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1.
Sci Rep ; 9(1): 18085, 2019 12 02.
Artículo en Inglés | MEDLINE | ID: mdl-31792241

RESUMEN

Age-related cognitive decline (ACD) is the gradual process of decreasing of cognitive function over age. Most genetic risk factors for ACD have been identified in European populations and there are no reports in admixed Latin American individuals. We performed admixture mapping, genome-wide association analysis (GWAS), and fine-mapping to examine genetic factors associated with 15-year cognitive trajectory in 1,407 Brazilian older adults, comprising 14,956 Mini-Mental State Examination measures. Participants were enrolled as part of the Bambuí-Epigen Cohort Study of Aging. Our admixture mapping analysis identified a genomic region (3p24.2) in which increased Native American ancestry was significantly associated with faster ACD. Fine-mapping of this region identified a single nucleotide polymorphism (SNP) rs142380904 (ß = -0.044, SE = 0.01, p = 7.5 × 10-5) associated with ACD. In addition, our GWAS identified 24 associated SNPs, most in genes previously reported to influence cognitive function. The top six associated SNPs accounted for 18.5% of the ACD variance in our data. Furthermore, our longitudinal study replicated previous GWAS hits for cognitive decline and Alzheimer's disease. Our 15-year longitudinal study identified both ancestry-specific and cosmopolitan genetic variants associated with ACD in Brazilians, highlighting the need for more trans-ancestry genomic studies, especially in underrepresented ethnic groups.


Asunto(s)
Envejecimiento , Disfunción Cognitiva/genética , Polimorfismo de Nucleótido Simple , Factores de Edad , Anciano , Brasil/epidemiología , Cognición , Disfunción Cognitiva/etiología , Estudios de Cohortes , Femenino , Estudios de Seguimiento , Predisposición Genética a la Enfermedad , Estudio de Asociación del Genoma Completo , Humanos , Masculino , Persona de Mediana Edad
2.
J Allergy Clin Immunol ; 125(2): 336-346.e4, 2010 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-19910028

RESUMEN

BACKGROUND: Asthma is a complex disease characterized by striking ethnic disparities not explained entirely by environmental, social, cultural, or economic factors. Of the limited genetic studies performed on populations of African descent, notable differences in susceptibility allele frequencies have been observed. OBJECTIVES: We sought to test the hypothesis that some genes might contribute to the profound disparities in asthma. METHODS: We performed a genome-wide association study in 2 independent populations of African ancestry (935 African American asthmatic cases and control subjects from the Baltimore-Washington, DC, area and 929 African Caribbean asthmatic subjects and their family members from Barbados) to identify single-nucleotide polymorphisms (SNPs) associated with asthma. RESULTS: A meta-analysis combining these 2 African-ancestry populations yielded 3 SNPs with a combined P value of less than 10(-5) in genes of potential biologic relevance to asthma and allergic disease: rs10515807, mapping to the alpha-1B-adrenergic receptor (ADRA1B) gene on chromosome 5q33 (3.57 x 10(-6)); rs6052761, mapping to the prion-related protein (PRNP) gene on chromosome 20pter-p12 (2.27 x 10(-6)); and rs1435879, mapping to the dipeptidyl peptidase 10 (DPP10) gene on chromosome 2q12.3-q14.2. The generalizability of these findings was tested in family and case-control panels of United Kingdom and German origin, respectively, but none of the associations observed in the African groups were replicated in these European studies. Evidence for association was also examined in 4 additional case-control studies of African Americans; however, none of the SNPs implicated in the discovery population were replicated. CONCLUSIONS: This study illustrates the complexity of identifying true associations for a complex and heterogeneous disease, such as asthma, in admixed populations, especially populations of African descent.


