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

BACKGROUND: Most 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. METHODS: The 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/height(2) ≥ 30 kg/m(2) 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. RESULTS: Abdominal 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. CONCLUSION: Measures 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.

A frequency questionnaire to estimate free-living physical activity among Tunisian preadolescent and adolescent children.

OBJECTIVE: To develop a child- and adolescent-appropriate physical activity frequency questionnaire (PAFQ) in Tunisia, North Africa. DESIGN: A PAFQ was developed from a physical activity (PA) inventory that comprised major activity components (at home, preparing meals, school time, transport, non-sport leisure, sports, prayer and sleeping time). Then, type and duration of each activity undertaken during the past week were estimated. Total energy expenditure (TEE) estimated by the PAFQ was compared with data derived from two criterion methods: heart-rate monitoring (HRM) and a 24 h PA recall (24h-R), both collected during a 3 d period including one weekday and two weekend days. SETTING: Two elementary schools and two high schools of the most developed and urbanized area, Greater Tunis. SUBJECTS: One hundred and forty-two volunteer children and adolescents aged 10-19 years. RESULTS: The PAFQ strongly was correlated with both HRM (r = 0·70; 95% CI 0·62, 0·76) and 24h-R (r = 0·81; 95% CI 0·77, 0·84). It featured acceptable agreement with both criterion measures, slightly underestimating TEE compared with 24h-R (-2·8%, mean of individual differences -272·7 kJ/d; 95% CI -490·6, -57·4 kJ/d) and moderately overestimating it compared with HRM (+11·3%, mean of individual differences +1106·2 kJ/d; 95% CI 845·8, 1366·6 kJ/d). Reliability ranged from moderate to good (weighted kappa coefficients from 0·47 to 0·78 and intra-class correlation coefficients between 0·79 and 0·86 for energy expenditure by PA categories), indicating strong agreement between the two assessments. CONCLUSIONS: This PAFQ could be useful in the description and surveillance of PA patterns or for the evaluation of population-based interventions directed at promoting PA in Tunisian children and adolescents.

Prevalence of diabetes in Northern African countries: the case of Tunisia.

BACKGROUND: Although diabetes is recognized as an emerging disease in African and Middle East, few population-based surveys have been conducted in this region. We performed a national survey to estimate the prevalence of type 2 diabetes (T2D) and to evaluate the relationship between this diagnosis, demographic and socioeconomic variables. METHODS: The study was conducted on a random sample of 6580 households (940 in each region). 7700 subjects adults 35-70 years old were included in the analyses. T2D was assessed on the basis of a questionnaire and fasting blood glucose level according to the WHO criteria. Access to health care and diabetes management were also assessed. RESULTS: Overall, the prevalence of T2D was 15.1%. There were sharp urban vs. rural contrasts, the prevalence of diabetes being twice higher in urban area. However, the ratio urban/rural varied from 3 in the less developed region to 1.6 in the most developed ones. A sharp increase of prevalence of T2D with economic level of the household was observed. For both genders those with a family history of T2D were much more at risk of T2D than those without. Awareness increase with age, economic level and were higher amongst those with family history of T2D. Drugs were supplied by primary health care centers for 57.7% with a difference according to gender, 48.9% for men vs. 66.0% women (p < 0.001) and area, 53.3% on urban area vs. 75.2% on rural one (p < 0.001). CONCLUSIONS: Through its capacity to provide the data on the burden of diabetes in the context of the epidemiological transition that North Africa is facing, this survey will not only be valuable source for health care planners in Tunisia, but will also serve as an important research for the study of diabetes in the region where data is scarce. In this context, NCDs emerge as an intersectoral challenge and their social determinants requiring social, food and environmental health policy.

Adequacy of child anthropometric indicators for measuring nutritional stress at population level: a study from Niakhar, Senegal.

