Figure 7. Association Between Each Additional Half an Egg Consumed per Day and Incident CVD Among Different Subgroups.

See the Figure 1 footnote for conditions included in the incident cardiovascular disease (CVD) definition. Adjustment covariates included age, sex, race/ethnicity (white, black, Hispanic, Chinese), education (<high school, high school, ≥some college), total energy, smoking status (current, former, never), smoking pack-years (0, 0.1-4.9, 5.0-9.9, 10-19.9, 20-29.9, 30-39.9, ≥40), cohort-specific physical activity z score, alcohol consumption (gram), and use of hormone therapy (y/n), where relevant. Mean egg consumption in the United States was approximately half an egg per day, based on the National Health and Nutrition Examination Survey 2011-2012 data.²⁸ The results can be interpreted using the following sex-specific estimates as an example: in men, each additional half an egg consumed per day was not significantly associated with a higher relative risk (RR) of incident CVD (adjusted hazard ratio [HR], 1.03 [95% CI, 0.99-1.08]) and a higher absolute risk of incident CVD (adjusted absolute risk difference [ARD], 1.02% [95% CI, −0.34% to 2.38%]) over a follow-up of 30 years. In women, each additional half an egg consumed per day was significantly associated with a higher RR of incident CVD (adjusted HR, 1.13 [95% CI, 1.07-1.20]) and a higher absolute risk of incident CVD (adjusted ARD, 1.86% [95% CI, 0.62%-3.10%]) over a follow-up of 30 years. The association was stronger in women than in men (P value for interaction = .009).

^aAbsolute risk difference was estimated using 3 R packages: riskRegression,³³ survival,³⁴ and pec,³⁵ and 95% CIs were derived from 100 bootstrap samples. A follow-up time of 30 years (not all subgroups had the maximum follow-up of 31.3 years), mean of the included covariates, and a difference of half an egg per day consumed were used.

^bCohort-stratified cause-specific hazard models were used for incident CVD.

^cThe maximum follow-up time for the older group was 22.8 years. All other subgroups used 30 years as specified in footnote “a.”

^dHispanic and Chinese participants were combined with white participants (all categorized as other) due to small sample size.

^eBody mass index was calculated as weight in kilograms divided by height in meters squared.

^fFasting glucose (≥126 mg/dL) or HbA_1c (≥6.5%) or taking glucose-lowering medications.

^gBlood pressure (≥140/90 mm Hg) or taking antihypertensive medications.

^hTotal cholesterol (≥240 mg/dL) or taking lipid-lowering medications.

ⁱLow-density lipoprotein cholesterol (<70 mg/dL) or non-high density lipoprotein cholesterol (<100 mg/dL) among those who did not take lipid-lowering medications.

^jAlternate Healthy Eating Index (aHEI) 2010 score in the highest quartile (≥51.5). The original version of the aHEI-2010 score has a range of 0 to 110 points, but the score in this study had a range of 0 to 100 points due to the removal of the meat item.

^kPercent of energy consumed from saturated fat in the highest quartile (≥13.8%).

^lPercent of energy consumed from saturated fat (<7%).