Hemoglobin concentration of high-altitude Tibetans and Bolivian Aymara.

Elevated hemoglobin concentrations have been reported for high-altitude sojourners and Andean high-altitude natives since early in the 20th century. Thus, reports that have appeared since the 1970s describing relatively low hemoglobin concentration among Tibetan high-altitude natives were unexpected. These suggested a hypothesis of population differences in hematological response to high-altitude hypoxia. A case of quantitatively different responses to one environmental stress would offer an opportunity to study the broad evolutionary question of the origin of adaptations. However, many factors may confound population comparisons. The present study was designed to test the null hypothesis of no difference in mean hemoglobin concentration of Tibetan and Aymara native residents at 3,800-4,065 meters by using healthy samples that were screened for iron deficiency, abnormal hemoglobins, and thalassemias, recruited and assessed using the same techniques. The hypothesis was rejected, because Tibetan males had a significantly lower mean hemoglobin concentration of 15.6 gm/dl compared with 19.2 gm/dl for Aymara males, and Tibetan females had a mean hemoglobin concentration of 14.2 gm/dl compared with 17.8 gm/dl for Aymara females. The Tibetan hemoglobin distribution closely resembled that from a comparable, sea-level sample from the United States, whereas the Aymara distribution was shifted toward 3-4 gm/dl higher values. Genetic factors accounted for a very high proportion of the phenotypic variance in hemoglobin concentration in both samples (0.86 in the Tibetan sample and 0.87 in the Aymara sample). The presence of significant genetic variance means that there is the potential for natural selection and genetic adaptation of hemoglobin concentration in Tibetan and Aymara high-altitude populations.

Quantitative genetic analysis of arterial oxygen saturation in Tibetan highlanders.

This study was designed to test the hypothesis that genetic differences inferred from biological kinship relationships among individuals contribute to individual variation in percentage of oxygen saturation of arterial hemoglobin (SaO2) in a high-altitude native population. SaO2 data were obtained by pulse oximetry from 354 nonpregnant, healthy Tibetan residents of Pen-Dri, two rural agropastoral villages at 3800-4065 m altitude in Lhasa Municipal District, Tibet Autonomous Region, China. Statistical analyses of these data from 46 pedigrees tested the hypothesis of a significant genetic contribution to SaO2 variation. The average SaO2 was 89.4 +/- 0.2%, with a range of 76-97%. Additive genetic effects account for 44% of the interindividual phenotypic variation in SaO2 in the sample. Complex segregation analysis and variance decomposition analysis determined that 21% of the total phenotypic variation could be explained by a major gene influencing SaO2. Homozygotes for the low-SaO2 allele have a mean SaO2 of 83.6%, whereas heterozygotes and homozygotes for the high-SaO2 allele have means of 87.6% and 88.3%, respectively. This confirms findings in another Tibetan sample and extends the known geographic distribution of the major gene. These results suggest the hypothesis that individuals with the dominant allele for higher SaO2 have a selective advantage in their high-altitude hypoxic environment.

Ventilation and hypoxic ventilatory response of Tibetan and Aymara high altitude natives.

