[Monitoring TSH levels using the TRH test].
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Adult↗
Biomedical subjects
F Hawkins
Publications and source records attributed to F Hawkins.
[A comparison between double-photon absorptiometry (DEXA), impedance and anthropometry in the study of the body composition of obese subjects].
Dual-energy X ray absorptiometry (DEXA) is primarily used in the assessment of bone mineral. However, the transmissions of the two different energy beams in nonbone areas can be processed to calculate the amount of fat and free-fat mass of the soft tissues. We have compared the estimation of body fat mass (FM) by DEXA with data derived from anthropometric (A) (During & Womersley formula) and impedance (BIA) measurements. We have studied 10 subjects, 8 female and 2 male, age 39 +/- 17, weight 97.4 +/- 17.2 kg. The results were: FM 44.4 +/- 8.5 kg (DEXA), 40.6 +/- 6.3 kg (A) and 38.4 +/- 9.8 kg (BIA); FFM 52.1 +/- 14.1 kg (DEXA), 56.8 +/- 13.9 kg (A) and 58.8 +/- 13.6 kg (BIA). The correlation was higher between DEXA and A (r = 0.88, for women r = 0.94). BIA results change depending on the equation used to derive Lean Body Mass (LBM) according to different authors. DEXA measurements are independent from the explorer, whereas A and BIA determinations can change in separate occasions with the same or different observer. Therefore, DEXA method seems more reliable than BIA for the assessment of FM. If DEXA technology is not available, our results support the use of anthropometric over impedance measurements.
Absorptiometry, Photon↗
[Comparative study of impedance-based predictive models of body composition].
It was proposed to analyse impedance (BIA) to determine bodily composition: water content, fat-free mass (FFM) and fat mass. Different regression equations were accordingly designed which related impedance obtained by BIA to age, weight, height and sex. We analyzed the result obtained with five different models, already described, in a population comprising 46 persons, 13 men and 33 women, of ages 42.9 +/- 17.7 and 38.6 +/- 15.8 (mean +/- DE) respectively. The results for FFM (Kg) obtained from the different equations were highly spread (43.8 +/- 6.5 to 48.2 +/- 7.6 in women, and 48.7 +/- 10.5 to 59.1 +/- 12.7 in men). The significant coefficients of correlation varied between 0.99 and 0.70 for men and 0.98 and 0.71 in women. In most of the equations, weight is the variable which best correlates with FFM. The results obtained point to the need to seek the predictive equation which best adjusts to the population studied, and to develop more accurate methods for determining body composition.
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