OBJECTIVE: To compare the responsiveness of different anthropometric indicators for measuring nutritional stress among children in developing countries. DESIGN: Growth was studied within 6-month intervals in a rural Senegalese community during one dry and two rainy (hungry) seasons. Responsiveness was defined as the change divided by the standard deviation of each anthropometric indicator. Contrast was defined as the difference in responsiveness between dry and rainy seasons. SETTING: The study was conducted in Niakhar, a rural area of Senegal under demographic surveillance, with contrasted food and morbidity situations between rainy and dry seasons. SUBJECTS: Some 5000 children under 5 years of age were monitored at 6-month intervals in 1983­1984. The present analysis was carried out on a sub-sample of children aged 6­23 months with complete measures, totalling 2803 children-intervals. RESULTS: In both univariate and multivariate analysis, mid-upper arm circumference was found to be more responsive to nutritional stress than the commonly used weight-for-height Z-score (contrast = -0.64 for mid-upper arm circumference v. -0.53 for weight-for-height Z-score). Other discriminant indicators were: muscle circumference, weight-for-height, BMI and triceps skinfold. Height, head circumference and subscapular skinfold had no discriminating power for measuring the net effect of nutritional stress during the rainy season. CONCLUSIONS: The use of mid-upper arm circumference for assessing nutritional stress in community surveys should be considered and preferred to other nutritional indicators. Strict standardization procedures for measuring mid-upper arm circumference are required for optimal use.

Prevalence and determinants of the metabolic syndrome among Tunisian adults: results of the Transition and Health Impact in North Africa (TAHINA) project.

OBJECTIVE: To determine the prevalence of metabolic syndrome (MetS) and its components and to evaluate the relationship between this diagnosis and cardiovascular risk factors, demographic and socio-economic variables. DESIGN: A cross-sectional study using a questionnaire including information on sociodemographic and CVD risk factors. Blood pressure, anthropometric indices, fasting glucose and lipid profile were measured. MetS was defined according to the criteria of the National Cholesterol Education Program, Adult Treatment Panel III. SETTING: The whole Tunisian territory; Transition and Health Impact in North Africa (TAHINA) project. SUBJECTS: A total of 4654 individuals (1840 men and 2814 women), aged 35 to 74 years, who participated in the Tunisian national survey. RESULTS: The overall prevalence of MetS was 30·0 %, higher in women (36·1 %) than in men (20·6 %; P < 0·001). In both genders MetS prevalence increased significantly with age (P < 0·001), but this increase was more important in women. Multiple regression analyses showed that the odds for MetS increased significantly with urban area for both men and women (P < 0·05 and P < 0·001, respectively). The multivariate models showed also that the odds for MetS increased significantly with increasing level of education and in those with a family history of CVD for men (both P < 0·05) and after the menopausal transition for women (P < 0·05). CONCLUSIONS: The study highlights the MetS problem in a middle-income developing country. There is an urgent need for a comprehensive, integrated, population-based intervention programme to ameliorate the growing problem of MetS in Tunisians.

Blood pressure and associated factors in a North African adolescent population. a national cross-sectional study in Tunisia.

BACKGROUND: In southern and eastern Mediterranean countries, changes in lifestyle and the increasing prevalence of excess weight in childhood are risk factors for high blood pressure (BP) during adolescence and adulthood. The aim of this study was to evaluate the BP status of Tunisian adolescents and to identify associated factors. METHODS: A cross-sectional study in 2005, based on a national, stratified, random cluster sample of 1294 boys and 1576 girls aged 15-19 surveyed in home visits. The socio-economic and behavioral characteristics of the adolescents were recorded. Overweight/obesity were assessed by Body Mass Index (BMI) from measured height and weight (WHO, 2007), abdominal obesity by waist circumference (WC). BP was measured twice during the same visit. Elevated BP was systolic (SBP) or diastolic blood pressure (DBP) ≥ 90th of the international reference or ≥ 120/80 mm Hg for 15-17 y., and SBP/DBP ≥ 120/80 mm Hg for 18-19 y.; hypertension was SBP/DBP ≥ 95th for 15-17 y. and ≥ 140/90 mm Hg for 18-19 y. Adjusted associations were assessed by logistic regression. RESULTS: The prevalence of elevated BP was 35.1%[32.9-37.4]: higher among boys (46.1% vs. 33.3%; P < 0.0001); 4.7%[3.8-5.9] of adolescents had hypertension. Associations adjusted for all covariates showed independent relationships with BMI and WC: - obesity vs. no excess weight increased elevated BP (boys OR = 2.1[1.0-4.2], girls OR = 2.3[1.3-3.9]) and hypertension (boys OR = 3.5[1.4-8.9], girls OR = 5.4[2.2-13.4]), - abdominal obesity (WC) was also associated with elevated BP in both genders (for boys: 2nd vs. 1st tertile OR = 1.7[1.3-2.3], 3rd vs.1st tertile OR = 2.8[1.9-4.2]; for girls: 2nd vs. 1st tertile OR = 1.6[1.2-2.1], 3rd vs.1st tertile OR = 2.1[1.5-3.0]) but only among boys for hypertension. Associations with other covariates were weaker: for boys, hypertension increased somewhat with sedentary lifestyle, while elevated BP was slightly more prevalent among urban girls and those not attending school. CONCLUSION: Within the limits of BP measurement on one visit only, these results suggest that Tunisian adolescents of both genders are likely not spared from early elevated BP. Though further assessment is likely needed, the strong association with overweight/obesity observed suggests that interventions aimed at changing lifestyles to reduce this main risk factor may also be appropriate for the prevention of elevated BP.

