Douglas E. Crews

Social context and psychosocial influences on blood pressure among American Samoans

This study explores social and explores social and economic influences on health within a model formulated to address explicitly both individual and household level phenomena. Dresslers lifestyle incongruity model is used as a basis from which to predict the effects of intracultural contexts of variability on blood pressure. The sample for this survey consists of 134 Samoan men and women living in American Samoa. Based on previous experience and ethnographic sources, two key intracultural contexts were examined; gender, i.e., male-female differences in response to psychosocial stress, and household employment as indicated by whether or not both spouses in a household are employed. Our analysis indicates that lifestyle incongruity, defined as the difference between the material culture presented by a household and the economic resources of the family, is significantly associated with both systolic and diastolic blood pressure. Furthermore, males and females show opposite blood pressure associations with both lifestyle incongruity (male blood pressure increases with increasing incongruity while female blood pressure does not) and household employment (male blood pressure is higher when both spouses work but female blood pressure is lower).

Subsistence patterns and blood pressure variation in two rural Caboclo communities of Marajó Island, Pará, Brazil

Blood pressure (BP) increases with age in westernized societies, is higher in men, and is correlated with the body mass index (BMI). Traditional societies present more variable patterns of BP. In 1991, BP and anthropometric data from two “Caboclo” (rural populations of mixed ancestry) groups from Marajó Island, Brazil, were collected: The Paricatuba group, (N = 20;12 women), with a subsistence base of fishing, collection of palm fruits, and traditional gardening; and the Praia Grande group (N = 26; 14 women), where subsistence is based on mechanized agriculture. In Paricatuba, mean BP is 109/74 mmHg in men and 101/70 mmHg in women. There are no significant differences between BP of men and women, and systolic blood pressure (SBP) increases with age. Both SBP and diastolic blood pressure (DBP) are associated with weight, but only DBP is associated with the BMI, while SBP is associated with stature. In Praia Grande, mean BP is 120/76 mmHg in men and 118/70 mmHg in women, with no significant differences between the sexes. In Praia Grande, SBP is higher than in Paricatuba, and both SBP and DBP are associated with age. Compared with urban groups, both Caboclo samples have low BP. Still, differences in BP and body habitus between the two groups support a hypothesis that degree of westernization influences mean levels of BP in rural Amazonian populations. Further, the results also may be interpreted as suggesting that associations of sex, age, and BMI with BP, commonly reported in urban samples, are a byproduct of westernization rather than a result of genetic factors.

Changes in some health status characteristics of American Samoan men: Preliminary observations from a 12-year follow-up study

One of the concomitants of the rapid socioeconomic and medical changes which occurred in American Samoa beginning with World War II has been an increase in chronic diseases, especially cardiovascular disease and diabetes. As part of the Samoan Studies Project, a 1976 survey focusing on obesity and blood pressure was conducted in American Samoa. A total of 624 men age 18 or greater were seen at that time. In 1989 we conducted a follow‐up examination of 31 of these men, reassessing blood pressure, and also examining blood glucose and previously diagnosed health problems, focusing on chronic diseases such as hypertension, stroke, cancer, and diabetes. In a prospective analysis of mortality, Crews (Hum. Biol. 60:417–433, 1988) found that 111 American Samoan men who had blood pressures measured in a public health department survey in 1975 and subsequently died between 1975 and 1981, had higher average systolic and diastolic blood pressures than the 2,588 survivors (140/88 vs. 129/84). Using these data, the 1989 sample was stratified according to the 1976 blood pressure measurement of the men and a sample of 14 normotensive men (1976 blood pressure <140/90) and 17 hypertensives (1976 blood pressure ≥140/90) was selected. The average age, weight, and number of cigarettes smoked per day was not significantly different for these two groups at the 12‐year follow‐up. However, several indicators of health status did differ. The hypertensive group had significantly higher systolic and diastolic blood pressures (P ≤ 0.001). Additionally, the hypertensive group had higher random blood glucose values (P ≤ 0.005) and were significantly more likely to be hypertensive and/or have impaired glucose tolerance (P ≤ 0.001). Change in weight was predictive of change in blood pressure, but not of absolute value of blood pressure. This paper notes the importance of elevated blood pressure as a predictor of future chronic disease risk for Samoan men.