Asunto(s)
Asma/genética , Población Negra/genética , Predisposición Genética a la Enfermedad/genética , Estudio de Asociación del Genoma Completo , Adulto , Negro o Afroamericano/genética , Barbados , Femenino , Genotipo , Humanos , Masculino , Persona de Mediana Edad , Polimorfismo de Nucleótido Simple
3.
Ethn Dis ; 9(2): 190-200, Spring-Summer, 1999.
Artículo en Inglés | MedCarib | ID: med-1380

RESUMEN

The prevalence of type 2 diabetes, impaired glucose tolerance and associated risk factors were compared in sample surveys in Africa and the Caribbean with the Third National Health and Nutrition Survey (NHANES-III) from the United States. A total of 856 Nigerians, 1286 Jamaicans, and 1827 US blacks were included in the study. Body mass index (BMI) increased in a stepwise fashion across the three population groups, ie, 23 kg/m2 in Nigerians, 26 kg/m2 in Jamaicans, and 28 kg/m2 in US blacks. The persons aged 25-74, were 1 percent, 12 percent, 13 percent. Jamaican women were found to have the same prevalence of type 2 diabetes as US women (14 vs 13 percent, respectively); mean BMI was likewise very similar (28 kg/m2 in Jamaican and 29 kg/m2 in US women). BMI and waist-to-hip ratio were both associated with type 2 diabetes prevalence. Findings of this study confirm the marked gradient in type 2 diabetes risk among these genetically related populations and suggest that the blacks in the island nations of the Caribbean and the United States are at particularly high risk. Nigerians exhibited remarkably well-preserved glucose tolerance. Understanding the factors that limit the risk of type 2 diabetes in West Africa, beyond relative absence of obesity, would have considerable public health significance.(Au)


Asunto(s)
Adulto , Anciano , Femenino , Humanos , Masculino , Persona de Mediana Edad , Negro o Afroamericano/estadística & datos numéricos , Índice de Masa Corporal , Diabetes Mellitus Tipo 2/etnología , Intolerancia a la Glucosa/etnología , Biometría , Distribución de Chi-Cuadrado , Jamaica/epidemiología , Nigeria/epidemiología , Oportunidad Relativa , Prevalencia , Análisis de Regresión , Factores de Riesgo , Estados Unidos/epidemiología
4.
Diabetes Care ; 21(11): 1836-42, Nov. 1998.
Artículo en Inglés | MedCarib | ID: med-1419

RESUMEN

OBJECTIVE: Prior studies have supported that waist circumference correlates better with visceral adipose tissue and is a better predictor of cardiovascular disease than are BMI and waist-to-hip ratio. In this study, we reexamine the role of waist size on the risk of hypertension and type 2 diabetes in African-origin populations from three contrasting environments. RESEARCH DESIGN AND METHODS: A cross-sectional survey was conducted of 5,042 men and women 25-74 years of age from Nigeria, Jamaica, and the U.S. The relationship between waist, blood pressure, and fasting blood glucose was assessed using multiple linear regression analyses. Logistic regression analyses using sex-specific empirical waist cut-points were used to determine the risks of hypertension and type 2 diabetes. RESULTS: Waist circumference was positively correlated with blood pressure and fasting blood glucose (P < 0.05). Increasing waist quartiles were significantly associated with higher risks of hypertension in the three populations, as estimated from age-adjusted odds ratios obtained from sex-specific logistic regression models. A highly elevated risk of type 2 diabetes-10-fold for Jamaican men and 23-fold for African-American women - was observed in the comparison of lowest to highest quartiles of waist circumference. CONCLUSIONS: Substantial reduction in hypertension and diabetes in men and women is achievable if the waist size is decreased in these populations. Intervention programs designed to reduce waist circumference through lifestyle modification, including exercise and diet, may have significant public health significance in reducing the incidence of hypertension and adult-onset diabetes in these populations (Au)


Asunto(s)
Adulto , Femenino , Humanos , Masculino , Persona de Mediana Edad , Anciano , Composición Corporal/fisiología , Diabetes Mellitus Tipo 2/etnología , Diabetes Mellitus Tipo 2/epidemiología , Hipertensión/etnología , Hipertensión/epidemiología , Negro o Afroamericano/estadística & datos numéricos , Glucemia/análisis , Enfermedades Cardiovasculares/complicaciones , Enfermedades Cardiovasculares/etnología , Estudios Transversales , Jamaica/epidemiología , Nigeria/epidemiología , Factores de Riesgo , Factores Sexuales , Estados Unidos/epidemiología
5.
Am J Clin Nutr ; 67(3): 391-6, Mar., 1998.
Artículo en Inglés | MedCarib | ID: med-1610

