Ethnic differences in body composition and other markers of cardiovascular disease risk: study in matched Haitian and White subjects from Quebec

Haitian Immigrants and Type 2 Diabetes: An Integrative Review

Type 2 diabetes (T2D) is a complex, lifelong condition that is disproportionately prevalent among minority populations. Haitian immigrants (HIs) living in the US with T2D have unique factors that influence diagnosis, treatment, and self-management. The purpose of this integrative review was to provide a synthesis of the research on T2D in the HI population. In a systematic literature search, 14 studies met the inclusion criteria. Three themes were identified: risk factors for less self-management and/or worse metabolic control; protective factors for better self-management and/or metabolic control; and mixed results. HIs had higher HbA_1c, yet better self-management, different genetic profiles, and lower levels of vitamin D and hemoglobin concentration compared to other ethnic groups. HIs also reported better dietary quality, less healthcare utilization, and higher perceived emotional/psychological stress compared to other ethnic groups. This study has implications for practice for integrating the unique cultural factors when assessing and intervening with HIs.

Optimal waist circumference cut-off points for predicting metabolic syndrome among low-income black South African adults

OBJECTIVE

Waist circumference has been identified as one of the strongest predictive tool for metabolic syndrome. This study determines the optimal cut-off point of waist circumference for metabolic syndrome among low-income earning South African black population, in Eastern Cape, South Africa. The optimal waist circumference cut-off point was determined through receiver operating characteristics analysis using the maximum Youden index.

RESULTS

Among men, waist circumference at a cut-off value of 95.25 cm yielded the highest Youden index of 0.773 (sensitivity = 98%, specificity = 79%, area under curve 0.893). For women, waist circumference of 89.45 cm yielded the highest Youden index of 0.339 (sensitivity = 88%, specificity = 46%, area under curve 0.713). The prevalence of metabolic syndrome among men, women and both sexes using the new cut-off points were: 17.8, 20.8 and 17.7%, respectively, compared to; 15.6, 24.8 and 21.8%, using the traditional cut-off values of 94 and 80 cm for men and women, respectively. The traditional waist circumference value slightly under-estimated the prevalence of metabolic syndrome among men and over-estimated among women and the overall population. A specific waist circumference cut-off point for South African blacks is needed for correct identification of the metabolic state of the populace in order to develop appropriate interventions.

Comparisons of Waist Circumference Measurements at Five Different Anatomical Sites in Chinese Children

This study compared the waist circumference (WC) measurements of Chinese children at different sites to determine the relationship between WC measurements and body fat. WC was measured at five sites in 255 subjects aged 9-19 years: immediately below the lowest rib (WC1), at the narrowest waist (WC2), the midpoint between the lowest rib and the iliac crest (WC3), 1 cm above the umbilicus (WC4), and immediately above the iliac crest (WC5). Body fat mass (FM), body fat percentage (% BF), body fat mass in the trunk (FM in the trunk), and fat percentage in the trunk (% BF in the trunk) were determined by dual-energy X-ray absorptiometry. The WCs were then compared through ANOVA with repeated measurement. The relationship of WC of each site with FM, % BF, FM in the trunk, and % BF in the trunk was examined through partial correlation. The WCs exhibited the following pattern: WC2 < WC1 < WC3 < WC4 < WC5 (p < 0.001) in males and WC2 < WC1 < WC4, WC3 < WC5 (p < 0.001) in females. The measured WCs were strongly correlated with FM, % BF, FM in the trunk, and % BF in the trunk. The WC measurements at five commonly used sites among Chinese children are different from one another. Results indicate that standardizing the anatomic point for the WC measurements is necessary.

Hypertension and aging in rural Haiti: results from a preliminary survey

Cross-sectional studies in the developed countries document strong relationships among age, systolic blood pressure (SBP) and pulse pressure (PP). There is little information about these trends and their impact in underdeveloped countries with different socioeconomic and lifestyle characteristics. We studied a convenience sample of 572 residents of rural Fontaine, Haiti: 193 males and 379 females (mean, s.d.) age 40.2 (17.1) years and performed intake questionnaires and BP measurements in participants' homes. Income and educational achievement were very low but most-recommended lifestyle factors were very favorable: very high physical activity, low dietary fat, virtually no obesity (body mass index 21.8 (4.9)), and low smoking prevalence. Rough estimates of salt intake were high (~13 g per day) as was the overall prevalence of hypertension: 34.4% (23.4% in males, 40.2% in females). SBP and PP were related closely to age (r²=0.28, P<0.001 and r²=0.22, P<0.001); for each decade of age, SBP increased by 7.6 mm Hg. Diastolic BP peaked in the 6th decade (polynomial r²=0.22, P<0.001) and the nadir of PP occurred in the 3rd decade. We conclude that, despite a favorable profile of lifestyle characteristics and no obesity, the prevalence of hypertension and rate of increase in SBP and PP with age in Haiti are at least as high as those of developed countries.

