Is Overweight in Stunted Preschool Children in Cameroon Related to Reductions in Fat Oxidation, Resting Energy Expenditure and Physical Activity?

Recent studies suggest that early modifications in metabolic pathways and behaviour, leading to energy conservation and reduced linear growth, could represent adaptations to nutritional constraints during foetal life and infancy. Impaired fat oxidation, low resting energy expenditure and reduced physical activity, resulting from these adaptations, could facilitate fat storage and development of overweight in growth-retarded children that consume more energy-dense food. This study aims at assessing whether: (1) dual-burden preschool children (simultaneously stunted and overweight) of Yaounde (Cameroon) have low birth-weight (indicator of foetal undernutrition) and reductions in fat oxidation, resting energy expenditure (REE) and physical activity, (2) fat oxidation, REE and physical activity are associated with foetal growth.162 children (24-72 months) were considered: 22 stunted-overweight (SO), 40 stunted (S), 41 overweight (O), and 59 non stunted-non overweight (NSNO). Nutritional status and body composition were assessed using anthropometry and multifrequency bioimpedance analysis. Fasting respiratory quotient (RQ) and REE were measured by indirect calorimetry. Physical activity was determined using accelerometers, food questionnaires were used for diet assessment and birth-weight was noted. Mean RQs and REE (weight adjusted) did not differ between stunted children (SO and S) and non-stunted children (O and NSNO). SO and S children spent more time in sedentary activities than O children (p = 0.01 and p = 0.02, respectively) and less time in moderate-to-vigorous activities than NSNO children (p = 0.05 and p = 0.04, respectively). SO children's diet was less diverse (p = 0.01) with less animal products (p = 0.006). Multiple linear regressions model revealed that birth-weight is predictive of RQ (β = 0.237, p<0.01, R(2) = 0.08).This study showed that growth retardation in stunted-overweight children could be associated with postnatal nutritional deficiencies. Overweight in stunted children could be associated with reduced physical activity in the context of nutrition transition. High birth-weight was a predictor of reduced lipid oxidation, a risk factor of fat deposition

Mean percentage, per group, of children who consumed one item of the food group.

<p>S-O: stunted-overweight children (n = 18), S: Stunted children (n = 34), O: Overweight children (n = 37), NSNO: Non-stunted-Non Overweight children (n = 59). p-values correspond to the Pearson’s chi-squared test; ns =  non significant. Relationships do exist between the consumption of “meat-poultry-fish-eggs” and the different nutritional status of children (p = 0.006): S-O children are less likely to consume these items than NSNO (p = 0.01), O (p = 0.01) and S (p = 0.001) children.</p

Physical activity for the four groups of children (gender, age and “being at school” adjusted).

1<p>C = counts/minute.</p>2<p>*<i>P<</i>0.05, ***<i>P<</i>0.001, ns: non significant.</p

Mean dietary diversity score (DDS) for each group of children.

<p>S-O: stunted-overweight children (n = 19), S: Stunted children (n = 35), O: Overweight children (n = 38), NSNO: Non-stunted-Non Overweight children (n = 59). p-value corresponds to the analysis of variance between the four groups. Error bars represent standard error of the mean. S-O children have a significantly less diversified diet than O children (p = 0.01, post hoc pair-wise comparison).</p

Characteristics of the four groups of subjects.

1<p>HAZ: height-for-age z-score; WAZ: weight-for-age z-score; R₅₀: resistance at 50 kHz; Z₂₀₀: Impedance at 200 Hz.</p>2<p>Sex and prematurity adjusted.</p>3<p>Age, gender and weight adjusted.</p>4*<p><i>P<</i>0.05, ***<i>P<</i>0.001, ns: non significant.</p

Respiratory quotient (RQ) and resting energy expenditure (REE) of subjects.

1<p>Age adjusted.</p>2<p>Age and sex adjusted.</p>3***<p><i>P<</i>0.001, ns: non significant.</p

Multiple regression models between RQ¹, REE², physical activity (dependant variables) and birth-weight, age, gender³ and H²/Z₂₀₀(independent variables).

1<p>Respiratory quotient.</p>2<p>Resting energy expenditure.</p>3<p>girls = 1 and boys = 0.</p>4<p>**P<0.01, ***P<0.001, ns: non significant.</p>5<p>Residual H²/Z₂₀₀ on age.</p