RESUMO
Little is known about brain aging or dementia in nonindustrialized environments that are similar to how humans lived throughout evolutionary history. This paper examines brain volume (BV) in middle and old age among two indigenous South American populations, the Tsimane and Moseten, whose lifestyles and environments diverge from those in high-income nations. With a sample of 1,165 individuals aged 40 to 94, we analyze population differences in cross-sectional rates of decline in BV with age. We also assess the relationships of BV with energy biomarkers and arterial disease and compare them against findings in industrialized contexts. The analyses test three hypotheses derived from an evolutionary model of brain health, which we call the embarrassment of riches (EOR). The model hypothesizes that food energy was positively associated with late life BV in the physically active, food-limited past, but excess body mass and adiposity are now associated with reduced BV in industrialized societies in middle and older ages. We find that the relationship of BV with both non-HDL cholesterol and body mass index is curvilinear, positive from the lowest values to 1.4 to 1.6 SDs above the mean, and negative from that value to the highest values. The more acculturated Moseten exhibit a steeper decrease in BV with age than Tsimane, but still shallower than US and European populations. Lastly, aortic arteriosclerosis is associated with lower BV. Complemented by findings from the United States and Europe, our results are consistent with the EOR model, with implications for interventions to improve brain health.
Assuntos
Envelhecimento , Sistema Cardiovascular , Humanos , Estados Unidos , Estudos Transversais , Encéfalo , América do SulRESUMO
INTRODUCTION: We evaluated the prevalence of dementia and mild cognitive impairment (MCI) in indigenous Tsimane and Moseten, who lead a subsistence lifestyle. METHODS: Participants from population-based samples ≥ 60 years of age (n = 623) were assessed using adapted versions of the Modified Mini-Mental State Examination, informant interview, longitudinal cognitive testing and brain computed tomography (CT) scans. RESULTS: Tsimane exhibited five cases of dementia (among n = 435; crude prevalence = 1.2%, 95% confidence interval [CI]: 0.4, 2.7); Moseten exhibited one case (among n = 169; crude prevalence = 0.6%, 95% CI: 0.0, 3.2), all age ≥ 80 years. Age-standardized MCI prevalence was 7.7% (95% CI: 5.2, 10.3) in Tsimane and 9.8% (95% CI: 4.9, 14.6) in Moseten. Cognitive impairment was associated with visuospatial impairments, parkinsonian symptoms, and vascular calcification in the basal ganglia. DISCUSSION: The prevalence of dementia in this cohort is among the lowest in the world. Widespread intracranial medial arterial calcifications suggest a previously unrecognized, non-Alzheimer's disease (AD) dementia phenotype.
Assuntos
Doença de Alzheimer , Disfunção Cognitiva , Demência , Humanos , Prevalência , Bolívia/epidemiologia , Disfunção Cognitiva/diagnóstico por imagem , Disfunção Cognitiva/epidemiologia , Disfunção Cognitiva/complicações , Neuroimagem , Demência/diagnóstico por imagem , Demência/epidemiologia , Demência/complicações , Doença de Alzheimer/epidemiologia , Progressão da DoençaRESUMO
In post-industrial settings, apolipoprotein E4 (APOE4) is associated with increased cardiovascular and neurological disease risk. However, the majority of human evolutionary history occurred in environments with higher pathogenic diversity and low cardiovascular risk. We hypothesize that in high-pathogen and energy-limited contexts, the APOE4 allele confers benefits by reducing innate inflammation when uninfected, while maintaining higher lipid levels that buffer costs of immune activation during infection. Among Tsimane forager-farmers of Bolivia (N = 1266, 50% female), APOE4 is associated with 30% lower C-reactive protein, and higher total cholesterol and oxidized LDL. Blood lipids were either not associated, or negatively associated with inflammatory biomarkers, except for associations of oxidized LDL and inflammation which were limited to obese adults. Further, APOE4 carriers maintain higher levels of total and LDL cholesterol at low body mass indices (BMIs). These results suggest that the relationship between APOE4 and lipids may be beneficial for pathogen-driven immune responses and unlikely to increase cardiovascular risk in an active subsistence population.
