Table 2.

Odds ratios (95% confidence intervals) for associations between erythrocyte folate, serum vitamin B12 and hearing loss in NHANES 2003–2004 participants (n = 1,149).

Model	Odds ratios (95% confidence intervals)*
	Quartiles of erythrocyte folate				Quartiles of serum vitamin B12
	1(low)	2	3	4 (high)	1 (low)	2	3	4 (high)
1†	1.00	0.94 (0.52, 1.72)	0.66 (0.47, 0.93)	0.98 (0.62, 1.56)	1.00	0.68 (0.45, 1.03)	0.71 (0.43, 1.18)	0.68 (0.34, 1.38)
2‡	1.00	0.85 (0.49, 1.49)	0.68 (0.47, 0.99)	1.05 (0.57, 1.94)	1.00	0.73 (0.48, 1.11)	0.80 (0.49, 1.31)	0.70 (0.35, 1.38)
3§	1.00	0.87 (0.49, 1.53)	0.70 (0.49, 1.00)	1.08 (0.61, 1.94)	1.00	0.73 (0.48, 1.12)	0.80 (0.49, 1.32)	0.72 (0.36, 1.41)

^*Odds ratios and 95% confidence intervals are from a logistic regression model implemented using the SURVEYLOGISTIC Procedure in SAS to account for sampling weights. Confidence intervals that do not include 1.00 are statistically significant at P ≤ 0.05. Variables for folate, vitamin B12, age and sex were included in all models simultaneously. Hearing loss was defined as having a PTA >25 dB at 0.5, 1.0, 2.0 or 4.0 kHz in any ear.

^†Model 1 included quartiles of erythrocyte folate, quartiles of serum vitamin B12, age (as a continuous variable) and sex (men vs. women).

^‡Model 2 additionally adjusted for smoking (never, past and current), alcohol use (yes or no), body mass index (continuous), race/ethnicity (non-Hispanic white, non-Hispanic black and other), exposure to loud noise or music in last 24 hours (yes or no), annual household income (<$20,000, $20,000–54,999 and ≥$55,000) and educational attainment (not completed high school, graduated from high school/GED and college or higher).

^§Additionally adjusted for the 2010 health eating index as a measure of quality of the overall diet.