Table 2. Means for Thyroid Hormone Levels by Select Metabolic Syndrome Components.

Variable	No. (%)	Thyroid hormones
		TSH, mU/L	T3, nmol/L	T4, nmol/L	T3-to-T4 ratio
BMI, kg/m2
Underweight (<18.5)	219 (2)	2.6±1.3a,*	1.67±0.28a,*	109.7±17.4a,‡	0.015±0.003a,*
Normal (18.5-24.9)	8,992 (66)	2.4±1.3a,*	1.71±0.28b,*	108.8±17.9a,‡	0.016±0.003b,*
Overweight (25-29.9)	4,042 (30)	2.2±1.2b,*	1.75±0.28c,*	108.0±17.9b,‡	0.017±0.003c,*
Obesity (≥30)	243 (2)	2.2±1.2b,*	1.79±0.26d,*	110.9±20.0c,‡	0.017±0.003c,*
Systolic BP, mm Hg
<130	10,272 (76)	2.3±1.3	1.71±0.28*	108.3±17.8*	0.016±0.003†
≥130e	3,224 (24)	2.3±1.3	1.76±0.29*	109.7±18.3*	0.017±0.003†
Diastolic BP, mm Hg
<85	10,756 (80)	2.3±1.3	1.71±0.28*	108.3±17.8*	0.016±0.003‡
≥85e	2,739 (20)	2.3±1.3	1.76±0.29*	109.9±18.5*	0.017±0.003‡
HDL-C, mg/dL
Lowf	1,555 (12)	2.5±1.3*	1.68±0.28*	108.8±17.7	0.016±0.003*
Highg	11,941 (88)	2.3±1.3*	1.73±0.28*	108.6±17.9	0.017±0.003*
Triglycerides, mg/dL
<150	9,966 (74)	2.3±1.3	1.70±0.28*	108.8±17.9	0.016±0.003*
≥150	3,530 (26)	2.4±1.3	1.80±0.28*	108.1±18.1	0.017±0.003*
Fasting glucose, mg/dL
<100	11,484 (85)	2.4±1.3*	1.72±0.28*	108.6±17.8	0.016±0.003*
≥100h	2,012 (15)	2.2±1.2*	1.75±0.29*	108.6±18.6	0.017±0.003*
HbA1c, %
<5.7	10,636 (79)	2.4±1.3a,‡	1.72±0.28a,*	108.5±17.8a,†	0.016±0.003a,*
5.7-6.4	1,992 (15)	2.3±1.3a,b,‡	1.75±0.29b,*	108.6±17.8a,†	0.017±0.003b,*
≥6.5h	868 (6)	2.2±1.3b,‡	1.73±0.30a,*	110.4±19.6b,†	0.016±0.003a,*

Values are expressed as mean±SD. Thyroid hormone levels of the study population with respect to the cut-off values of metabolic syndrome components were compared using an independent t test or one-way analysis of variance as appropriate for the variable.

TSH, thyroid stimulating hormone; T3, triiodothyronine; T4, thyroxine; BMI, body mass index; BP, blood pressure; HDL-C, high density lipoprotein cholesterol; HbA1c, glycated hemoglobin.

^a,b,c,dThe same letters indicate non-significant difference between groups based on Tukey's multiple comparison test; ^eInclude patients on antihyper-tensive medication regardless of systolic or diastolic BP levels; ^fHDL-C <40 mg/dL in men or <50 mg/dL in women; ^gHDL-C ≥40 mg/dL in men or ≥50 mg/dL in women; ^hInclude patients on antidiabetic medication regardless of fasting glucose or HbA1c levels; ^*P<0.001; ^†0.001≤P<0.01; ^‡0.01≤P<0.05.