A Significant Association of Upper Limb Muscle Strength with Thyroid Function in Overweight and Obese Population: A Study of the Sixth Korea National Health and Nutrition Examination Survey (KNHANES 2014-2015)

Table 3

Relation between upper limb muscle strength with thyroid hormone status according to BMI and age.

BMI and age group	FT4 β (95% CI)	-value	TSH β (95% CI)	-value
BMI <23 (n = 1522)	0.54 (−181, 2.89)	0.6515	0.04 (−0.13, 0.21)	0.6450
Age 19–39 (n = 780)	−0.28 (−3.78, 2.93)	0.8658	−0.04 (−0.29, 0.20)	0.7264
Age ≥40 (n = 742)	2.52 (−0.82, 5.85)	0.1383	0.10 (−0.12, 0.32)	0.3862
BMI ≥23 (n = 1981)	0.22 (−0.205, 2.49)	0.8494	−0.03 (−0.22, 0.16)	0.7682
Age 19–39 (n = 696)	−2.90 (−7.11, 1.30)	0.1750	−0.56 (−1.04, −0.09)	0.0209
Age ≥40 (n = 1285)	3.24 (0.53, 5.95)	0.0192	0.17 (−0.08, 0.41)	0.1836

Corrected by sex, smoking, drinking, diabetes, and exercise. BMI, body mass index (calculated as weight divided by height squared (kg/m²)). CI, confidential interval. FT4, free thyroxine. TSH, thyrotropin.