Genes contain the instructions needed for a cell to make molecules called proteins, which perform various roles in the body. Different variants of a gene can affect how the protein works, and in some cases, can increase a person's risk to develop certain diseases. For example, people who carry a version of the apolipoprotein E gene called APOE4 have a greater risk of developing Alzheimer's disease or heart disease. Individuals with two copies of this genetic variant have a 45% higher risk of heart disease and 12 times higher risk of Alzheimer's disease. Studies in industrialized countries suggest this increased risk may be the result of higher cholesterol and inflammation in people with APOE4. But if APOE4 is harmful, why does it continue to be so common worldwide? One potential explanation is that APOE4, which has been around since before modern humans, may be beneficial in some contexts. Cholesterol is essential for many vital tasks in the body. In physically demanding environments where parasitic infections are common conditions similar to those experienced by early humans APOE4 might be beneficial. Under those circumstances, having more cholesterol might help fuel metabolic activities, fight infections, or reduce inflammation caused by infections. Garcia et al. investigated the link between the APOE4 genetic variant, cholesterol and inflammation in 1,266 Indigenous Tsimane people from 80 villages in Bolivia. Tsimane people live an active lifestyle foraging and farming for food. Parasite infections are a common problem in their communities, but obesity rates are very low. Garcia et al. found that Tsimane people with at least one copy of the APOE4 have lower levels of inflammation and higher levels of cholesterol than those who have two copies of the APOE3 version of the gene. Very lean people with APOE4 had especially high levels of the so called "bad" low density lipoprotein (LDL) cholesterol compared to people with APOE3 only. However, in this situation, storing a little extra cholesterol may not be so bad. The findings contradict other studies that have linked obesity to higher LDL levels and APOE4 to higher levels of inflammation. For the majority of human history, humans lived in more physically strenuous and calorically restrictive environments, with less access to clean water. Garcia et al. suggest that the harmful effects of APOE4 seen in studies in more industrialized societies where people tend to be more sedentary and have less exposure to pathogens may reflect a mismatch between a person's environment and their genes. More studies that capture the diversity of environmental conditions under which people live will help clarify the role of APOE4 health and disease.
Assuntos
Apolipoproteína E4/genética , Imunidade Inata , Indígenas Sul-Americanos , Lipídeos/sangue , Clima Tropical , Biomarcadores/sangue , Índice de Massa Corporal , Bolívia , Dieta , Feminino , Genótipo , Humanos , Estilo de Vida , Masculino , Pessoa de Meia-Idade , Obesidade/sangue , Fatores de RiscoRESUMO
Brain atrophy is correlated with risk of cognitive impairment, functional decline, and dementia. Despite a high infectious disease burden, Tsimane forager-horticulturists of Bolivia have the lowest prevalence of coronary atherosclerosis of any studied population and present few cardiovascular disease (CVD) risk factors despite a high burden of infections and therefore inflammation. This study (a) examines the statistical association between brain volume (BV) and age for Tsimane and (b) compares this association to that of 3 industrialized populations in the United States and Europe. This cohort-based panel study enrolled 746 participants aged 40-94 (396 males), from whom computed tomography (CT) head scans were acquired. BV and intracranial volume (ICV) were calculated from automatic head CT segmentations. The linear regression coefficient estimate ß^T of the Tsimane (T), describing the relationship between age (predictor) and BV (response, as a percentage of ICV), was calculated for the pooled sample (including both sexes) and for each sex. ß^T was compared to the corresponding regression coefficient estimate ß^R of samples from the industrialized reference (R) countries. For all comparisons, the null hypothesis ßâT = ßâR was rejected both for the combined samples of males and females, as well as separately for each sex. Our results indicate that the Tsimane exhibit a significantly slower decrease in BV with age than populations in the United States and Europe. Such reduced rates of BV decrease, together with a subsistence lifestyle and low CVD risk, may protect brain health despite considerable chronic inflammation related to infectious burden.
Assuntos
Encéfalo , Doença da Artéria Coronariana , Inflamação/etnologia , Estilo de Vida , Adulto , Idoso , Idoso de 80 Anos ou mais , Bolívia/epidemiologia , Encéfalo/diagnóstico por imagem , Doença da Artéria Coronariana/etnologia , Feminino , Humanos , Povos Indígenas , Masculino , Pessoa de Meia-Idade , Tamanho do Órgão , América do Sul/epidemiologiaRESUMO
The sternal foramen, usually an asymptomatic osteological defect, can lead to catastrophic consequences if not recognized prior to certain medical procedures. This study reports the prevalence of a sternal foramen in two South Amerindian populations compared with other published populations. We evaluated the presence of sternal foramina using thoracic computed tomography scans of 1334 (48% female) participants from two indigenous populations of Bolivia (n = 900 Tsimane, 434 Moseten). The prevalence of sternal foramina was compared to two U.S. populations of similar sex/age distribution (n = 572 Midwest Americans, 131 self-identified Native North Americans) via similar CT scans. A sternal foramen was significantly more common in the two Bolivian populations (prevalence ranging from 12.8 to 13.4%), compared to 4.4-5.1% in the two U.S. groups, consistent with prior estimates in studies from industrialized populations. Males had higher frequency of a sternal foramen compared to females in each of the four groups (OR = 1.904, 95% CI: 1.418-2.568, p < 0.001). Age was not associated with sternal foramen presence. These data show both a higher rate of sternal foramina in the South Amerindian populations versus comparator populations in North America and the highest rate of any studied living population. Although it is not possible to determine from our data the relative contribution of genetics versus early life or environmental causes to the higher rates of sternal foramen, we note that small prior studies have likewise demonstrated a higher prevalence in lower income countries. Further determination of the contributing factors warrants greater investigation and research.
