Does impedance measure a functional state of the body fat?

The aim was to compare methods of body fat measurement in different BMI groups. An additional aim was to discuss differences reflecting the structural and functional changes of fat tissue. The study group included 130 adult Caucasian women stratified by body mass index (BMI): 18-24.99 (n=30), 25-29.99 (n=26), 30-34.99 (n=33), 35-39.99 (n=30), and BMI>/=40 (n=11). Bioelectrical impedance was performed using Tanita TBF 410 GS, Bodystat 1500, and Omron BF 300. A caliper type Best was also applied. Correspondence of four methods with DEXA was assessed using the Bland-Altman and ANOVA analyses. Measurements by BIA were not significantly different from DEXA up to BMI of 30, but DEXA significantly overestimated in the higher BMI subgroup by all three methods. Caliper measurement significantly underestimated DEXA in all BMI subgroups. BIA methods overestimated DEXA for the obese subjects. Tanita did statistically the best. The Caliper test appeared less preferable than the BIA methods, especially in the higher BMI subgroup. DEXA and Caliper measurements seem to be the best estimate of structural (anatomical) fat quantity. We hypothesize that BIA methods could also measure some other physiopathological conditions like inflammation, hydration or cell infiltration of fat.

Post-exercise changes of beta hydroxybutyrate as a predictor of weight changes.

The aim was to find the differences in ketogenesis initiation in the early period after the exercise in obese patients and to find if these changes may predict the weight loss during the physical activity program. 96 females were enrolled. A clamped heart rate test (CHR) was performed to establish comparable exercise intensity. Blood samples for beta hydroxybutyrate (BOHB) assessment were collected prior, immediately after and 60 min after the test. Patients underwent a three month fitness program. Anthropometric measurements (fat mass and biochemical parameters) were measured. An energy intake was monitored and comparable in all subjects. A significant increase of BOHB was found in 60(th) minute after the test, when compared with initiation levels (BOHB1 vs. BOHB3; p=0.03). This increase correlates with % fat mass (R=0.196; p=0.02) and negatively with age (R= -0.147; p=0.05) and with weight reduction during the three-month program (R= -0.299; p=0.03). Serum BOHB increase after the single exercise may detect individuals with an ability to induce lipolysis in three-month program of physical activity for obese patients.

[Regular aerobic physical activity improves the lipid profile in persons with excessive body weight]. / Pravidelná aerobní pohybová aktivita zlepsuje lipidový profil u osob s vyssí nez normální telesnou hmotností.

UNLABELLED: A review of physical activity-induced lipid changes is presented. The review was compared with results we obtained in a reconditioning program involving 25 untrained obese patients who attended the reconditioning centre of the 1st Faculty of Medicine of Charles University for three months. A significant decrease was found in both HDL-cholesterol, triglycerides and the atherosclerosis index. No significant changes were recorded in the total and LDL-cholesterol level. CONCLUSION: Aerobic physical activity can induce changes in lipid levels in overweight and obese patients. Indication of regular aerobic physical activity should not be omitted in current practice.