Table 1. Geometric means for TSH, fT₃, and fT₄ levels by select characteristics of male and female participants, NHANES 2007–2008.

	No. participants	Hormone concentrations
		TSH (mIU/L)	fT3 (pg/mL)	fT4 (ng/dL)
Sex
Men	1,623	1.58	3.26	0.77
Women	1,491	1.61	3.08	0.76
Age (years)
20–34	851	1.43	3.27	0.77
35–49	911	1.57	3.18	0.75
50–64	751	1.72	3.13	0.76
65–80	601	1.85	2.99	0.79
Race/ethnicity
Non-Hispanic white	1,487	1.66	3.16	0.76
Hispanic	925	1.49	3.28	0.77
Non-Hispanic black	565	1.30	3.13	0.75
Other	137	1.55	3.19	0.81
BMI (kg/m2): WHO categories a
15–18.4 (underweight)	49	1.59	3.13	0.80
18.5–24.9 (normal)	932	1.48	3.13	0.77
25–29.9 (overweight)	1,158	1.63	3.18	0.76
30–34.9 (obese class I)	598	1.69	3.21	0.76
35–50 (obese class II & III)	377	1.63	3.21	0.76
Waist circumference (cm)
<90	1,044	1.51	3.13	0.76
90–99	839	1.61	3.18	0.76
100–109	666	1.64	3.21	0.76
≥110	565	1.69	3.22	0.76
Smoking status b
Never	1,681	1.62	3.15	0.76
Former	733	1.66	3.14	0.76
Current	699	1.46	3.25	0.76
Alcohol intake (drinks/day) b
None	1,085	1.61	3.15	0.77
1–2	1,061	1.65	3.13	0.76
>2	809	1.52	3.25	0.76

^aWorld Health Organization classification of adult underweight, normal-weight, overweight, and obesity according to BMI [37].

^bDoes not include missing values.