Newcomers acclimatizing to high altitude and adult male Tibetan high altitude natives have increased ventilation relative to sea level natives at sea level. However, Andean and Rocky Mountain high altitude natives have an intermediate level of ventilation lower than that of newcomers and Tibetan high altitude natives although generally higher than that of sea level natives at sea level. Because the reason for the relative hypoventilation of some high altitude native populations was unknown, a study was designed to describe ventilation from adolescence through old age in samples of Tibetan and Andean high altitude natives and to estimate the relative genetic and environmental influences. This paper compares resting ventilation and hypoxic ventilatory response (HVR) of 320 Tibetans 9-82 years of age and 542 Bolivian Aymara 13-94 years of age, native residents at 3,800-4,065 m. Tibetan resting ventilation was roughly 1.5 times higher and Tibetan HVR was roughly double that of Aymara. Greater duration of hypoxia (older age) was not an important source of variation in resting ventilation or HVR in either sample. That is, contrary to previous studies, neither sample acquired hypoventilation in the age ranges under study. Within populations, greater severity of hypoxia (lower percent of oxygen saturation of arterial hemoglobin) was associated with slightly higher resting ventilation among Tibetans and lower resting ventilation and HVR among Aymara women, although the associations accounted for just 2-7% of the variation. Between populations, the Tibetan sample was more hypoxic and had higher resting ventilation and HVR. Other systematic environmental contrasts did not appear to elevate Tibetan or depress Aymara ventilation. There was more intrapopulation genetic variation in these traits in the Tibetan than the Aymara sample. Thirty-five percent of the Tibetan, but none of the Aymara, resting ventilation variance was due to genetic differences among individuals. Thirty-one percent of the Tibetan HVR, but just 21% of the Aymara, HVR variance was due to genetic differences among individuals. Thus there is greater potential for evolutionary change in these traits in the Tibetans. Presently, there are two different ventilation phenotypes among high altitude natives as compared with sea level populations at sea level: lifelong sustained high resting ventilation and a moderate HVR among Tibetans in contrast with a slightly elevated resting ventilation and a low HVR among Aymara.

Major gene for percent of oxygen saturation of arterial hemoglobin in Tibetan highlanders.

This report employs a statistical genetic approach to analyze quantitative oxygen transport variables in a high-altitude (4,850-5,450 m) native Tibetan population and demonstrates the presence of a major gene influencing % O2 saturation of arterial hemoglobin. This result suggests the hypothesis that individuals with the dominant allele for higher % O2 saturation have a selective advantage at high altitude. Studies of the biologically distinctive Himalayan and Andean populations have greatly influenced thinking about ongoing human evolution and adaptation; this is the first statistical evidence for a major gene enhancing oxygen transport in a high-altitude native population.

Income and family support among rural elderly in Zhejiang Province, China.

This paper examines the net income of a sample of 100 elderly living in two villages in Zhejiang Province. A natural experimental study design was employed to examine village differences in prosperity while controlling for other linguistic and cultural/regional factors that might influence the economic status of the elderly. The paper examines the different sources of income for the sample elderly and assesses their general economic status. It found that while most of the income of the elderly derived from their own farming and sideline work, children also assisted elderly parents and provided a safety-net for them as their physical capacity waned. However, having many sons did not improve the economic status of the elderly and the majority of elderly now preferred only one son.

Household composition of the elderly in two rural villages in the People's Republic of China.

This paper reports on the household composition of a sample of elderly residing in two villages in Zhejiang Province, China, one that is prospering under the post 1978 economic reforms and another that is not. It reveals that while a large proportion of the elderly in both the study villages are part of single generation households, the two villages differ with respect to the composition of the single generation household category. In the prosperous village, 50% of the elderly are living alone or with a spouse and 6% are living "by turns" (rotating between son's residences). In the less prosperous village, 26% are living alone or with a spouse while 22% participate in "by turns" arrangements. The paper suggests that a failure to separate analytically the "by turns" arrangements obscures the extent to which China's rural elderly now live in economic units separate from their offspring and masks important aspects of the differential impact of the new economic reforms on the household situation of the elderly in different villages.

Esthetic orthodontic appliances for the adult.

There is no malocclusion in the adult that cannot be treated as well with esthetic appliances as with the conventional metal brackets. In a study about adult orthodontic patients. Breece and Nieberg found that most people wait until they are adults to start treatment because no one recommended it previously. It is essential that the dental practitioner understand the positive psychological impact of esthetic appliances upon the attitude of the adult and recommend that the adult needing orthodontic treatment enjoy the benefits of these technologic advances in esthetics and comfort.

Hemoglobin concentration of pastoral nomads permanently resident at 4,850-5,450 meters in Tibet.

