Prevalence and predictors of overweight and obesity among Cameroonian women in a national survey and relationships with waist circumference and inflammation in Yaoundé and Douala.

Information on the distribution and predictors of obesity in Africa is needed to identify populations at risk and explore intervention options. Our objectives were to (a) examine the prevalence and geographic distribution of overweight and obesity among Cameroonian women; (b) evaluate change in anthropometric indicators among urban women between 2009 and 2012; (c) examine associations between household and individual characteristics and overweight and obesity; and (d) examine relationships between body mass index (BMI), abdominal obesity, and inflammation. We analysed data from a nationally representative survey conducted in 3 geographic strata (North, South, and Yaoundé/Douala) in Cameroon in 2009 and a survey in Yaoundé/Douala in 2012. Participants selected for this analysis were nonpregnant women, ages 15-49 years (n = 704 in 2009; n = 243 in 2012). In 2009, ~8% of women were underweight (BMI < 18.5) and 32% overweight or obese (BMI ≥ 25.0). Underweight was most common in the North (19%) and overweight and obesity in the South (40%) and Yaoundé/Douala (49%). Prevalence of BMI ≥ 25.0 in Yaoundé/Douala did not differ in 2012 compared with 2009 (55.5% vs. 48.7%; P = 0.16). Residence in urban areas, greater maternal age, and TV ownership were independently related to overweight and obesity in national and stratified analyses. In Yaoundé/Douala in 2012, 48% (waist-to-hip ratio > 0.85) to 73% (waist circumference > 80 cm) had abdominal obesity. Body mass index was positively associated with abdominal obesity and inflammation. Though causal inferences cannot be drawn, these findings indicate population subgroups at greatest risk for overweight and associated health consequences in Cameroon.

Iron, Zinc, Folate, and Vitamin B-12 Status Increased among Women and Children in Yaoundé and Douala, Cameroon, 1 Year after Introducing Fortified Wheat Flour.

Background: Few data are available on the effectiveness of large-scale food fortification programs.Objective: We assessed the impact of mandatory wheat flour fortification on micronutrient status in Yaoundé and Douala, Cameroon.Methods: We conducted representative surveys 2 y before and 1 y after the introduction of fortified wheat flour. In each survey, 10 households were selected within each of the same 30 clusters (n = ∼300 households). Indicators of inflammation, malaria, anemia, and micronutrient status [plasma ferritin, soluble transferrin receptor (sTfR), zinc, folate, and vitamin B-12] were assessed among women aged 15-49 y and children 12-59 mo of age.Results: Wheat flour was consumed in the past 7 d by ≥90% of participants. Postfortification, mean total iron and zinc concentrations of flour samples were 46.2 and 73.6 mg/kg (target added amounts were 60 and 95 mg/kg, respectively). Maternal anemia prevalence was significantly lower postfortification (46.7% compared with 39.1%; adjusted P = 0.01), but mean hemoglobin concentrations and child anemia prevalence did not differ. For both women and children postfortification, mean plasma concentrations were greater for ferritin and lower for sTfR after adjustments for potential confounders. Mean plasma zinc concentrations were greater postfortification and the prevalence of low plasma zinc concentration in women after fortification (21%) was lower than before fortification (39%, P < 0.001); likewise in children, the prevalence postfortification (28%) was lower than prefortification (47%, P < 0.001). Mean plasma total folate concentrations were ∼250% greater postfortification among women (47 compared with 15 nmol/L) and children (56 compared with 20 nmol/L), and the prevalence of low plasma folate values was <1% after fortification in both population subgroups. In a nonrepresentative subset of plasma samples, folic acid was detected in 77% of women (73% of those fasting) and 93% of children. Mean plasma and breast-milk vitamin B-12 concentrations were >50% greater postfortification.Conclusion: Although the pre-post survey design limits causal inference, iron, zinc, folate, and vitamin B-12 status increased among women and children in urban Cameroon after mandatory wheat flour fortification.

Regional, Socioeconomic, and Dietary Risk Factors for Vitamin B-12 Deficiency Differ from Those for Folate Deficiency in Cameroonian Women and Children.

BACKGROUND: Representative data on folate and vitamin B-12 dietary intake and status in low-income countries are rare, despite the widespread adoption of folic acid fortification. OBJECTIVE: The purpose of this study was to evaluate folate and vitamin B-12 intake, status, and risk factors for deficiency before implementation of a national fortification program in Cameroon. METHODS: A nationally representative cross-sectional cluster survey was conducted in 3 ecologic zones of Cameroon (South, North, and the 2 largest cities, Yaoundé/Douala), and information on dietary intake was collected from 10 households in each of 30 randomly selected clusters per zone. In a subset of women and their 12- to 59-mo-old children (n = 396 pairs), plasma folate and vitamin B-12, as well as breast milk vitamin B-12, were analyzed. RESULTS: Vitamin B-12 and folate dietary intake patterns and plasma concentrations were similar for women and children. In the subsample, 18% and 29% of women and 8% and 30% of children were vitamin B-12 (≤ 221 pmol/L) and folate (< 10 nmol/L) deficient, respectively. Mean dietary folate ranged from 351 µg dietary folate equivalents/d in the North to 246 µg dietary folate equivalents/d in Yaoundé/Douala; plasma folate was negatively associated with socioeconomic status (P = 0.001). Plasma vitamin B-12 deficiency was similar in the South and North, 29% and 40%, respectively, but was only 11% in Yaoundé/Douala, and was positively associated with socioeconomic status. Mean breast milk vitamin B-12 was statistically significantly lower in the North (101 pmol/L) than in the South (296 pmol/L) or Yaoundé/Douala (349 pmol/L). CONCLUSIONS: Folate intake and status are inadequate among women and young children in Yaoundé/Douala, whereas low vitamin B-12 intake and status are more common in poor and rural areas, especially in the North. Different strategies may be needed to control deficiency of these nutrients in different regions of Cameroon.

