Human nutrition. Clinical nutrition最新文献

In order to determine the within-subject variability of creatinine excretion, the 24-h output was measured over 5 consecutive d in 12 subjects. The mean within-subject coefficient of variation was 3.6 per cent. There was much greater variation between subjects. The creatinine excretion in g/d was 30-40 per cent lower in Burmese subjects than in Europeans and North Americans, but the excretion per kg was slightly higher, suggesting that the Burmese are more muscular.

The validity of the deuterium dilution technique as a method of measuring fluid intake was investigated by comparing values obtained with this technique and direct measurements of milk intake in 10 exclusively bottle-fed infants recovering from protein-energy malnutrition. Values for total body water were derived from body weight and length using Friis-Hansen's formula. During a 15-d period, average daily milk intake, measured with the deuterium technique, ranged between 519 and 963 ml and was similar to values obtained by direct measurement (range 531-1002 ml). Correlation between both sets of values was highly significant (r = 0.97; P less than 0.001). The data indicate that the deuterium dilution method provides good estimates of daily fluid intake in young infants.

Composite meals with mashed potatoes, polished rice or mashed white beans were administered to eleven diabetic subjects (seven Type II and four Type I). As earlier reported in non-diabetic subjects (Torsdottir et al., 1984) the difference in gastric emptying, measured by 51Cr-technique, correlated with the difference in blood glucose response when comparing the meals including mashed potatoes and polished rice, rs = 0.93 (P less than 0.01), but no such correlation was found after the meal with white beans.

Iron status, folacin status, haemoglobinopathies, malarial infection and intestinal parasitosis frequencies were assessed in a representative sample of 586 subjects living in a rural district of South Benin. Anaemia according to WHO reference values for haemoglobin was observed in 42 per cent of subjects. The prevalence was higher in children and menstruating women. Iron deficiency, defined by two or more abnormal values in the four independent indicators of iron status used (transferrin saturation, erythrocyte protoporphyrin, serum ferritin, and mean corpuscular volume) was present in 30 per cent of subjects. Half of the anaemias were associated with iron deficiency. Folate deficiency was associated with anaemia in 20 per cent of subjects. Anaemia, iron and folacin status were not significantly related to the degree of malarial infection nor to the type of haemoglobin. Although hookworm infection was very common, there was no significant relationship between egg count and haemoglobin level or haematological parameters of iron and folacin status. The lack of correlation can be explained by the low wormload observed.

The resting metabolic rates (RMRs) of 5 male subjects of body mass index around 20 were estimated for 6 consecutive weeks on a 5 X 5 randomized Latin Square design. Analysis of variance (ANOVA) showed a distinct training effect with an exponential decline in RMR of all the subjects, while the mean of the coefficient of variation of intra-individual and inter-individual differences were of the order of 3.1 and 5.8 per cent respectively. The coefficient of variation of the measurement error was 2.93 per cent.

A method is proposed for estimating the respiratory quotients (RQ) required in the calculation of free-living energy expenditure measured by the doubly-labelled water technique in man. Worked examples show that, in most normal subjects, measured or predicted food quotients (FQ) can be used in place of RQs since energy balance is usually maintained over the 10-20-d periods of double-isotope measurements. Examples of observed FQs in the UK are: omnivorous adults, 0.845 +/- 0.013 (s.d.); vegetarians, vegans and Asian immigrants, 0.860-0.880; breast-fed infants, 0.835 rising to 0.870 as weaning progresses; bottle-fed infants, 0.840-0.880. Alcohol intakes in excess of 2-3 per cent of total energy lower the FQ value. In most communities in the developing world FQs are substantially higher (0.900-0.955) due to the low contribution of fat to overall energy intakes; but FQs decrease progressively as the diet becomes more westernized. In the UK the between- and within-subject coefficients of variation based on 4-d weighed intakes are only 1.5 and 0.7 per cent respectively. A single 4-d measurement of dietary composition can therefore be used to predict a subject's FQ. In subjects in energy imbalance (eg, during growth, illness or when dieting) errors in calculated energy expenditure will rarely exceed 3-5 per cent even if the imbalance is ignored; in practice anabolism or catabolism can be accounted for and the FQ adjusted when converting FQ to RQ. The error incurred due to the substitution of adjusted FQ for RQ in the doubly-labelled water method will usually be negligible and should never exceed +/- 2 per cent.

Young adults with both parents in either the upper or lower quartile of blood pressure for their age groups were monitored for 13 d to assess whether there was a selective relationship between blood pressure and sodium excretion in the adults from the hypertensive but not from the normotensive families. Twelve 24-h urine measurements of sodium and potassium excretion were related to the mean of daily blood pressure measurements. Although a significant correlation between sodium excretion and blood pressure was found for the whole group, this related to the co-correlation of blood pressure and sodium excretion with the body weights of the subjects, no links being found in adults of either parental type once an allowance was made for body weight differences.

The feasibility of dark adaptation measurement, using a Friedmann Visual Field Analyser, was assessed under field conditions in an isolated rural community in The Gambia, West Africa. It was found to be possible to obtain meaningful and reliable measurements on nearly all of the 117 subjects tested in two communities. Measurements were made throughout the cycle of pregnancy and in early lactation. No deterioration was observed in the later stages of pregnancy, in contrast to the deterioration reported previously in some vitamin A-deficient communities. Nearly all measurements were within the normal range quoted by the manufacturer. No evidence of improved adaptation was detected in women receiving a food supplement containing vitamin A. There were moderate variations with age of subject and with season, although the latter were not closely correlated with variations in vitamin A intake. Better nourished Gambian and Caucasian subjects showed slightly better performance than the village subjects, but this seems simply to reflect their better understanding of the test, since a small learning effect was observed. It is concluded that, despite limited comprehension of the nature of the test, reliable measurements could, with care, be obtained on illiterate adults from an unsophisticated society, and that in the marginally nourished community studied, a substantial increase in vitamin A intake had no discernible effect in improving dark adaptation performance.

Thyroxine-binding prealbumin (TBPA) seems to be more useful than other biochemical markers for the detection of subclinical protein-energy malnutrition. Accordingly, one can question whether its sensitivity to nutritional supply could be used in healthy populations for the discrimination of groups with low or high energy intakes; if such were the case, could TBPA serve as an index of overnutrition? In order to answer these questions, we measured TBPA circulating levels in three groups of healthy French subjects from a working population, with relatively low, medium or high levels of energy intake. We also observed the correlations of this protein with nutrient intakes and with some biological parameters related to the general nutritional status of the subjects. The observed figures did not support the hypothesis that TBPA could be used to discriminate healthy subjects with relatively low or high energy intake nor as an index of overnutrition. This study disclosed a positive relation of TBPA with alcohol consumption and related parameters such as body mass index or gamma-glutamyl transferase as well as a negative one with alpha 2-globulin and gamma-globulin. Other investigators have found similar results in chronic alcoholics, surgical patients, or patients suffering from severe illnesses such as cancer. Here, the study population consisted of adult men, neither undernourished nor suffering from any severe pathology and who could not be considered excessive drinkers. Positive relations were also observed between TBPA and apolipoprotein A1 and HDL cholesterol levels, which are negatively associated with coronary heart disease risk.