This paper presents data on the hemoglobin concentration of a sample of 103 pastoral nomads who are lifelong residents of Phala, at 4,850-5,450 m, on the northern plateau of the Tibet Autonomous Region of the Peoples' Republic of China. This native population resides at the highest altitude of which we are aware and is thus exposed to the most extreme chronic hypoxic stress. However, they do not exhibit the most pronounced physiological adaptations, i.e., hemoglobin concentrations exceeding those found in all other high-altitude populations. Adult male and female mean hemoglobin concentrations of 18.2 and 16.7 gm/dl, respectively, were found. These data, in conjunction with earlier studies of ethnic Tibetans living at 3,400 m, demonstrate a pattern of increasing hemoglobin concentration (erythrocytosis) at increasing altitude of residence in the Himalayas and Tibet. At the same time, however, the hemoglobin concentration is lower than that found among Andean highlanders. These new data raise the possibility of quantitative population differences in hematological adaptation to high altitude hypoxia.

Semen cryopreservation and artificial insemination for Hodgkin's disease.

Seventy-nine men with Hodgkin's disease were treated with chemotherapy protocols at Memorial Sloan-Kettering Cancer Center and had pretreatment semen analysis performed at the area semen bank. The patients were evaluated to determine: the quality of pretreatment semen, the effect of treatment on spermatogenesis, and the success rate of artificial insemination after semen cryopreservation. Pretreatment sperm concentration, fresh motility, fresh progression, postthaw motility and postthaw progression were all significantly decreased in men with Hodgkin's disease compared with normal controls. Posttreatment semen analysis in 44 men showed azoospermia in 80%, sperm concentration, less than or equal to 10 X 10(6)/mL in 11%, and sperm concentration greater than 10 X 10(6)/mL in 9%. Eleven couples attempted artificial insemination using cryopreserved semen, thus far resulting in three pregnancies. Semen cryopreservation and artificial insemination offer a partial solution to posttreatment azoospermia in this population, but further methods are needed to minimize gonadal toxicity without compromising therapy for Hodgkin's disease.

Age differences in sensory and cognitive function in elderly Nepalese.

This paper describes age differences in sensory and cognitive function in a cross-sectional sample of 117 Nepalese men aged 50 to 88 years living in a traditional agrarian society. The prevalence of impairment of vision, hearing, vibration sensitivity, and cognitive function is progressively higher in successively older age categories in this society as it is in Western industrial societies. This has practical consequences for everyday life. Men with vision impairment are less likely to retain the esteemed social role of head of an extended household. Men with visual and hearing impairment leave their household compounds less frequently, have less frequent social contacts outside their households, and remain inactive a greater proportion of the time. In this technologically simple society without modern medical remedies, vision and hearing impairments are associated with social roles and daily activity patterns that foster economic and political dependence and social isolation.

Proximate determinants of fertility in the Kathmandu Valley, Nepal: an anthropological case study.

PIP: The analytical model of Bongaarts and Potter is employed to compare the proximate determinants of fertility among 3 populations in Nepal's Kathmandu valley. 3 sub-groups are studied: high caste (Brahmin and Chetri) urban residents, high caste urban fringe residents, and low caste untouchables (Sarki). Both survey and anthropological methods are employed. According to the analytical model, the transition in fertility follows 4 phases. The changes in fertility levels from Phase 1 to Phase 4 generally indicate that the transition from natural to controlled fertility is characterized by declines in the proportions of women married and the duration of postpartum infecundability, and a substantial increase in the prevalence and effectiveness of contraceptive practices. The results of this study show that Nepal as a whole is entrenched in Phase 1 of the fertility transition. However, data from the 3 populations reported here clearly indicate that each has begun to experience a demographic transition to different degrees. The Sarkis in this study fall between Phases 2 and 3, as indicated by the total fertility rate (TFR). The rural high castes most closely approximate a population in Phase 3, while urban high castes included in this study are approaching Phase 4. Each of the 3 populations is characterized by a decline in the proportion of women married when compared to all of Nepal. It is also apparent that the relative use-effectiveness of contraceptive methods currently employed is high. Gains in the reduction of fertility, then, will have to be made from increasing and retaining the number of acceptors and in reducing the desired family size of those at reproductive risk.^ieng

Family planning in Nepal from the user's and nonuser's perspectives.