Specific cut-off points for waist circumference and waist-to-height ratio as predictors of cardiometabolic risk in Black subjects: a cross-sectional study in Benin and Haiti

PURPOSE

Waist circumference (WC) and waist-to-height ratio (WHtR) are widely used as indicators of abdominal adiposity and the cut-off values have been validated primarily in Caucasians. In this study we identified the WC and WHtR cut-off points that best predicted cardiometabolic risk (CMR) in groups of African (Benin) and African ancestry (Haiti) Black subjects.

METHODS

This cross-sectional study included 452 apparently healthy subjects from Cotonou (Benin) and Port-au-Prince (Haiti), 217 women and 235 men from 25 to 60 years. CMR biomarkers were the metabolic syndrome components. Additional CMR biomarkers were a high atherogenicity index (total serum cholesterol/high density lipoprotein cholesterol ≥4 in women and ≥5 in men); insulin resistance set at the 75th percentile of the calculated Homeostasis Model Assessment index (HOMA-IR); and inflammation defined as high-sensitivity C-reactive protein (hsCRP) concentrations between 3 and 10 mg/L. WC and WHtR were tested as predictors of two out of the three most prevalent CMR biomarkers. Receiver operating characteristic (ROC) curves, Youden's index, and likelihood ratios were used to assess the performance of specific WC and WHtR cut-offs.

RESULTS

High atherogenicity index (59.5%), high blood pressure (23.2%), and insulin resistance (25% by definition) were the most prevalent CMR biomarkers in the study groups. WC and WHtR were equally valid as predictors of CMR. Optimal WC cut-offs were 80 cm and 94 cm in men and women, respectively, which is exactly the reverse of the generic cut-offs. The standard 0.50 cut-off of WHtR appeared valid for men, but it had to be increased to 0.59 in women.

CONCLUSION

CMR was widespread in these population groups. The present study suggests that in order to identify Africans with high CMR, WC thresholds will have to be increased in women and lowered in men. Data on larger samples are needed.

Association of body mass index and abdominal adiposity with atherogenic lipid profile in Nigerians with type 2 diabetes and/or hypertension

Background:

We explored the relationship between anthropometric indices (obesity and abdominal adiposity) and the presence of an atherogenic lipid profile in Nigerians with major cardiovascular risk factors (type 2 diabetes mellitus-T2DM, hypertension-HBP, and concomitant disease).

Materials and Methods:

Using a prospective design, 278 patients with T2DM, HBP, or concomitant disease, attending out-patient diabetes and hypertension clinics at a tertiary institution in Nigeria were evaluated. All patients were cholesterol-lowering oral medication naοve. Demographic and clinical data and anthropometric measurements were documented. Fasting lipid profiles were measured in all cases. The cut-off points for defining dyslipidaemia were: Elevated total cholesterol (TC) (mg/dL) ≥200, elevated low-density lipoprotein cholestrol (LDL-C) (mg/dL) ≥100, low high-density lipoprotein cholesterol (HDL-C) (mg/dL) <40 for men and <50 for women, and high triglycerides (TG) (mg/dL) ≥150 mg/dL.

Results:

We found a significantly higher mean BMI (kg/m²) in the HBP group (30.5 ± 6.0) compared to T2DM (28.1 ± 5.9) and concomitant HBP and T2DM groups (29.4 ± 5.2) (ANOVA; P = 0.02). The most frequent dyslipidaemia was elevated LDL-C in 92 (96.8%) HBP, 73 (85.9%) T2DM and 79 (80.6%) concomitant disease. The frequency of low HDL-C was highest in T2DM (68.2%) compared to the other 2 groups (P = 0.03).

Conclusions:

Only TG levels were found to relate with any anthropometric index (waist circumference (WC) in this case) in Nigerians with major cardiovascular risk factors in this study. Routine anthropometric indices do not appear to be reliable surrogates for atherogenicity measured by abnormalities in TC, LDL-C and HDL-C.

