Oxygen saturation and heart rate in healthy school children and adolescents living at high altitude.

This study was conducted to establish reference values for percent oxygen saturation of hemoglobin (SaO2, %) and heart rate (HR, bpm) in children living at high altitude (4,100 m) and to relate possible differences in the variables with ethnic origin. Healthy children from a mine-located school (Tintaya, n = 417), a nearby school (Marquiri, n = 474), and a rural Andean community (Nuñoa, n = 373) were investigated. The samples included different ethnic combinations, with the Nuñoa children having a predominant Quechua ancestry. Mean SaO2 for all ages was substantially lower in all high altitude children compared to values considered normal for sea level. Among the three samples, SaO2 was higher (91.3 +/- 2.7) and HR was lower (84.8 +/- 13.6) in Nuñoa than in Tintaya (SaO2, 89.8 +/- 2.5; HR, 91.7 +/- 14.9) and Marquiri (SaO2, 89.6 +/- 3.1; HR, 88.5 +/- 12.9) (P < 0.05). There was no sex difference and only a weak age-dependent trend for SaO2. Values considered abnormal at sea level were observed in all healthy high-altitude children. Higher SaO2 and lower HR in Nuñoa children may suggest a better degree of acclimatization to altitude.

Growth of children in two economically diverse Peruvian high-altitude communities.

The growth of children living in two high-altitude communities associated with an active copper mine in southern Peru was examined. In the community directly associated with mining operations, nutritional and health conditions were believed to be relatively favorable as a result of the substantial mine-related infrastructure that had developed over the previous 12 years. In contrast, few such benefits were available in the other community, which provides limited part-time labor at the mine. Anthropometric data, including measurements of height, weight, skinfold thicknesses, upper arm circumference, and chest dimensions, and determination of bone age, were collected from a total of 880 children between the ages of 4 and 18 years. There were significant differences between the two communities, with those in the mining community exhibiting significantly greater height and weight, a higher level of body fat, and more rapid skeletal development. Among children over the age of 12 years, a plateau in height was seen, suggesting that the benefits to growth resulting from mining-related development were more noticeable in younger children. Compared with Peruvian high-altitude populations examined during the 1960s, both samples from the present study were substantially taller and heavier, suggesting that despite local differences in socioeconomic conditions between the communities studied, overall conditions for growth are generally more favorable than those that existed among Peruvian high-altitude populations surveyed in the 1960s.

Influence of maternal body habitus and glucose tolerance on birth weight.

Many physicians believe that macrosomia is a hallmark of a pregnancy complicated by glucose intolerance. Because the prevalence of obesity is increased among women with gestational diabetes, fetal overgrowth may be attributable at least in part to maternal obesity. We studied 2069 black, Latina, Chinese, and white mother-infant pairs to determine the interaction between maternal body habitus, maternal glucose homeostasis, and certain indices of fetal growth. Chinese women had a significantly higher serum glucose 1 hour after administration of 50 g glucose (136.6 +/- 32.7 mg/dL) than any of the other three ethnic groups. Black women had a significantly lower value for glucose (114.8 +/- 28.2 mg/dL) than either Chinese or Latina women (124.9 +/- 31.4 mg/dL). Results for Latina and white women (121.5 +/- 26.2 mg/dL) were not significantly different. Body mass index (BMI) was used to classify the subjects. The regression coefficient for the entire sample indicated a modest association of glucose with increased birth weight when maternal BMI was controlled. The BMI of the Chinese infants had a significant association with higher concentrations of glucose after administration of 50 g glucose. Maternal body habitus should be considered a major confounder in studies of the relationship of maternal glucose tolerance and infant birth weight.

Prevalence of overweight and obesity in US Hispanic populations.

Previous studies showed that Hispanics have higher levels of overweight and obesity than do US whites. The Hispanic Health and Nutritional Examination Survey (1982-1984) provides the basis for examining the physical characteristics of this population on a wider scale than previously possible. Data for body mass index (BMI; weight/height2) and triceps and subscapular skinfold thicknesses were examined for the 7052 Mexican Americans, 1307 Cubans, and 2690 Puerto Ricans for whom each of these measurements were available. Prevalence of obesity and overweight was defined as BMI in excess of the 95th and 85th percentiles, respectively, of US reference standards. In male adults prevalence values were, respectively, 10.6% and 33.5% for Mexican Americans, 9.6% and 31.3% for Puerto Ricans, and 9.0% and 34.0% for Cubans. In female adults prevalence values were, respectively, 15.1% and 42.3% for Mexican Americans, 7.8% and 40.7% for Puerto Ricans, and 15.0% and 38.2% for Cubans. Skinfold-thickness data for these populations indicate a centralized distribution of adipose tissue, especially in males, and increased subscapular skinfold thicknesses in older women.