RESUMEN

The role of leptin in humans remains controversial. Leptin concentrations are highly correlated with body fat stores. We tested whether or not this relation was consistent across the range of body composition encompassing the lean as well as the obese. Individuals participating in community-based comparative research in Nigeria (n = 363), Jamaica (n = 372), and the United States (Maywood, IL; n = 699) had their plasma leptin concentrations and body compositions (with bioelectrical impedance analysis) measured. All participants identified themselves as being black. Body mass index (in KG/m2) ranged from across populations for both men and women in Nigeria, Jamaica, and the United States, respectively (men: 2.8, 3.9, and 6.8 microg/L; women: 10.3, 18.6, and 27.7 microg/L). An exponential function fit the relation between percentage body fat or total fat mass and leptin for men and women at each site. For women and men the exponential function with either percentage body fat or total fat mass was of the same shape, but increased by a constant in women, yielding higher leptin concentrations than in men at every level of body fat. On the basis of this broad distribution of body composition, the data suggest an exponential response of leptin to increase in body fat stores, consistent with the development of leptin resistance in individuals developing obesity. These findings likewise confirm that men and women exhibit different set points in terms of leptin production(AU)


Asunto(s)
Adulto , Estudio Comparativo , Femenino , Humanos , Masculino , Persona de Mediana Edad , Proteínas/metabolismo , Composición Corporal , Tejido Adiposo , Jamaica/etnología , Nigeria/etnología , Estados Unidos/etnología
6.
Am J Hypertens ; 10((7 pt 1)): 804-12, July, 1997.
Artículo en Inglés | MedCarib | ID: med-1949

RESUMEN

The excess of hypertension among blacks has been recognized since early in this century and explains a substantial portion of the black health disadvantage. In a cohort study begun in the 1970s, hypertension accounted for 20 percent of all-cause mortality among blacks, compared to 10 percent among whites. National data on trends in hypertension (140/90 mm Hg or treatment) prevalence from 1960 to 1990 suggest a decline from 44 percent to 32 percent, although differences in survey technique likely account for this pattern. During this period the prevalence ratio of black:white remained constant at 1.5, suggesting that secular trends in causal factors, if any, effected both groups equally. Recent data demonstrated a gradient in risk across the African diaspora, with standardized prevalence of 14 percent in West Africa and 26 percent in the Caribbean, compared to 33 percent in the US. This pattern parallels the gradient in known risk factors, with obesity alone accounting for a third of the excess in the US compared to Africa. Why the black excess of hypertension in the US?. Despite widespread speculation, unique characteristics of hypertension among blacks have yet to be established. Consistent evidence demonstrates a similar impact of the known risk factors in all population groups. Epidemiologic evidence likewise suggests that a similar risk of complications exists with blood pressure elevation among blacks and whites, level for level. Although the genetic epidemiology of hypertension is still in its infancy, no clear cross-population differences are yet apparent. Pathophysiologic traits that are known to be part of the casual etiologic pathway have not been shown to vary across groups. Unique features of this condition among blacks are likely to be restricted to the different mixes and intensities of risk factors. In the absence of evidence to support the hypothesis, it is perhaps surprising that credence continues to be given to the notion of black exceptionalism.(AU)


Asunto(s)
Humanos , Hipertensión/epidemiología , Hipertensión/genética , Estados Unidos/epidemiología
7.
Am J Epidemiol ; 145(7): 620-8, Apr. 1, 1997.
Artículo en Inglés | MedCarib | ID: med-2030

