Agnès Gartner

Perceptions of healthy and desirable body size in urban Senegalese women

OBJECTIVE: To examine the cultural ideals for body size held by urban Senegalese women; to determine the body size that women associate with health; and to estimate the change in prevalence of female obesity in an urban neighbourhood of Dakar.DESIGN: Cross-sectional, population-based study in the subjects home, using a structured interviewer-administered questionnaire, conducted in the same Dakar neighbourhood as that of a previous survey conducted in 1996.SUBJECTS: A total of 301 randomly selected women, aged 20–50 y, living in a specific Dakar neighbourhood, Senegal.MEASUREMENTS: A total of 32 items concerning body satisfaction, social status, health and individual attributes to associate with one of six photographic silhouettes; body mass index (BMI), waist circumference, waist-to-hip ratio by anthropometry; and measures of economic status.RESULTS: In all, 26.6% of women were overweight (BMI 25–29.9 kg/m2) and 18.6% were obese (BMI ≥30 kg/m2) compared with 22.4 and 8.0% respectively in 1996. Overweight was the most socially desirable body size, although obesity itself was seen as undesirable, associated with greediness and the development of diabetes and heart disease. Lay definitions of overweight and normal weight differed substantially from health definitions, as one-third of the sample saw the ‘overweight’ category as normal. Over a third of women with BMI ≥25 kg/m2 wanted to gain more weight.CONCLUSION: There has been a sharp rise in the prevalence of obesity in Senegalese women living in a Dakar neighbourhood over the last 7 y. In general, overweight body sizes (but not obese) were seen in a positive light. The finding that the term ‘overweight’ made little sense to these Senegalese women could have important implications for developing public health policies.

Abdominal vs. overall obesity among women in a nutrition transition context: geographic and socio-economic patterns of abdominal-only obesity in Tunisia

BackgroundMost assessments of the burden of obesity in nutrition transition contexts rely on body mass index (BMI) only, even though abdominal adiposity might be specifically predictive of adverse health outcomes. In Tunisia, a typical country of the Middle East and North Africa (MENA) region, where the burden of obesity is especially high among women, we compared female abdominal vs. overall obesity and its geographic and socio-economic cofactors, both at population and within-subject levels.MethodsThe cross-sectional study used a stratified, three-level, clustered sample of 35- to 70-year-old women (n = 2,964). Overall obesity was BMI = weight/height2 ≥ 30 kg/m2 and abdominal obesity waist circumference ≥ 88 cm. We quantified the burden of obesity for overall and abdominal obesity separately and their association with place of residence (urban/rural, the seven regions that compose Tunisia), plus physiological and socio-economic cofactors by logistic regression. We studied the within-subject concordance of the two obesities and estimated the prevalence of subject-level “abdominal-only” obesity (AO) and “overall-only” obesity (OO) and assessed relationships with the cofactors by multinomial logistic regression.ResultsAbdominal obesity was much more prevalent (60.4% [57.7-63.0]) than overall obesity (37.0% [34.5-39.6]), due to a high proportion of AO status (25.0% [22.8-27.1]), while the proportion of OO was small (1.6% [1.1-2.2]). We found mostly similar associations between abdominal and overall obesity and all the cofactors except that the regional variability of abdominal obesity was much larger than that of overall obesity. There were no adjusted associations of AO status with urban/rural area of residence (P = 0.21), education (P = 0.97) or household welfare level (P = 0.94) and only non-menopausal women (P = 0.093), lower parity women (P = 0.061) or worker/employees (P = 0.038) were somewhat less likely to be AO. However, there was a large residual adjusted regional variability of AO status (from 16.6% to 34.1%, adjusted P < 0.0001), possibly of genetic, epigenetic, or developmental origins.ConclusionMeasures of abdominal adiposity need to be included in population-level appraisals of the burden of obesity, especially among women in the MENA region. The causes of the highly prevalent abdominal-only obesity status among women require further investigation.

