Arterial stiffness in black adults from Angola and Brazil.

Ethnicity is an important determinant of blood pressure levels, being black individuals affected more than any other ethnic group. Arterial stiffening, an independent risk factor for hypertension, is also influenced by ethnicity. However, whether black individuals from different continents would have different patterns of arterial stiffening is still unknown. Thus, the authors aimed to compare pulse wave velocity (PWV) in black subjects living in Angola and Brazil. A total of 677 black individuals from two independent cross-sectional studies conducted in Brazil and Angola were included in this analysis. Carotid-to-femoral PWV was measured following the same protocols for both studies, as well as clinical and anthropometric variables. Adjusted PWV was higher in Brazilian blacks than in Angolans, regardless of sex (men from Brazil: 10.7 ± 1.8 vs men from Angola: 9.9 ± 1.8 m/s, P < .001; women from Brazil: 10.3 ± 1.5 vs women from Angola: 9.2 ± 1.3 m/s, P < .001). Although the cf-PWV was higher in Brazilian blacks, the age-related increase in cf-PWV was higher in Angolan men compared to Brazilians, but not in women. SBP showed the strongest association with cf-PWV, regardless of sex and country. However, age was associated with cf-PWV in all groups, except in Brazilian men. Our results clearly show a difference in PWV between two black populations, and highlight for sex differences in the hemodynamic parameters that might affect blood pressure levels in these populations.

Prevalence and Clinical Correlates of Left Ventricular Hypertrophy in Black Africans.

INTRODUCTION: African-Americans present higher prevalence of left ventricular hypertrophy (LVH) when compared with white populations. However, there is a lack of information about the prevalence and determinants of LVH in black individuals living in Africa. METHODS: A cross-sectional study was performed with a non-probabilistic sample comprised of 609 University workers from Angola/Africa, describing the prevalence of LVH and the determinants of left ventricular mass. Echocardiographic measurements were performed and left ventricular mass was indexed to body surface area. Systolic and diastolic blood pressures were measured, along with anthropometric and clinical variables. RESULTS: Chamber diameter and wall thickness were higher in men compared to women. Additionally, LVM was higher in men (114.2 ± 36 vs 98.4 ± 31.9, P < 0.001), and the overall prevalence of LVH in black Angolans was 41.1%, which tended to be higher in women (44.5 vs 37.4%, P = 0.096). In men, systolic blood pressure and BMI were independently associated with LVM, while age, systolic blood pressure and waist circumference were associated with LVM in women. CONCLUSIONS: In summary, blood pressure levels were the main determinants of LVH in black Africans, although different anthropometric variables showed mild influence in LVM. Our data suggests that LVH prevalence and determinants in black Africans are similar to that reported for African-Americans.

Distribution of Serum Uric Acid in Black Africans and Its Association With Cardiovascular Risk Factors.

Hyperuricemia is associated with cardiovascular disease and its prevalence is unknown in black Africans. This study reports hyperuricemia distribution and its association with cardiovascular risk factors in a selected Angolan population. A cross-sectional study in 585 black Africans was performed. Hyperuricemia was defined as uric acid >7.0 mg/dL in men or >5.7 mg/dL in women. Overall prevalence was 25%. Hyperuricemia was associated with hypertension (odds ratio [OR], 2.20; confidence interval [CI], 95% 1.41-3.47), high waist circumference (OR, 1.67; CI, 95% 1.05-2.65), and metabolic syndrome (OR, 1.66; CI, 95% 1.07-2.57). Compared to those with uric acid levels in the first quartile, individuals in the fourth quartile showed higher body mass index, waist circumference, systolic blood pressure, and plasma levels of creatinine and triglycerides. Hypertension, high waist circumference, and metabolic syndrome were the major cardiovascular risk factors associated with hyperuricemia.

Gender-specific determinants of blood pressure elevation in Angolan adults.

BACKGROUND: Hypertension affects African-American adults more than any other ethnic group in the US. However, some of the black populations living outside Africa are well adapted to food and lifestyle. We aimed to describe the clinical characteristics underlying the gender-specific determinants of BP and the risk of hypertension in public-sector workers living in Angola. MATERIALS AND METHODS: 609 volunteers (48% men) were included in this cross-sectional and descriptive study. Demographic, socioeconomic and life style data were collected during an interview. Systolic BP (SBP) and diastolic BP (DBP) were measured, along with some anthropometric and clinical variables. RESULTS: The prevalence of hypertension is 45.2% without difference between genders. Obesity was more prevalent in women (29.2% vs. 8.9%, p < 0.05). The age-related increment in SBP is higher in women (14.2 ± 1.1 vs 9.5 ± 1.3 mmHg/decade, p < 0.05). In men, age, BMI, cholesterol and LDLc/HDLc explained 21, 4, 2.5 and 2.9% of SBP variability, respectively. In women, age, BMI and HC explain 27, 2 and 1% of SBP variability, respectively. The risk for hypertension is 5 × high among men aged ≥45 years, and 3.5× in those having BMI ≥25. Women aged 45 years or older have 8 × risk of hypertension and 2× the risk by having BMI ≥25. CONCLUSIONS: We found that advanced age (≥45) and overweight/obesity (BMI ≥25) are the main risk factors for hypertension in adults from Angola. However, our data suggest that age and BMI may have different influence on increasing BP in men and women.