Assuntos
Anormalidades Congênitas/epidemiologia , Esterno/anormalidades , Adulto , Idoso , Idoso de 80 Anos ou mais , Bolívia , Anormalidades Congênitas/diagnóstico por imagem , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Prevalência , Esterno/diagnóstico por imagem , Tomografia Computadorizada por Raios X , Estados UnidosRESUMO
Modern humans have more fragile skeletons than other hominins, which may result from physical inactivity. Here, we test whether reproductive effort also compromises bone strength, by measuring using computed tomography thoracic vertebral bone mineral density (BMD) and fracture prevalence among physically active Tsimane forager-horticulturalists. Earlier onset of reproduction and shorter interbirth intervals are associated with reduced BMD for women. Tsimane BMD is lower versus Americans, but only for women, contrary to simple predictions relying on inactivity to explain skeletal fragility. Minimal BMD differences exist between Tsimane and American men, suggesting that systemic factors other than fertility (e.g. diet) do not easily explain Tsimane women's lower BMD. Tsimane fracture prevalence is also higher versus Americans. Lower BMD increases Tsimane fracture risk, but only for women, suggesting a role of weak bone in women's fracture etiology. Our results highlight the role of sex-specific mechanisms underlying skeletal fragility that operate long before menopause.
Assuntos
Densidade Óssea , Etnicidade , Comportamento Alimentar , Fraturas Ósseas/epidemiologia , Comportamento Reprodutivo , Adulto , Idoso , Idoso de 80 Anos ou mais , Bolívia , Feminino , Fraturas Ósseas/diagnóstico por imagem , Humanos , Masculino , Pessoa de Meia-Idade , Prevalência , Fatores Sexuais , Tomografia Computadorizada por Raios X , Estados UnidosRESUMO
BACKGROUND: Conventional coronary artery disease risk factors might potentially explain at least 90% of the attributable risk of coronary artery disease. To better understand the association between the pre-industrial lifestyle and low prevalence of coronary artery disease risk factors, we examined the Tsimane, a Bolivian population living a subsistence lifestyle of hunting, gathering, fishing, and farming with few cardiovascular risk factors, but high infectious inflammatory burden. METHODS: We did a cross-sectional cohort study including all individuals who self-identified as Tsimane and who were aged 40 years or older. Coronary atherosclerosis was assessed by coronary artery calcium (CAC) scoring done with non-contrast CT in Tsimane adults. We assessed the difference between the Tsimane and 6814 participants from the Multi-Ethnic Study of Atherosclerosis (MESA). CAC scores higher than 100 were considered representative of significant atherosclerotic disease. Tsimane blood lipid and inflammatory biomarkers were obtained at the time of scanning, and in some patients, longitudinally. FINDINGS: Between July 2, 2014, and Sept 10, 2015, 705 individuals, who had data available for analysis, were included in this study. 596 (85%) of 705 Tsimane had no CAC, 89 (13%) had CAC scores of 1-100, and 20 (3%) had CAC scores higher than 100. For individuals older than age 75 years, 31 (65%) Tsimane presented with a CAC score of 0, and only four (8%) had CAC scores of 100 or more, a five-fold lower prevalence than industrialised populations (p≤0·0001 for all age categories of MESA). Mean LDL and HDL cholesterol concentrations were 2·35 mmol/L (91 mg/dL) and 1·0 mmol/L (39·5 mg/dL), respectively; obesity, hypertension, high blood sugar, and regular cigarette smoking were rare. High-sensitivity C-reactive protein was elevated beyond the clinical cutoff of 3·0 mg/dL in 360 (51%) Tsimane participants. INTERPRETATION: Despite a high infectious inflammatory burden, the Tsimane, a forager-horticulturalist population of the Bolivian Amazon with few coronary artery disease risk factors, have the lowest reported levels of coronary artery disease of any population recorded to date. These findings suggest that coronary atherosclerosis can be avoided in most people by achieving a lifetime with very low LDL, low blood pressure, low glucose, normal body-mass index, no smoking, and plenty of physical activity. The relative contributions of each are still to be determined. FUNDING: National Institute on Aging, National Institutes of Health; St Luke's Hospital of Kansas City; and Paleocardiology Foundation.
