Adjusted associations between quartile diet quality Alternative Healthy Eating Index (AHEI-2010) score and pre-bronchodilator lung function outcomes
| Lung function measures# | |||
| FEV1 mL | FVC mL | FEV1/FVC ratio % | |
| Total sample n=10 428 | |||
| Model 1¶ | |||
| Quartile 1 (3.0–37.5) | Reference | Reference | Reference |
| Quartile 2 (35.5–46.0) | 91.3 (45.4–137.3) | 82.3 (35.7–128.9) | 0.81 (0.15–1.47) |
| Quartile 3 (43.7–55.4) | 102.2 (63.1–141.2) | 106.7 (58.6–154.7) | 0.64 (0.09–1.19) |
| Quartile 4 (52.5–94.6) | 167.7 (122.5–212.9) | 180.7 (131.2–230.1) | 0.77 (0.06–1.49) |
| Model 2+ | |||
| Quartile 1 (3.0–37.5) | Reference | Reference | Reference |
| Quartile 2 (35.5–46.0) | 14.82 (−45.53–75.17) | 16.02 (−45.37–77.40) | 0.19 (−0.48–0.85) |
| Quartile 3 (43.7–55.4) | 10.46 (−35.91–56.83) | 33.96 (−17.56–85.49) | 0.01 (−0.69–0.71) |
| Quartile 4 (52.5–94.6) | 47.92 (2.27–93.57) | 80.23 (34.03–126.42) | −0.11 (−0.79–0.58) |
| Interaction of AHEI and smoking status (p-value) | 0.532 | 0.231 | 0.585 |
| Model 3§ | |||
| Quartile 1 (3.0–37.5) | Reference | Reference | Reference |
| Quartile 2 (35.5–46.0) | 78.66 (9.86–147.46) | 76.86 (16.66–137.07) | 0.52 (−0.22–1.26) |
| Quartile 3 (43.7–55.4) | 63.17 (10.13–116.21) | 80.31 (23.27–137.35) | 0.07 (−0.58–0.73) |
| Quartile 4 (52.5–94.6) | 95.52 (41.74–149.31) | 119.49 (69.67–169.31) | 0.04 (−0.74–0.83) |
| Interaction of AHEI and race/ethnicity (p-value) | 0.109 | 0.029 | 0.355 |
| Subgroup analysis by race/ethnicity ƒ,## | |||
| Non-Hispanic white (n=4452) | 64.43 (2.09–126.78) | 106.94 (48.24–165.64) | −0.18 (−1.15–0.79) |
| Interaction of AHEI and smoking status (p-value) | 0.484 | 0.107 | 0.496 |
| Non-Hispanic black (n=2185) | 58.99 (−25.91–143.89) | 69.88 (−20.36–160.12) | 0.30 (−1.24–1.84) |
| Interaction of AHEI and smoking status (p-value) | 0.586 | 0.568 | 0.258 |
| Hispanic (n=2918) | 11.05 (−65.82–87.93) | 14.98 (−70.38–100.33) | −0.08 (−0.87–0.71) |
| Interaction of AHEI and smoking status (p-value) | 0.011 | 0.306 | 0.039 |
| Subgroup analysis by smoking statusƒ,¶¶ | |||
| Never-smoker (n=5066) | 19.03 (−38.23–76.30) | 76.84 (19.40–134.28) | −0.99 (−1.87–−0.10) |
| Interaction of AHEI and race/ethnicity (p-value) | 0.872 | 0.730 | 0.236 |
| Former smoker (n=2070) | 85.60 (−15.69–186.88) | 106.76 (5.79–207.72) | −0.05 (−1.26–1.16) |
| Interaction of AHEI and race/ethnicity (p-value) | 0.174 | 0.276 | 0.477 |
| Current smoker (n=3292) | 160.18 (54.41–265.95) | 165.72 (61.31–270.13) | 0.93 (−0.74–2.61) |
| Interaction of AHEI and race/ethnicity (p-value) | 0.117 | 0.491 | 0.322 |
FEV1: forced expiratory volume in 1 s; FVC: forced vital capacity. #: β-coefficients (95% confidence interval) obtained from separated weighted linear regression model between diet quality and various lung function measures. Diet quality quartile ranges are summarised across all National Health and Nutrition Examination Survey (NHANES) cycle years (2007–2012) and may overlap as the quartiles were generated based on the sample distribution within each NHANES cycle year (2007–2008, 2009–2010, 2011–2012). Bold indicates statistical significance (p<0.05). ¶: Model 1 – Quartile AHEI-2010 score adjusted for age (years), sex (male, female) and height (cm). +: Model 2 – Quartile AHEI-2010 score adjusted for age (years), sex (male, female), height (cm), race/ethnicity (non-Hispanic white, non-Hispanic black, Hispanic, other), total energy intake (kcal), education (≤high school, >high school, unknown), household income (USD 0–25 000, 25 000–55 000, ≥55 000 or unknown), body mass index (BMI) category (underweight, normal, overweight, obese), physically active (yes, no), and the interaction between AHEI and smoking status (nonsmoker, former smoker, current smoker). §: Model 3 – Quartile AHEI-2010 score adjusted for age (years), sex (male, female), height (cm), total energy intake (kcal), education (≤high school, >high school, unknown), household income (USD 0–25 000, 25 000–55 000, ≥55 000 or unknown), BMI category (underweight, normal, overweight, obese), physically active (yes, no), smoking status (nonsmoker, former smoker, current smoker), and the interaction between AHEI and ethnicity (non-Hispanic white, non-Hispanic black, Hispanic, other). ƒ: Quartile 4 versus Quartile 1 β-coefficients presented for subgroup analyses by race/ethnicity and smoking status. ##: subgroup analysis by race/ethnicity adjusted for the covariates described in Model 2 (excluding race/ethnicity). ¶¶: subgroup analysis by smoking status adjusted for the covariates described in Model 2 (excluding smoking status).