Mid-upper arm circumference and weight-for-height to identify high-risk malnourished under-five children.

The World Health Organization and UNICEF define non-oedematous severe acute malnutrition (SAM) either by a mid-upper arm circumference (MUAC) less than 115 mm or by a weight-for-height z-score (WHZ) less than -3. The objective of this study was to assess whether there was any benefit to identify malnourished children with a high risk of death to combine these two diagnostic criteria. Data of a longitudinal study examining the relationship between anthropometry and mortality in rural Senegal and predating the development of community-based management of SAM were used for this study. First, the receiver operating characteristic (ROC) curves of MUAC and of WHZ to predict mortality were drawn, and then the points corresponding to WHZ less than -3 and/or MUAC less than 115 mm were positioned in relation to these curves. MUAC had the highest ROC curve, which indicates that it identifies high-risk children better than WHZ. Both points representing WHZ less than -3 and/or MUAC less than 115 mm were below the MUAC ROC curve. It is concluded that to identify high-risk malnourished children, there is no benefit in using both WHZ less than -3 and/or MUAC less than 115 mm, and that using MUAC alone is preferable.

Characteristics of energy under-reporting in children and adolescents.

Under-reporting (UR) of food intake is an issue of concern, as it may distort the relationships studied between diet and health. This topic has been scarcely addressed in children. The objective of the study was to assess the extent of UR in French children and investigate associated covariates. A total of 1455 children aged 3-17 years were taken from the nationally representative cross-sectional French étude Individuelle Nationale des Consommations Alimentaires (INCA2) dietary survey (2006-7). Food intake was reported in a 7 d diet record. Socio-economic status, sedentary behaviour, weight perception variables and food habits were collected by questionnaires. Weight and height were measured. Under-reporters were identified according to the Goldberg criterion adapted to children. Multivariate logistic regressions investigated the associations between UR and covariates. Rates of under-reporters were 4·9 and 26·0 % in children aged 3-10 and 11-17 years, respectively (P < 0·0001), without significant differences between boys and girls. Overall, UR was positively associated with a lower socio-economic status, overweight, skipping breakfast and dinner, a higher contribution of proteins to energy intake (EI), and a lower contribution of simple carbohydrates to EI. Under-reporters aged 3-10 years also had a higher sedentary behaviour and a lower snack-eating frequency. In adolescents, UR was also associated with a less-frequent school canteen attendance, a perception of being overweight, a wish to weigh less, and current and past restrictive diets. In conclusion, under-reporters differ from plausible reporters in several characteristics related to diet, lifestyle, weight status and socio-economic status. Therefore, it is important to consider this differential UR bias when investigating diet-disease associations in children.

Nutrition transition among adolescents of a south-Mediterranean country: dietary patterns, association with socio-economic factors, overweight and blood pressure. A cross-sectional study in Tunisia.