Estimating the Effective Coverage of Programs to Control Vitamin A Deficiency and Its Consequences Among Women and Young Children in Cameroon.

BACKGROUND: To compare the cost-effectiveness of nutrition programs, the anticipated nutritional benefits of each intervention must be expressed using a common metric. OBJECTIVE: We present the methodology for estimating the benefits of vitamin A (VA)-related interventions among women and children in Cameroon. METHODS: We estimated "reach" (proportion of the population that receives a program), "coverage" (proportion that is deficient and receives a program), and "effective coverage" (proportion that "converts" from inadequate to adequate VA intake following an intervention) using dietary data collected during a national survey in 3 macro-regions of Cameroon (North, South, and Yaoundé/Douala). Effective coverage of programs such as (bio)fortification and micronutrient powders was estimated by adding the dietary VA contributed by the intervention to baseline VA intakes, including the contribution of increased maternal VA intake to infant VA intake through increases in breast milk VA. For interventions that provide VA-related benefits through other pathways (eg, periodic high-dose VA supplements and deworming), we developed alternative methods of estimating "daily VA intake equivalents. " RESULTS: Baseline VA intakes and intervention reach varied by geographic macro-region. On average, estimates of program reach were greater than the effective coverage estimates by ∼50%. Effective coverage varied by intervention package and macro-region, ranging from <20 000 (deworming, Yaoundé/Douala) to >400 000 (micronutrient powder or VA supplement, North) children effectively covered per year. CONCLUSION: These estimates of effective coverage, along with macro-region-specific information on the costs of each intervention package, serve as inputs into an economic optimization model to identify the most cost-effective package of VA interventions for each macro-region of Cameroon.

Simulations based on representative 24-h recall data predict region-specific differences in adequacy of vitamin A intake among Cameroonian women and young children following large-scale fortification of vegetable oil and other potential food vehicles.

BACKGROUND: The WHO recommends assessing food and nutrient intakes to design food-fortification programs, but nationally representative dietary data are seldom available in low-income countries. OBJECTIVE: Prior to initiation of food fortification in Cameroon, we measured intake of vitamin A (VA) and fortifiable foods (vegetable oil, sugar, wheat flour, and bouillon cube) to simulate the effects of fortification with different foods and VA amounts on prevalence of inadequate and excessive VA intake. METHODS: Twenty-four-hour recalls were conducted among 912 women and 883 children (with duplicates in a subset) in a nationally representative cluster survey stratified by region (North, South, Yaoundé/Douala). Usual intake distributions were estimated by the National Cancer Institute method. RESULTS: Nationally, 53% of women had a usual intake of <500 µg retinol activity equivalents/d, and 59% of nonbreastfeeding children had an intake of <210 µg retinol activity equivalents/d, although VA intake varied by region. The current fortification program (12 mg/kg VA in oil) would decrease the prevalence of inadequate intakes to 35% among both women and children, without increasing the proportion with retinol intakes >3000 µg/d among women or >600 µg/d among children. However, inadequate VA intake would remain >50% in the North, where VA deficiency was most common. Increasing VA in oil or fortifying a second food (sugar, wheat flour, or bouillon cube) would further decrease the prevalence of inadequate intakes, but, depending on the food vehicle and region, would also increase the prevalence of retinol intakes above the tolerable upper intake level, mainly among children. CONCLUSIONS: The current food-fortification program can be expected to improve dietary VA adequacy without increasing the risk of excessive intake among women and children in Cameroon. Modifications to the program must balance the potential to further increase VA intake with the risk of excessive intake among children.

Breast milk retinol and plasma retinol-binding protein concentrations provide similar estimates of vitamin A deficiency prevalence and identify similar risk groups among women in Cameroon but breast milk retinol underestimates the prevalence of deficiency among young children.