The estimated cost of treating unmet dental restorative needs of Mexican-American children from Southwestern US HHANES, 1982-83.

The dental restorative treatment needs of Mexican-American children, aged 1-17 years, were assessed from the 1982-83 Southwestern US Hispanic Health and Nutrition Examination Survey (HHANES). This report analyzed those needs and applied a dollar cost to them, using 1982 median fees of US general practitioners. The total estimated cost required to meet those needs for the population estimate of 3,396,770 children was $236,856,772 (95% CI: $198,575,174 to $275,138,370). The mean cost per child was $69.73 (SE: 5.75). Although a majority of the children had no unmet need, 15-, 16-, and 17-year-olds had extensive needs for crowns, endodontics, and prosthetic replacement of teeth, with accompanying high costs: mean total cost per examinee was $177 (SE: 28.97), $161 (SE: 32.20), and $237 (SE: 33.26), respectively. The treatment needs were compared with the previously published regional data from the 1979-80 NIDR survey, which used the same dental restorative treatment needs (DRTN) index. The findings indicated a great need for dental treatment among Mexican-American children that appeared to exceed that of the general school-aged population. Our analysis, in providing estimates of the cost of needed treatment, might be useful in planning dental treatment programs and in comparing surveys.

Glucose tolerance in pregnancy: ethnic variation and influence of body habitus.

Little is known about ethnic differences in glucose tolerance during pregnancy. In this study we examined 3366 Hispanic, Chinese, black, and non-Hispanic white women in a universal screening program for gestational diabetes mellitus. After maternal age and body mass index were controlled, Chinese women had a significantly higher serum glucose level 1 hour after 50 gm of oral glucose (134.8 +/- 1.2, mean +/- SE) than any of the remaining three groups. Black women had a significantly lower value (113.3 +/- 1.3, mean +/- SE) than either Chinese or Hispanic women (124.4 +/- 0.9, mean +/- SE). Results for Hispanic women and non-Hispanic white women (121.4 +/- 1.6, mean +/- SE) were not different. The screening glucose levels of Chinese women were substantially higher than other ethnic groups even when women with gestational diabetes were removed from the analysis, indicating that the observed differences were not solely due to a higher frequency of gestational diabetes among the Chinese. The incidence of gestational diabetes was significantly greater for Chinese (7.3%) and Hispanic (4.2%) women than for black (1.7%) and non-Hispanic white (1.6%) women. Among women who had a 3-hour glucose tolerance test, the area under the glucose curve was significantly associated with maternal age and body mass index. The demonstrated heterogeneity of glucose tolerance between ethnic groups may be of importance in determining the threshold for diabetic fetopathy, and it is possible that ethnicity-specific standards will need to be developed.

Growth of immigrant children in the newcomer schools of San Francisco.

A semilongitudinal study on growth and development was initiated on immigrant and refugee school-aged children in San Francisco. Anthropometric values (height, weight, arm circumference, and triceps and subscapular skinfolds) were collected soon after their arrival in the United States and repeated at 3-month intervals for 1 year. Data were analyzed by age-gender cohorts. z Score calculations for measures of height-for-age, weight-for-age, and weight-for-height demonstrated a significant overall deficiency in height-for-age and weight-for-age at the time of the first measurement. Comparisons with a US standard indicated that most of the children were between the fifth and 25th percentiles in these measures. There were fewer children who were significantly deficient in weight-for-height. Calculations for median growth rate indicated that most cohorts exhibited a median growth velocity that was close to or exceeded the median for US white children. There was also significant improvement in weight-for-age. The results indicated that these immigrant and refugee children accelerated their growth markedly in an optimum nutritional environment and were in a period of catch-up growth.

Short and plump physique of Mexican-American children.

