Table 2. Baseline Values and Changes in Metabolic Parameters during the 4-Year Follow-up Period.

Variable	<50 yr (n=62,132)	≥50 yr (n=3,724)	P value	Men (n=39,156)	Women (n=26,700)	P value
Age, yr	38.2±5.4	54.5±5.3	<0.01	39.5±6.6	38.5±6.3	<0.01
Male sex	36,703 (59.1)	2,453 (65.9)	<0.01	-	-	-
Body weight, kg	66.1±12.3	65.4±10.1	<0.01	72.9±9.8	56.0±7.7	<0.01
Body mass index, kg/m2	23.3±3.1	23.8±2.6	<0.01	24.4±2.9	21.8±2.8	<0.01
Muscle mass, kg	46.9±9.3	46.1±8.3	<0.01	53.2±5.7	37.6±3.8	<0.01
Body fat mass, kg	16.4±5.4	16.5±4.8	0.04	16.5±5.5	16.2±5.1	<0.01
Body weight change, kg	0.40±3.5	−0.34±2.7	<0.01	0.40±3.5	0.30±3.3	0.52
Percent change of body weight, %	0.70±5.2	−0.45±4.1	<0.01	0.65±4.8	0.62±5.6	<0.01
Lean mass change, kg	−0.48±1.7	−0.92±1.7	<0.01	−0.46±1.8	−0.58±1.5	<0.01
Percent change of lean mass, %	−0.74±2.5	−1.41±2.5	<0.01	−0.61±2.5	−1.03±2.7	<0.01
Annual percent change of lean mass, kg	−0.18±0.6	−0.35±0.6	<0.01	−0.15±0.6	−0.26±0.7	<0.01
Fat mass change, kg	0.92±2.9	0.71±2.4	<0.01	0.93±2.9	0.88±2.9	0.04
Percent change of fat mass, %	1.50±4.4	1.16±3.7	<0.01	1.36±3.9	1.66±5.0	<0.01
Annual percent change of fat mass, kg	0.38±1.1	0.29±0.9	<0.01	0.34±1.0	0.42±1.2	<0.01

Values are expressed as mean±SD or number (%).