RESUMEN

Body mass index (BMI) is the most commonly used measure of obesity. Recently, some investigators have advocated direct measurement of adiposity rather than use of the BMI. This study was undertaken to determine the ability of BMI to predict body fat levels in three populations of West Africa heritage living in different environments. A total of 1,054 black men and women were examined in Nigeria, Jamaica, and the United States during 1994 and 1995. A standardized protocol was used to measure height, weight, waist and hip circumferences, and blood pressure at all sites; percentage of body fat was estimated using bioelectrical impedance analysis. Percentage of body fat and BMI were highly correlated within site- and sex-specific groups, and the resulting r2 ranged from 0.61 to 0.85. The relation was quadratic in all groups except Nigerian men, in whom it was linear. The regression coefficients were similar across sites, yet the mean body fat levels differed significantly (p < 0.001) as estimated by the intercept, making intersite comparison difficult. Compared with BMI, percentage of body fat was not a better predictor of blood pressure or waist or hip circumference.(AU)


Asunto(s)
Adulto , Estudio Comparativo , Femenino , Humanos , Masculino , Persona de Mediana Edad , Índice de Masa Corporal , Obesidad/epidemiología , Composición Corporal , Análisis por Conglomerados , Impedancia Eléctrica , Jamaica/epidemiología , Modelos Lineales , Nigeria/epidemiología , Distribución por Sexo , Distribución por Edad , Estados Unidos/epidemiología
8.
Diabetes Care ; 20(3): 343-8, Mar. 1997.
Artículo en Inglés | MedCarib | ID: med-2015

RESUMEN

OBJECTIVES: Rates of non-insulin-dependent diabetes mellitus have risen sharply in recent years among blacks in the U.S. and the U.K. Increase in risk have likewise been observed in the island nations of the Caribbean and in urban West Africa. To date, however, no systematic comparison of the geographic variation of NIDDM among black populations have been undertaken. RESEARCH DESIGN AND METHODS: In the course of an international collaborative study on cardiovascular disease, we used a standardized protocol to determine the rates of NIDDM and associated risk factors in populations of the African diaspora. Representative samples were drawn from sites in Nigeria, St. Lucia, Barbados, Jamaica, the United States, and the United Kingdom. A total of 4,823 individuals aged 25-74 years were recruited, all sites combined. RESULTS: In sharp contrast to a prevalence of 2 percent in Nigeria, age-adjusted prevalences of self-reported NIDDM were 9 percent in the Caribbean and 11 percent in the U.S. and the U.K. Mean BMI ranged from 22 kg/m2 among men in West Africa to 31 kg/m2 in women in the U.S. Disease prevalence across sites was essentially collinear with obesity, pointing to site differences in the balance between energy intake and expenditure as the primary determinant of differential NIDDM risk among these populations. CONCLUSIONS: In ethnic groups sharing a common genetic ancestry, these comparative data demonstrate the determing influence of changes in living conditions on the population risk of NIDDM.(AU)


Asunto(s)
Adulto , Anciano , Estudio Comparativo , Femenino , Humanos , Masculino , Persona de Mediana Edad , Diabetes Mellitus Tipo 2/epidemiología , Índice de Masa Corporal , Diabetes Mellitus Tipo 2/etnología , Diabetes Mellitus Tipo 2/genética , Factores de Edad , África Occidental/etnología , Constitución Corporal , Reino Unido/epidemiología , Nigeria/epidemiología , Prevalencia , Factores de Riesgo , Distribución por Sexo , Estados Unidos/epidemiología , Indias Occidentales/epidemiología
9.
Am J Public Health ; 87(2): 160-8, Feb. 1997.
Artículo en Inglés | MedCarib | ID: med-1990