Recent data from Nepal indicate that in the urban areas reproductive attitudes are changing much more rapidly than behavior, resulting in many unwanted births. Based on transcripts from in-depth interviews conducted in 1982 by the Urban Fertility and Contraceptive Use Project, this article analyzes the "contraceptive lag" in urban Nepal by examining contraceptive decision-making among urban couples in Kathmandu. Tracing links between attitudes, knowledge, values, and specific behavioral outcomes, the analysis reveals that for the majority of the couples in the study, unwanted births occurred for reasons that might have been obviated through more effective provision of family planning services.

Family change, caste, and the elderly in a rural locale in Nepal.

This study reports research conducted in a rural Nepalese Hindu Community to examine three questions: (1) the nature of family structure of the elderly roughly 4 decades ago; (2) whether the family structure at that time was the same for high and low castes; and (3) whether the past situation differs from that today. Four decades ago 78% of elderly high caste males were living in the ideal Hindu joint family structure compared with only 24% of the low castes. Today just 50% of the high castes and 42% of the low castes live in joint families. The difference in the past derives from access to and control over economic resources. Economic changes since 1950 have increased access to economic resources and altered the family structure of the high castes but not the low castes.

The physical fitness of elderly Nepalese farmers residing in rugged mountain and flat terrain.

This paper reports the results of a natural experimental test of the hypothesis that elderly residents of rugged terrains are more physically fit than their counterparts in flat terrains due to the additional lifelong daily exertion occasioned by the inescapable need to walk up and down steep slopes. Cycle ergometer tests of physiological response to work were undertaken by two groups of high caste Hindu male farmers, aged 50 to 79, living in Central Nepal. One comprised an experimental group resident in rugged terrain and the other a control group resident in flat terrain. No differences in heart rate and blood pressure measured at submaximal workloads, at peak effort, or during recovery from exercise were demonstrated. Measurements of physical exertion revealed that few people in either terrain engaged in activity sufficiently strenuous to raise heart rates to a level where training could occur. Despite a rural agricultural lifestyle, these men were not especially physically fit.

Barriers to effective family planning in Nepal.

To investigate why family planning (FP) services in the Kathmandu Valley of Nepal are underused, a study was initiated under the auspices of the Nepal Family Planning/Maternal--Child Health Project. The study was intended to provide a user perspective, by examining interactions between FP clinic staff and their clientele. "Simulated" clients were sent to 16 FP clinics in Kathmandu to request information and advice. The study revealed that in the impersonal setting of a family planning clinic, clients and staff fall into traditional, hierarchical modes of interaction. In the process, the client's "modern" goal of limiting her family size is subverted by the service system that was created to support this goal. Particularly when status differences are greatest, that is, with lower-class and low caste clients, transmission of information is inhibited.

PIP: To investigate why family planning (FP) services in the Kathmandu Valley of Nepal are underused, a study was initiated under the auspices of the Nepal Family Planning/Maternal Child Health Project. The question behind the study was whether the professional providers of family planning services are themselves inhibiting effective use of contraception. The purpose of the study was to examine interactions between family planning clinic staff and their clientele. For this purpose, 6 couples and 2 individual women with different socioeconomic backgrounds posed as clients (simulated clients) and were sent to 16 of the 25 family planning clinics in the Kathmandu Valley over a period of about a month. The simulated clients were trained individually and as couples, using role-playing techniques and acting out roles that did not deviate much from their actual life situations. 3 groups of simulated clients with different taste, class and educational backgrounds were trained and sent to nearby family planning clinics. Group A consisted of 2 high caste, urban couples. Group B consisted of 2 lower middle-class couples and 2 individual women. The 2 couples in Group C were lower-class. The accounts provided by the simulated clients were analyzed qualitatively for overall content, and rated using a scale of 1 through 3, based on the accuracy of the family planning information provided, attitude of the staff toward the client and bias of the staff toward the client. The underlying assumption was that a good attitude and lack of bias on the part of family planning staff would be conducive to a desirable outcome, that is, a well-informed, free decision by the client to adopt a particular family planning method. Directly and indirectly, the study revealed a number of barriers to provision and effective use of family planning services in the urban areas of Nepal. The scores indicate that the family planning information provided at most clinics is inadequate or incorrect in many cases. The manner in which the information is presented is apt to drive clients away. In the impersonal setting of a family planning clinic, clients and staff fall into traditional, hierarchical modes of interaction. Moreover, the quality of the services was positively related to the socioeconomic status of the client. Unsophisticated lower-class clients are likely to receive scantier, less accurate information and less courteous treatment than educated middle-class clients. The former's negative perceptions of family planning and family planning clinics probably become disseminated among friends and neighbors. A neighborhood-based program would be more effective than the clinic-based system as it now functions. An alternative or complementary program might focus on upgrading the communication skills of family planning staff within clinics.

