TABLE 2.
Age-adjusted baseline characteristics by quintile of glycemic load1
| Quintile of glycemic load |
|||||
| Variable | 1 | 2 | 3 | 4 | 5 |
| Nurses’ Health Study (1984) | |||||
| No. of participants | 14,689 | 14,849 | 14,849 | 14,920 | 14,941 |
| Median glycemic load | 75.0 | 90.0 | 99.0 | 108.0 | 123.0 |
| Age (y) | 50.2 ± 6.92 | 50.0 ± 7.0 | 50.0 ± 7.2 | 50.3 ± 7.3 | 50.8 ± 7.4 |
| White (%) | 99 | 98 | 98 | 98 | 96 |
| BMI (kg/m2) | 25.0 ± 4.6 | 25.1 ± 4.7 | 24.9 ± 4.5 | 24.8 ± 4.6 | 24.3 ± 4.4 |
| Physical activity (MET-h/wk) | 14.2 ± 21.7 | 14.1 ± 19.6 | 14.0 ± 19.9 | 14.2 ± 19.8 | 14.5 ± 23.2 |
| Family history of diabetes (%) | 28 | 29 | 29 | 28 | 28 |
| History of hypertension (%) | 8 | 7 | 7 | 7 | 8 |
| History of hypercholesterolemia (%) | 3 | 3 | 3 | 3 | 4 |
| Current smoker (%) | 33 | 25 | 22 | 21 | 20 |
| Current postmenopausal hormone use (%) | 26 | 26 | 24 | 24 | 24 |
| Dietary factors | |||||
| Total energy intake (kcal/d) | 1699 ± 536 | 1782 ± 527 | 1795 ± 527 | 1767 ± 523 | 1677 ± 524 |
| Alcohol (g/d) | 15.2 ± 17.7 | 7.9 ± 10.5 | 5.5 ± 7.9 | 4.1 ± 6.4 | 2.6 ± 4.8 |
| Glycemic index | 50.3 ± 4.2 | 52.4 ± 3.0 | 53.4 ± 2.8 | 54.4 ± 2.7 | 56.1 ± 2.9 |
| Cereal fiber (g/d) | 2.8 ± 1.5 | 3.7 ± 1.7 | 4.2 ± 1.9 | 4.7 ± 2.2 | 5.3 ± 3.1 |
| Magnesium (mg/d) | 293 ± 85 | 291 ± 69 | 288 ± 70 | 287 ± 71 | 281 ± 82 |
| PUFAs (g/d) | 12.9 ± 3.9 | 12.3 ± 3.0 | 11.9 ± 2.7 | 11.4 ± 2.6 | 10.4 ± 2.6 |
| SFAs (g/d) | 25.1 ± 5.3 | 23.6 ± 4.0 | 22.4 ± 3.5 | 21.0 ± 3.3 | 18.4 ± 3.6 |
| trans Fatty acids (g/d) | 3.5 ± 1.1 | 3.5 ± 1.1 | 3.5 ± 1.1 | 3.4 ± 1.0 | 3.0 ± 1.1 |
| Protein (g/d) | 79.0 ± 15.0 | 75.1 ± 11.4 | 71.8 ± 10.5 | 68.4 ± 9.9 | 61.8 ± 10.3 |
| Total coffee (cups/d)3 | 2.9 ± 1.9 | 2.7 ± 1.9 | 2.5 ± 1.8 | 2.3 ± 1.8 | 1.8 ± 1.7 |
| Nurses’ Health Study II (1991) | |||||
| No. of participants | 18,082 | 18,084 | 18,091 | 18,065 | 18,089 |
| Median glycemic load | 95.8 | 110.3 | 120.3 | 131.0 | 148.7 |
| Age (y) | 36.5 ± 4.6 | 36.3 ± 4.6 | 36.0 ± 4.6 | 35.8 ± 4.7 | 35.8 ± 4.7 |
| White (%) | 98 | 97 | 98 | 97 | 93 |
| BMI (kg/m2) | 25.6 ± 5.8 | 25.0 ± 5.4 | 24.5 ± 5.0 | 24.0 ± 4.8 | 23.5 ± 4.8 |
| Physical activity (MET-h/wk) | 19.5 ± 25.9 | 19.9 ± 24.9 | 20.6 ± 26.0 | 21.5 ± 28.3 | 23.0 ± 30.9 |
| Family history of diabetes (%) | 35 | 36 | 34 | 33 | 33 |
| History of hypertension (%) | 8 | 6 | 5 | 5 | 6 |
| History of hypercholesterolemia (%) | 15 | 14 | 14 | 14 | 15 |
| Current smoker (%) | 18 | 12 | 11 | 9 | 10 |
| Menopausal status and postmenopausal hormone use (%) | |||||
| Premenopausal | 96.4 | 96.7 | 96.6 | 96.5 | 96.2 |
| Postmenopausal + never user | 0.2 | 0.2 | 0.2 | 0.2 | 0.2 |
| Postmenopausal + past user | 0.3 | 0.3 | 0.3 | 0.3 | 0.4 |
| Postmenopausal + current user | 2.7 | 2.4 | 2.5 | 2.6 | 2.8 |