RESUMEN

OBJECTIVE: This study was undertaken to describe the distribution of blood pressures, hypertension prevalence, and associated risk factors among seven populations of West African origin. METHODS: The rates of hypertension in West Africa (Nigeria and Cameroon), the Caribbean (Jamaica, St. Lucia, Barbados), and the United States (metropolitan Chicago, Illinois) were compared on the basis of a highly standardized collaborative protocol. After researchers were given central training in survey methods, population-based samples of 800 to 2500 adults over the age of 25 were examined in seven sites, yielding a total sample of 10014. RESULTS: A consistent gradient of hypertension prevalence was observed, rising from 16 percent in West Africa to 26 percent in the Caribbean and 33 percent in the United States. Mean blood pressures were similar among persons aged 25 to 34, while the increase in hypertension prevalence with age was twice as steep in the United States as in Africa. Environmental factors, most notably obesity and the intake of sodium and potassium, varied consistently with disease prevalence across regions. CONCLUSION: The findings demonstrate the determining role of social conditions in the evolution of hypertension risk in these populations.(AU)


Asunto(s)
Adulto , Estudio Comparativo , Femenino , Humanos , Masculino , Persona de Mediana Edad , Hipertensión/etnología , Salud Urbana , Factores Sexuales , Salud Rural , Factores de Riesgo , Prevalencia , Nigeria/epidemiología , Comparación Transcultural , Región del Caribe/epidemiología , Camerún/epidemiología , Presión Arterial , Distribución por Edad
10.
Am J Hypertens ; 10(5 part 1): 519-24, 1997.
Artículo en Inglés | MedCarib | ID: med-1980

RESUMEN

An insertion/deletion (I/D) polymorphism of the angiotensin I converting enzyme gene influences the level of serum angiotensin converting enzyme activity and has been associated with risk of several cardiovascular conditions. The relationship to blood pressure remains uncertain, however. We conducted a population-based survey in Kingston, Jamaica, to examine the association between angiotensin converting enzyme genotype, angiotensin converting enzyme serum activity and blood pressure. Serum angiotensin converting enzyme activity was measured and genotyping performed for the I/D polymorphism in 500 community residents. The overall prevalence of the D allele was 59.3 percent. Angiotensin converting enzyme genotype was not significantly related to blood pressure (P - 16), although it did influence angiotensin-converting enzyme activity, leading to an increase of 35 percent among individuals with the DD as compared with II genotype. Angiotensin converting enzyme levels were significantly higher in hypertensives as compared with normotensives (P < .05). A modest correlation was observed between blood pressure and angiotensin converting enzyme activity among untreated individuals (r = 0.11; P = .04), although this did not persist in multivariate analysis. A relationship between body mass index and angiotensin converting enzyme activity was identified in both men and women that was independent of genotype. These data demonstrated findings among blacks which are consistent with other studies and suggest a relationship between angiotensin converting enzyme genotype, and serum activity which is influenced by both genetic and environmental factors. The potential role of ACE on blood pressure control in the population remains uncertain.(AU)


Asunto(s)
Adulto , Anciano , Femenino , Humanos , Masculino , Persona de Mediana Edad , Presión Arterial/genética , Hipertensión/etnología , Obesidad/fisiopatología , Peptidil-Dipeptidasa A/genética , Sistema Renina-Angiotensina/fisiología , Presión Arterial/fisiología , Hipertensión/etiología , Jamaica , Análisis Multivariante , Peptidil-Dipeptidasa A/metabolismo
11.
J Hypertens ; 14(4): 495-501, Apr. 1996.
Artículo en Inglés | MedCarib | ID: med-2992

RESUMEN

Cardiovascular diseases represent the most common cause of death in the English-speaking Caribbean, and hypertension represents the most important predisposing condition. However, direct between-country comparative studies in the Caribbean have not previously been undertaken. OBJECTIVE: To obtain estimates of hypertension prevalence, awareness, treatment and control in three countries in the Caribbean. DESIGN: Population-based samples of adults aged 25-74 years in St. Lucia, Barbados and Jamaica were surveyed regarding their cardiovascular health and their blood pressures were measured using a highly standardized protocol. A reference site was available from a collaborative study among blacks in metropolitan Chicago, Illinois, USA, RESULTS: At the 160/95 mmHg threshold, age-adjusted hypertension prevalence estimates for Jamaica, St. Lucia and Barbados were 17.5, 18.3 and 21.5 percent, respectively, and 24.7, 26.9 and 27.9 percent, respectively, at the 140/90 mmHg threshold. The corresponding estimate for the Chicago site at the 140/90 mmHg threshold was 33.2 percent. The gradient in prevalence resembled the gradient in body mass index (25.7 kg/m2 in Jamaica to 29.3 kg/m2 in the USA). At the 160/95 mmHg threshold, the proportion of all hypertensives who were aware of their disease, pharmacologically treated and controlled was highest in Barbados (90, 85 and 72 percent, respectively) and lowest in St. Lucia (74, 59 and 35 percent respectively). Men, particularly those aged less than 55 years, were less likely to have their hypertension treated and controlled. CONCLUSIONS: Compared with estimates from earlier independent surveys, considerable progress has been made in hypertension detection and control in these countries, which should lead to sizable reductions in the burden of cardiovascular disease (AU)