Social structure and intracohort variation in physical fitness among elderly males in a traditional Third World society.

This paper examines the relationship between physical fitness and activity among elderly males in the traditional rural community of Chetbesi, Nepal. It takes advantage of the unique character of the Hindu caste system to implement a quasiexperimental research design that approximates random assignment to high and low activity levels. The members of the Sarki caste have lower heart rates and systolic blood pressure, relative to other castes, at each of three submaximal workloads and during recovery from bicycle ergometer exercise. Direct observation and physiologic monitoring show that the Sarkis engage in more frequent and extended periods of heavy labor. Thus intracohort variation in physical fitness and activity patterns among the Chetbesi elderly is a function of birth into a socially defined group rather than of self-selection. This pattern of differential fitness may typify the process of aging in many stratified traditional and modernizing societies where socially delimited segments of the population perform the bulk of the hard work. Intrapopulation differences aside, comparison of Sarkis and non-Sarkis with other samples reveals that both lie within the reported range of variation. The rural, unmechanized, agricultural lifestyle and mountain environment of Chetbesi do not result in exceptional fitness for residents. The Chetbesi data suggest that the popular notion that aging is less debilitating in traditional agrarian societies located in rugged mountain terrains may be a myth. The demonstration of the influence of social forces on physical fitness suggests that future research might concentrate profitably on identifying social structures that produce high levels of physical fitness.

Social and economic forces affecting intergenerational relations in extended families in a Third World country: a cautionary tale from South Asia.

This paper questions the implicit assumption derived from modernization theory that elderly persons in the Third World lead secure and satisfying lives because they still live in extended families. Data from elderly Hindus living in Kathmandu, Nepal, are presented and demonstrate that, although these elderly people do continue to live in extended families, social and economic changes have transformed the nature of intergenerational social relations within these families to the detriment of the elderly family members.

From a mountain-rural to a plains-urban society: implications of the 1981 Nepalese Census.

PIP: Preliminary results of the 1981 Nepal census are analyzed as to urbanization and population movement to the Terai. Noting the substantial shift in the pattern of Nepal's population distribution occurring between 1971-81, and projecting these rates of change for the future, the paper reports a process of transformation wherein Nepal is shifting from a rural hill and mountain society to an urban-subtropical plains (Terai) state. While the flow of migrants to urban areas and the Terai region is well known, the increase in rate of change poses a serious challenge for the Nepalese government. Economic development planning must readjust its goals and assumptions to take into account the massive metamorphosis that is occurring in Nepal. Development efforts aimed at rural hill and mountain areas may need to be reevaluated in light of the changing distribution of population.^ieng

Indirect modernization and the status of the elderly in a rural Third World setting.

Currently the majority of the world's elderly reside in less developed countries and their proportion is increasing. This paper presents evidence that the process of modernization can have a negative impact on the elderly in even the most remote rural Third World settings, even though those settings are not modernized or in the process of modernization in any of the normal uses of that concept. Fieldwork was conducted in Helambu, Nepal on a sample of 37 persons over the age of 50 that included 86% of population aged 60 and over. Despite high levels of activity, health, social and economic status, the elderly were greatly dissatisfied with their situation. The paper demonstrates the manner in which modernization in India has profoundly changed household/family organization in Helambu and produced this situation.