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Biomedical subjects

S J Ulijaszek

Publications and source records attributed to S J Ulijaszek.

At least 19 recordsLinked to original sources

Changing patterns of social variation in stature in Poland: effects of transition from a command economy to the free-market system?

The aim of this analysis was to examine the effects on stature in two nationally representative samples of Polish 19-year-old conscripts of maternal and paternal education level, and of degree of urbanization, before and after the economic transition of 1990. Data were from two national surveys of 19-year-old Polish conscripts: 27,236 in 1986 and 28,151 in 2001. In addition to taking height measurements, each subject was asked about the socioeconomic background of their families, including paternal and maternal education, and the name of the locality of residence. The net effect of each of these social factors on stature was determined using four-factor analysis of variance. The secular trend towards increased stature of Polish conscripts has slowed down from a rate 2.1 cm per decade across the period 1965-1986 to 1.5 cm per decade between 1986 and 2001. In both cohorts, mean statures increase with increasing size of locality of residence, paternal education and maternal education. The effect of each of these three social factors on conscript height is highly significant in both cohorts. However, the effect of maternal education has increased substantially while that of size of locality of residence and paternal education diminished between 1986 and 2001. These results imply that the influence of parental education on child growth cannot be due solely to a relationship between education and income, but is also perhaps a reflection of household financial management which benefits child health and growth by better educated parents, regardless of level of income. In addition they suggest that, irrespective of whether there are one or two breadwinners in the family, it is the mother, more so than the father, who is principally responsible for the extent to which such management best favours child health and growth. The asymmetry between the importance of maternal as against paternal education for child growth, clearly seen in the 1986 cohort, became more accentuated in 2001, after the abrupt transition from a command to a free-market economy in the early 1990s.

Adult↗

Waiting for Trivers and Willard: do the rich really favor sons?

Parental investment theory has been put forward as a major evolutionary argument explaining male or female biased birth sex ratio, the Trivers-Willard (T-W) hypothesis, predicting that parents living in good circumstances will bias their investment to sons, whereas parents in poor circumstances will bias their investment toward daughters. Tests of the T-W hypothesis on human beings have shown limited evidence for parents appearing to differentiate their investment to sons or daughters according to the reproductive potential of each sex. The present study tests the T-W hypothesis among a large contemporary Polish sample using first birth interval and extent of breastfeeding as measures of parental investment, and economic status and level of parental education as measures of parental condition. The extents to which parental investment and markers of parental condition vary by sex of the child were examined using log-linear analysis. Weak support for the T-W effect is found among families where fathers were best educated, where a greater proportion of first-born boys are breastfed longer than girls, while the opposite trend is observed among families with fathers with lowest levels of education. Although the present study does not fully support the T-W hypothesis, it gives evidence of greater investment in female offspring at the lower extremes of income, and greater investment in males at higher levels of income.

Adult↗

Potential seasonal ecological challenge of heat strain among Australian Aboriginal people practicing traditional subsistence methods: a computer simulation.

It has been largely accepted that Australian Aboriginal people practicing hunting and gathering traditionally underused their objective economic possibilities by working short hours relative to nonhunter-gatherer populations. However, the possibility that their subsistence quest might have been limited by potential heat strain has not been considered for Australian hunter-gatherers. In this article the influence of work and heat load on the potential for heat strain among adult male Australian Aboriginal people is modelled. The possibility that the short working day of Arnhem Land adults reported in the literature might reflect ecologically limited work scheduling by way of potential heat strain is examined. Three climatic regions of the North of Western Australia and the Northern Territory were identified, using data available from the Australian Bureau of Meteorology. Data from the months of January, April, July, and October were used with the United States Army Heat Strain Model, along with assumptions with respect to work load and time scheduling. Predictive modelling indicates that a late start to the working day could carry considerable risks of potential heat strain during the summer, when humidity and maximum daily temperature are highest for all three climatic regions, but especially in the tropical coastal region. While extended work times may have been needed to acquire adequate food under traditional conditions, work output could have been limited by potential heat strain under some conditions likely to have prevailed.

Adaptation, Physiological↗

Body size and physical activity levels of adults on Rarotonga, the Cook Islands.

