TABLE 2.
Age-standardized characteristics of the Nurses’ Health Study participants at the time of blood collection by telomere length z score quartiles1
| Quartile 1 (n = 1195) | Quartile 2 (n = 1195) | Quartile 3 (n = 1195) | Quartile 4 (n = 1195) | P | |
| Age,2 y | 60.1 ± 6.3 | 59.7 ± 6.4 | 59.0 ± 6.6 | 58.2 ± 6.8 | <0.0001 |
| Smoking,3 pack-y | 14.4 ± 20.1 | 12.6 ± 18.3 | 12.6 ± 19.5 | 12.2 ± 18.3 | 0.0017 |
| Percentage of ever smokers, % | 57.2 | 55.8 | 53.0 | 52.8 | |
| BMI, kg/m2 | 25.6 ± 4.8 | 25.4 ± 4.5 | 25.2 ± 4.5 | 25.5 ± 4.4 | 0.31 |
| Physical activity, MET-h/wk | 16.1 ± 26.2 | 16.8 ± 20.9 | 16.2 ± 19.1 | 16.6 ± 18.1 | 0.88 |
| Alcohol consumption, g/d | 5.5 ± 9.4 | 5.6 ± 9.5 | 5.4 ± 9.9 | 5.4 ± 8.9 | 0.61 |
| Trans fat consumption, g/d | 2.6 ± 1.0 | 2.6 ± 1.0 | 2.6 ± 1.0 | 2.5 ± 1.0 | 0.027 |
| Alternate Mediterranean Diet Score | 4.2 ± 1.8 | 4.2 ± 1.7 | 4.1 ± 1.8 | 4.4 ± 1.8 | 0.042 |
| Caffeine consumption, mg/d | 280 ± 184 | 268 ± 191 | 277 ± 188 | 289 ± 197 | 0.054 |
| Total coffee consumption, cups/d | 2.0 ± 1.4 | 1.9 ± 1.3 | 2.0 ± 1.4 | 2.1 ± 1.5 | 0.050 |
Values are means ± SDs for all variables, except percentage of ever smokers (of which the values are percentages). The P values and SDs were standardized by the age distribution of the study population. Telomere length z score quartile-specific means ± SDs are −1.3 ± 0.5 for quartile 1, −0.3 ± 0.2 for quartile 2, 0.3 ± 0.2 for quartile 3, and 1.3 ± 0.5 for quartile 4. MET-h, metabolic equivalent task hours.
The P values and SDs involving the age variable were not age-adjusted.
Pack-y of smoking were calculated among ever smokers (n = 2608). The P value for smoking was calculated among ever and never smokers (n = 4767).