Asunto(s)
Humanos , Adulto , Anciano , Femenino , Masculino , Persona de Mediana Edad , Hipertensión/epidemiología , Barbados/epidemiología , Jamaica/epidemiología , Estados Unidos/epidemiología , Prevalencia , Hipertensión/prevención & control , Hipertensión/terapia
12.
West Indian med. j ; West Indian med. j;45(suppl. 2): 15, Apr. 1996.
Artículo en Inglés | MedCarib | ID: med-4655

RESUMEN

The distribution of two proposed candidate genes for hypertension (HTN), the insertion/deletion (I/D) polymorphism of the angiotensin converting enzyme (ACE) and the M235 and T174 variants of the angiotensin gene (AGT) as well as an AGT-associated micro satellite (GT) were studied in populations in Ibadan, Nigeria (n = 135), Chicago, USA (n = 223) and Kingston, Jamaica (n = 500). Participants were recruited during on-going house-to-house surveys of the prevalence of hypertension in the three populations. Frequency of the D allele was similar (54 percent, Nigeria; 63 percent, USA and 59 percent, Jamaica). The 235T and 174M alleles were more common in Nigerians than among American and Jamaican blacks (93 vs 81 percent, respectively). The distribution of the GT repeats was consistent in the three groups with the '-4' and '-10' marker being the most common. The lower frequency of 235T allele in the US and Jamaica compared to Nigeria (at rates significantly higher than in whites) is consistent with 25 percent in European and Japanese populations. Overall, there was not much variation at the RAS loci, yet there are large differences in hypertension prevalence, 15 percent for men and women in Nigeria, 20 percent and 30 percent in Jamaican and US men, respectively (rates were higher for women in these groups). These results show that despite a common genetic background there are different rates of hypertension and argue strongly for a role for the environment in the aetiology of hypertension (AU)


Asunto(s)
Humanos , /genética , Hipertensión/genética , Nigeria , Jamaica , Hipertensión/epidemiología
13.
J Hypertens ; 14(3): 315-21, Mar. 1996.
Artículo en Inglés | MedCarib | ID: med-2993

RESUMEN

OBJECTIVE: To examine the association between blood pressure, angiotensinogen levels, angiotensin converting enzyme activity and polymorphisms of the angiotensinogen and angiotensin converting enzyme genes in a population-based sample. METHOD: Five hundred participants were recruited in a house-to-house survey of three communities in metropolitan areas of Kingston and St. Andrew, in Jamaica. Demographic data, anthropometric and blood pressure measurements were obtained for each participant during a brief clinic visit. Circulating levels of angiotensinogen and angiotensin converting enzyme genes were determined. RESULTS: A weak association between angiotensinogen level, angiotensin converting enzyme activity and blood pressure was identified in this population, but substantial joint effect of angiotensin converting enzyme activity and agiotensinogen level on blood pressure was apparent. Variants of the angiotensinogen gene had inconsistent effects on blood pressure and on the risk of hypertension. Angiotensinogen level and angiotensin converting enzyme activity were significantly related to several measures of obesity, including body mass index, waist circumference and skin fold thickness. CONCLUSION: The angiotensinogen and angiotensin converting enzyme genetic variants which were studied appear to have only a modest relationship with blood pressure and associated anthropometric risk factors among blacks. (AU)