Assuntos
Aterosclerose/etnologia , Doença da Artéria Coronariana/etnologia , Adulto , Distribuição por Idade , Idoso , Idoso de 80 Anos ou mais , Antropometria/métodos , Aterosclerose/sangue , Aterosclerose/diagnóstico por imagem , Aterosclerose/etiologia , Bolívia/epidemiologia , Estudos de Coortes , Angiografia Coronária/métodos , Doença da Artéria Coronariana/sangue , Doença da Artéria Coronariana/diagnóstico por imagem , Doença da Artéria Coronariana/etiologia , Estudos Transversais , Feminino , Humanos , Mediadores da Inflamação/sangue , Estilo de Vida , Lipídeos/sangue , Masculino , Pessoa de Meia-Idade , Fatores de Risco , Índice de Gravidade de Doença , Tomografia Computadorizada por Raios XRESUMO
The apolipoprotein E4 (E4) allele is present worldwide, despite its associations with higher risk of cardiovascular morbidity, accelerated cognitive decline during aging, and Alzheimer's disease (AD). The E4 allele is especially prevalent in some tropical regions with a high parasite burden. Equatorial populations also face a potential dual burden of high E4 prevalence combined with parasitic infections that can also reduce cognitive performance. We examined the interactions of E4, parasite burden, and cognitive performance in a traditional, nonindustrialized population of Amazonian forager-horticulturalists (N = 372) to test whether E4 protects against cognitive decline in environments with a heavy pathogen burden. Contrary to observations in industrial populations, older adult E4 carriers with high parasite burdens either maintained or showed slight improvements in cognitive performance, whereas non-E4 carriers with a high parasite burden showed reduced cognitive performance. Being an E4 carrier is the strongest risk factor to date of AD and cognitive decline in industrial populations; it is associated with greater cognitive performance in individuals facing a high parasite and pathogen load, suggesting advantages to the E4 allele under certain environmental conditions. The current mismatch between postindustrial hygienic lifestyles and active parasite-rich environs may be critical for understanding genetic risk for cognitive aging.-Trumble, B. C., Stieglitz, J., Blackwell, A. D., Allayee, H., Beheim, B., Finch, C. E., Gurven, M., Kaplan, H. Apolipoprotein E4 is associated with improved cognitive function in Amazonian forager-horticulturalists with a high parasite burden.
Assuntos
Alelos , Apolipoproteínas E/genética , Transtornos Cognitivos/genética , Doenças Parasitárias/genética , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Brasil , Criança , Transtornos Cognitivos/epidemiologia , Feminino , Heterozigoto , Humanos , Indígenas Sul-Americanos/genética , Masculino , Pessoa de Meia-Idade , Doenças Parasitárias/epidemiologiaRESUMO
The Tres Ventanas mummies of Peru are thought to be among the oldest mummies in existence, dating to between 8,000 and 10,000 years ago. A preliminary assessment is made of the potential of these mummies for use in future research on mummified remains. Although the Tres Ventanas cave and the four mummies were explored and then excavated by Frederic Engel in 1966-67, and the project is named in his honor as the "Engel Study Group", the importance of both the physical remains and the context in which they were found has only come to light in the last few years. Most important is the paleopathological examination of these remains, since these mummies are found in a high altitude area of Peru where adaptation to the limited partial pressure of oxygen is perhaps a key component in broadening our understanding of human diversity in past populations.
Assuntos
Múmias/patologia , Humanos , Paleopatologia , PeruRESUMO
Although atherosclerosis is widely thought to be a disease of modernity, computed tomographic evidence of atherosclerosis has been found in the bodies of a large number of mummies. This article reviews the findings of atherosclerotic calcifications in the remains of ancient people-humans who lived across a very wide span of human history and over most of the inhabited globe. These people had a wide range of diets and lifestyles and traditional modern risk factors do not thoroughly explain the presence and easy detectability of this disease. Nontraditional risk factors such as the inhalation of cooking fire smoke and chronic infection or inflammation might have been important atherogenic factors in ancient times. Study of the genetic and environmental risk factors for atherosclerosis in ancient people may offer insights into this common modern disease.