Cardiovascular risk factors in pre-pubertal schoolchildren in Angola.

METHODS: The incidence of obesity is increasing worldwide, especially in countries with accelerated economic growth. We determined the prevalence of and associations between overweight/obesity and cardiovascular risk factors in pre-pubertal (seven- to 11-year-old) schoolchildren (both genders, n = 198) in Luanda, Angola. Biochemical (fasting blood) and clinical examinations were obtained in a single visit. Data are reported as prevalence (95% confidence intervals) and association (r, Pearson). RESULTS: Prevalence of overweight/obesity was 17.7% (12.4- 23.0%), high blood pressure (BP > 90% percentile) was 14.6% (9.7-19.5%), elevated glucose level was 16.7% (11.5-21.9%) and total cholesterol level > 170 mg/dl (4.4 mmol/l) was 69.2% (62.8-75.6%). Significant associations between body mass index (BMI) and systolic and diastolic BP (r = 0.46 and 0.40, respectively; p < 0.05) were found. No association between BMI and elevated glucose or cholesterol levels was found. CONCLUSION: The prevalence of cardiovascular risk factors was high in pre-pubertal schoolchildren in Angola and fat accumulation was directly associated with blood pressure increase but not with other cardiovascular risk factors.

Predictors and Reference Values of Pulse Wave Velocity in Prepubertal Angolan Children.

Carotid-femoral pulse wave velocity (PWV) has been used as the gold standard method to estimate arterial stiffness. However, its use in clinical practice is still limited because reference values for specific groups, such as black children, remain unknown. The authors aimed to investigate predictors and to propose preliminary reference values of PWV in this population. Prepubertal schoolchildren (N=157; mean age, 9.36±1.41 year) from Luanda (Angola) with normal blood pressure values and without obesity were included. Mean PWV was 5.73±0.68 m/s, with no difference between the sexes. Univariate regression analysis showed a significant (P<.05) positive correlation between PWV and height, age, body weight, lean body weight, and blood pressure. In multivariate analysis, however, only height remained an independent predictor of PWV [PWV=0.018×height (cm)+3.230]. Curves of PWV percentiles as a function of height are proposed, thus identifying normal PWV in black children.

Knowledge, attitude and behaviour regarding dietary salt intake among medical students in Angola.

BACKGROUND: Levels of salt consumption and its awareness among medical students in Angola remain insufficiently studied. This study determined salt intake and assessed medical students' knowledge, attitude and behaviour regarding salt consumption. METHODS: Were collected 24-hour urine samples from a random sample of 123 undergraduate medical students aged 17-43 years who were studying at the University of Agostinho Neto in Luanda. Their knowledge, attitude and behaviour regarding dietary salt were surveyed. Socio-demographic, clinical and anthropometric data were collected. RESULTS: Average salt intake was 14.2 ± 5.1 g/day, without significant difference between genders (p = 0.221). In total, 96.7% consumed over 5 g/day, but only 6.5% of participants were aware of their excessive salt intake. The majority knew about salt-related health consequences and 45.5% reported they controlled their salt intake. CONCLUSIONS: This study indicated a high salt intake and inadequate behaviour regarding dietary salt consumption among medical students studying at the University of Agostinho Neto. This highlights the need for nutritional education to improve their dietary habits and future role in counselling.

Prevalence of the metabolic syndrome and determination of optimal cut-off values of waist circumference in university employees from Angola.

BACKGROUND: Estimates of the prevalence of the metabolic syndrome in Africans may be inconsistent due to lack of African-specific cut-off values of waist circumference (WC). This study determined the prevalence of the metabolic syndrome and defined optimal values of WC in Africans. METHODS: This cross-sectional study collected demographic, anthropometric and clinical data of 615 Universitary employees, in Luanda, Angola. The metabolic syndrome was defined using the third report of the National Cholesterol Education Program Adult Treatment Panel (ATPIII) and the Joint Interim Statement (JIS) criteria. Receiver operating characteristics curves were constructed to assess cut-off values of WC. RESULTS: The crude prevalence of the metabolic syndrome was higher with the JIS definition (27.8%, age-standardised 14.1%) than with the ATP III definition (17.6%, age-standardised 8.7%). Optimal cut-off values of WC were 87.5 and 80.5 cm in men and women, respectively. CONCLUSION: There was a high prevalence of the metabolic syndrome among our African subjects. Our data suggest different WC cut-off values for Africans in relation to other populations.