BACKGROUND: The increase in the burden of chronic diseases linked to the nutrition transition and associated dietary and lifestyle changes is of growing concern in south and east Mediterranean countries and adolescents are at the forefront of these changes. This study assessed dietary intake and association with socio-economic factors and health outcomes among adolescents in Tunisia. METHODS: Cross-sectional survey (year 2005); 1019 subjects 15-19 y. from a clustered random sample. Dietary intake was assessed by a validated semi-quantitative frequency questionnaire (134 items) as was physical activity; the Diet Quality Index International measured diet quality; dietary patterns were derived by multiple correspondence analysis from intakes of 43 food groups. Body Mass Index (BMI) ≥ 85th and 95th percentile defined overweight and obesity. Waist Circumference (WC) assessed abdominal fat. High blood pressure was systolic (SBP) or diastolic blood pressure (DBP) ≥ 90th of the international reference for 15-17 y., and SBP/DBP ≥ 120/80 mm Hg for 18-19 y. RESULTS: Energy intake levels were quite high, especially for females. The macro-nutrient structure was close to recommendations but only 38% had a satisfactory diet quality. A main traditional to modern dietary gradient, linked to urbanisation and increased economic level, featured an increasing consumption of white bread, dairy products, sugars, added fats and fruits and decreasing consumption of oils, grains, legumes and vegetables; regarding nutrients this modern diet score featured a decreasing relationship with total fat and an increase of calcium intake, but with an increase of energy, sugars and saturated fat, while vitamin C, potassium and fibre decreased. Adjusted for age, energy and physical activity, this modern pattern was associated with increased overweight in males (2nd vs. 1st tertile: Prevalence Odds-Ratio (POR) = 4.0[1.7-9.3], 3rd vs. 1st: POR = 3.3[1.3-8.7]) and a higher WC. Adjusting also for BMI and WC, among females, it was associated with decreased prevalence of high blood pressure (2nd vs. 1st tertile: POR = 0.5[0.3-0.8], 3rd vs. 1st tertile: POR = 0.4[0.2-0.8]). CONCLUSION: The dietary intake contrasts among Tunisian adolescents, linked to socio-economic differentials are characteristic of a nutrition transition situation. The observed gradient of modernisation of dietary intake features associations with several nutrients involving a higher risk of chronic diseases but might have not only negative characteristics regarding health outcomes.

Trends in food intake in French children from 1999 to 2007: results from the INCA (étude Individuelle Nationale des Consommations Alimentaires) dietary surveys.

The objectives of the present study were to assess the intake of different food groups in French children aged 3-17 years (n 1455), and to analyse trends since a dietary survey undertaken 8 years ago. Dietary intake was evaluated using data from the 2006-7 cross-sectional INCA2 national dietary survey (étude Individuelle Nationale sur les Consommations Alimentaires), based on a 7 d food record. Dietary intake (percentage of subjects consuming the food group and amount eaten) was assessed for thirty-nine food categories. We observed variations in food consumption by age, sex, North-South regional gradient, seasonal period and educational level of the responding parent. Trends in dietary intake between 1999 and 2007 were determined by comparing the INCA1 (n 1126) and the INCA2 surveys. Both surveys had been carried out using the same methodology. The findings showed a decrease in energy intake in children aged 3-14 years, due to a reduction in the consumption of foods of animal origin and sweetened products. In adolescents aged 15-17 years, energy intake remained rather stable; during this 8-year period, the consumption of meat decreased, whereas the consumption of savoury snacks such as sandwiches and hamburgers significantly increased. These trends occurred during a time of growing concern about overweight and the associated co-morbidities in France. A number of public health measures were implemented over this period to improve dietary habits and physical activity patterns in children and adults. The periodic monitoring of dietary patterns through the INCA surveys is an essential part of the surveillance network in France.

Food shopping transition: socio-economic characteristics and motivations associated with use of supermarkets in a North African urban environment.

