Table 2.
Regression coefficients for cubic equations relating IGF axis and age. For second and higher order terms, Aage is centered near the mean age of male and female respondents (43 and 45 respectively) to reduce colinearity.
| Term* | Males | Females | ||||||
|---|---|---|---|---|---|---|---|---|
| a (S.E.) | b** (S.E.) | c (S.E.) | d (S.E.) | a (S.E.) | b (S.E.) | c (S.E.) | d (S.E.) | |
| A. IGF-I (ng/ml) | ||||||||
| Non-Hispanic White (S.E) | 395.3 (11.4) | −2.78 (0.25) | 0.059 (0.015) | −0.00075 (0.00039) | 418.3 (15.8) | −4.03 (0.28) | 0.068 (0.015) | 0.000028 (0.00046) |
| Non-Hispanic Black (S.E) | 341.5 (29.0) | −2.18 (0.67) | 0.153 (0.020) | −0.00323 (0.00093) | 365.8 (14.5) | −2.52 (0.27) | 0.089 (0.017) | −0.001558 (0.00054) |
| Mexican-American (S.E) | 301.3 (17.7) | −1.77 (0.41) | 0.102 (0.015) | −0.00276 (0.00068) | 343.8 (19.9) | −3.03 (0.36) | 0.072 (0.018) | −0.001081 (0.00056) |
| B. IGFBP-3 (ng/ml) | ||||||||
| Non-Hispanic White (S.E) | 5302.6 (137.9) | −19.34 (3.18) | −0.039 (0.143) | −0.0021 (0.00423) | 5262.7 (173.0) | −17.55 (3.22) | 0.517 (0.153) | −0.009126 (0.00488) |
| Non-Hispanic Black (S.E) | 4350.6 (186.7) | −9.38 (4.33) | 0.587 (0.172) | −0.0230 (0.00605) | 4162.6 (200.0) | 0.99 (4.83) | 0.594 (0.137) | −0.024369 (0.00654) |
| Mexican-American (S.E) | 4763.7 (193.1) | −16.90 (4.59) | 0.019 (0.155) | −0.0152 (0.00906) | 4841.6 (230.2) | −16.20 (5.29) | 0.227 (0.174) | −0.024369 (0.00745) |
| C. Molar Ratio IGF-I/IGFBP-3 | ||||||||
| Non-Hispanic White (S.E) | 0.279 (7.635E-03) | −0.00126 (1.560E-04) | 0.0000436 (1.034E-05) | −4E-7 (2.787E-07) | 0.298 (8.967E-03) | −0.00239 (1.637E-04) | 0.0000269 (9.063E-06) | 4.48E-7 (2.647E-07) |
| Non-Hispanic Black (S.E) | 0.291 (1.650E-02) | −0.00145 (3.789E-04) | 0.0000895 (1.328E-05) | −1.17E-6 (5.751E-07) | 0.315 (1.326E-02) | −0.00208 (2.647E-04) | 0.0000326 (1.349E-05) | 7.76E-8 (5.108E-07) |
| Mexican-American (S.E) | 0.235 (1.819E-02) | −0.00074 (4.217E-04) | 0.0000786 (1.155E-05) | −1.23E-6 (6.423E-07) | 0.264 (1.471E-02) | −0.00182 (2.767E-04) | 0.0000428 (1.259E-05) | −1.94E-7 (4.353E-07) |
*
a, b, c, and d correspond to coefficients for the equation y = a + bx + c(x−43 or 45)2 + d(x − 43 or 45)3