The double burden of malnutrition and cardiometabolic risk widens the gender and socio-economic health gap: a study among adults in Burkina Faso (West Africa)

OBJECTIVE

To document the double burden of malnutrition and cardiometabolic risk factors (CMRF) in adults and its occurrence according to different sociodemographic parameters.

DESIGN

Population-based cross-sectional observational study. We first randomly selected 330 households stratified by tertile of the income levels proxy as low, middle and high income.

SETTING

Northern district of Ouagadougou, the capital city of Burkina Faso.

SUBJECTS

In each income stratum, 110 individuals aged 25-60 years and who had lived permanently in Ouagadougou for at least 6 months were randomly selected, followed with collection of anthropometric, socio-economic and clinical data, and blood samples.

RESULTS

The overall obesity/overweight prevalence was 24.2 % and it was twice as high in women as in men (34.1 % v. 15.5 %, P < 0.001). Hypertension, hyperglycaemia and low HDL cholesterol prevalence was 21.9 %, 22.3 % and 30.0 %, respectively, without gender difference. The prevalence of the metabolic syndrome was 10.3 %. Iron depletion and vitamin A deficiency affected 15.7 % and 25.7 % of participants, respectively, with higher rates in women. Coexistence of at least one nutritional deficiency and one CMRF was observed in 23.5 % of participants, and this 'double burden' was significantly higher in women than in men (30.4 % v. 16.1 %, P = 0.008) and in the low income group.

CONCLUSIONS

CMRF are becoming a leading nutritional problem in adults of Ouagadougou, while nutritional deficiencies persist. The double nutritional burden exacerbates health inequities and calls for action addressing both malnutrition and nutrition-related chronic diseases.

Ethnic differences in cardiometabolic risk profile at age 5-6 years: the ABCD study

BACKGROUND

To examine ethnic differences in cardiometabolic risk profile in early age, and explore whether such differences can be explained by differences in body mass index (BMI) or waist circumference (WC).

METHOD

Anthropometric measurements, blood pressure and (in a subsample) fasting blood were collected during a health check of 2,509 children aged 5-6 years. Four ethnic groups were distinguished: Dutch (n=2,008; blood n=1,300), African descent (n=199; blood n=105), Turkish (n=108; blood n=57) and Moroccan (n=194; blood n=94). Ethnic differences in diastolic and systolic blood pressure (DBP/SBP), fasting glucose, low-density lipoprotein (LDL), high-density lipoprotein (HDL) and triglyceride levels were determined and the explanatory role of BMI and WC was examined with regression analysis.

RESULTS

After adjustment for confounders, African descent children showed higher DBP (β2.22 mmHg; 95%CI:1.09-3.36) and HDL levels (β:0.09 mmol/l; 95%CI:0.03-0.16) compared to Dutch children (reference group). Turkish children showed higher SBP (β:1.89 mmHg; 95%CI:0.25-3.54), DBP (β:2.62 mmHg; 95%CI:1.11-4.13), glucose (β:0.12 mmol/L; 95%CI:0.00-0.25) and triglyceride levels (β:0.13 mmol/L; 95%CI:0.02-0.25). Higher BMI values were found in all non-Dutch groups (differences ranged from 0.53-1.03 kg/m(2)) and higher WC in Turkish (β:1.68 cm; 95%CI:0.99-2.38) and Moroccan (β:1.65 cm; 95%CI:1.11-2.19) children. BMI and WC partly explained the higher SBP/DBP and triglyceride levels in Turkish children.

CONCLUSION

Ethnic differences in cardiometabolic profile exist early in life and are partly explained by differences in BMI and WC. African children showed favourable HDL levels and Turkish children the most unfavourable overall profile, whereas their Moroccan peers have less increased cardiometabolic risk in spite of their high BMI and WC.

Rising disparities in severe adverse birth outcomes among Haitians in Québec, Canada, 1981-2006

Perinatal health data for Haitians are scant. We evaluated adverse birth outcomes for Haitians in Québec, Canada. We analyzed 2,124,909 live births from 1981 to 2006. Haitian ethnicity was assessed using maternal birth country (Haiti, other Caribbean country, other foreign country, Canada) and home language (Creole, French/English but Creole mother tongue, French/English, other). Associations between ethnicity and preterm birth (PTB), low birth weight (LBW), and small-for-gestational-age (SGA) birth were calculated. Adverse birth outcomes were more common among mothers with Haitian ethnicity. Relative to Canadian-born mothers, odds for Haitian-born mothers were 4 times greater for extreme PTB (≤27 weeks), twice greater for very PTB (28-31 weeks), and 25% higher for moderate PTB (32-36 weeks). Patterns were similar for SGA birth and severe cases of LBW. Despite overall decreases LBW and SGA birth, relative and absolute inequalities increased over time. Perinatal health inequalities are increasing for Haitian-born mothers.