Few studies of physical activity and energy expenditure have been carried out in the Pacific Region. In this study, the physical activity levels (PALs) of adult Cook Islanders living a largely modernised lifestyle by age group and occupation category were determined by a 3 day activity recall diary method. The period of observation included the previous Sunday, as a representative non-working day. A volunteer sample of 332 Cook Islanders aged 22 to 86 years was obtained from the total adult population of Rarotonga. Older adults are significantly less active than younger adults during the working week, but not during the weekend. Males are more physically active than females during the working week, but not on weekends. The mean weekday PAL of males engaged in traditional subsistence or who are unemployed is 1.88, while the mean weekday PAL of females engaged in traditional subsistence or who are housewives is 1.69. Male manual workers have a weekday PAL of 1.96, while female manual workers have a weekday PAL of 1.67. The weekday PAL values for those employed in clerical and administrative work are 1.82 (males) and 1.64 (females), while values for professionals are 1.76 (males) and 1.65 (females). Weekday physical activity is negatively associated with age, in nonlinear fashion. The PALs of adult Cook Islanders living a largely modernised lifestyle is lower in older age groups but does not vary by occupation category.

Adult↗

Parental education, body mass index and prevalence of obesity among 14-year-old boys between 1987 and 1997 in Wrocław, Poland.

The main aim of this study was to examine changes in relative weight and prevalence of obesity across a ten-year period among 14-year-old boys according to parental education level. Data from two surveys, carried out in 1987 and 1997, of boys attending the 7th grade of primary schools in Wrocław were used in the analysis. The heights and weights of 3165 boys aged 14 years selected from cohort of 6969 7th and 8th grade boys from all primary schools of the city Wrocław were used. The data of the second sample of 14-year-old boys (n = 1014) were obtained from a health examination study carried out in the Silesian Centre for Preventive Medicine, 'DOLMED', in Wrocław in 1997. All boys attended the 7th grade of 34 randomly selected primary schools from a total of 129 schools in the city of Wrocław. Social status was assessed on the basis of parental education level scored to four categories: university, secondary school, trade school, and elementary school. The prevalence of overweight and obesity was defined as the percentage of children above the 85th and 95th percentiles of the body mass index (BMI), the means of which were 21.27 and 23.75 kg/m2 respectively. Prevalence of overweight among boys is slightly lower in the 1997 sample, whereas the prevalence of obesity shows the opposite trend and is higher by more than one percent in comparison with the 1987 sample. Similar trends of declining medians and increasing variance are observed in all educational groups. The differences in medians between the two samples within educational groups did not achieve statistical significance for the groups with parents with education at elementary level and fathers with university education. There is a trend toward increasing prevalence of obesity across the decade considered, according to father's education level. With respect to mother's education levels, the most dramatic changes in BMI and obesity occurred in the elementary education group, where the percentage of obese subjects increased more than twofold. A significant increase is also observed in the group with parents attaining university education.

Adolescent↗

Age differences in physique of adult males aged 30 to 86 years in Rarotonga, the Cook Islands.

In the Pacific Region, some adult populations have shown a steady rise in overweight and obesity across the 1970s and into the 1990s. While younger adults have been shown to have lower body mass index (BMI) than older ones in both the least and most modernised Samoan populations, among intermediately modernised Samoan populations, BMI has been found to be higher in younger adults than in older ones. A survey in the Cook Islands carried out in 1966 showed no age group differences in height, weight and BMI among adult males, but significantly higher mean weight and BMI among adult males aged 30 years and above. The present analysis gives mean height, weight, BMI and skinfolds of adult males above 30 years of age on Rarotonga in 1996, and examines whether the BMI-age group relationship now shows a similar transitional pattern to that observed on American Samoa. In addition, the 1996 values are compared with values obtained in 1986, to determine whether changes in physique have taken place across this time. In the 1996 volunteer sample of 142 male Cook Islanders, older adults are significantly shorter, lighter, with lower BMI than younger adults. Furthermore, the younger adults of the 1996 survey are significantly heavier, with greater BMI than the 1986 sample. This suggests that the adult male Rarotongan population is in an intermediate position with respect to lifestyle transition, the secular trend in body size and increasing prevalence of obesity, and that there has been a rapid increase in body fatness prevalence among younger adults.

Adult↗

Nutrition, infection and child growth in Papua New Guinea.

