Sleep Disorders / 2012 / Article / Tab 2

Research Article

Association of Plasma Homocysteine with Self-Reported Sleep Apnea Is Confounded by Age: Results from the National Health and Nutrition Examination Survey 2005-2006

Table 2

Sociodemographic, clinical, and relevant biochemical characteristics of the population included in this study (total ).

CharacteristicSleep apnea ( )No sleep apnea ( )

Age (yrs); mean(SD)56.5 (15.2)48.1 (19.0)<0.001
Males; n (%)116 (65.5)2036 (47.2)<0.001
Race/ethnicity; n (%)<0.001
 Mexican American11 (6.2)899 (20.8)
 Other Hispanic2 (1.1)136 (3.12)
 Non-Hispanic White120 (67.8)2144 (49.7)
 Non-Hispanic Black40 (22.6)962 (22.3)
 Others4 (2.3)172 (4.0)
Country of birth; n (%)<0.001
 United States168 (94.9)3345 (77.6)
 Mexico4 (2.3)583 (13.5)
 Elsewhere5 (2.8)385 (8.9)
Education; n (%)0.039
 Less than 9th grade10 (5.7)543 (12.6)
 9–11th grade20 (11.3)670 (15.5)
 High school48 (27.1)1018 (23.6)
 Some college education53 (29.9)1228 (28.5)
 College graduate46 (26.0)849 (19.7)
 Refused/do not know0 (0.0)5 (0.1)
Marital status; n (%)0.016
 Married121 (68.4)2340 (54.3)
 Widowed11 (6.2)388 (9.0)
 Divorced15 (8.5)412 (9.6)
 Separated5 (2.8)130 (3.0)
 Never married14 (7.9)675 (15.7)
 Living with partner11 (6.2)365 (8.5)
 Refused to answer0 (0.0)3 (0.1)
Poverty income ratio; mean (SD)2.84 (1.64)2.68 (1.59)0.194
Body mass index (Kg/m2); mean (SD)34.90 (0.62)28.55 (0.10)<0.001
Ever smoking; n (%)101 (57.06)2026 (46.97)0.008
Ever alcohol use; n (%)41 (23.16)682 (15.81)0.009
Plasma homocysteine (μmol/L); mean (SD)9.49 (3.75)8.44 (4.62)0.003
RBC folate (ng/mL); mean (SD)326.7 (180.4)297.0 (135.4)0.005
Plasma folate (ng/mL); mean (SD)14.65 (15.4)13.8 (9.5)0.255

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