Vnitřní lékařství 2/2020

P Ů VODNÍ PRÁCE Relation between testosterone levels and body composition, physical functioning and selected biochemical parameters in adult males | 39 / Vnitř Lék 2020; 66(E-2): 37–42 / VNITŘNÍ LÉKAŘSTVÍ www.casopisvnitrnilekarstvi.cz Physical function Muscle strength of lower extremities was measured by predicted dynamic leg press 1RM frommultiple repetition maximum testing (10) on seated leg press machine (Technogym, Italy). For upper extremities, handgrip strength was measured by best of the 3 trials with 60 second rest period after warming up with 3 trials (approximately 50 and twice 80% of maximal voluntary contraction) with the resting period of 20 seconds using digital hand dynamometer (Camry, USA). Cardio-respiratory fitness was measured by The Single Stage Treadmill (Woodway Pro, USA) Walking Test, which is a submaximal aerobic fitness test that estimates VO 2max . It is suitable for low risk, apparently healthy, non-athletic adults 20–59 years of age. The walking pace required throughout the test also makes it appropriate for parti- cipants who experience problems such as knee pain when exercising at a jogging pace. The test can be administered to moderate sized groups of participants with low to moderate fitness levels and requires only a treadmill and a HR monitor VO 2max was estimated from heart rate results of the walking test using protocols calculation (11). Biochemical parameters Fasting morning venous blood samples were collected between 8 : 00 AM to 10 : 00 AM into closed system collection tubes containing beads coated with a clotting activator and polyacryl ester-gel (Sarstedt AG & Co, Germany). The samples were centrifuged at 2 000 rpm for 10 Fig. 1. Relationship between total testosterone levels and abdominal circumference (r = -0.639, p < 0.01 Tab. 1. Demographic and biochemical data N = 17 average ± SD Age (year) 50.2 ± 8.1 Total body weight (kg) 92.37 ± 19.49 Lean mass (kg) 62.55 ± 7.46 Overall body fat mass (kg) 29.82 ± 12.71 Overall body fat mass (%) 31.34 ± 5.55 BMI (kg.m -2 ) 30.04 ± 6.50 Abdominal circumference (cm) 104.50 ± 9.96 Total testosterone (nmol/l) 11.45 ± 3.81 (6.9–26.1) SHBG (nmol/l) 30.00 ± 11.62 (14.5–94.6) Total cortisol (nmol/l) 491.87 ± 87.48 (118.6–618) Total cholesterol (mmol/l) 5.34 ± 1.33 (3.2–5) LDL-cholesterol (mmol/l) 3.68 ± 1.07 (1–3) HDL-cholesterol (mmol/l) 1.19 ± 0.20 (1–2) HOMA-IR 3.96 ± 2.99 (0.4–2.0) Glucose (mmol/l) 5.44 ± 1.33 (3.3–5.6) Insulin (mIU/l) 15.82 ± 10.35 (3–25) Predicted Legress 1RM relative to lean mass (kg) 2.49 ± 0.44 Handgrip average (kg) 50.26 ± 7.68 *VO 2max (mlO 2 .kg BW-1.min-1) 33.88 ±1.12 Data are presented as means of the group with standard deviations. Biochemical parameters were analysed from fasting morning plasma. Reference values for a local male population are in parentheses. BMI – Body Mass Index, SHBG – Sex Hormone Binding Globulin, LDL – LowDensi- ty Lipoprotein, HDL – High Density Lipoprotein, HOMA-IR – The Homeostatic Mo- del Assessment – Insulin Resistance, *indirect assessment