Growth patterns of populations in Papua New Guinea (PNG) have traditionally shown considerable variation, with the greatest difference lying between coastal and highland populations. While genetic differences in explaining these patterns cannot be excluded, the generally poor growth relative to western growth references is largely due to the complex interactive effects of undernutrition and infection. The effects of diet, nutrition and infection on the nutritional status of a child vary with age, the general disease ecology and the type and extent of exposure to it, patterns of infant and young child feeding, and types of food consumed. There are two possible ways in which the relationship between undernutrition and infection can begin; one in which poor nutritional status leads to impaired immunocompetence and reduced resistance to infection, and the other in which exposure to infectious disease can lead to a range of factors that reduce food intake, absorption of nutrients, or increase nutrient requirements. In PNG prior to, and at early stages of modernisation, primary malnutrition is likely to have been the usual initiating factor in the onset of growth faltering due to undernutrition-infection interactions. However, the possibility that infection may have been the initiating event in some societies cannot be excluded. This would have happened by way of early dietary supplementation of infants with foods of minor nutritional significance, which could have acted as a vehicle for the introduction of infectious disease to the child. With modernisation and adoption of primary health care principles, earlier supplementation of infant diet than was previously the case became common in PNG. This has lead to general improvements in growth and nutritional status. However, in populations where undernutrition is still common, infection has become more important than primary malnutrition as the initiator of growth faltering due to undernutrition-infection interactions.

Adolescent↗

Daily energy expenditure across the course of lactation among urban Bangladeshi women.

Measures of energy intake of lactating women in developing countries show that intakes are often lower than those recommended by international bodies, while fat-mass losses are often substantially less than the 3-4 kg used in the calculations of recommendations, suggesting that physiological adaptation must be commonplace among such women. The cost of lactation may be met by reduction in energy expenditure, including reduced physical activity, as well as by mobilization of bodily soft tissue. However, daily energy expenditure of lactating women has been shown to increase across the course of lactation among women in a rural population in the Philippines and an urban population in India, with a decline in body weight across the course of lactation in both studies. In the present study, total daily energy expenditure and anthropometric body composition were measured longitudinally in 68 mothers from a poor urban area of Dhaka, Bangladesh, at 0, 1, 2, 4, and 8 months of lactation, to determine whether the increasing energy expenditure across lactation observed elsewhere also occurs in Bangladeshi women. In addition, the extent to which an extended period of lactation was accompanied by weight and body fat change in these women was determined. Energy expenditure by heart-rate monitoring and activity report, and body composition from anthropometry was carried out four times across the 8-month period of lactation. A small decline in body fat mass and a significant increase in total energy expenditure across this period were observed, confirming similar observations elsewhere in the developing world.

Adult↗

Anthropometric measurement error and the assessment of nutritional status.

Anthropometry involves the external measurement of morphological traits of human beings. It has a widespread and important place in nutritional assessment, and while the literature on anthropometric measurement and its interpretation is enormous, the extent to which measurement error can influence both measurement and interpretation of nutritional status is little considered. In this article, different types of anthropometric measurement error are reviewed, ways of estimating measurement error are critically evaluated, guidelines for acceptable error presented, and ways in which measures of error can be used to improve the interpretation of anthropometric nutritional status discussed. Possible errors are of two sorts; those that are associated with: (1) repeated measures giving the same value (unreliability, imprecision, undependability); and (2) measurements departing from true values (inaccuracy, bias). Imprecision is due largely to observer error, and is the most commonly used measure of anthropometric measurement error. This can be estimated by carrying out repeated anthropometric measures on the same subjects and calculating one or more of the following: technical error of measurement (TEM); percentage TEM, coefficient of reliability (R), and intraclass correlation coefficient. The first three of these measures are mathematically interrelated. Targets for training in anthropometry are at present far from perfect, and further work is needed in developing appropriate protocols for nutritional anthropometry training. Acceptable levels of measurement error are difficult to ascertain because TEM is age dependent, and the value is also related to the anthropometric characteristics of the group of population under investigation. R > 0.95 should be sought where possible, and reference values of maximum acceptable TEM at set levels of R using published data from the combined National Health and Nutrition Examination Surveys I and II (Frisancho, 1990) are given. There is a clear hierarchy in the precision of different nutritional anthropometric measures, with weight and height being most precise. Waist and hip circumference show strong between-observer differences, and should, where possible, be carried out by one observer. Skinfolds can be associated with such large measurement error that interpretation is problematic. Ways are described in which measurement error can be used to assess the probability that differences in anthropometric measures across time within individuals are due to factors other than imprecision. Anthropometry is an important tool for nutritional assessment, and the techniques reported here should allow increased precision of measurement, and improved interpretation of anthropometric data.