OBJECTIVE: In the context of the nutrition transition and associated changes in the food retail sector, to examine the socio-economic characteristics and motivations of shoppers using different retail formats (large supermarkets (LSM), medium-sized supermarkets (MSM) or traditional outlets) in Tunisia. DESIGN: Cross-sectional survey (2006). Socio-economic status, type of food retailer and motivations data were collected during house visits. Associations between socio-economic factors and type of retailer were assessed by multinomial regression; correspondence analysis was used to analyse declared motivations. SETTING: Peri-urban area around Tunis, Tunisia, North Africa. SUBJECTS: Clustered random sample of 724 households. RESULTS: One-third of the households used LSM, two-thirds used either type of supermarket, but less than 5 % used supermarkets only. Those who shopped for food at supermarkets were of higher socio-economic status; those who used LSM were much wealthier, more often had a steady income or owned a credit card, while MSM users were more urban and had a higher level of education. Most households still frequently used traditional outlets, mostly their neighbourhood grocer. Reasons given for shopping at the different retailers were most markedly leisure for LSM, while for the neighbourhood grocer the reasons were fidelity, proximity and availability of credit (the latter even more for lower-income customers). CONCLUSIONS: The results pertain to the transition in food shopping practices in a south Mediterranean country; they should be considered in the context of growing inequalities in health linked to the nutritional transition, as they differentiate use and motivations for the choice of supermarkets v. traditional food retailers according to socio-economic status.

Influence of acculturation among Tunisian migrants in France and their past/present exposure to the home country on diet and physical activity.

OBJECTIVE: To study how dietary patterns and physical activity vary with acculturation and with past and current exposure to socio-cultural norms of the home country among Tunisian migrants. DESIGN: A retrospective cohort study was conducted using quota sampling (n 150) based on age and residence. Dietary intake was assessed using a validated FFQ. Physical activity level and dietary aspects were compared according to length of residence (acculturation), age at migration (past exposure) and social ties with the home country (current exposure). SUBJECTS AND SETTING: Tunisian migrant men residing in the South of France. RESULTS: Migrants who had lived in France for more than 9 years had a higher percentage contribution of meat to energy intake (P = 0.04), a higher Na intake (P = 0.04), a lower percentage contribution of sugar and sweets (P = 0.04) and a lower percentage of carbohydrates (P = 0.03) than short-term migrants. Men who migrated before 21 years of age had a higher Na intake than 'late' migrants (P = 0.02). Men who had distant social ties with Tunisia had a lower physical activity level (P = 0.01) whereas men who had close ties had a higher percentage of fat (P = 0.01) and a higher ratio of MUFA to SFA (P = 0.02). CONCLUSIONS: Acculturation led to a convergence of some characteristics to those of the host population, while some results (meat and salt consumption) were at variance with other acculturation studies. Past and current exposure to the home country helped maintain some positive aspects of the diet. Nevertheless, present dietary changes in Tunisia could soon lessen these features.

Incidence and duration of severe wasting in two African populations.

OBJECTIVE: The present study aimed to compare two situations of endemic malnutrition among <5-year-old African children and to estimate the incidence, the duration and the case fatality of severe wasting episodes. DESIGN: Secondary analysis of longitudinal studies, conducted several years ago, which allowed incidence and duration to be calculated from transition rates. The first site was Niakhar in Senegal, an area under demographic surveillance, where we followed a cohort of children in 1983-5. The second site was Bwamanda in the Democratic Republic of Congo, where we followed a cohort of children in 1989-92. Both studies enrolled about 5,000 children, who were followed by routine visits and systematic anthropometric assessment, every 6 months in the first case and every 3 months in the second case. RESULTS: Niakhar had less stunting, more wasting and higher death rates than Bwamanda. Differences in cause-specific mortality included more diarrhoeal diseases, more marasmus, but less malaria and severe anaemia in Niakhar. Severe wasting had a higher incidence, a higher prevalence and a more marked age profile in Niakhar. However, despite the differences, the estimated mean durations of episodes of severe wasting, calculated by multi-state life table, were similar in the two studies (7.5 months). Noteworthy were the differences in the prevalence and incidence of severe wasting depending on the anthropometric indicator (weight-for-height Z-score

Dietary and physical activity patterns in French children are related to overweight and socioeconomic status.