Four-Year Trends in Cardiometabolic Risk Factors according to Baseline Abdominal Obesity Status in West-African Adults: The Benin Study

The study examined whether abdominal obesity (AO) according to waist circumference was associated with more unfavourable changes in other cardiometabolic risk (CMR) factors in sub-Saharan Africans. The study included 541 randomly selected and apparently healthy subjects (50% women) aged 25-60 years. Complete data at baseline, 24, and 48 months later was available in 366 subjects. AO was associated with higher CMR at baseline and over the follow-up period, except for high blood pressure. A significantly higher incidence of high ratio of total cholesterol : HDL-cholesterol (TC/HDL-C) was associated with AO. Controlling for WC changes, age, baseline diet, and lifestyles, the relative risk (RR) of low HDL-C and high TC/HDL-C was 3.2 (95% CI 1.06-9.61) and 7.4 (95% CI 2.01-25.79), respectively, in AO men; the RR was not significant in women. Over a four-year period, AO therefore appeared associated with an adverse evolution of cholesterolemia in the study population.

Optimal cut-off values and population means of waist circumference in different populations

Abdominal obesity is a risk factor for cardiometabolic disease, and has become a major public health problem in the world. Waist circumference is generally used as a simple surrogate marker to define abdominal obesity for population screening. An increasing number of publications solely rely on the method that maximises sensitivity and specificity to define ‘optimal’ cut-off values. It is well documented that the optimal cut-off values of waist circumference vary across different ethnicities. However, it is not clear if the variation in cut-off values is a true biological phenomenon or an artifact of the method for identifying optimal cut-off points. The objective of the present review was to assess the relationship between optimal cut-offs and population waist circumference levels. Among sixty-one research papers, optimal cut-off values ranged from 65·5 to 101·2 cm for women and 72·5 to 103·0 cm for men. Reported optimal cut-off values were highly correlated with population means (correlation coefficient: 0·91 for men and 0·93 for women). Such a strong association was independent of waist circumference measurement techniques or the health outcomes (dyslipidaemia, hypertension or hyperglycaemia), and existed in some homogeneous populations such as the Chinese and Japanese. Our findings raised some concerns about applying the sensitivity and specificity approach to determine cut-off values. Further research is needed to understand whether the differences among populations in waist circumference were genetically or environmentally determined, and to understand whether using region-specific cut-off points can identify individuals with the same absolute risk levels of metabolic and cardiovascular outcomes among different populations.

Metabolic syndrome in three ethnic groups using current definitions

According to two current definitions, the prevalence of the metabolic syndrome (MetS) among black Haitians of Montreal was <20%, 30%-36% in Algonquin Indians of Quebec, and >45% in Mexicans of Oaxaca (all aged 35-60 y). Although phenotypes were different, high triglycerides and fasting dysglycemia were good predictors of MetS in all three groups using both definitions. The international cut-offs for abdominal obesity were not predictive of MetS in the Haitian subjects.

Ethnicity, energy expenditure and obesity: are the observed black/white differences meaningful?

PURPOSE OF REVIEW

Recent studies have suggested that black individuals have lower energy expenditure than whites. Many investigators hypothesized that this is why black women experience higher rates of obesity than white women. These findings initiated much research on race as a primary biological determinant of obesity and energy expenditure as a potential pathway. Race is a difficult construct to use in biomedical research.

RECENT FINDINGS

Recent findings have included: an explanation for the lower resting energy expenditure observed among black adults, data showing that relative resting energy expenditure may not be a significant predictor of weight change in African-origin populations, and inconsistent data on the role of activity energy expenditure as a determinant of children's weight change.

SUMMARY

The data suggest that black individuals have lower resting energy expenditure and possibly activity energy expenditure than white individuals. The lower resting energy expenditure is probably caused by a smaller mass of high metabolically active organs. It is unlikely that increased weight gain is associated with lower resting energy expenditure or activity among blacks, because no association has been found within populations. Clinically, it is important to focus on personal modifiable risk factors, e.g., energy intake and physical activity levels.