Mexican-American children are shorter but relatively heavier than non-Hispanic whites and blacks. The objectives of this paper are to assess the extent to which this "short and plump" physique occurs in data collected in two national surveys (HANES I and II); to determine variations by age, sex, and socioeconomic status; and to investigate the anthropometric characteristics that may account for the overweight. Three groups, defined on the basis of reported ancestry and observed race, are studied: Mexican-Americans (MEXAME), non-Hispanic Whites, (EURAME), and blacks (BLACK). Short stature was clearly associated with the poverty index (PI) in all three groups. MEXAMEs with a PI greater than 1.6 were similar in stature to EURAMEs at the same income level at ages 1-11 years but not at 12-17 years. On the other hand, MEXAMEs were shorter than BLACKs at all ages and income levels. The body mass index (kg/cm2) and poverty were unrelated. With respect to the anthropometric characteristics examined that are related to the body mass index, MEXAMEs and EURAMEs were similar in sitting height as a proportion of total height, arm muscle and fat areas, and triceps skinfold but different in the following ways: MEXAMEs had narrower elbow but broader bitrochanteric breadths and larger chest circumferences and subscapular skinfolds. Greater upper body dimensions and fatfolds seem to best describe the physique of MEXAMEs. However, in multiple regressions, these anthropometric characteristics failed to account fully for the greater relative weight of MEXAMEs as compared to EURAMEs.

Migration and biocultural adaptation: Samoans in California.

The consequences of migration for the Samoan population of California are discussed within the context of other studies focusing on Samoan native and migrant populations in Samoa and Hawaii. The social, cultural and economic characteristics of California Samoans are described and data are presented for body morphology, blood pressure, psychosocial stress and social support, general morbidity patterns and mortality rates for 1978-1982. Although the nature of disease risks appear profound in this population, particularly patterns of extreme obesity and psychosocial stress, mortality rates for heart disease and stroke are less than might be expected among other American groups. Such unexpectedly low mortality rates may represent the relatively healthy experience of older cohorts of migrants, or be a result of proportionally few individuals having lived long enough in California to develop cardiovascular and other chronic disease that have lengthy natural histories. We postulate that at present Samoan social structure, particularly the high status that accrues with aging in traditional Samoan society, may act as a buffer for the risk factors we observed and their expected outcomes. If so, the U.S.-born Samoans who are currently passing through childhood and early adult years with progressively less awareness of Samoan values of family and social structure will exhibit the same risks we describe here, but lack the available social buffers that currently exist for their parents.

High frequency of triplicated alpha-globin loci and absence or low frequency of alpha thalassemia in Polynesian Samoans.

Most of the population in certain areas of Melanesia have one alpha-globin gene deletion (alpha thal2). It is thought that the high frequencies of alpha thal2 in this population is due to a selective advantage given by malaria infection to carriers of alpha thal2. We are interested in neighboring Polynesia which, although adjacent to Melanesia, has always been free of malaria due to the absence of the vector anopheles. We studied 60 Polynesian Samoans and 150 Malaysians by restriction endonuclease gene mapping using Eco RI, Bam HI, and Bgl II and hybridization to 32P-labeled alpha-globin gene probe. Seven among the 60 (11.7%) Samoans had triplicated alpha-globin loci type 1, while none had alpha thal2. On digestion with Bgl II the third alpha-globin gene was found in an additional 3.7 kb fragment in all seven Samoans with triplicated alpha-globin loci, while digestion with Bam HI produced an abnormal elongated 18.2 kb fragment carrying alpha-globin genes in addition to the normal 14.5 kb fragment. None of the Polynesian Samoans had alpha thal2 or alpha thal1. Only two of the Malaysians had triplicated alpha-globin loci.

Biocultural risks in longevity: Samoans in California.