Assessment of iron deficiency in the context of the obesity epidemic: importance of correcting serum ferritin concentrations for inflammation

BACKGROUND The correction of serum ferritin (SF) concentrations for inflammation because of infectious or parasitic diseases was recently proposed, especially in developing countries, but in many countries, adiposity has become the main cause of inflammation. OBJECTIVE We assessed, overall and by adiposity status, the bias in the estimation of iron deficiency (ID) on the basis of uncorrected SF. DESIGN A cross-sectional survey in 2010 in Rabat-Salé, Morocco, used a random sample of 811 women aged 20-49 y. Adiposity was assessed by body mass index (BMI) (in kg/m²) (normal: BMI <25; overweight: BMI ≥25 to <30; obese: BMI ≥30), waist circumference, and body fat. Inflammation was indicated by a C-reactive protein (CRP) concentration >2 mg/L. ID was indicated by an SF concentration <15 μg/L. The correction factor of SF for inflammation was derived from our sample. Differential effects of SF correction on ID status on the basis of adiposity were assessed by models that included adiposity × correction interactions and accounted for the within-subject correlation. RESULTS The prevalence of overweight was 33.0% and of obesity was 34.0%. Inflammation (42.3%) was strongly linked with adiposity (20.1%, 37.6%, and 68.4% in normal, overweight, and obese subjects, respectively; P < 0.0001). SF increased from a CRP concentration >2 mg/L. The correction factor of SF was 0.65. The prevalence of ID (37.2% compared with 45.2%; difference -8.0%, P < 0.0001) was underestimated by not correcting SF, and the difference increased with adiposity (-2.9%, -8.5%, and -12.4% in normal, overweight, and obese subjects, respectively; P-interaction < 0.0001). Analogous results were observed for other adiposity measures. CONCLUSION In developing countries where ID remains prevalent but rates of obesity are already high, corrected SF should be used when assessing ID status, even if infectious or parasitic diseases are no longer widespread. This trial was registered at clinicaltrials.gov as NCT01844349.

Obesity and Association with Area of Residence, Gender and Socio-Economic Factors in Algerian and Tunisian Adults

Introduction The epidemiological transition has resulted in a major increase in the prevalence of obesity in North Africa. This study investigated differences in obesity and its association with area of residence, gender and socio-economic position among adults in Algeria and Tunisia, two countries with socio-economic and socio-cultural similarities. Methods Cross-sectional studies used stratified, three-level, clustered samples of 35–70 year old adults in Algeria, (women n = 2741, men n = 2004) and Tunisia (women n = 2964, men n = 2379). Thinness was defined as Body Mass Index (BMI) = weight/height <18.5 kg/m2, obesity as BMI ≥30, and abdominal obesity as waist circumference/height ≥0.6. Associations with area of residence, gender, age, education, profession and household welfare were assessed. Results Prevalence of thinness was very low except among men in Algeria (7.3% C.I.[5.9–8.7]). Prevalence of obesity among women was high in Algeria (30.1% C.I.[27.8–32.4]) and Tunisia (37.0% C.I.[34.4–39.6]). It was less so among men (9.1% C.I.[7.1–11.0] and 13.3% C.I.[11.2–15.4]).The results were similar for abdominal obesity. In both countries women were much more obesity-prone than men: the women versus men obesity Odds-Ratio was 4.3 C.I.[3.4–5.5] in Algeria and 3.8 C.I.[3.1–4.7] in Tunisia. Obesity was more prevalent in urban versus rural areas in Tunisia, but not in Algeria (e.g. for women, urban versus rural Odds-Ratio was 2.4 C.I.[1.9–3.1] in Tunisia and only 1.2 C.I.[1.0–5.5] in Algeria). Obesity increased with household welfare, but more markedly in Tunisia, especially among women. Nevertheless, in both countries, even in the lowest quintile of welfare, a fifth of the women were obese. Conclusion The prevention of obesity, especially in women, is a public health issue in both countries, but there were differences in the patterning of obesity according to area of residence and socio-economic position. These specificities must be taken into account in the management of obesity inequalities.

