TABLE 5.
Percentage changes (95% CIs) in hearing thresholds (dB) by joint effect between antioxidant and magnesium intakes1
| Change (95% CI) |
|||
| Low magnesium | High magnesium | P-interaction | |
| % | |||
| Speech-frequency PTA (n = 2543)2 | |||
| Low β-carotene | 0 (Reference) | −7.87 (−14.94, −0.21)* | 0.670 |
| High β-carotene | −9.32 (−16.74, −1.23)* | −14.21 (−20.26, −7.71)‡ | |
| Low vitamin C | 0 (Reference) | −1.68 (−12.26, 10.17) | 0.329 |
| High vitamin C | −3.39 (−11.42, 5.38) | −11.87 (−18.60, −4.59)† | |
| Low vitamin E | 0 (Reference) | −3.23 (−12.46, 6.97) | 0.425 |
| High vitamin E | −5.75 (−13.42, 2.60) | −13.74 (−18.02, −9.23)‡ | |
| High-frequency PTA (n = 2535)3 | |||
| Low β-carotene | 0 (Reference) | −0.80 (−8.86, 7.99) | 0.082 |
| High β-carotene | −4.98 (−11.54, 2.06) | −14.82 (−20.50, −8.74)‡ | |
| Low vitamin C | 0 (Reference) | 2.13 (−8.49, 13.97) | 0.090 |
| High vitamin C | −1.33 (−9.37, 7.42) | −10.72 (−16.57, −4.45)† | |
| Low vitamin E | 0 (Reference) | −4.68 (−12.73, 4.11) | 0.934 |
| High vitamin E | −6.89 (−15.90, 3.08) | −11.71 (−16.78, −6.32)‡ | |
Low compared with high cutoff points for vitamins C (75 mg/d for men; 60 mg/d for women) and E (12 mg/d) and magnesium (350 mg/d for men; 265 mg/d for women) were defined as the Estimated Average Requirements of Dietary Reference Intakes. We used the median for β-carotene (771 μg/d) because no Estimated Average Requirements for β-carotene were available. All models were adjusted for age, age2, sex, race-ethnicity, BMI, ototoxic medication use, pack-years of cigarette smoke, hypertension, diabetes, occupational noise, recreational noise, and firearm noise. *P < 0.05, †P < 0.01, ‡P < 0.001. PTA, pure-tone average.
At 0.5, 1, 2, and 4 kHz.
At 3, 4, and 6 kHz.