Table 1.

—Characteristics of the Study Sample by Sleep-Disordered Breathing Severity

Variable	AHI < 5.0 (n = 3,413)	AHI 5.0-14.9(n = 1,808)	AHI 15.0-29.9 (n = 739)	AHI ≥ 30.0(n = 392)
Age,a y	61.3 (11.1)	64.8 (10.6)	65.1 (10.5)	64.6 (10.7)
BMI,a kg/m2	27.0 (4.5)	29.5 (5.3)	30.7 (5.8)	32.1 (6.1)
Sex,a %
Women	63.3	45.4	35.7	29.3
Men	36.7	54.6	63.3	70.7
Race,a %
White	77.7	76.7	75.5	74.2
African American	8.1	6.9	8.1	9.2
Native American	7.9	11.2	12.0	12.2
Hispanic	4.7	3.7	3.8	3.6
Other	1.6	1.5	0.5	0.8
Smoking  status,a %
Never	47.7	43.4	44.5	42.4
Former	38.5	47.9	45.9	51.3
Current	13.9	8.7	9.6	6.4
Caffeinated  soda,a %
None	70.6	67.1	68.2	58.2
1 can/d	18.2	20.3	17.9	22.3
2 cans/d	6.6	7.2	8.3	10.0
3 cans/d	2.5	3.1	2.8	4.1
≥ 4 cans/d	2.1	2.3	2.8	5.4
Caffeinated  coffee, %
None	37.2	39.2	38.7	35.2
1 cup/d	16.7	14.8	15.1	17.9
2 cups/d	17.6	18.1	17.2	16.3
3 cups/d	11.1	11.9	12.2	12.2
≥ 4 cups/d	17.4	16.0	16.8	18.4
Caffeinated  tea, %
None	74.9	74.6	74.1	75.5
1 cup/d	13.0	12.2	13.7	12.5
2 cups/d	6.6	7.2	6.1	5.9
3 cups/d	2.7	2.8	2.7	3.1
≥ 4 cups/d	2.8	3.2	3.4	3.0

AHI = apnea-hypopnea index (events/h).

^aP < .001 for comparisons of age, sex, race, smoking status, BMI, and caffeinated soda intake across AHI categories.