Breast milk vitamin A (BMVA) has been proposed as an indicator of population vitamin A status but has rarely been applied in large-scale surveys or compared with conventional vitamin A biomarkers. We assessed the prevalence of, and risk factors for, low BMVA and its relation to vitamin A intake, plasma retinol-binding protein (pRBP), and markers of inflammation in a national survey in Cameroon. We randomly selected 30 clusters in each of 3 strata (South, North, and Cities). Casual milk samples were collected from approximately 5 women per cluster (n = 440). pRBP, plasma C-reactive protein (pCRP), plasma α1-acid glycoprotein (pAGP), and 24-h vitamin A intake were assessed in 10 women aged 15-49 y and 10 children aged 12-59 mo per cluster, including a subset of lactating women (n = 253). Low BMVA was infrequent: 7.2% (95% CI: 4.7, 9.8) of values were <1.05 µmol/L, and 9.3% (95% CI: 5.8, 12.7) were <8 µg/g fat, consistent with the low prevalence of pRBP <0.78 µmol/L among women (< 5%) but lower than the prevalence of pRBP <0.83 µmol/L among children (35%). Risk factors for both low BMVA and pRBP included living in the North and low maternal education. BMVA was positively associated with inflammation-adjusted pRBP among women in the lowest vitamin A intake tertile [<115 µg retinol activity equivalents (RAEs)/d, P < 0.01] but not in the highest tertile (>644 µg RAEs/d, P > 0.4). Controlling for milk fat, BMVA was negatively associated with pCRP (P < 0.02) but not pAGP (P > 0.5). BMVA and pRBP provide similar estimates of vitamin A deficiency prevalence and identify the same risk groups among women in Cameroon, but BMVA underestimates the prevalence of vitamin A deficiency among young children.

Stunting prevalence, plasma zinc concentrations, and dietary zinc intakes in a nationally representative sample suggest a high risk of zinc deficiency among women and young children in Cameroon.

Before initiating a mass zinc fortification program, this study assessed the prevalence of and risk factors for low zinc status among Cameroonian women and children. In a nationally representative survey, we randomly selected 30 clusters in each of 3 strata (North, South, and Yaoundé/Douala) and 10 households per cluster, each with a woman aged 15-49 y and a child aged 12-59 mo (n = 1002 households). Twenty-four-hour dietary recalls (with duplicates in a subset) and anthropometric measurements were conducted, and non-fasting blood was collected to measure plasma zinc concentration (PZC) and markers of inflammation. PZC was adjusted for methodologic factors (time of collection and processing, and presence of inflammation). The prevalence of stunting was 33% (32% South; 46% North; 13% Yaoundé/Douala). Among women, 82% had low adjusted PZC (<50 µg/dL for pregnant women; <66 µg/dL for others; 79% South, 89% North, 76% Yaoundé/Douala). Among children, 83% had low adjusted PZC (<65 µg/dL; 80% South, 92% North, 74% Yaoundé/Douala). Risk factors for low PZC among women and children and for low height-for-age Z-score among children were similar and included residence in the North region and rural areas and households with low socioeconomic status. Using estimated average requirement values from the International Zinc Nutrition Consultative Group (IZiNCG), 29 and 41% of women had inadequate zinc intakes, assuming moderate and low bioavailability, respectively, but only 8% of children had inadequate zinc intake. Depending on the estimated physiologic zinc requirement applied, 17% (IZiNCG) and 92% (Institute of Medicine) of women had inadequate absorbable zinc intakes. Total zinc intakes were greatest in the North region, possibly because of different dietary patterns in this area. Zinc deficiency is a public health problem among women and children in Cameroon, although PZC and dietary zinc yield different estimates of the prevalence of deficiency. Large-scale programs to improve zinc nutrition, including food fortification, are needed.

Plasma ferritin and soluble transferrin receptor concentrations and body iron stores identify similar risk factors for iron deficiency but result in different estimates of the national prevalence of iron deficiency and iron-deficiency anemia among women and children in Cameroon.

Available iron status indicators reflect different aspects of metabolism. We compared the prevalence and distribution of iron deficiency (ID) and iron-deficiency anemia (IDA) among Cameroonian women and children, as measured by plasma ferritin, and soluble transferrin receptor concentrations, body iron stores (BIS), and hemoglobin, and evaluated the impact of adjustments for inflammation on these measures. In a nationally representative survey, we randomly selected 30 clusters in each of 3 zones (north, south, and large cities) and 10 households/ cluster, each with a child aged 12-59 mo and a woman 15-49 y. Ferritin and BIS were mathematically adjusted for inflammation, using plasma C-reactive protein and α(1)-acid glycoprotein both as continuous and categorical variables. Inflammation was present in 48.0% of children and 20.8% of women and anemia was diagnosed in 57.6% of children and 38.8% of women. Depending on the iron status indicator applied, the prevalence of ID ranged from 14.2 to 68.4% among children and 11.5 to 31.8% among women, and the prevalence of IDA ranged from 12.0 to 47.4% among children and 9.0 to 19.4% among women; the proportion of anemia associated with ID ranged from 20.8 to 82.3% among children and 23.2 to 50.0% among women. The different iron indicators generally identified similar groups at greatest risk of deficiency, using both conventional and derived cutoffs: younger children, pregnant women, and women and children in the north and rural areas. Research is needed to clarify the relationships between iron status indicators, particularly in the presence of inflammation, to harmonize global data on prevalence of ID.