Anthropometric measured fat-free mass as essential determinant of resting energy expenditure for pregnant and non-pregnant women.

OBJECTIVE: There is conflicting evidence as to whether anthropometric parameters are related to resting energy expenditure (REE) during pregnancy. The aim of this prospective longitudinal study was to precisely assess a major anthropometric determinant of REE for pregnant and non-pregnant women with verification of its use as a possible predictor. METHODS: One hundred fifty-two randomly recruited, healthy, pregnant Czech women were divided into groups G1 and G2. G1 (n = 31) was used for determination of the association between anthropometric parameters and REE. G2 (n = 121) and a group of non-pregnant women (G0; n = 24) were used for verification that observed relations were suitable for the prediction of REE during pregnancy. The women in the study groups were measured during four periods of pregnancy for REE by indirect calorimetry and anthropometric parameters after 12 h of fasting. RESULTS: Associations were found in all groups between measured REE by indirect calorimetry and anthropometric parameters such as weight, fat mass, fat-free mass (FFM), body surface area, and body mass index (P < 0.0001). The best derived predictor, REE/FFM (29.5 kcal/kg, r = 0.70, P < 0.0001), in group G1 was statistically verified in group G2 and compared with G0. CONCLUSION: Anthropometrically measured FFM with its metabolically active components is an essential determinant of REE in pregnancy. REE/FFM can be used for the prediction of REE in pregnant and non-pregnant woman.

Serum lipids and neopterin in urine as new biomarkers of malnutrition and inflammation in the elderly.

OBJECTIVE: Levels of serum lipids are influenced by malnutrition and inflammation. The study aimed to find the relation of the lipidogram to positive and negative markers of inflammation in geriatric patients. Attention was paid to neopterin in urine as a non-protein positive bioindicator of inflammation. METHODS: It was a local, monocentric, prospective clinical study in hospitalized patients older than 80 y. The study included 101 patients (54 women, 47 men). The average age of the entire group was 85.37 +/- 4.88 y. The dependence of the values of total cholesterol, high-density lipoprotein (HDL), low-density lipoprotein (LDL), and triacylglycerols (TAGs) on C-reactive protein (CRP), neopterin in urine, and prealbumin was examined. RESULTS: When we compared CRP and serum lipids, we found a statistically significant negative correlation between levels of CRP and total cholesterol (P < 0.05), HDL (P < 0.01), and LDL (P < 0.05). Also the level of neopterin in urine was negatively correlated with levels of total cholesterol (P < 0.05) and HDL (P < 0.01). A statistically highly significant interaction was demonstrated between levels of prealbumin and total cholesterol (P < 0.001), HDL (P < 0.001), LDL (P < 0.001), and TAG (P < 0.05). CONCLUSION: A significant negative correlation between levels of inflammation markers (neopterin in urine, CRP) and total cholesterol and HDL was found. LDL was influenced to a lesser extent. A close relation between serum lipids and prealbumin was also demonstrated. Total cholesterol, HDL, and LDL can be considered novel biomarkers of malnutrition and inflammation in geriatric patients.

Comparison of potential markers of the biological age of healthy male adults and paraplegics.

The actual level of the true aging of an organism is characterized by its biological age. By the means of measuring the function ability of its physiological systems, it is possible to evaluate the biological age and use it as an indicator of premature aging. Inclusion of the biological age screening among the basic health precautions should offer yet another viewpoint on how to objectively measure the changes in an organism corresponding to aging. The article presents a comparison of age dependency of selected biomarkers between groups of healthy men and paraplegics. The measurement of the battery of biomarkers was run in a group of 25 healthy male adults between 36 and 54 years of age. The second group was formed by 20 paraplegics - men between 33 and 50 years of age. In spite of small size of the groups, significant differences were found in 4 of 6 biomarkers.

A changed view of serum prealbumin in the elderly: prealbumin values influenced by concomitant inflammation.