| Missing information | 0.4 | 0.4 | 0.4 | 0.5 | 0.5 |
| Oral contraceptive use (%) | |||||
| Never user | 13.2 | 14.7 | 15.8 | 16.2 | 17.4 |
| Past user | 76.4 | 74.7 | 73.7 | 72.9 | 71.1 |
| Current user | 10.4 | 10.6 | 10.5 | 10.9 | 11.5 |
| Dietary factors | |||||
| Total energy intake (kcal/d) | 1760 ± 560 | 1820 ± 541 | 1819 ± 539 | 1799 ± 535 | 1748 ± 556 |
| Alcohol (g/d) | 5.8 ± 9.9 | 3.4 ± 5.6 | 2.7 ± 4.5 | 2.2 ± 4.0 | 1.5 ± 2.9 |
| Glycemic index | 51.2 ± 3.4 | 52.9 ± 2.7 | 53.8 ± 2.6 | 54.8 ± 2.6 | 56.5 ± 2.8 |
| Cereal fiber (g/d) | 4.2 ± 1.8 | 5.2 ± 2.1 | 5.7 ± 2.5 | 6.2 ± 3.0 | 6.8 ± 4.4 |
| Magnesium (mg/d) | 311 ± 67 | 316 ± 67 | 318 ± 69 | 319 ± 75 | 314 ± 92 |
| PUFAs (g/d) | 12.7 ± 3.2 | 11.9 ± 2.5 | 11.4 ± 2.3 | 10.8 ± 2.2 | 9.7 ± 2.2 |
| SFAs (g/d) | 26.7 ± 4.8 | 24.2 ± 3.7 | 22.6 ± 3.4 | 20.9 ± 3.3 | 17.8 ± 3.7 |
| trans Fatty acids (g/d) | 3.6 ± 1.3 | 3.5 ± 1.2 | 3.3 ± 1.2 | 3.1 ± 1.1 | 2.8 ± 1.1 |
| Protein (g/d) | 97.1 ± 15.9 | 91.3 ± 12.8 | 87.1 ± 12.0 | 83.0 ± 11.7 | 73.6 ± 12.8 |
| Total coffee (cups/d) | 2.0 ± 1.9 | 1.7 ± 1.7 | 1.6 ± 1.7 | 1.4 ± 1.6 | 1.1 ± 1.5 |
| Health Professionals Follow-Up Study (1986) | |||||
| No. of participants | 8132 | 7927 | 7941 | 8388 | 8110 |
| Median glycemic load | 93 | 111 | 124 | 137 | 156s |
| Age (y) | 53.7 ± 9.1 | 52.8 ± 9.3 | 52.7 ± 9.4 | 52.5 ± 9.6 | 52.7 ± 9.8 |
| White (%) | 96 | 96 | 96 | 95 | 92 |
| BMI (kg/m2) | 25.5 ± 5.0 | 25.2 ± 5.0 | 24.9 ± 5.0 | 24.6 ± 4.7 | 24.2 ± 4.6 |
| Physical activity (MET-h/wk) | 18.6 ± 26.2 | 20.2 ± 26.4 | 21.8 ± 32.1 | 22.2 ± 30.6 | 24.5 ± 31.3 |
| Family history of diabetes (%) | 20 | 21 | 20 | 20 | 20 |
| History of hypertension (%) | 22 | 19 | 18 | 18 | 18 |
| History of hypercholesterolemia (%) | 9 | 9 | 10 | 11 | 12 |
| Current smoker (%) | 15 | 11 | 8 | 6 | 5 |
| Dietary factors | |||||
| Total energy intake (kcal/d) | 1963 ± 638 | 2020 ± 621 | 2032 ± 611 | 2014 ± 613 | 1951 ± 619 |
| Alcohol (g/d) | 22.9 ± 22.0 | 13.5 ± 14.8 | 9.4 ± 11.3 | 6.9 ± 9.1 | 4.3 ± 6.9 |
| Glycemic index | 50.2 ± 3.9 | 52.3 ± 2.9 | 53.3 ± 2.8 | 54.2 ± 2.8 | 55.7 ± 3.0 |
| Cereal fiber (g/d) | 3.7 ± 2.3 | 5.0 ± 2.7 | 5.8 ± 3.0 | 6.6 ± 3.6 | 8.1 ± 5.6 |
| Magnesium (mg/d) | 344 ± 80 | 348 ± 75 | 348 ± 76 | 352 ± 79 | 367 ± 99 |
| PUFAs (g/d) | 14.4 ± 4.3 | 13.8 ± 3.3 | 13.4 ± 3.0 | 12.9 ± 2.9 | 11.5 ± 2.9 |
| SFAs (g/d) | 28.6 ± 6.7 | 26.7 ± 5.2 | 25.3 ± 4.7 | 23.3 ± 4.5 | 19.3 ± 4.9 |
| trans Fatty acids (g/d) | 2.9 ± 1.1 | 3.0 ± 1.1 | 3.0 ± 1.1 | 2.9 ± 1.1 | 2.4 ± 1.1 |
| Protein (g/d) | 99.2 ± 19.3 | 95.9 ± 15.1 | 92.7 ± 13.9 | 89.4 ± 13.4 | 82.7 ± 14.2 |
| Total coffee (cups/d) | 2.5 ± 1.9 | 2.2 ± 1.8 | 1.9 ± 1.7 | 1.7 ± 1.7 | 1.3 ± 1.6 |
1
Values are age-standardized with the exception of age. MET-h, metabolic equivalent task hours.
2
Mean ± SD (all such values).
3
1 cup = 240 mL.