Table 5.
Odds Ratios for Type 2 Diabetes per Unit of Increase in the Sex Hormone–Binding Globulin (SHBG) Level.*
| Analysis | Odds Ratio (95% CI) |
|---|---|
| Mendelian randomization analysis† | |
| Allele rs6259 and rs6257 | |
| Women | 0.28 (0.13–0.58) |
| Men | 0.29 (0.15–0.58) |
| Allele rs6259 | |
| Women and men‡ | 0.23 (0.10–0.54) |
| Women only | 0.19 (0.04–1.01) |
| Men only | 0.25 (0.09–0.65) |
| Allele rs6257 | |
| Women and men‡ | 0.40 (0.19–0.88) |
| Women only | 0.39 (0.17–0.88) |
| Men only§ | 0.53 (0.05–5.22) |
| Conventional multivariable analysis¶ | |
| Women | |
| Simple model 1 | 0.40 (0.31–0.51) |
| Multivariable model | 0.34 (0.26–0.45) |
| Men | |
| Simple model 1 | 0.43 (0.31–0.59) |
| Multivariable model | 0.39 (0.27–0.58) |
The unit of increase measured was the natural-log standard-deviation in sex-specific control distributions.
The mendelian randomization analyses involved SHBG genotypes as instrumental variables in multivariable generalized linear models.31
P = 0.78 and P = 0.81 for the difference between men and women in carriage of a variant rs6259 allele and carriage of a variant rs6257 allele, respectively. All P = 0.001 for mendelian instrument rs6259 and for joint analyses. P = 0.02 for mendelian instrument rs6257, and P<0.001 for the conventional multivariable analyses.
The variant of the odds ratio associated with the rs6257 variant, for men only, was calculated with the use of a robust variance estimator.
Conventional models were adjusted for covariates as described for each model in Table 3.