Assuntos
Aterosclerose/diagnóstico por imagem , Múmias/diagnóstico por imagem , Tomografia Computadorizada por Raios X , Áustria , Egito , Humanos , Itália , América do Norte , PeruRESUMO
BACKGROUND: Evidence of atherosclerotic plaques in ancient populations has led to the reconsideration of risk factors for heart disease and of the common belief that it is a disease of modern times. METHODS: Fifty-one wrapped mummy bundles excavated from the sites of Huallamarca, Pedreros, and Rinconada La Molina from the Puruchuco Museum collection in Lima, Peru, were scanned using computed tomography to investigate the presence of atherosclerosis. Funerary artifacts contained within the undisturbed mummy bundles were analyzed as an attempt to infer the social status of the individuals to correlate social status with evidence of heart disease in this ancient Peruvian group. This work also provides an inventory of the museum mummy collection to guide and facilitate future research. RESULTS: Statistical analysis concluded that there is little association between the types of grave goods contained within the bundles when the groups are pooled together. However, some patterns of artifact type, material, atherosclerosis, and sex emerge when the 3 excavation sites are analyzed separately. CONCLUSIONS: From the current sample, it would seem that social class is difficult to discern, but those from Huallamarca have the most markers of elite status. We had hypothesized that higher-status individuals may have had lifestyles that would place them at a higher risk for atherogenesis. There seems to be some indication of this within the site of Huallamarca, but it is inconclusive in the other 2 archeological sites. It is possible that a larger sample size in the future could reveal more statistically significant results.
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Arqueologia , Aterosclerose , Rituais Fúnebres , Múmias , Classe Social , Adulto , Criança , Pré-Escolar , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Peru , Adulto JovemRESUMO
BACKGROUND: Atherosclerosis is thought to be a disease of modern human beings and related to contemporary lifestyles. However, its prevalence before the modern era is unknown. We aimed to evaluate preindustrial populations for atherosclerosis. METHODS: We obtained whole body CT scans of 137 mummies from four different geographical regions or populations spanning more than 4000 years. Individuals from ancient Egypt, ancient Peru, the Ancestral Puebloans of southwest America, and the Unangan of the Aleutian Islands were imaged. Atherosclerosis was regarded as definite if a calcified plaque was seen in the wall of an artery and probable if calcifications were seen along the expected course of an artery. FINDINGS: Probable or definite atherosclerosis was noted in 47 (34%) of 137 mummies and in all four geographical populations: 29 (38%) of 76 ancient Egyptians, 13 (25%) of 51 ancient Peruvians, two (40%) of five Ancestral Puebloans, and three (60%) of five Unangan hunter gatherers (p=NS). Atherosclerosis was present in the aorta in 28 (20%) mummies, iliac or femoral arteries in 25 (18%), popliteal or tibial arteries in 25 (18%), carotid arteries in 17 (12%), and coronary arteries in six (4%). Of the five vascular beds examined, atherosclerosis was present in one to two beds in 34 (25%) mummies, in three to four beds in 11 (8%), and in all five vascular beds in two (1%). Age at time of death was positively correlated with atherosclerosis (mean age at death was 43 [SD 10] years for mummies with atherosclerosis vs 32 [15] years for those without; p<0·0001) and with the number of arterial beds involved (mean age was 32 [SD 15] years for mummies with no atherosclerosis, 42 [10] years for those with atherosclerosis in one or two beds, and 44 [8] years for those with atherosclerosis in three to five beds; p<0·0001). INTERPRETATION: Atherosclerosis was common in four preindustrial populations including preagricultural hunter-gatherers. Although commonly assumed to be a modern disease, the presence of atherosclerosis in premodern human beings raises the possibility of a more basic predisposition to the disease. FUNDING: National Endowment for the Humanities, Paleocardiology Foundation, The National Bank of Egypt, Siemens, and St Luke's Hospital Foundation of Kansas City.