Because migration is such a widespread phenomenon, studies of the effects of accompanying life change on the health and well-being of the migrant have special significance in areas like California that support large migrant communities. Previous studies have shown that increased weight and elevated blood pressure may be linked to changes in diet, exercise habits, and the altered sociocultural milieu of the migrant. Among Samoans, a Pacific Island population of Polynesian descent, these changes appear to be particularly prominent in segments of the population that have moved to the environment of Hawaii, which epidemiologic studies have characterized as "intermediate-modern.' Preliminary findings from a survey of weight, height, blood pressure, fasting glucose levels, and mortality records among Samoans living in California indicate that individuals living under more highly urbanized conditions exhibit even more pronounced changes. Adult weight among Samoans in California (San Francisco) greatly exceeds that of their counterparts in Hawaii and Samoa. Elevated blood pressures are also seen, though the extent to which this is associated with excessive weight gain is unclear. The number of individuals with high (greater than or equal to 160 mg/dl) fasting plasma glucose levels would be consistent with a population in which the prevalence of diabetes is many times higher than in the U.S. population. Although mortality patterns are difficult to determine for this population, available records suggest an excess mortality from cardiovascular diseases of all types among adult Samoans under age 50. Further investigations will attempt to link biobehavioral changes in the migrants' lifestyle to these observed patterns of risk.

Massive obesity in a migrant Samoan population.

Peoples of the Pacific Islands tend to become overweight when they migrate or are exposed to modernization in situ. Recent evidence suggests that Samoans are particularly susceptible, exhibiting a high prevalence of obesity and hypertension following migration to Hawaii. We report the preliminary results of a survey of height, weight, blood pressure, and fasting plasma glucose (FPG) among an urbanized Samoan community the the San Francisco Bay Area. Although the participants' average height fell between the 25th and 50th percentile of the US population, about one-half our sample exceeded the 95th percentile for weight. The extreme overweight was accompanied by elevated blood pressure and, in females, by elevated FPG. The massive adult weight of migrants from the Pacific Islands carries serious public health implications for areas that support large migrant communities.

The influence of family characteristics on the heights, weights and skinfolds of highland and lowland children in Ethiopia.

In Ethiopian children residing at either high or low altitude, the relationship between growth (in stature, body weight and skinfold thickness) and age and family size (broken down into birth rank and number of younger sibs) was examined. Contrary to expectation, when children were grouped for similar ages, the impact of family characteristics appeared to be small. However, there was some evidence that among low-altitude girls, growth was significantly and positively related to the number of younger sibs. It is suggested tentatively that the relative lack of observed effects is due to the nuclear family being subsumed in a larger kinship group which forms the principal economic unit.

Cultural factors affecting the demographic structure of a high altitude Nepalese population.

PIP: Surveys were undertaken to study the fertility of Sherpa and Tibetan women living at altitudes over 3400 meters in Nepal. 2 teams independently collected demographic data during 1970 and 1971. Of all women who reported their ages to be 15 years and older, 348 (37.0%) provided menarchial data, 294 (31.2%) related the age at which they first became pregnant, and 420 (44.6%) replied to questions on the number of live births, neonatal deaths, infant deaths, child deaths, and the number of living children. The average completed fertility (4.77 live births) and estimated crude birthrate (31-33/1000) are low relative to low altitude peasant populations as well as to high altitude Andean peasants. Environmental phenomena (hypoxia, iodine deficiency) may be associated with retarded menarchial age and high infant mortality, but the major factors causing the low fertility seem to be cultural rather than environmental. Traditional ceremonial requirements delay the age at marriage until the mid or late twenties. Male and female celibacy is promoted by religious practices. Migrant females and women married to migrant males report reduced fertility. This is possibly due to poor nutrition and health care. Nonmigrant women living in villages participating extensively in the cash economy have greater access to the growing market economy, health care, and education and report higher numbers of live births and fewer child deaths.^ieng

Growth characteristics of populations of Tibetan origin in Nepal.

Previous growth studies of highland-dwelling populations in the ecologically diverse areas of Peru and Ethiopia have yielded highly varied results: the retarded growth of the Peruvian sample was attributed to the effects of hypoxia, while the increased height and weight of the highland Ethiopian sample could be traced to better health conditions in the highland village than in the lowland village studied. In an attempt to provide a basis for evaluating studies of growth at high altitude, the present study compared Sherpa children living in the Everest region of Nepal with Tibetan children living in Kathmandu. It was found that: (1) the growth of Sherpa and Tibetan children is considerably retarded compared to other high altitude populations; (2) despite conditions favorable for optimum growth among the Tibetans, their growth resembled that of the Sherpas and (3) increased chest circumference, which seems to reflect a developmental acclimatization to hypoxia among Peruvian high-altitude natives, was not seen among the Sherpas.