Table 3. Relative risk of overweight at the age of 15 years according to the IOTF associated with early weight and BMI measures in the NFBC1966 and the NFBC1986.
| NFBC66 (N = 1911) | NFBC86 (N = 3709) | Total(N = 5620) | |||||||
| N | n(%) | RR(95%CI) | N | n(%) | RR(95%CI) | N | n(%) | RR(95%CI) | |
| Weight at 5 months (kg) | |||||||||
| <50 percentile | 949 | 65(7) | 1 | 1878 | 198(11) | 1 | 2827 | 263(9) | 1 |
| ≥50–<75 | 482 | 52(11) | 1.7(1.2–2.4) | 931 | 175(19) | 1.7(1.4–2.1) | 1413 | 227(16) | 1.7(1.5–2.0) |
| ≥75–<90 | 290 | 24(8) | 1.4(0.9–2.2) | 547 | 109(20) | 1.8(1.5–2.3) | 837 | 133(16) | 1.7(1.4–2.1) |
| ≥90 | 190 | 26(14) | 2.3(1.5–3.6) | 353 | 95(27) | 2.4(1.9–3.0) | 543 | 121(22) | 2.4(1.9–2.9) |
| Weight at 1 year (kg) | |||||||||
| <50 percentile | 955 | 62(6) | 1 | 1868 | 196(10) | 1 | 2823 | 258(9) | 1 |
| ≥50–<75 | 483 | 46(10) | 1.6(1.1–2.4) | 931 | 158(17) | 1.6(1.3–1.9) | 1414 | 204(14) | 1.6(1.3–1.9) |
| ≥75–<90 | 284 | 26(9) | 1.6(1.0–2.4) | 551 | 121(22) | 2.0(1.6–2.5) | 835 | 147(18) | 1.9(1.6–2.3) |
| ≥90 | 189 | 33(17) | 3.0(2.0–4.5) | 359 | 102(28) | 2.6(2.1–3.2) | 548 | 135(25) | 2.7(2.2–3.2) |
| BMI at 2 years (kg/m2) | |||||||||
| <50 percentile | 955 | 48(5) | 1 | 1872 | 174(9) | 1* | 2827 | 222(8) | 1 |
| ≥50–<75 | 477 | 37(8) | 1.6(1.0–2.4) | 918 | 141(15) | 1.6(1.3–2.0) | 1395 | 178(13) | 1.6(1.3–1.9) |
| ≥75–<90 | 284 | 46(16) | 3.3(2.2–4.8) | 563 | 135(24) | 2.5(2.0–3.1) | 847 | 181(21) | 2.7(2.2–3.2) |
| ≥90 | 195 | 36(18) | 3.7(2.5–5.6) | 356 | 127(36) | 3.7(3.0–4.5) | 551 | 163(30) | 3.7(3.1–4.4) |
| BMI at 3 years (kg/m2) | |||||||||
| <50 percentile | 954 | 35(4) | 1 | 1870 | 131(7) | 1* | 2824 | 166(6) | 1* |
| ≥50–<75 | 479 | 42(9) | 2.5(1.6–3.8) | 919 | 150(16) | 2.3(1.9–2.9) | 1398 | 192(14) | 2.3(1.9–2.8) |
| ≥75–<90 | 279 | 39(14) | 3.9(2.5–6.0) | 565 | 144(25) | 3.5(2.9–4.4) | 844 | 183(22) | 3.6(3.0–4.4) |
| ≥90 | 199 | 51(26) | 7.0(4.7–10.4) | 355 | 152(43) | 6.0(4.9–7.3) | 554 | 203(37) | 6.2(5.1–7.4) |
| BMI at 4 years (kg/m2) | |||||||||
| <50 percentile | 955 | 23(2) | 1 | 1868 | 97(5) | 1* | 2823 | 120(4) | 1 |
| ≥50–<75 | 475 | 37(8) | 3.3(2.0–5.5) | 930 | 144(15) | 3.0(2.3–3.8) | 1405 | 181(13) | 3.0(2.4–3.8) |
| ≥75–<90 | 287 | 40(14) | 5.8(3.6–9.6) | 549 | 149(27) | 5.1(4.0–6.5) | 836 | 189(23) | 5.3(4.2–6.5) |
| ≥90 | 194 | 67(35) | 14.3(9.2–22.4) | 362 | 187(52) | 9.7(7.9–12.2) | 556 | 254(46) | 10.7(8.8–13.0) |
| BMI at 5 years (kg/m2) | |||||||||
| <50 percentile | 952 | 24(3) | 1 | 1876 | 89(5) | 1 | 2828 | 113(4) | 1 |
| ≥50–<75 | 475 | 31(7) | 2.6(1.6–4.4) | 920 | 129(14) | 2.9(2.3–3.8) | 1395 | 160(11) | 2.8(2.3–3.6) |
| ≥75–<90 | 290 | 45(16) | 6.2(3.9–10.1) | 549 | 165(30) | 6.2(4.9–7.9) | 839 | 210(25) | 6.2(5.0–7.7) |
| ≥90 | 194 | 67(35) | 13.5(8.7–21.0) | 364 | 194(53) | 11.1(8.9–13.9) | 558 | 261(47) | 11.7(9.6–14.3) |
*Statistically significant difference between genders. No statistically significant differences between the cohorts found. BMI- Body mass index. IOTF – overweight/obese according to the International Obesity Task Force. NFBC1966 and NFBC1986 – Northern Finnish Birth Cohorts born in 1966 and 1986.