Table 2.
Fall/Winter to Spring/Summer Differences
| Fall/Winter, mean (SD) across individuals | Spring/Summer, mean (SD) across individuals | Within-Individual Fall/Winter to Spring/Summer Differences (95% CI) | |
|---|---|---|---|
| Objective measures | |||
| Walking, steps/day | 4,901 (2,464) | 5,659 (2,611) | -758 (-1,037 to -479) |
| Hemoglobin A1Ca, % | 7.6 (1.3) | 7.7 (1.3) | -0.10 (-0.21 to 0) |
| Systolic blood pressure, mm Hg | 137 (16) | 133 (14) | 4.0 (2.3 to 5.7) |
| Diastolic blood pressure, mm Hg | 80 (10) | 79 (9) | 1.4 (0.4 to 2.4) |
| BMI, kg/m2 | 30.2 (6.0) | 30.2 (6.0) | 0.07 (-0.04 to 0.18) |
| Waist circumference, cm | |||
| Women | 98.7 (14.1) | 98.9 (13.8) | -0.2 (-1.0 to 0.5) |
| Men | 104.2 (13.0) | 104.8 (12.7) | -0.5 (-1.3 to 0.2) |
| Waist/hip | |||
| Women | 0.879 (0.063) | 0.882 (0.061) | -0.003 (-0.01 to 0.004) |
| Men | 0.967 (0.060) | 0.971 (0.060) | -0.004 (-0.01 to 0.004) |
| Self-reported measures | |||
| Total energy intake, kcal/dayb | 1,730 (684) | 1,700 (662) | 30.0 (-37.9 to 98.0) |
| Carbohydrate intake, g/dayb | 187 (76) | 182 (74) | 5.7 (-2.9 to 14.4) |
| Salt intake, mg/dayb | 2,598 (1353) | 2,546 (1182) | 51.9 (-86.3 to 190) |
| Total physical activity, metabolic equivalent-minutes/weekc | 2,598 (2463) | 2,921 (2700) | -451 (-872 to -30.4) |
SD, standard deviation; CI, Confidence interval
a Given that A1C reflects glycemic control over the prior two to three months, winter/spring A1C values may reflect fall/winter glycemic control and summer/fall A1C values may reflect spring/summer glycemic control. We therefore also computed Winter/spring to Summer/Fall difference in A1C which was 0.012% (95% CI -0.10% to 0.13%).
b Shatenstein and colleagues' Food Frequency Questionnaire [21]
c International Physical Activity Questionnaire (Short Last 7 days format) [20]