Table 1.
Summary Statistics for the 10,389 Observations (5,958 Participants) From the Framingham Offspring Cohort Examination 7 (1998–2001), Examination 8 (2005–2008), Third Generation Cohort Examination 1 (2002–2005), or Examination 2 (2008–2011).
| Characteristics | Offspring cohort Mean(SD) or N[%] |
Third Generation cohort Mean(SD) or N[%] |
||
|---|---|---|---|---|
| Examination cycle | 7 | 8 | 1 | 2 |
| No. of participants | 2,415 | 1,925 | 3,281 | 2,768 |
| Age, years | 60.4 (9.5) | 65.7 (9.0) | 39.8 (8.7) | 46.1 (8.5) |
| Women | 1,332 [55.2] | 1,093 [56.8] | 1,793 [54.7] | 1,510 [54.6] |
| BMI, kg/m2 | 27.8 (5.1) | 27.8 (5.1) | 26.8 (5.4) | 27.7 (5.5) |
| Alcohol, drinks/week | 5.2 (7.7) | 4.6 (7.1) | 4.8 (7.1) | 4.8 (6.7) |
| Smoking statusa | ||||
| Non-smoker | 893 [37.0] | 742 [38.6] | 1,862 [56.8] | 1,621 [58.6] |
| Former smoker | 1,187 [49.2] | 966 [50.2] | 835 [25.5] | 821 [29.7] |
| Current smoker | 335 [13.9] | 182 [9.5] | 584 [17.8] | 326 [11.8] |
| Pack year | 16.9 (22.2) | 15.4 (21.0) | 6.7 (11.4) | 6.8 (12.0) |
| Educational attainmentb | ||||
| High school or less | 788 [32.6] | 571 [29.7] | 541 [16.5] | 406 [14.7] |
| Some college | 729 [30.2] | 599 [31.1] | 1,063 [32.4] | 845 [30.5] |
| College graduate | 852 [35.3] | 753 [39.1] | 1,670 [50.9] | 1,516 [54.8] |
|
| ||||
| Fasting plasma glucosec,d,e, mg/dl | 97.0 (9.7) | 99.9 (9.1) | 92.6 (8.4) | 93.3 (8.7) |
| Insulinc,d,e, pmol/l | − | 57.9 (33.8) | 27.0 (13.0) | 55.7 (31.5) |
| HOMA-IRc,d,e | − | 2.1 (1.3) | 1.0 (0.5) | 1.8 (1.1) |
| HbA1cc,e, % | − | 5.5 (0.3) | − | 5.4 (0.3) |
| Adiponectinc,e, µg/ml | 8.8 (5.4) | − | 7.2 (4.8) | − |
| Leptinc,e, ng/ml | − | − | 7.3 (7.7) | − |
| Resistinc,e, ng/ml | 12.8 (5.1) | − | − | − |
|
| ||||
| 2003 annual average PM2.5, µg/m3 | 10.6 (1.3) | 10.6 (1.3) | 10.7 (1.5) | 10.6 (1.5) |
| Distance to a major roadwayf, m | 264 (244) | 268 (249) | 268 (252) | 283 (259) |
| Distance categoryf | ||||
| <50 m | 521 [23.6] | 415 [23.9] | 624 [21.6] | 514 [21.1] |
| 50-<100 m | 203 [9.2] | 161 [9.3] | 331 [11.4] | 255 [10.5] |
| 100-<200 m | 385 [17.5] | 292 [16.8] | 529 [18.3] | 418 [17.2] |
| 200-<400 m | 551 [25.0] | 430 [24.8] | 666 [23.0] | 555 [22.8] |
| 400-<1,000 m | 544 [24.7] | 437 [25.2] | 744 [25.7] | 689 [28.3] |
Abbreviation: HOMA-IR, homeostasis model assessment of insulin resistance; HbA1c, hemoglobin A1c; PM2.5, fine particulate matter; SD, standard deviation.
35 (1.8%) participants in the Offspring cohort examination cycle 8 were missing smoking status and were assigned missing indicators.
46 (1.9%), 2 (0.1%), 7 (0.2%), and 1 (0.04%) participants in examination cycle 7, 8, 1, and 2, respectively, were missing educational attainment data and were assigned missing indicators.
The total number of available observations for fasting glucose, insulin, HOMA-IR, HbA1c, adiponectin, leptin, and resistin are 10,389, 7,657, 7,657, 4,690, 5,282, 3,266, and 2,030, respectively.
4,431 participants had two measurements of fasting glucose, 2,379 participants had two measurements of insulin and HOMA-IR.
Geometric mean and standard deviation.
Calculated based on participants who lived < 1,000 m from the nearest major roadway. 211 (8.7%), 190 (9.9%), 387 (11.8%), and 337 (12.2%) participants in examination cycle 7, 8, 1, and 2, respectively, lived ≥1,000 m from the nearest major roadway and were excluded in proximity analyses.