Body composition predicted from skinfolds in African women: a cross-validation study using air-displacement plethysmography and a black-specific equation.

Skinfold thickness (SF) measurements are commonly used for the indirect assessment of body composition. It is necessary to know how large the bias is when using Caucasian SF-based prediction equations Africans, as no specific equations exist. Our first aim was to test the validity of the equation of Durnin & Womersley for predicting body density from SF in Africans. The second aim was to determine the effect of calculating percentage body fat (%BF) from body density using a black-specific formula rather than the Siri equation, thus taking into account the higher fat-free mass (FFM) density in blacks than in whites. A total of 196 African women volunteered. Mean age was 29.5 (sd 8.7) years and mean BMI was 22.5 (sd 4.6) kg/m2. We compared body density values predicted from SF with those measured by air-displacement plethysmography, and %BF values obtained from body density using the Siri equation or the black-specific calculation. The bias (reference minus prediction) was 0.0100 kg/cm3 in body density (P<10(-4)) and 6.5 % BF (P<10(-4)), and the error (sd of the bias) 0.0097 kg/l and 4.5 % BF. With the black-specific equation, the bias was reduced by 1.9 % BF, while error remained similar. As the %BF prediction required an SF-based equation followed by a body density-based calculation, the lack of validity we observed in Africans may be due to known differences between blacks and whites in the distribution of subcutaneous adipose tissue and, as demonstrated, in the FFM density. Equations thus need to be established using SF values specific to Africans.

A Double Burden of Overall or Central Adiposity and Anemia or Iron Deficiency Is Prevalent but with Little Socioeconomic Patterning among Moroccan and Tunisian Urban Women

In North Africa, overnutrition has dramatically increased with the nutrition transition while micronutrient deficiencies persist, resulting in clustering of opposite types of malnutrition that can present a unique difficulty for public health interventions. We assessed the magnitude of the double burden of malnutrition among urban Moroccan and Tunisian women, as defined by the coexistence of overall or central adiposity and anemia or iron deficiency (ID), and explored the sociodemographic patterning of individual double burden. In cross-sectional surveys representative of the region around the capital city, we randomly selected 811 and 1689 nonpregnant women aged 20-49 y in Morocco and Tunisia, respectively. Four double burdens were analyzed: overweight (body mass index ≥25 kg/m(2)) or increased risk abdominal obesity (waist circumference ≥80 cm) and anemia (blood hemoglobin <120 g/L) or ID (C-reactive protein-corrected serum ferritin <15 μg/L). Adjusted associations with 9 sociodemographic factors were estimated by logistic regression. The prevalence of overweight and ID was 67.0% and 45.2% in Morocco, respectively, and 69.5% and 27.0% in Tunisia, respectively, illustrating the population-level double burden. The coexistence of overall or central adiposity with ID was found in 29.8% and 30.1% of women in Morocco, respectively, and in 18.2% and 18.3% of women in Tunisia, respectively, quite evenly distributed across age, economic, or education groups. Generally, the rare, associated sociodemographic factors varied across the 4 subject-level double burdens and the 2 countries and differed from those usually associated with adiposity, anemia, or ID. Any double burden combining adiposity and anemia or ID should therefore be taken into consideration in all women. This trial was registered at clinicaltrials.gov as NCT01844349.

Process evaluation of the Senegal-Community Nutrition Project: an adequacy assessment of a large scale urban project

Objective  Although essential for understanding the reasons for success or failure of large scale nutritional interventions, process evaluation results are rarely reported. Our objective was to assess whether the process output objectives of the Community Nutrition Project (CNP) in Senegal, West Africa, were adequately met.