Sedentary behavior (SED) has already been identified as a risk factor of childhood overweight (OW) but less is known about the dietary patterns related to adiposity. Our objective was to investigate if lifestyle patterns combining overall diet and physical activity were associated with childhood OW and if they were involved in the reverse association between socioeconomic status (SES) and OW. Dietary intake was assessed using a 7-d food record in 748 French children aged 3-11 y from the 1998-1999 cross-sectional French Enquête Individuelle et Nationale sur les Consommations Alimentaires national food consumption survey. Weight and height, leisure time physical activity, SED (television viewing), and SES were reported by parents or children by answering questionnaires. Scores for lifestyle patterns were assessed with factor analysis and their relationship with OW was explored by logistic regression analysis. Two similar lifestyle patterns were identified in children aged 3-6 y and 7-11 y: "snacking and sedentary" and "varied food and physically active." The snacking and sedentary pattern was positively associated with OW in the youngest children (P-trend = 0.0161) and partly mediated the negative association of SES to OW. The varied food and physically active pattern was inversely correlated with OW in the eldest children only (P-trend = 0.0401). A third pattern called "big eaters at main meals" was derived in children aged 7-11 y and was positively correlated with OW (P-trend = 0.0165). From a public health perspective, the combinations of identifiable dietary and physical activity behaviors may be useful as a basis for recommendations on preventing OW.

Regular users of supermarkets in Greater Tunis have a slightly improved diet quality.

Despite the recent and rapid expansion of supermarkets in developing countries, their association with diet quality has been hardly studied. The study took place in Tunisia, where incidences of obesity and nutrition-related diseases are rising. The target population was households of the Greater Tunis area where supermarkets are mostly located. Households (n = 724) were selected by a 2-stage clustered random sampling. A purposely developed quantitative questionnaire assessed food retail habits. Socioeconomic data were collected at individual and household levels. The diet quality index-international (DQI-I) derived from a FFQ specific for Tunisia measured diet quality. Data analysis by regression or logistic regression models adjusted for energy intake and socioeconomic confounders when relevant. Overall, 60% of the households used supermarkets. Most households still used the nearby grocer; only 26% shopped at the market. Characteristics associated with supermarket use were urban milieu, small-sized households, greater educational attainment, higher economic level, steady income, or easy access. Associations between these variables and using supermarkets as a first shopping place (20% of households) were even stronger. After adjustment for energy intake and socioeconomic and access data, using supermarkets chosen as first food shopping place vs. other retail resulted in a slightly higher DQI-I (63.2 vs. 59.6; P = 0.0004). Despite the long-standing presence of supermarkets in Tunis, shopping at supermarkets has not yet spread to the whole population. Supermarkets do not yet markedly modify food consumption in the Greater Tunis. However, a slight improvement of diet quality can be observed among those people who use supermarkets regularly.

Has the first implementation phase of the Community Nutrition Project in urban Senegal had an impact?

OBJECTIVE: We evaluated the impact of the Community Nutrition Project (CNP) of Senegal, West Africa on the population. In poor urban districts, the CNP provided underweight 6- to 35-mo-old children with growth monitoring/promotion and food supplementation, and education for mothers for a period of 6 mo. METHODS: A before/after intervention and intervention zone (IZ)/control zone (CZ) design was used to assess whether CNP had an impact 18 mo after it began in Diourbel. Exhaustive samples included children 6-35 mo old in the CZ (n = 895 before and 917 after) and IZ (n = 912 and 759). The impact was assessed by the differential effect of the zone on changes in underweight, wasting, and stunting defined by the threshold of -2 or -3 z scores. RESULTS: The decrease in wasting was higher in the CZ (from 13.7% to 8.6% versus 11.3% to 10.8%, P = 0.042). Changes in stunting did not differ between zones (18.8% to 14.5% versus 15.1% to 14.7%, P = 0.21). However, in the IZ, severe wasting, stunting, and underweight disappeared in children 6-11 mo of age. In the CZ, the socioeconomic data and some outcomes in children reflected a favorable context independent of the CNP. CONCLUSION: Despite a globally satisfactory decrease in malnutrition in the IZ, no impact was demonstrated because the same or an even larger decrease was observed in the CZ, highlighting the importance of relying on a quasi-experimental design. This may be explained in part by weaknesses in the process, which probably interfered with a potential impact, and by the high degree of population mobility, which could have interfered with efficiency assessed on a geographic scale.

Influence of socio-economic and lifestyle factors on overweight and nutrition-related diseases among Tunisian migrants versus non-migrant Tunisians and French.

