Table 2.
Characteristics of participants according to energy-adjusted dietary glycemic index1
| Dietary glycemic index quintile | ||||||
|---|---|---|---|---|---|---|
| 1 | 2 | 3 | 4 | 5 | P value2 | |
| Dietary glycemic index3 | 50.5 ± 0.1 | 54.3 ± 0.0 | 56.2 ± 0.0 | 58.3 ± 0.0 | 61.8 ± 0.1 | |
| N | 379 | 381 | 378 | 380 | 380 | |
| % Female | 61.2 | 55.9 | 56.1 | 49.24 | 48.14 | <0.0001 |
| Risk factors for type 2 diabetes | ||||||
| Age (years)3 | 75.0 ± 0.1 | 75.0 ± 0.1 | 75.3 ± 0.1 | 74.9 ± 0.1 | 75.5 ± 0.1 | 0.0216 |
| Race (% White)5 | 69.1 | 71.9 | 69.3 | 67.4 | 58.44 | 0.0006 |
| Education (% completed high school)5 | 84.7 | 84.3 | 81.8 | 80.5 | 70.54 | <0.0001 |
| Smoking (lifetime pack-years)5 | 18.9 ± 1.4 | 16.6 ± 1.4 | 18.3 ± 1.4 | 18.0 ± 1.4 | 18.7 ± 1.4 | 0.6635 |
| Alcohol (% any consumption)5 | 64.1 | 61.4 | 52.94 | 47.94 | 46.64 | <0.0001 |
| Physical activity (kcal/week)5 | 1196 ± 92 | 1200 ± 92 | 1104 ± 92 | 1065 ± 92 | 939 ± 92 | 0.0120 |
| Fasting glucose (mg/dL)3 | 93.4 ± 0.5 | 92.9 ± 0.5 | 91.7 ± 0.5 | 93.0 ± 0.5 | 92.6 ± 0.5 | 0.2433 |
| BMI (kg/m2)3 | 27.2 ± 0.2 | 26.7 ± 0.2 | 26.7 ± 0.2 | 27.0 ± 0.2 | 26.5 ± 0.2 | 0.1247 |
| Dietary factors3 | ||||||
| Total calorie intake (kcal) | 1807 ± 33 | 1882 ± 33 | 1822 ± 33 | 1842 ± 33 | 1820 ± 33 | 1.0000 |
| % kcal from carbohydrate | 50.8 ± 0.4 | 52.8 ± 0.44 | 53.5 ± 0.44 | 54.6 ± 0.44 | 55.7 ± 0.44 | <0.0001 |
| % kcal from protein | 14.9 ± 0.2 | 14.5 ± 0.2 | 14.5 ± 0.2 | 14.3 ± 0.24 | 13.5 ± 0.24 | <0.0001 |
| % kcal from fat | 33.7 ± 0.4 | 33.6 ± 0.4 | 33.3 ± 0.4 | 32.7 ± 0.4 | 32.3 ± 0.44 | 0.0001 |
| % kcal from saturated fat | 9.7 ± 0.1 | 9.6 ± 0.1 | 9.6 ± 0.1 | 9.4 ± 0.1 | 9.2 ± 0.14 | 0.0002 |
| Total dietary fiber (g) | 16.7 ± 0.4 | 18.3 ± 0.4 | 17.4 ± 0.4 | 18.0 ± 0.4 | 16.7 ± 0.4 | 0.8560 |
| Daily servings of vegetables | 3.1 ± 0.1 | 3.2 ± 0.1 | 2.9 ± 0.1 | 3.1 ± 0.1 | 2.5 ± 0.14 | <0.0001 |
| Daily servings of fruit and fruit juice | 2.3 ± 0.1 | 2.3 ± 0.1 | 2.0 ± 0.14 | 1.8 ± 0.14 | 1.4 ± 0.14 | <0.0001 |
1
Means ± SEM, unless otherwise specified.
2
Linear regression was used for continuous variables, and Mantel-Haenszel chi-square test for trend across quintiles was used for categorical variables.
3
Values from year 2 of the Health ABC study.
4
Significantly different from quintile 1, P ≤ 0.05 (Dunnett’s test for continuous variables and chi-square test for categorical variables).
5
Values from baseline of the Health ABC study.