Anthropometry↗

Immunology and growth faltering of Anga children, Papua New Guinea: preliminary work.

Nutrition-infection interactions among poor children of the less-developed world influence growth and development. However, the relative importance of each is difficult to determine, because the relationship is mediated by immunological status. In this analysis, relationships between immunological measures and anthropometry were sought among 41 Anga, Papua New Guinea children aged 0-7 years. These had elevated serum total leucocyte and leucocyte subset counts relative to western reference values. Although there was no correlation between anthropometric nutritional status and total leucocytes and leucocyte subsets for this group, the small group (n=8) with very high total leucocyte count (greater than 15,000/mm2) had significantly lower mean Z score of stature for age (-3.78), and weight for stature (-1.35) than those with leucocyte counts lower than this cut-off (weight for stature Z score: -0.59; stature for age Z score: -2.68, respectively. Low stature-for-age Z score was associated with lower total lymphocyte count and increasing age, against a background of elevated lymphocyte levels relative to western reference values among the older children; low weight-for-stature Z score was associated with lower neutrophil count, against a background of normal neutrophil levels across all age groups. The pattern of weight and stature growth seen in the Anga may reflect extended nutritional deficits which result in stunting of a degree to which the most growth-compromised children die, leaving those above a threshold associated with high mortality alive. Thus, the anthropometric and immunological characteristics of the older children in this small sample may reflect the biology of survival under severe ecological conditions, where poor linear growth and elevated leucocyte status relative to normative values are characteristics of survivorship.

Age Factors↗

Hypertension among adults of the Purari delta of the Gulf Province, Papua New Guinea.

This study, carried out in 1995, found evidence of high blood pressure in a rural population in the Gulf Province of Papua New Guinea. Although the prevalence of obesity as assessed by the body mass index has increased since 1980, blood pressure was not associated with height or weight. Rather, it was associated with fat patterning: increased truncal fatness was associated with greater systolic blood pressure in both males and females. Of the modernization variables examined, the only one associated with blood pressure was type of income, and this for systolic blood pressure among females only. Body mass index was also associated with type of income, this being greatest among the small number of adults with some form of paid employment. Blood pressure showed no association with age, thus conforming to the hypertension pattern seen at early stages of modernization.

Adolescent↗

Anthropometry in health assessment: the importance of measurement error.

Anthropometry is the hallmark technique of biological anthropology, and has become increasingly important in health assessments across this century. Although the need for accurate anthropometric measurement has been repeatedly stressed, the ways in which measurement error can influence the characteristics of anthropometric data is poorly appreciated. In this article, guidelines for acceptable measurement error are examined critically, and in light of repeat measurements data collected by the two authors on adults in Papua New Guinea.

Adult↗

Body mass index and illness in rural Sarawak.

This paper reports findings of a cross-sectional anthropometric survey of 447 men and 564 women aged > 18 years of the Iban tribe in rural Sarawak. The percentage of each approximately 10 year cohort with body mass index (BMI: kg/m2) < 18.5 increased progressively with age > 40 years in both sexes. BMI and arm-muscle plus bone cross-sectional area (AMBA) were influenced significantly by reported single symptoms in men and two concurrent symptoms in women. Sensitivity of BMI < 18.5 for identifying those reporting symptoms of illness was 21% in men and 29% in women. Independently of illness effects, values of stature, BMI and AMBA in men, and stature alone in women, were significantly greater in those farming plots with the shortest time left fallow, suggesting their comparative success. The BMI of men may reflect primarily their economic activities, while that of women their experience of illness; the AMBA may also be a better overall index of health than BMI in this population.

Adolescent↗

Relationships between anthropometry and retrospective morbidity in poor men in Calcutta, India.

