ABSTRACT
Hemoglobin oxygen binding properties and acid-base status were investigated in Colombian athletes (A) and controls (C) from Cali (C-1000 m) and Bogotá (B-2600 m). [Hb] and Hct values were not influenced by altitude, but Hct was lower in the blood of athletes (in Cali 2.6%, in Bogotá 1.4%). Both training and altitude produced a right-shift of the standard oxygen dissociation curve (P50 in CC 28.5 +/- 0.9 mmHg, AC 31.0 +/- 1.4 mmHg, CB 29.6 +/- 1.5 mmHg) leading to highest P50 in blood of altitude athletes (32.3 +/- 1.1 mmHg). Opposite to the position of the ODC the slope "n" was only increased by altitude influence (delta "n" in controls 0.07, in athletes 0.28). The BCCO2 was increased in AC over the whole saturation range, whereas BCLac was neither significantly influenced by training nor by altitude. All altitude effects can be explained by higher [DPG] (delta[DPG] in controls 5.0 mumol/gHb, in athletes 3.9 mumol/gHb), but the cause for the training effects still remains unclear. The acid base status in altitude residents was characterized by low BE and pCO2, which was most pronounced in altitude athletes, the latter correcting the actual venous pH to normal values. No significant variations of the Hb-O2-binding properties could be detected in athletes one day after leaving high altitude when compared with blood samples of athletes taken at high altitude, whereas BE and venous pCO2 were already increased. It is concluded that high altitude athletes are favoured during aerobic and handicapped during anaerobic exercise after the rapid descent to low altitude.
Subject(s)
Acid-Base Equilibrium/physiology , Oxygen Consumption/physiology , Oxygen/blood , Physical Endurance/physiology , Adult , Altitude , Colombia , Hematology , Humans , Male , SportsABSTRACT
The maximum treadmill oxygen consumption was measured in 1013 boys, 6 to 16 yr of age classified as nutritionally normal, low weight for age and low weight for height in upper socioeconomic urban and lower socioeconomic urban and rural groups. The marginally malnourished children (low weight for age and height) in both lower socioeconomic urban and rural groups had significantly depressed maximum treadmill oxygen consumption (85%) compared to normal boys, associated with smaller body weights. It is suggested that the reduced body size and maximum treadmill oxygen consumption resulting from marginal malnutrition during growth will have a detrimental effect on work capacity and productivity of these children when they become engaged in heavy physical work as adults. There was no statistically significant correlation between blood Hb concentration (approximately 10 to 15 g x dl-1) and aerobic capacity.
Subject(s)
Nutrition Disorders/physiopathology , Physical Exertion , Adolescent , Body Weight , Child , Colombia , Hemoglobins/analysis , Humans , Male , Oxygen Consumption , Socioeconomic Factors , Work Capacity EvaluationABSTRACT
In 49 chronically undernourished adult males, classified as having mild, intermediate, or severe nutritional compromise, comparisons were made of body fat calculated from total body water with values obtained from triceps and scapular skinfolds. These same comparisons were followed in 19 of the severely undernourished subjects during a 2 1/2-month period of dietary repletion. Results indicate that the correlations between fat estimates obtained from body water and skinfolds are good (r greater than 0.8) in mildly undernourished subjects, but that they are progressively reduced as the nutritional compromise becomes more severe until statistical significance disappears. Dietary repletion of 2 1/2-month duration did not restore a statistically significant relationship between fat and triceps and scapular skinfolds. These data imply that the triceps and scapular skinfolds do not adequately represent body fat in chronically undernourished adult males and that new empirical equations are required which take into account nutritional status and possible shifts in fat deposit sites in chronic undernutrition.
Subject(s)
Body Composition , Body Water/analysis , Protein Deficiency/pathology , Skinfold Thickness , Adult , Energy Intake , Humans , MaleABSTRACT
A method is described for deriving polynomial equations which describe weight and height for age and weight and height for children between 6 and 16 yr of age. Data for Colombian boys and girls have been utilized to illustrate the procedure.
