Table 4.

Weighted odds ratios (95% confidence intervals) for having trouble falling asleep across quartiles of pyridoxal 5′-phosphate (PLP) concentrations stratified by age (NHANES 2005–2008).

	Model 2 a
	18 ≤ Age < 40 Years	40 ≤ Age < 60 Years	Age ≥ 60 Years
Q1 (<27.3)	1.00 (ref)	1.00 (ref)	1.00 (ref)
Q2 (27.3 to <44.0)	1.03 (0.64–1.64)	0.93 (0.62–1.40)	0.68 (0.48–0.97) *
Q3 (44.0 to <76.3)	0.95 (0.66–1.37)	1.01 (0.69–1.49)	0.69 (0.49–0.96) *
Q4 (≥76.3)	0.82 (0.52–1.30)	1.56 (0.97–2.50)	0.75 (0.51–1.10)

Calculated using binary logistic regression models. ^a Model 2 adjusted for age, sex, race/ethnicity, education level, household poverty ratio, marital status, body mass index, physical activity, smoking status, caffeine intake, energy, alcohol consumption, hypertension, diabetes, depressive symptoms, and sampling season. * p < 0.05.