Sensitivity and specificity of the body mass index to assess low percent body fat in African women

The objective of this study was to evaluate the ability of the body mass index (BMI, kg/m2) to reflect low percent body fat (%BF) in a population with a rather mild but widespread prevalence of low BMI. A sample of 586 women was studied in the Plateau Koukouya, a rural area of the Republic of Congo, Central Africa. Percent BF was estimated from bioelectrical impedance (BIA). BIA parameters were assumed to reflect lean body mass. The correlation between %BF and BMI was high (r = 0.84; P < 0.001). Low %BF or low BIA parameters were defined as the first quartile of the distribution. Sensitivity, specificity, positive and negative predictive value of BMI <18.5, an accepted international cutoff for thinness, in relation to %BF was 58.5%, 93.6%, 75.4%, and 87.1%, respectively. A continuous sensitivity/specificity analysis (receiver operator characteristic [ROC] curves) for characterizing low %BF or low BIA parameters was done for a large range of BMI values. ROC curve analysis for %BF suggested that an acceptable trade‐off between sensitivity (89.8%) and specificity (77.9%) occurred at a BMI of 19.7 kg/m2. However, the positive predictive value was low (57.6%). For the prediction of low BIA parameters, results were similar, showing moderate sensitivity and high specificity for BMI <18.5, a cutoff point of BMI = 19.6, and low positive predictive values (<48%). The data suggest that BMI was not a good predictor of low %BF. This is consistent with the assumption of a decrease in both fat and fat free body mass in cases of low BMI. Am. J. Hum. Biol. 12:25–31, 2000.

Validity of impedance-based predictions of total body water as measured by 2H dilution in African HIV/AIDS outpatients.

Measurements of body composition are crucial in identifying HIV-infected patients at risk of malnutrition. No information is available on the validity of indirect body composition methods in African HIV-infected outpatients. Our first aim was to test the validity of fifteen published equations, developed in whites, African-Americans and/or Africans who were or not HIV-infected, for predicting total body water (TBW) from bioelectrical impedance analysis (BIA) in HIV-infected patients. The second aim was to develop specific predictive equations. Thirty-four HIV-infected patients without antiretroviral treatment and oedema at the beginning of the study (age 39 (SD 7) years, BMI 18.7 (SD3.7) kg/m2, TBW 30.4 (SD7.2) kg) were measured at inclusion then 3 and 6 months later. In the resulting eighty-eight measurements, we compared TBW values predicted from BIA to those measured by 2H dilution. Range of bias values was 0.1-4.3 kg, and errors showed acceptable values (2.2-3.4 kg) for fourteen equations and a high value (10.4) for one equation. Two equations developed in non-HIV-infected subjects showed non-significant bias and could be used in African HIV-infected patients. In the other cases, poor agreement indicated a lack of validity. Specific equations developed from our sample showed a higher precision of TBW prediction when using resistance at 1000 kHz (1.7 kg) than at 50 kHz (2.3 kg), this latter precision being similar to that of the valid published equations (2.3 and 2.8 kg). The valid published or developed predictive equations should be cross-validated in large independent samples of African HIV-infected patients.

The Use of Bioelectrical Impedance Analysis in Newborns. The Need for Standardization

Rapid growth occurs during fetal and neonatal development. The duration and quality of intrauterine development affect neonate body composition. Weight is routinely used to assess and monitor the nutritional status of newborns. Any weight loss or gain in hospitalized newborn infants may reflect shifts in water balance rather than changes in body mass, and have strong implications for investigating the nutritional status of newborns. It is, however, difficult to measure the body composition of newborns. Bioelectrical impedance analysis (BIA) is a relatively new technique for estimating body composition. It is based on the fact that the conduction of an applied electrical signal is far greater in fat-free tissues (because of water and electrolyte content) than in fat. BIA has been gaining wide usage for the estimation of body composition in adults1,2, and should be a very suitable method for use in children, because of its noninvasiveness, simplicity and reliability.