Validity of Bioimpedance Spectroscopy in the Assessment of Total Body Water and Body Composition in Wrestlers and Untrained Subjects.

Bioimpedance spectroscopy (BIS) is an easy tool to assess hydration status and body composition. However, its validity in athletes remains controversial. We investigated the validity of BIS on total body water (TBW) and body composition estimation in Japanese wrestlers and untrained subjects. TBW of 49 young Japanese male subjects (31 untrained, 18 wrestlers) were assessed using the deuterium dilution method (DDM) and BIS. De Lorenzo's and Moissl's equations were employed in BIS for TBW estimation. To evaluate body composition, Siri's 3-compartment model and published TBW/fat-free mass (FFM) ratio were applied in DDM and BIS, respectively. In untrained subjects, DDM and BIS with de Lorenzo's equation showed consistent TBW estimates, whereas BIS with Moissl's equation overestimated TBW (p < 0.001 vs. DDM). DDM and BIS with de Lorenzo's equation estimated FFM and percent of fat mass consistently, whereas BIS with Moissl's equation over-estimated and under-estimated them (p < 0.001 vs. DDM). In wrestlers, BIS with de Lorenzo's and Moissl's equations assessed TBW similarly with DDM. However, the Bland-Altman analysis revealed a proportional bias for TBW in BIS with de Lorenzo's equation (r = 0.735, p < 0.001). Body composition assessed with BIS using both equations and DDM were not different. In conclusion, BIS with de Lorenzo's equation accurately estimates the TBW and body composition in untrained subjects, whereas BIS with Moissl's equation is more valid in wrestlers. Our results demonstrated the usefulness of BIS for assessing TBW and body composition in Japanese male wrestlers.

A pilot assessment of oxidative stress byproducts and antioxidant activities among Indian patients with various stages of hypertension.

In humans, hypertension is considered a state of oxidative stress that can contribute to the development of atherosclerosis and other hypertension-induced organ damages. The objective of this study was to evaluate oxidative status, antioxidant activities, and oxidative stress by-products among Indian patients with various stages of hypertension. Lipid profile, enzymatic and non-enzymatic antioxidants, lipid peroxidation as thiobarbituric acid reactive substances (TBARS), C-reactive protein, electrolytes, and minerals were analyzed in the blood of newly diagnosed prehypertensives, stage I and II hypertensives (n = 20 in each group) and were compared to their age-matched normotensives. Elevated levels of lipid profile (except high density lipoprotein cholesterol [HDL-C]) were observed in stage I and II hypertensive patients. Enzymatic and non-enzymatic antioxidants were significantly (P < 0.05) lower, while TBARS and C-reactive protein were higher in prehypertensives, and stage I and II hypertensives. Significant (P <0.05) changes were also observed in the plasma Na(+) and K(+) concentrations among the hypertensive groups. Serum levels of zinc, copper, and magnesium were significantly (P < 0.05) lower in prehypertensives, and stage I and II hypertensives as compared to normotensives. The study indicated a strong association between blood pressure (BP) and oxidative stress-related parameters and suggests a possible role of oxidative stress in the development of elevated BP.