Brief communication: Oxygen isotopes as a biomarker for sickle-cell disease? Results from transgenic mice expressing human hemoglobin S genes

The origins of sickle-cell disease (SCD) are well understood, as are its evolutionary pressures on humans and pathological presentation. However, because it has not been possible to identify SCD in archaeological contexts, its biocultural effects on past populations are unknown. Previous research investigating oxygen isotope fractionation during respiration among anemics suggests that oxygen isotopes in bone apatite may provide a biological marker for SCD in skeletal remains. This pilot study reports δ(18) O ratios in bone apatite of transgenic laboratory mice expressing human SCD globins and compares them to healthy control mice. The δ(18) O ratios of sick mice are significantly lower than those of healthy mice (-5.6‰ vs. -4.5‰; P = 0.002), and the sickest mice exhibit the lowest ratios of all (mean δ(18) O = -5.8‰). These preliminary results suggest that this method may be usefully applied to skeletal materials of past human populations whose diets and water sources do not differ substantially.

Social support and health among elderly kuwaitis

The aim of this study was to examine differences in several aspects of health between Kuwaiti men and women aged 60 years and over across three age categories (60-69, 70-79, 80+ years). The relationships between several social support variables, somatic symptoms and systolic and diastolic blood pressures were examined. A total of 1427 adult men (472) and women (955) aged 60 years and over representing all six governorates were selected. Data were collected during 2008-2009 by interview and completion of a questionnaire by participants in their own homes, after obtaining their informed consent. The Social Support Scale (SSS), Frequency of Contact Scale (FOC), Strength of Relations (SOR), Somatic Symptoms Inventory (SSI) and self-rated scales of general health were included. Systolic and diastolic blood pressures were measured. The data show that self-rated health and health in the last year differ significantly across age groups. Glycaemia differed significantly across the three age groups for the total sample. Systolic and diastolic blood pressure were higher in older respondents than younger ones, but no significant differences were observed between men and women. No significant differences in somatic symptoms were observed across the three age groups. Strength of relationship, frequency of contact, social support and children living with an elderly adult were all associated with fewer somatic symptoms, and all, except social support, were associated with lower systolic and diastolic blood pressure. Having children, the perception of social support, frequency of contact with, and strength of, relationships with kin are important modulators of somatic symptoms and blood pressure among elderly Kuwaitis.

Anthropological Issues in Biological Gerontology

Biological anthropologists have contributed substantially to the development of growth standards and measures of biological age. They have also examined morphological and physiological variation and change during adulthood. Nevertheless, relatively little research has focused on the later stages of human life.

Allostatic load differs by sex and diet, but not age in older Japanese from the Goto Islands.

Abstract Background: Lifelong exposure to stressors promotes physiological dysregulation and produces an allostatic load (AL). In European-derived samples, AL associates significantly with sex, age and health. Aim: To assess associations of AL with age, sex, socio-demographic differences and self-reports of diet and ability to complete activities of daily living in older Japanese residing in rural Nagasaki Prefecture. Subjects and methods: In 2011, 96 older residents of Nagasaki Prefecture, Japan, were assessed for components of AL. They also self-reported their age, principal life-long occupational activity, educational attainments, marital status, dietary choices and abilities to complete daily living activities. Results: Average age was 67.9 years (range = 55–89; SD = 8.65). Among these 48 men and 48 women, AL was not related significantly to age, although women showed lower AL than men. AL did not differ significantly between respondents by occupation, marital status, education or abilities to complete daily activities. Women who reported eating more green/yellow vegetables or consuming more meat had lower AL than their counterparts. Men who reported drinking more alcohol spirits had higher AL. Conclusions: Among older Japanese residing outside a major urban area, AL varies significantly by sex, but not age, while being associated with dietary choices. Although lack of association with life ways was not expected, AL apparently assesses physiological dysregulation cross-culturally.

Allostatic load and biological anthropology.

