Table 5.
Adjusted mean difference in log-transformed plasma SHBG concentrations in relation to age, BMI, lifestyle factors, reproductive history, and use of exogenous estrogen in the WHI, 1993–1998.
| Variable | Difference in log-SHBG concentrations (n = 8712) | |
|---|---|---|
| Pooled meana | 95% CIa | |
| Age, per 5-year increment | 0.037 | 0.026–0.047 |
| BMI, per unit | −0.028 | −0.033 to −0.024 |
| Physical activity, per 7.5 MET-h/week | 0.034 | 0.012 to 0.056 |
| Alcohol, per 10 g/day | −0.0003 | −0.0008 to 0.0003 |
| Cigarettes, per 10/day | −0.010 | −0.021 to 0.000 |
| Regular coffee, per cup/day | 0.025 | 0.018 to 0.032 |
| Red meat, per serving/day | −0.077 | −0.171 to 0.016 |
| Fish, per serving/day | 0.026 | −0.032 to 0.085 |
| Eggs, per serving/day | 0.000 | −0.201 to 0.202 |
| Dairy, per serving/day | −0.016 | −0.036 to 0.003 |
| Soy, per serving/day | −0.013 | −0.018 to 0.082 |
| Fruits, per serving/day | 0.011 | −0.021 to 0.043 |
| Vegetables, per serving/day | 0.002 | −0.010 to 0.013 |
| Whole grains, per serving/day | 0.001 | −0.014 to 0.017 |
| Refined grains, per serving/day | −0.009 | −0.017 to 0.000 |
| Potatoes, per serving/day | −0.015 | −0.053 to 0.024 |
| Sweets, per serving/day | 0.013 | −0.002 to 0.027 |
| Oral contraceptive use, ever vs never | −0.013 | −0.037 to 0.011 |
| Exogenous estrogen use, current vs past/never | 0.225 | 0.043 to 0.408 |
| Exogenous estrogen use, ever vs never | 0.083 | 0.012 to 0.153 |
| Years since menopause, per 5-year increment | 0.001 | −0.007 to 0.010 |
| Menarche age, ≥13 vs <13 years | −0.000 | −0.021 to 0.021 |
| Number of parities, ≥5 vs <5 | −0.028 | −0.062 to 0.006 |
| Marital status, currently married vs not married | −0.033 | −0.062 to −0.003 |
Random-effects models were used to estimate adjusted means and CIs of log-transformed SHBG concentrations per 5-year age increment, BMI unit, 7.5 MET-h/week for physical activity, 10 cigarettes smoked/day, 10 grams of alcohol ingested/day, and 1 serving/day for dietary factors and according to exogenous estrogen use, oral contraceptive use, and reproductive history (years since menopause, menarche age, number of parities, and marital status) with adjustment for age (continuous), BMI (continuous), physical activity [MET-h/week (continuous)], cigarettes smoked per day (continuous), alcohol ingestion per day [in grams (continuous)], total energy intake (continuous), and all dietary factors and indices of reproductive history listed in the table that were not examined as the primary independent variable.