Subject(s)
Body Height , Body Weight , Child Nutritional Physiological Phenomena , Adolescent , Aging , Child , Colombia , Computers , Female , Humans , Male , Mathematics , Nutrition Surveys , Sex FactorsABSTRACT
Oxygen consumption in maximal exercise (VO2max) was found to increase during nutritional rehabilitation of severely undernourished, sedentary adult males only when dietary protein was increased from 27 to 100 g/day. Adequate caloric intake, maintained for 45 days before the increase in protein content of the diet, had no effect on VO2max. The VO2max values were found to correlate best with the creatinine excretion rates (an index of the muscle cell mass) at the different stages of repletion. The average increment in VO2max/muscle cell mass ratio, although significant, was of a small magnitude (+15%). The VO2max/muscle cell mass ratio correlated only with the blood and plasma volumes at the different stages of repletion. After 2.5 months of protein repletion the VO2max values were still lower than those in mildly undernourished or normal Colombian adult males. Maximal endurance time at 80% aerobic load decreased significantly from an average of 113 min at the beginning of hospitalization to 42 min at the end of the period of protein repletion. This could be the result of replacing carbohydrate calories with protein in the diet, producing depletion of muscle glycogen stores, and/or to "detraining" effects associated with sedentary hospital life.
Subject(s)
Nutrition Disorders/diet therapy , Physical Endurance , Physical Exertion , Adult , Body Composition , Colombia , Dietary Proteins/administration & dosage , Dietary Proteins/therapeutic use , Humans , Male , Nutrition Disorders/metabolism , Nutrition Disorders/physiopathology , OxygenABSTRACT
Body composition was studied in severely undernourished adult male inhabitants of a rural area of Colombia to evaluate the extent and the time course of the changes occurring upon nutritional repletion. During a 45-day basal period on a low (26g/day) protein diet containing adequate calories, body fat depots increased significantly (mean +/- SD = +3.02 +/- 2.9 kg), and there was a significant decrease in cell hydration from 81.8 to 76.4% (-5.4 +/- 9.1%). Upon protein repletion (100 g/day), cell hydration decreased significantly to 71.4%, while body cell mass increased markedly (9.0 +/- 1.1 kg). During protein repletion, muscle cell mass increased significantly (+5.5 +/- 0.6 kg) and rapidly, while the increase in nonmuscle cells (+3.5 +/- 3.8 kg) and specifically in red cell mass lagged behind. With repletion, the changes in the absolute values for plasma volume (+0.4 +/- 0.13 liters) were significant, but those in extracellular fluid volume (-0.7 +/- 1.9 liters) were not. Thus, the major compositional changes observed occurred in the body fat and the body cell mass components; these occurred independently of each other.
Subject(s)
Body Composition , Dietary Proteins/administration & dosage , Nutrition Disorders/metabolism , Adipose Tissue/pathology , Adult , Blood Proteins/metabolism , Body Constitution , Body Fluid Compartments , Colombia , Dietary Proteins/therapeutic use , Humans , Male , Middle Aged , Muscles/pathology , Nutrition Disorders/diet therapy , Nutrition Disorders/pathology , Protein Deficiency/metabolism , Skinfold ThicknessABSTRACT
The regional distribution of the peripheral vascular resistance was studied in normotensive and hypertensive Wistar rats. Two models of experimental hypertension were investigated: (I) in 32 animals the right renal artery was constricted by a silver clip (two-kidney Goldblatt hypertension); (II) in 46 animals the left kidney was removed and the right renal artery was clipped as in the first group (one-kidney Goldblatt hypertension). The normotensive control group comprised 61 untreated animals of the same strain and age. The distribution of cardiac output to 14 tissues was determined by means of the particle distribution technique. The resistance was increased in all regions investigated, a decreased or unchanged resistance was not observed. For most of the investigated tissues the regional resistance was increased exactly in proportion to the total peripheral resistance (TPR). Exceptions to this were found in 2 regions where the change of local resistance deviated from that of TPR: the splanchnic area and the skeletal muscle. In both cases the 2 models differed from each other. In the two-kidney model the increase of resistance in the splanchnic circulation was more intense than in other organs. In contrast, in the one-kidney model the local change of resistance was less than that of TPR. The change of skeletal muscle resistance was not significantly different from the change of TPR in the two-kidney model, while in the one-kidney model the increase of local resistance was significantly higher than that of TPR. It is concluded that the etiology of the abnormal resistance is different in the 2 models investigated and that known extrinsinc pressor factors may play a role in the two-kidney, but not in the one-kidney Goldblatt hypertension.