Prevalence of cardiovascular risk factors and socioeconomic level among public-sector workers in Angola.

BACKGROUND: Cardiovascular diseases are the leading cause of death in the majority of developed and developing countries. African countries are currently facing an increase in both cardiovascular and transmitted diseases. In addition, cardiovascular risk varies among different socioeconomic groups. Thus, we determined the prevalence of modifiable cardiovascular risk factors in apparently healthy public-sector workers and investigated possible relationships with socioeconomic status. METHODS: We employed a cross-sectional study comprising 42.2% (n = 615) of the public-sector workers at Agostinho Neto University, 48% (n = 294) male and 52% (n= 321) female, with ages between 20 and 72 years and from various socioeconomic groups. The study was conducted from February 2009 to December 2010. Personal, anthropometric, biochemical, hemodynamic, socioeconomic, and physical activity data were collected. RESULTS: The prevalence rates of cardiovascular risk factors were as follows: hypertension, 45.2% (men 46.3%, women 44.2%, P > 0.05); hypercholesterolemia, 11.1% (men 10.5%, women 11.5%, P > 0.05); low high-density lipoprotein (HDL) cholesterol, 50.1% (men 36.9%, women 62.3%; P < 0.05); hypertriglyceridemia, 10.6% (men 12.6%, women 8.7%, P > 0.05); smoking, 7.2% (men 10.2%, women 4.4%; P < 0.05); diabetes, 5.7% (men 5.5%, women 5.9%, P > 0.05); overweight, 29.3% (men 27.3%, women 31.2%, P > 0.05); obesity, 19.6% (men 9.2%, women 29.0%; P < 0.05); sedentary lifestyle, 87.2% (men 83.0%, women 91,0%, P < 0.05); and left ventricular hypertrophy, 20% (men 32.0%, women 9.0%; P < 0.05). At least one risk factor was present in 27.7% of the sample; 15.2% had two risk factors, and 31.4% had three or more risk factors. Among the individuals with low socioeconomic status, 41.0% had three or more risk factors. CONCLUSIONS: The results of this study suggest the existence of a high prevalence of multiple risk factors for cardiovascular disease in apparently healthy public-sector workers in Angola. The workers in lower socioeconomic groups had higher incidences of hypertension, smoking, and left ventricular hypertrophy.

Age- and gender-specific reference values of pulse wave velocity for African adults: preliminary results.

Pulse wave velocity (PWV) is an independent predictor of cardiovascular (CV) risk. Higher PWV values have been observed in Africans; however, there are no established age- and gender-adjusted reference values for this population. Therefore, PWV was measured using a validated device (Complior SP) in 544 subjects recruited from an occupational cohort of employees of a public university in Angola. Since high blood pressure (BP) is an important factor influencing PWV, a subsample of 301 normotensive subjects (aged 22-72 years) was selected for this study. A subset of 131 individuals without CV risk factors was considered the healthy group (HG), while the entire group (n = 301) comprised the less healthy group (LHG). Predictors of PWV were evaluated using multiple regression analyses and age- and gender-specific percentile tables and curves were constructed. Age and PWV means were 36 ± 9.7 years and 6.6 ± 1.0 m/s in the HG, respectively, and 39.9 ± 10.2 years and 7.3 ± 1.3 m/s in the LHG. Age and plasma uric acid (UA) were the only significant PWV predictors in the HG, while age, mean BP (MBP), and gender showed significant prediction of PWV in the multiple regression analysis in the LHG. Age- and gender-adjusted reference values of PWV were provided for healthy and less healthy normotensive Africans. Considering the small sample size of our cohort, these preliminary results should be used cautiously until data on robust sample of the general population can be obtained.

Arterial stiffness in lower limb amputees.

BACKGROUND: A high carotid-femoral pulse wave velocity (PWV) has been related to increased cardiovascular morbidity and mortality, but has not been previously evaluated in amputees. The aim of this study was to compare PWV between amputees and nonamputees. METHODS: In this cross-sectional study, data were collected from 60 male lower limb amputees and 86 male age-matched nonamputees. PWV was measured noninvasively using a Complior(®) device. All participants underwent laboratory investigations and anthropometry. The difference in PWV between amputee and nonamputees was estimated. Multivariate regression was used to adjust for differences between the groups as a result of potential confounders. RESULTS: PWV was higher in amputees than in nonamputees (10.8 ± 1.9 m/sec versus 9.9 ± 1.8 m/sec, P = 0.008, respectively). This difference remained even after adjusting for confounding factors. CONCLUSION: A higher PWV was demonstrated in lower limb amputees. Routine assessment of PWV may contribute to cardiovascular risk stratification in amputees.