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Aterosclerose/história , Múmias/patologia , Adulto , Fatores Etários , Alaska/etnologia , Aterosclerose/etnologia , Egito/etnologia , Feminino , História do Século XV , História do Século XVI , História do Século XVII , História do Século XVIII , História do Século XIX , História do Século XX , História Antiga , História Medieval , Humanos , Masculino , Peru/etnologia , Sudoeste dos Estados Unidos/etnologia , Tomografia Computadorizada por Raios X , Calcificação Vascular/etnologia , Calcificação Vascular/históriaRESUMO
The Tsimane of lowland Bolivia are an indigenous forager-farmer population living under conditions resembling pre-industrial European populations, with high infectious morbidity, high infection and inflammation, and shortened life expectancy. Analysis of 917 persons ages 5 to 60+ showed that allele frequencies of 9 SNPs examined in the apolipoprotein E (apoE), C-reactive protein (CRP), and interleukin-6 (IL-6) genes differed from some European, African, and north Asian-derived populations. The apoE2 allele was absent, whereas four SNPs related to CRP and IL-6 were monomorphic: CRP (rs1800947, rs3093061, and rs3093062) and IL-6 (rs1800795). No significant differences in apoE, CRP, and IL-6 variants across age were found CRP levels were higher in carriers of two CRP proinflammatory SNPs, whereas they were lower in carriers of apoE4. Taken together the evidence for (1) different allele frequencies between the Tsimane and other populations and (2) the correlations of CRP and apoE alleles with blood CRP may suggest that these variants are under selection in response to a high infection environment.
Assuntos
Apolipoproteínas E/genética , Proteína C-Reativa/genética , Doenças Transmissíveis/etnologia , Doenças Transmissíveis/genética , Indígenas Sul-Americanos/genética , Interleucina-6/genética , Adolescente , Adulto , Apolipoproteínas E/sangue , Bolívia/epidemiologia , Proteína C-Reativa/metabolismo , Estudos de Casos e Controles , Criança , Pré-Escolar , Feminino , Predisposição Genética para Doença/genética , Humanos , Interleucina-6/sangue , Análise dos Mínimos Quadrados , Expectativa de Vida/etnologia , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Polimorfismo de Nucleotídeo ÚnicoRESUMO
OBJECTIVES: Little is known about blood cholesterol (blood-C) levels under conditions of infection and limited diet. This study examines blood-C and markers of infection and inflammation in the Tsimane of the Bolivian Amazon, indigenous forager farmers living in conditions that model preindustrial European populations by their short life expectancy, high load of infections and inflammation, and limited diets. METHODS: We use multivariate models to determine the relationships between lipid levels and markers of infection and inflammation. Adult Tsimane (N = 418, age 20-84) were characterized for blood lipids, cells, and inflammatory markers in relation to individual loads of parasites and village region. RESULTS: Most of the Tsimane (60%) carried at least one parasite species, averaging 1.3 species per person. Serum high-density lipoprotein cholesterol (HDL-C), total cholesterol (total-C), and low-density lipoprotein cholesterol (LDL-C) were below the U.S. norms and varied inversely with markers of infection and inflammation: C-reactive protein (CRP), interleukin-6 (IL-6), erythrocyte sedimentation rate (ESR), immunoglobulin (Ig) E and eosinophil count. Although no relationship of parasite load to blood-C was found, there was an association between anemia and parasite prevalence. CONCLUSIONS: We conclude that the highly infected environment of the Tsimane is related to low levels of blood total-C, HDL-C, and LDL-C. This may suggest a potential reason why arterial disease is largely absent in the Tsimane.
Assuntos
Indígenas Sul-Americanos , Lipídeos/sangue , Doenças Parasitárias/etnologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Biomarcadores/sangue , Pesos e Medidas Corporais , Bolívia/epidemiologia , Feminino , Inquéritos Epidemiológicos , Humanos , Inflamação/sangue , Masculino , Pessoa de Meia-Idade , Doenças Parasitárias/sangue , Fatores SexuaisRESUMO
Humans evolved in a world with high levels of infection resulting in high mortality across the life span and few survivors to advanced ages. Under such conditions, a strong acute-phase inflammatory response was required for survival; however, inflammatory responses can also promote chronic diseases of aging. We hypothesize that global historical increases in life span at older ages are partly explained by reduced lifetime exposure to infection and subsequent inflammation. To begin a test of this hypothesis, we compare C-reactive protein (CRP); levels in two populations with different epidemiological environments: the Tsimane of Bolivia and persons in the United States. High CRP is significantly more prevalent among the Tsimane up through middle age; by age 35, the Tsimane have spent more years with high CRP than have Americans at age 55. Further testing of the links among infection, inflammation, and chronic diseases of aging among the Tsimane requires collection of age-specific indicators of atherosclerosis and cardiac function.