Table 4.

General characteristics and serum levels of metabolites in healthy volunteers

Age	26.11 ± 3.01
Sex, males (%)	44 (60.3)
Education, higher (%)	23 (31.5)
BMI, kg/m2	22.95 ± 2.58
Waist circumference (cm)	78.71 ± 10.03
Cigarette smoking, n (%)	22 (30.1)
FTND score	1.30 ± 2.29
Pack-year index	1.09 ± 2.38
l-Arginine (μM)	112.84 ± 45.20
Dimethylamine (μM)	0.94 ± 0.39
ADMA (μM)	0.38 ± 0.05
SDMA (μM)	0.33 ± 0.04
l-Citrulline (μM)	24.54 ± 6.11
l-Arginine: ADMA	297.85 ± 126.12

Data expressed as mean ± SD for continuous variables and the number of cases (%) for categorical variables

FTND Fagerström test for nicotine dependence