16 (−39 to 7)33 (1)49.8TT150−12 (−28 to 5)
AT1663 (−9 to 15)AT262−11 (−26 to 4)
TT201172 (164-180)AA152173 (161-185)
rs978458Intron 323 (3)28.0TT28−13 (−37 to 10)337.5TT839 (−10 to 28)
CT1644 (−8 to 16)CT2597 (−6 to 20)
CC202172 (163-180)CC224160 (151-170)
rs5742692Intron 32.133 (2)11.7GG1114 (−31 to 58)
AG1718 (−11 to 46)AG1114 (−12 to 19)
AA382171 (166-177)AA444164 (157-170)
rs11111262Intron 329.9AG, AA76−4 (−19 to 10)2.7AG, AA2740 (11-68)
GG321173 (167-180)GG536163 (157-169)
rs1520220Intron 323 (4)19.1GG13−33 (−65 to 0)33 (3)34.7GG7310 (−9 to 29)
CG1247 (−6 to 19)CG2506 (−7 to 19)
CC258171 (164-178)CC245161 (151-170)
rs3730204Exon 4; 3′ untranslated2.3CT18−24 (−52 to 3)0.3CT36 (−79 to 90)
TT378173 (168-179)TT562165 (159-171)
rs6214Exon 4; 3′ untranslatedOutside3 (5)39.8TT6717 (0-34)Outside3 (4)45.2CC124−3 (−20 to 14)
CT183−2 (−14 to 11)CT263−4 (−18 to 10)
CC148170 (161-180)TT178167 (156-178)
rs6219Exon 4; 3′ untranslated34 (1)10.0CT, TT78−6 (−20 to 9)44 (1)9.1CT, TT9416 (−1 to 32)
CC321174 (167-180)CC475162 (155-169)
rs2946834Downstream34 (2)33.0AA39−7 (−28 to 13)44 (2)49.3AA14216 (0-33)
AG1811 (−11 to 13)AG2792 (−12 to 17)
GG175172 (164-181)GG147159 (147-171)
  • * Represent tag SNPs except for 2 SNPs that were selected a priori: rs3729846 (Thr52Thr) and rs17884626 (Ala115Thr).

  • LD blocks consist of SNPs with MAF ≥ 5% in strong LD (95% of pairwise SNP comparisons with one-sided 95% CIs for D′ within 0.70-0.98). Group refers to SNP combination for diplotype estimation; position refers to SNP order in each group. SNPs were excluded from diplotype estimation based on either Tagger algorithm (r2 ≥ 0.8) or MAF < 5% for tag SNPs or MAF < 3% for SNPs selected a priori. For African Americans, rs9308315 was the substitute for rs4764883 (Hardy-Weinberg P < 0.01).

  • Based on total n = 402 (Caucasians) and total n = 582 (African Americans).

  • § Caucasians: n = 401, excluded 1 missing plasma IGF-I. African Americans: n = 574, excluded 8 missing plasma IGF-I.

  • Mean plasma IGF-I levels for reference genotypes estimated from linear regression intercepts are italicized in the last row for each SNP. Mean differences in plasma IGF-I levels for heterozygous and homozygous variants relative to reference genotypes were estimated from β values in linear regression models.