AIMS: We are currently witnessing changes in views on the evaluation of serum proteins. A decrease may signal not only malnutrition. It may also be an indicator of simultaneously occurring inflammatory disease. Prealbumin, due to its short half-life, is a suitable indicator of changes in protein-energy balance, but its levels show, as with other serum proteins, a decrease in the case of inflammation too. The present study aimed to determine the prealbumin values of hospitalized geriatric patients and how they are affected by inflammatory disease. METHODS: In 101 patients aged over 80 years, the relationships were compared between prealbumin and C-reactive protein in the whole group and then in the subgroups with normal and increased C-reactive protein. RESULTS: In 67.33 % of hospitalized geriatric patients prealbumin was below the limit of the norm. A statistically highly significant dependence (p < 0.001) was demonstrated between a decrease in prealbumin and an increase in C-reactive protein in the whole group. In the subgroup with normal C-reactive protein, no statistically significant decrease in prealbumin was demonstrated, whereas in the subgroup with increased C-reactive protein a significant decrease in prealbumin (p < 0.001 for the whole group, p < 0.01 men, p < 0.05 women) was found. CONCLUSIONS: The study demonstrated subnormal mean initial values of prealbumin and a highly statistically significant negative correlation between a decrease in prealbumin and an increase in C-reactive protein in the whole group. We confirm that in inflammation there is a statistically significant decrease in serum concentration of prealbumin.

A new approach to the concept and computation of biological age.

The lack of exact definition of the concept of biological age (BA) is a typical feature of works concerning BA. That is why comparison of results of various published methods makes little sense and eventual proof of their optimality is impossible. Based on natural and simple presumptions, an attempt to express mathematically the supposed relation between chronological age (CA) and BA has proven to be unexpectedly fruitful. In the present paper, an optimum method of estimation of BA, which is easily applicable even in nonlinear cases, is derived. Moreover, the method allows evaluating the precision of the estimates and also offers tools for validation of presumptions of the method. A special feature of the method is that CA should be used as a standard biomarker, leading to essential improving the precision of BA-estimate and illuminating relativity of the known "paradox of biomarkers". All theoretical results of the method were fully approved by means of a special simulation program. Further, the theory and the results of the simulation have proven that many published results of BA-estimates using multiple linear regression (MLR) are very probably disserviceable because CA is typically more precise estimate of BA than estimates computed by MLR. This unpleasant conclusion also concerns methods, which use MLR as the final step after transformation of the battery of biomarkers by factor analysis or by principal component analysis.

Non-linear mechanical behavior of visco-elastic biological structures--measurements and models.

Mechanical properties of biological structures affect functional ability of organism. Current knowledge is prevailingly concentrated on static characteristics. The present work analyzed dynamic mechanical responses of various biological materials. Following biological structures were measured: samples of aorta walls of human origin and from model organisms, human body surface, and samples of bones of various types and origin. Linear approximation leads in case of aortas and bones to simple Voight's model. Modules of elasticity (in tensile loading) of aortas were from 10(2) kPa to 10(3) kPa. Module of elasticity of bones were from 10(6) Pa to 10(10) Pa. Viscous coefficients of aortas were from 102 Pa.s to 10(3) Pa.s. Viscous coefficients of bones were from 10(0) Pa.s to 10(2) Pa.s. Nonlinearities: We found that following types of nonlinearities are significant: strain-stress relationship, time-dependent changes in elastic as well as viscose bodies. Strain and stress is well approximated by quadratic function sigma = a epsilon2 + b epsilon + c with parameters a = 1833, b = 135, c = 20.0 (porcine aorta). Time-dependence in elastic coefficient: At the beginning of responses the elastic coefficient was of 42% lower then at 0.02 s of duration of the response (porcine aortas). Analogical results follow also from experiments on other structures (skin, bones).

Visco-elastic response of human skin and aging.

UNLABELLED: The changes in visco-elastic properties of skin belong to the most conspicuous manifestations of cutaneous aging. In spite of apparent simplicity, the measurement of mechanical parameters of skin in vivo presents both theoretical and practical problems. Reproducibility, standardization, duration of measurement, discomfort for experimental subjects are the main complications. Measurement and analysis of transient deformation response to pressure stress provides theoretically consistent and practically applicable methodology. EXPERIMENT: The transient deformation response of skin was measured in two groups consisting of 15 healthy men and 17 healthy women. The range of age interval was 20 to 58 years. The deformation response was measured as reaction of skin on sudden change of pressure stress between two levels of loading on skin surface. RESULTS: Transient response of human skin consists of sum of two exponential curves. A "rapid" exponential curve has time constant typically of order 10 ms, while "slow" exponential curve has a time constant of order 0.1 to 1s. Both time constants increase with chronological age. Time for drop of deformation on 12.5% of full deformation proved to be a simple and sensitive criterion of skin aging, with strong correlation with chronological age. Main advantage of the method: Measurement is quantitative and reproducible. Procedure is easy to repeat. Its average duration is approx. 2 minutes and it does not represent any discomfort for test subjects.