BACKGROUND: Migrant studies in France revealed that Mediterranean migrant men have lower mortality and morbidity than local-born populations for non-communicable diseases (NCDs). We studied overweight and NCDs among Tunisian migrants compared to the population of the host country and to the population of their country of origin. We also studied the potential influence of socio-economic and lifestyle factors on differential health status. METHODS: A retrospective cohort study was conducted to compare Tunisian migrant men with two non-migrant male groups: local-born French and Tunisians living in Tunisia, using frequency matching. We performed quota sampling (n = 147) based on age and place of residence. We used embedded logistic regression models to test socio-economic and lifestyle factors as potential mediators for the effect of migration on overweight, hypertension and reported morbidity (hypercholesterolemia, type-2 diabetes, cardiovascular diseases (CVD)). RESULTS: Migrants were less overweight than French (OR = 0.53 [0.33-0.84]) and had less diabetes and CVD than Tunisians (0.18 [0.06-0.54] and 0.25 [0.07-0.88]). Prevalence of hypertension (grade-1 and -2) and prevalence of hypercholesterolemia were significantly lower among migrants than among French (respectively 0.06 [0.03-0.14]; 0.04 [0.01-0.15]; 0.11 [0.04-0.34]) and Tunisians (respectively OR = 0.07 [0.03-0.18]; OR = 0.06 [0.02-0.20]; OR = 0.23 [0.08-0.63]). The effect of migration on overweight was mediated by alcohol consumption. Healthcare utilisation, smoking and physical activity were mediators for the effect of migration on diabetes. The effect of migration on CVD was mediated by healthcare utilisation and energy intake. No obvious mediating effect was found for hypertension and hypercholesterolemia. CONCLUSION: Our study clearly shows that lifestyle (smoking) and cultural background (alcohol) are involved in the observed protective effect of migration.

Validity of impedance-based equations for the prediction of total body water as measured by deuterium dilution in African women.

BACKGROUND: Little information is available on the validity of simple and indirect body-composition methods in non-Western populations. Equations for predicting body composition are population-specific, and body composition differs between blacks and whites. OBJECTIVE: We tested the hypothesis that the validity of equations for predicting total body water (TBW) from bioelectrical impedance analysis measurements is likely to depend on the racial background of the group from which the equations were derived. DESIGN: The hypothesis was tested by comparing, in 36 African women, TBW values measured by deuterium dilution with those predicted by 23 equations developed in white, African American, or African subjects. These cross-validations in our African sample were also compared, whenever possible, with results from other studies in black subjects. RESULTS: Errors in predicting TBW showed acceptable values (1.3-1.9 kg) in all cases, whereas a large range of bias (0.2-6.1 kg) was observed independently of the ethnic origin of the sample from which the equations were derived. Three equations (2 from whites and 1 from blacks) showed nonsignificant bias and could be used in Africans. In all other cases, we observed either an overestimation or underestimation of TBW with variable bias values, regardless of racial background, yielding no clear trend for validity as a function of ethnic origin. CONCLUSIONS: The findings of this cross-validation study emphasize the need for further fundamental research to explore the causes of the poor validity of TBW prediction equations across populations rather than the need to develop new prediction equations for use in Africa.

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/m(2)) 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/m(2). 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. Copyright 2000 Wiley-Liss, Inc.

Bringing together viewpoints of mothers and health workers to enhance monitoring and promotion of growth and development of children: a case study from the Republic of Congo.

In 1996, the Government of the Republic of Congo launched a pilot project to improve the child growth and development component of primary healthcare. The present study was carried out (i) to explore perceptions and practices of mothers and health workers regarding child growth, health, and development, and (ii) to design culturally-appropriate tools to enhance their monitoring and promotion. The study was carried out in two randomly-selected health centres in Brazzaville. Qualitative data collected included 16 focus-group discussions with 174 mothers, two focus-group discussions with 18 health workers, and 20 individual interviews with paediatricians or psychologists. The health workers reported that the main indicator of child growth was weight, while the mothers used broader concepts for evaluating growth and development of their toddlers. A strategy encompassing anthropometrics, developmental milestones, and acquisition of social skills was elaborated to enhance communication between health workers and mothers. A new growth chart was designed, and a new calendar of systematic visits, including key tasks and messages, was established. However, these new tools derived from the formative research still need to be carefully tested.