TABLE 3.
Associations between serum folate, vitamin B-12, total homocysteine levels and PHQ score: Multiple logistic and zero-inflated poisson regression modelsa
| PHQ score≥10 |
PHQ continuous score |
|||||
|---|---|---|---|---|---|---|
| All | Men | Women | All | Men | Women | |
| OR 95% CI | OR 95% CI | OR 95% CI | β±SEE | β±SEE | β±SEE | |
| MODEL 1c | (n=2,388) | (n=1,030) | (n=1,358) | (n=2,388) | (n=1,030) | (n=1,358) |
| Serum folate, ng/mL | ||||||
| T1 : 7.02±0.08 | 1.00 | 1.00 | 1.00 | Ref | Ref | Ref |
| T2 : 12.0±0.06 | 0.74(0.52; 1.06) | 0.62(0.27; 1.40) | 0.82(0.48; 1.38) | −0.03±0.04 | −0.10±0.07 | 0.01±0.07 |
| T3 : 21.1±0.29 | 0.43(0.27; 0.69) b | 0.76(0.42; 1.39) | 0.31(0.13; 0.72) b | −0.20±0.06b | −0.14±0.07b | −0.22±0.09b |
| Serum vitamin B-12, pg/mL | ||||||
| T1 : 289.2±3.0 | 1.00 | 1.00 | 1.00 | Ref | Ref | Ref |
| T2 : 467.1±2.5 | 0.88(0.54; 1.41) | 1.03(0.47; 2.25) | 0.80(0.38; 1.66) | −0.07±0.07 | 0.02±0.10 | −0.13±0.11 |
| T3 : 807.2±10.1 | 0.97(0.61; 1.57) | 0.95(0.36; 2.53) | 1.03(0.52; 2.02) | +0.00±0.07 | 0.08±0.12 | −0.05±0.11 |
| Serum total homocysteine, μmol/L | ||||||
| T1 : 5.5±0.04 | 1.00 | 1.00 | 1.00 | Ref | Ref | Ref |
| T2 : 7.6±0.03 | 0.92(0.57; 1.48) | 1.12(0.52; 2.43) | 0.93(0.52; 1.69) | −0.06±0.07 | 0.04±0.08 | −0.10±0.08 |
| T3 : 11.5±0.2 | 1.11(0.64; 1.90) | 1.59(0.55; 4.60) | 0.95(0.49; 1.81) | +0.01±0.09 | 0.07±0.13 | −0.00±0.10 |
| MODEL 2d | (n=2,178) | (n=918) | (n=1,260) | (n=2,178) | (n=918) | (n=1,260) |
| Serum folate, ng/mL | ||||||
| T1 : 7.02±0.08 | 1.00 | 1.00 | 1.00 | Ref | Ref | Ref |
| T2 : 12.0±0.06 | 0.79(0.55; 1.12) | 0.55(0.24; 1.25) | 0.94(0.52; 1.69) | −0.00±0.04 | −0.08±0.10 | 0.05±0.08 |
| T3 : 21.1±0.29 | 0.52(0.35; 0.76) b | 0.85(0.41; 1.74) | 0.37(0.17; 0.80) b | −0.13±0.05b | −0.06±0.09 | −0.17±0.07b |
| Serum vitamin B-12, pg/mL | ||||||
| T1 : 289.2±3.0 | 1.00 | 1.00 | 1.00 | Ref | Ref | Ref |
| T2 : 467.1±2.5 | 0.92(0.56; 1.53) | 0.95(0.46; 1.96) | 0.86(0.38; 1.93) | −0.07±0.08 | 0.00±0.10 | −0.13±0.10 |
| T3 : 807.2±10.1 | 1.09(0.71; 1.69) | 1.04(0.37; 2.87) | 1.15(0.63; 2.10) | +0.03±0.06 | 0.08±0.12 | −0.02±0.10 |
| Serum total homocysteine, μmol/L | ||||||
| T1 : 5.5±0.04 | 1.00 | 1.00 | 1.00 | Ref | Ref | Ref |
| T2 : 7.6±0.03 | 1.00(0.56; 1.70) | 1.33(0.64; 2.77) | 0.97(0.46; 2.06) | −0.06±0.07 | 0.08±0.08 | −0.12±0.07 |
| T3 : 11.5±0.2 | 1.15(0.65; 2.03) | 1.74(0.51; 5.89) | 1.02(0.51; 1.02) | +0.01±0.08 | 0.10±0.16 | −0.00±0.09 |
Abbreviations: CI=confidence interval; Met=Metabolic Equivalent; NHANES=National Health and Nutrition Examination Survey; OR=odds ratio; Ref=Referent category; SEE=Standard error of the estimate; T=tertile.
Values are odds ratios with 95% confidence intervals or β±SEE. Sampling design complexity is taken into account in all analyses.
P<0.05 for null hypothesis that β=0 or Loge(OR)=0 based on Wald test.
Model 1 included all three exposures simultaneously and adjusted only for socio-demographic factors: age, sex, race/ethnicity, marital status, educational level and poverty income ratio.
Model 2 is model 1 but additionally adjusted for other potential confounders: Lifestyle and health-related factors (smoking status, BMI, physical activity: Mets.hr.wk−1, recoded as “0–<5”; “5–10”; “>10”) and dietary intakes (total energy intake (as is), alcohol, caffeine, vitamin B-6, β-carotene, vitamin C, vitamin E and n-3 HUFA intakes, expressed as tertiles).