Multiple stressors affect developing and adult organisms, thereby partly structuring their phenotypes. Determining how stressors influence health, well-being, and longevity in human and nonhuman primate populations are major foci within biological anthropology. Although much effort has been devoted to examining responses to multiple environmental and sociocultural stressors, no holistic metric to measure stress-related physiological dysfunction has been widely applied within biological anthropology. Researchers from disciplines outside anthropology are using allostatic load indices (ALIs) to estimate such dysregulation and examine life-long outcomes of stressor exposures, including morbidity and mortality. Following allostasis theory, allostatic load represents accumulated physiological and somatic damage secondary to stressors and senescent processes experienced over the lifespan. ALIs estimate this wear-and-tear using a composite of biomarkers representing neuroendocrine, cardiovascular, metabolic, and immune systems. Across samples, ALIs are associated significantly with multiple individual characteristics (e.g., age, sex, education, DNA variation) of interest within biological anthropology. They also predict future outcomes, including aspects of life history variation (e.g., survival, lifespan), mental and physical health, morbidity and mortality, and likely health disparities between groups, by stressor exposures, ethnicity, occupations, and degree of departure from local indigenous life ways and integration into external and commodified ones. ALIs also may be applied to similar stress-related research areas among nonhuman primates. Given the reports from multiple research endeavors, here we propose ALIs may be useful for assessing stressors, stress responses, and stress-related dysfunction, current and long-term cognitive function, health and well-being, and risk of early mortality across many research programs within biological anthropology.

A pilot study of allostatic load among elderly Japanese living on Hizen-Oshima Island.

BackgroundBetween July and September 2005, a preliminary sampling of the elderly population of Hizen-Oshima Island, Nagasaki Prefecture, Japan was conducted by the local hospital’s nursing staff.ResultsReported here are preliminary results from this sample of 27 individuals with an average age of 71 years. Their ages ranged from 51 to 82 years, with a standard deviation (sd) of 7.4 years. In total, 33 aspects of physical and physiological variation were assessed on these 15 women and 12 men. As expected from previous studies of Japanese elders, our sample shows slightly elevated average blood pressure (142/81 mmHg, sd 16/10), but they are relatively lean (waist/hip = .9: sd 0.06) when compared to European or American standards. However, their average total cholesterol (TC = 210 mg/dl, sd = 42.8) is high compared to standards, as is their high-density lipoprotein cholesterol (HDLc = 55.4 mg/dl, sd = 15.1). Means, standard deviations (sd), ranges and upper bounds for quartile cut-points for all 10 variables used in the calculation of allostatic load (AL) were assessed. The overall average estimate for AL in this sample is 3.1 (sd = 1.58) and ranges from 1 to 7.ConclusionAL shows variability across men and women, has little correlation with age, and is associated with physiological variation in blood glucose, dopamine and uric acid.

Diurnal blood pressure patterns in long-term care settings.

BackgroundSome research suggests that individuals whose blood pressure does not decline at night may be at increased risk of end-organ damage. Few studies have examined ambulatory blood pressure among elders, particularly those living in institutions. This study therefore evaluates ambulatory blood pressure variation in two groups of institutionalized elderly, independent living and nursing home residents. It was suggested that the nursing home sample would have a higher rate of non-dipping than the independent-living residents. Design and methodsTwenty-seven residents (aged 87 ± 8 years) of a nursing home facility and 29 residents (aged 80 ± 6 years) from two independent living facilities wore ambulatory monitors for approximately 24 h. Several definitions of dipping were examined. ResultsNeither mean daytime nor mean night-time systolic blood pressure differed between the two groups. Daytime diastolic blood pressure was significantly higher in the independent living sample, as was night-time diastolic pressure in the nursing home residents. Neither asleep nor awake blood pressure varied significantly between groups. The decline in night-time blood pressure and sleep blood pressure was significantly greater among the independent living residents (P  < 0.05). Ratios of night-time/daytime and asleep/awake blood pressure were significantly higher in the nursing home group. Non-dippers were significantly more frequent among the nursing home residents. ConclusionsNursing home residents were significantly more likely to be non-dippers. Both groups of resident were more frequently non-dippers than were individuals in community-dwelling samples. The high prevalence of non-dipping among institutionalized elderly people may be a result of age, health status or institutional activity patterns.