Table 5.

Multivariate Regression Analysis Identifies Clinical Parameters Associated With the Serum Free T₃:Free T₄ Ratio

	LT4-Treated (n = 469)		Matched Controls (n = 469)
	Regression Coefficient	P Value	Regression Coefficient	P Value
Age (5 yr increase)	−0.14	<.0001	−0.10	<.0001
Female	—	NS	−0.32	<.0001
BMI (5 kg/m2 increase)	—	NS	—	NS
Total cholesterol (50 mg/dl increase)	—	NS	—	NS
Triglyceride (50 mg/dl increase)	—	NS	—	NS
Creatinine (0.5 mg/dl increase)	—	NS	—	NS
1000 MET activity (work and recreation)	—	NS	—	NS
1000 calories consumed	0.20	.05	—	NS
Beta-blocker prescription	—	NS	—	NS
Currently smoking daily	—	NS	—	NS
Number of alcoholic drinks consumed per day	—	NS	—	NS

Abbreviation: MET, metabolic equivalent.

Age was scaled to 5 y, BMI scaled to 5 kg/m², total cholesterol scaled to 50 mg/dl, triglyceride scaled to 50 mg/dl, creatinine scaled to 0.5 mg/dl, beta-blocker use, current smoker, number of alcohol drinks consumed per day, total METs scaled to 1000 MET, and calorie intake scaled to 1000 calories. HDL and LDL were omitted because of multicollinearity with total cholesterol.