OBJECTIVE: The evaluation of body mass index (BMI) and other anthropometric measures as possible indicators of chronic energy deficiency, by examination of the relationships between these measures and retrospective morbidity in a group of very poor men in Calcutta, India. DESIGN: Anthropometric measurement and retrospective recording of treatment history over the previous year, from health records. SETTING: A primary care centre, the Middleton Row street clinic. SUBJECTS: All men attending the clinic for either provision of basic needs (food, clothing, plastic sheeting for building of shelter) or medical treatment during July and August, 1992. 190 men with 1-year retrospective treatment records were measured. INTERVENTIONS: None. RESULTS: Values for mean height, weight, arm circumference and triceps skinfold were lower than for any population of Indian males thus far reported. 44% of the men had BMI < 16, retrospective morbidity being two to three times higher in those below this cut-off than those above it. BMI < 16 was associated with greater retrospective morbidity due to respiratory tract infection and tuberculosis. For men aged 18-64 years, weight, height, arm circumference and age were significant discriminators of retrospective respiratory morbidity, while calf circumference, height, weight and age were significant discriminators of retrospective tuberculosis morbidity. Of the derived variables, BMI was a better discriminator of retrospective respiratory morbidity than arm fat area and percentage body fat, and the only discriminator of retrospective tuberculosis morbidity. For men aged > or = 65 years, weight and calf circumference were significant discriminators of respiratory infection, while age was the only discriminator of tuberculosis morbidity. Of the derived variables, BMI alone discriminated retrospective respiratory infection. CONCLUSION: BMI was the best overall discriminator of retrospective morbidity in this group of poor Calcutta men. Anthropometric criteria were better discriminators of retrospective morbidity in men between the ages of 18 and 64 years than in men aged 65 years and over.

Adolescent↗

Between-population variation in pre-adolescent growth.

Between-population differences in rates of physical growth and development and attained body size are well documented, but it is difficult to determine the extent to which these differences can be attributed to genetic and environmental factors. The greatest differences are to be found between populations in industrialised and non-industrialised nations, and between well-off and poorer groups within countries. Although genetic factors cannot be discounted, such differences can largely be attributed to differences in environmental quality experienced, influencing growth largely through differentials in nutritional well-being and exposure to, and treatment of, infectious disease. Growth patterns of well-off populations and groups of high socio-economic status are less heterogeneous, but differences between major global population groupings may still exist, bringing into question the validity of the concept of an international reference for the growth of young children. In this article, information pointing to genetic differences in the growth of children of different populations is summarised, and the acceptability of the NCHS (National Center for Health Statistics, 1977) references for height by age for international use is examined. It is concluded that the growth patterns of all major population groupings are likely to have similar genetic potential, with the exception of Asiatics. However, there are no data on either secular trends or well-off groups from populations that have until recently been genetically isolated, and it is not known whether they share the same potential for growth as the major populations that surround them. In addition, very little is known about the genetic potential for growth of Aboriginal populations in Australia, or in Pacific Islands populations. It is suggested that the growth references for height by age in current international use are at best only imperfect yardsticks for nutritional assessment.

Body Constitution↗

Influence of birth interval and child labour on family energy requirements and dependency ratios in two traditional subsistence economies in Africa.

The consequences of different birth intervals on dietary energy requirements and dependency ratios at different stages of the family lifecycle are modelled for Gambian agriculturalists and !Kung hunter-gatherers. Energy requirements reach a peak at between 20 and 30 years after starting a family for the Gambians, and between 15 and 20 years for the !Kung. For the Gambians, shorter birth interval confers no economic advantage over the traditional birth interval of 30 months. For the !Kung, the lack of participation in subsistence activities by children gives an output:input ratio in excess of that reported in other studies, suggesting that they are in a state of chronic energy deficiency.

Adolescent↗

Body mass index, ageing and differential reported morbidity in rural Sarawak.

Classifications of adult low energy nutritional status based on the Quetelet or body mass index (weight/height2) have often assumed independence of age and sex. This paper reports findings of a study of 447 men and 564 women aged over 18 years and belonging to the Iban tribe of central Sarawak, East Malaysia. BMI and fat-free mass fell markedly in both sexes, and fat mass in women but not men, after about 40 years of age. In men over age 40, and women aged 18-40, BMI was sensitive to reported morbidity. For subjects aged over 40 years, BMI was related to morbidity independently of age effects in men, and to age alone in women. These findings suggest that the functional significance of low BMI differs between the sexes and with age.

Adult↗