Asunto(s)
Adulto , Humanos , Femenino , Masculino , Persona de Mediana Edad , Anciano , Angiotensina II , Angiotensinógeno/sangre , Presión Arterial , Secuencia de Bases , Hipertensión/genética , Datos de Secuencia Molecular , Peptidil-Dipeptidasa A/sangre , Jamaica
14.
Epidemiol ; 7(4): 398-405, July 1996.
Artículo en Inglés | MedCarib | ID: med-1991

RESUMEN

Obesity has been shown to be associated with hypertension in Africa, the Caribbean, and the United States, but there has not previously been an opportunity to compare the magnitude of this relation and estimate the contribution of obesity to hypertension risk across these populations. The International Collaborative Study on Hypertension in Blacks (ICSHIB) used age-stratified sampling and a standardized protocol to measure blood pressure and hypertension risk factors. We analyzed data on 9,102 men and women, aged 25-74 years, from seven sites. We studied hypertension (140/90 mmHg or medication) in relation to body mass index (BMI) and sex-specific BMI cutpoints designating "overweight" and "obesity". The prevalence of these conditions ranged from 6 percent to 63 percent for overweight, from 1 percent to 36 percent for obesity, and from 12 percent to 35 percent for hypertension. Adjusted relative risks were similar in most sites, ranging form 1.3 to 2.3 for both cutpoints. We found that 6-29 percent of hypertension in each population was attributable to overweight and 0-16 percent to obesity. Comparing rural Africa with the United States, 43 percent of the difference in hypertension prevalence for women was attributable to overweight, and 22 percent for men, whereas respective values for obesity were 14 percent and 11 percent. These results indicate that the association between adiposity and hypertension is roughly constant across a range of environments, with little evidence for variation in susceptibility to effects of overweight in these groups.(AU)


Asunto(s)
Adulto , Anciano , Estudio Comparativo , Femenino , Humanos , Masculino , Persona de Mediana Edad , Hipertensión/etnología , Obesidad/etnología , África/epidemiología , Presión Arterial , Índice de Masa Corporal , Región del Caribe/epidemiología , Estudios Transversales , Hipertensión/fisiopatología , Obesidad/fisiopatología , Oportunidad Relativa , Prevalencia , Análisis de Regresión , Factores de Riesgo , Estados Unidos/epidemiología
15.
J Clin Epidemiol ; 49(8): S69-S77, 1996.
Artículo en Inglés | MedCarib | ID: med-1992

RESUMEN

In the context of a collaborative study of hypertension in populations of West Africa origin procedures of standardization on the measurement of blood pressure were evaluated. Comparisons of means levels of blood pressure, which in large part determine prevalence rates, are highly sensitive to differences in technique. While rotating a single field team may be the ideal approach to multisite studies, it is not practical in international collaborative research. Appropriate techniques to standardize multiple teams over a long period of time have not been developed, however. In the present study 8981 individuals were examined in eight sites in six countries with the standard mercury sphygmomanometer. An evaluation of the effectiveness of central training, site visits, monitoring of digit preference, and the use of an electronic device for internal standardization is described. In all but one of the sites reliability was high and comparable to the observers at the Coordinating Center. Digit preference for the entire set of measurements was limited (frequency of terminal zero = 23.5 percent for systolic and 28.9 percent for diastolic readings) and could be shown to have virtually no effect on prevalence rates on correlation estimates. Mean differences among observers within a given site and between sites were small (ñ-5 mmHg). While logistically complex, these methods can provide the basis for standardization in international comparative blood pressure surveys.(AU)


Asunto(s)
Adulto , Anciano , Femenino , Humanos , Masculino , Persona de Mediana Edad , Determinación de la Presión Sanguínea/normas , Hipertensión/epidemiología , Monitores de Presión Sanguínea , Vigilancia de la Población , Factores de Riesgo
16.
Hypertension ; 27(part 2): 558-63, 1996.
Artículo en Inglés | MedCarib | ID: med-1996

