TABLE 2.
HRs (95% CIs) for incident type 2 diabetes according to whole egg consumption in the NHS, the NHS II, and the HPFS1
| Frequency of egg consumption | P for trend2 | HR (95% CI) per 1-egg/d increase | ||||||
|---|---|---|---|---|---|---|---|---|
| <1/mo | 1 to <4/mo | 1 to <3/wk | 3 to <5/wk | 5 to <7/wk | ≥1/d | |||
| NHS (n = 82,750) | ||||||||
| Cases/person-years | 248/78,663 | 1500/380,448 | 4416/1,024,000 | 2404/600,955 | 394/96,090 | 264/67,968 | ||
| Model 13 | 1.00 (Ref) | 1.09 (0.95, 1.25) | 1.21 (1.06, 1.38) | 1.54 (1.35, 1.76) | 1.69 (1.44, 1.98) | 1.83 (1.53, 2.18) | <0.0001 | 1.52 (1.42, 1.62) |
| Model 24 | 1.00 (Ref) | 1.09 (0.95, 1.25) | 1.11 (0.98, 1.27) | 1.31 (1.15, 1.50) | 1.37 (1.16, 1.61) | 1.43 (1.20, 1.70) | <0.0001 | 1.26 (1.17, 1.36) |
| Model 35 | 1.00 (Ref) | 1.08 (0.94, 1.23) | 1.06 (0.93, 1.21) | 1.22 (1.06, 1.39) | 1.25 (1.06, 1.48) | 1.32 (1.10, 1.58) | <0.0001 | 1.19 (1.10, 1.29) |
| NHS II (n = 89,636) | ||||||||
| Cases/person-years | 531/261,236 | 2362/829,877 | 3189/857,139 | 982/290,016 | 148/27,049 | 70/14,099 | ||
| Model 13 | 1.00 (Ref) | 1.21 (1.10, 1.33) | 1.48 (1.35, 1.62) | 1.79 (1.61, 1.99) | 2.38 (1.98, 2.85) | 2.17 (1.69, 2.79) | <0.0001 | 1.99 (1.82, 2.18) |
| Model 24 | 1.00 (Ref) | 1.08 (0.98, 1.19) | 1.19 (1.08, 1.31) | 1.28 (1.15, 1.43) | 1.48 (1.23, 1.78) | 1.33 (1.03, 1.72) | <0.0001 | 1.35 (1.22, 1.49) |
| Model 35 | 1.00 (Ref) | 1.05 (0.95, 1.15) | 1.09 (0.99, 1.20) | 1.13 (1.01, 1.26) | 1.28 (1.06, 1.55) | 1.14 (0.88, 1.47) | 0.007 | 1.15 (1.02, 1.30) |
| HPFS (n = 41,412) | ||||||||
| Cases/person-years | 340/113,957 | 944/253,241 | 1498/345,060 | 915/218,960 | 165/36,212 | 144/34,989 | ||
| Model 13 | 1.00 (Ref) | 1.23 (1.08, 1.39) | 1.42 (1.26, 1.60) | 1.59 (1.40, 1.80) | 1.70 (1.41, 2.05) | 1.54 (1.26, 1.87) | <0.0001 | 1.29 (1.18, 1.40) |
| Model 24 | 1.00 (Ref) | 1.14 (1.01, 1.30) | 1.25 (1.11, 1.42) | 1.37 (1.21, 1.56) | 1.44 (1.19, 1.75) | 1.36 (1.11, 1.66) | <0.0001 | 1.19 (1.09, 1.30) |
| Model 35 | 1.00 (Ref) | 1.10 (0.96, 1.25) | 1.13 (0.99, 1.28) | 1.18 (1.02, 1.36) | 1.21 (0.98, 1.48) | 1.14 (0.92, 1.42) | 0.15 | 1.07 (0.96, 1.18) |
| Pooled results (n = 213,798) | ||||||||
| Cases/person-years | 1119/453,856 | 4806/1,463,566 | 9103/2,226,199 | 4301/1,109,931 | 707/159,351 | 478/117,056 | ||
| Model 13 | 1.00 (Ref) | 1.18 (1.11, 1.26) | 1.38 (1.29, 1.47) | 1.69 (1.58, 1.80) | 1.90 (1.72, 2.09) | 1.86 (1.67, 2.07) | <0.0001 | 1.52 (1.46, 1.59) |
| Model 24 | 1.00 (Ref) | 1.11 (1.04, 1.19) | 1.19 (1.11, 1.27) | 1.34 (1.26, 1.44) | 1.43 (1.30, 1.58) | 1.41 (1.27, 1.58) | <0.0001 | 1.26 (1.20, 1.32) |
| Model 35 | 1.00 (Ref) | 1.07 (1.00, 1.14) | 1.09 (1.02, 1.16) | 1.18 (1.10, 1.27) | 1.24 (1.12, 1.37) | 1.23 (1.09, 1.37) | <0.0001 | 1.14 (1.07, 1.20) |
HPFS, Health Professionals’ Follow-up Study; NHS, Nurses’ Health Study.
P values for trend were based on a continuous egg variable derived from the median egg intake in each category of consumption.
Cox proportional hazards regression model 1 was stratified by calendar year in 2-y intervals and by cohort (in pooled analysis only), and adjusted for age (mo).
Cox proportional hazards regression model 2 included model 1 and was further adjusted for race/ethnicity (Caucasian/other), family history of diabetes (yes/no), history of hypertension at baseline (yes/no), history of hypercholesterolemia at baseline (yes/no), smoking status (never, former, current), BMI (in kg/m2: <21.0, 21.0–22.9, 23.0–24.9, 25.0–26.9, 27.0–29.9, 30.0–34.9, ≥35.0), physical activity (MET-h/wk: <3.0, 3.0–8.9, 9.0–17.9, 18.0–26.9, ≥27.0), oral contraceptive use (never, former, current; in the NHS II only), postmenopausal hormone use (premenopausal, never, former, current; in the NHS and NHS II only), statin use (yes/no), cumulative average alcohol intake (g/d; quintiles), multivitamin use (yes/no), and physical examination during the 2-y cycle (yes/no). All covariates (except race, family history of diabetes, baseline hypercholesterolemia, and baseline hypertension) were updated every 2 y.
Cox proportional hazards regression model 3 included model 2 with updated cumulative average of daily intake of total calories (quintiles), bacon (servings/d; in categories), red meat (servings/d; in categories), other processed red meats (servings/d; in categories), refined grains (servings/d; in categories), potatoes (servings/d; in categories), fruits (servings/d; in categories), vegetables (servings/d; in categories), full-fat milk (servings/d; in categories), coffee (servings/d; in categories), fruit juices (servings/d; in categories), and sugar-sweetened beverages (servings/d; in categories).