RESUMEN

Within the context of an international collaborative study of the evolution of hypertension in the black disapora, we determined the allelic distribution of hypertension candidate genes for the renin-angiotensin system in three populations of African origin. The insertion/deletion (I/D) polymorphism of the angiotensin-converting enzyme (ACE) and the M235T and T174M variants of the angiotensinogen (AGT) gene were examined in individuals from Nigeria, Jamaica, and the United States. Large differences in the prevalence of hypertension were recorded in door-to-door surveys, ranging from 16 percent in Nigeria to 33 percent in the United States. The frequency of the D allele was similar in all groups (54 percent, 59 percent and 63 percent in Nigeria, Jamaica, and the United States, respectively). The 235T allele of the AGT gene was found in 81 percent of US and Jamaican blacks and 91 percent of Nigerians: very little variation was seen for the T174M marker. Despite larger differences in hypertension rates, genetic variation at the index loci among these groups was modest. Overall, the frequency of the ACE D allele was only slightly higher than that reported for European and Japanese populations, whereas the AGT 235T allele was twice as common. Compared with blacks in the western hemisphere. Nigerians had a higher frequency of the 235T allele, which is consistent with 25 percent European admixture in Jamaica and the United States. The results indicate the potential for etiolgic heterogeneity in genetic factors related to hypertension across the ethnic groups while suggested that environmental exposures most likely explain the gradient in risk in the comparison among black populations.(AU)


Asunto(s)
Angiotensinógeno/genética , Hipertensión/genética , Peptidil-Dipeptidasa A/genética , Alelos , Negro o Afroamericano , Hipertensión/etnología , Jamaica/etnología , Nigeria/etnología , Polimorfismo Genético , Estados Unidos/etnología
17.
Ethn Dis ; 3: 404-11, 1993.
Artículo en Inglés | MedCarib | ID: med-4781

RESUMEN

A stratified random sample of 464 persons aged 40 ato 79 years, drawn from enumeration registers in the Bridgetown area of Barbados, participated in this survey. The prevalence of hypertension (defined as systolic blood pressure of at least 160mm Hg, diastolic blood pressure of at least 95 mm Hg, or use of antihypertensive medication) was 47 percent and 43 percent for women and men, respectively. Diabetes was present in 17 percent of all subjects (18 percent of women and 15 percent of men). Of the 209 hypertensive subjects, 82 percent were aware of their blood pressure status. The proportion of previously diagnosed hypertensive subjects on medication was 72 percent for men and 68 percent for women. Fifty-three percent of men and 42 percent of women were overweight (body mass indices [weight in kilograms divided by height in meters squared] between 25 and 30. However, 30 percent of women and 10 percent of men were obese (body mass indices over 30), supporting the growing recognition of the marked gender disparity in obesity among persons of African origin in the Caribbean. Body mass index was positively associated with hypertension (OR=1.33; 95 percent CI: 1.1-1.6). Obese persons experienced a 2.6 times greater risk of hypertension compared to those with body mass indices below 25. Similar statistically significant associations were observed between diabetes and body mass index: Or comparing body mass index over 30 with body mass index under 25 was 2.5 (95 percent CI: 1.3-5.1) for all subjects, 1.0 (0.3-4.1) for men only, and 5.2 (1.9-14) for women only. Preventing obesity in this population could reduce the incidence of hypertension and diabetes by approximately 30 percent and 33 percent among men and women, respectively. (Au)


Asunto(s)
Femenino , Humanos , Masculino , Hipertensión/epidemiología , Diabetes Mellitus/epidemiología , Barbados/epidemiología , Presión Arterial , Índice de Masa Corporal , Conductas Relacionadas con la Salud , Hipertensión/complicaciones , Hipertensión/prevención & control , Conocimientos, Actitudes y Práctica en Salud , Prevalencia , Oportunidad Relativa , Diabetes Mellitus/complicaciones , Diabetes Mellitus/prevención & control , Encuestas y Cuestionarios , Factores de Riesgo , Persona de Mediana Edad , Anciano , Adulto
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