Denis Garnier

Relationship between stunting in infancy and growth and fat distribution during adolescence in Senegalese girls.

Objective: To study the long-term impact of stunting during infancy on maturation, growth and fat distribution in adolescence.Design: A cohort of 406 Senegalese adolescent girls of rural origin underwent clinical and growth assessments every year from 1995 to 1999.Subjects: Mean coverage rate was 82% at each round. Adolescent girls were 11.4±0.5 y of age in 1995 and 15.5±0.5 y of age in 1999. Their growth status during infancy was known. About 20% of the girls had a height–age (H–age) below −2 Z-scores (chronic malnutrition or stunting) when they were 6–18 months of age. As adolescents, the girls were divided into two groups on the basis of H–age: those stunted and those non-stunted during infancy.Measurements: Sexual maturation was assessed by stage of breast development and menarche. Height, body mass, sitting height, bi-iliac and bi-acromial diameters, and six skinfolds were measured.Results: Differences in sexual maturation between previously stunted and non-stunted girls were not significant. Girls stunted at infancy caught up in body weight and subcutaneous fat mass during puberty, but they did not catch up on stature, sitting height or skeletal breadths (bi-acromial and bi-iliac diameters) until the final observation in 1999. Stunted girls did not have less subcutaneous fat (sum of six skinfolds) or a lower BMI. Regional variation in subcutaneous fat distribution (Z-score profile) indicated greater accretion at the biceps and subscapular sites in stunted compared to the non-stunted girls. Regional fat distribution was also assessed by principal component analysis (PCA) performed on the residuals of the six skinfolds measured during the final round (1999). PCA identified three components. Stunted and non-stunted girls were similar for the first (trunk–extremity contrast) and second (anterior–posterior contrast) components. However, there was a difference for the third component: stunted girls tended to accumulate more subcutaneous fat on the upper part of the body (trunk or arms) than non-stunted girls.Conclusion: Stunted Senegalese girls have a potential for catching up in growth during puberty. The greater accumulation of subcutaneous fat on the upper body in stunted girls may be a consequence of complex hormonal adjustments at the onset of puberty.Sponsorship: Institut de Recherche pour le Développement (IRD anciennement ORSTOM) and the Nestlé Foundation.European Journal of Clinical Nutrition (2001) 55, 50–58

Nutritional status, growth and sleep habits among Senegalese adolescent girls

Objective: To study the relation between sleep habits, nutritional status, growth and maturation in a group of African adolescent girls. The main hypothesis to be tested was that sleep length could be an effective way to spare energy, and thus malnourished girls sleep longer than normal girls.Design: Three repeated yearly surveys (1997–1999) on a subsample of girls drawn from a larger study cohort on growth at adolescence.Setting: The Niakhar district in the central part of Senegal.Subjects: In total, 40 girls were initially drawn. Missing girls were replaced at each round by girls having the same characteristics and belonging to the same cohort.Interventions: At each round, data on pubertal development (breast stages and occurrence of menarche), growth and nutritional status were collected. Adolescents wore an accelerometer for three or four consecutive nights and days at each round.Results: At the beginning of the survey, girls were 13.3±0.5 y old. They were under international reference values in weight and height. Their mean sleep duration was 8.5±0.9 h. Their puberty status did not influence their sleep habits; however, they slept more in March than in June, which was related to the seasonal change in daylight. There was a significant relation between body mass index and sleep habits: thinner girls slept a longer time and more quietly than the more corpulent girls.Conclusions: The nutritional status of these girls influenced their sleep habits: this may have been either a direct causal relation or a consequence of a protective attitude on the part of the mothers towards the frailer girls.Sponsorship: The R024 ‘Epidémiologie et Prévention’ of the IRD (France) and the Nestlé Foundation.

Habitual physical activity of Senegalese adolescent girls under different working conditions, as assessed by a questionnaire and movement registration

Summary. Objective: The aim of this study was to measure habitual physical activity in a group of Sereer adolescent females from Senegal. The hypothesis tested was that physical activity levels of adolescent Senegalese girls differ according to location and living conditions and may have a negative impact on growth and nutritional status. Design: Studies of physical activity within the framework of a longitudinal study of growth during puberty. Methods: All the adolescents were born and had been raised in the same rural communities, but some worked as maids in the cities during the dry season (migrants) while the others remained in the villages all year round in order to help their families in daily domestic and agricultural tasks (non-migrants). The study was undertaken in both rural and urban settings on a subsample of 40 migrant and 40 non-migrant girls aged 13.4-15.3, drawn from a cohort of 406 adolescents followed up since 1995. Nutritional status was estimated from anthropometric measurements; sexual maturation was based on stage of breast development and occurrence of menarche. Intensity and patterns of physical activity were derived from movement registration by accelerometry for a 3-day period. The nature and frequency of daily tasks were evaluated by questionnaires. Results: As a whole, the adolescents studied here were smaller, thinner and less mature than girls of the same age from developed countries. Migrants weighed 3.5kg more than nonmigrants and had more muscularity and a thicker fat subcutaneous layer. The day-to-day reliability of accelerometry counts was excellent (intraclass correlation coefficient: 0.90, 95% CI: 0.85-0.93). Mean daily (24h) physical activity counts were higher for migrants than for non-migrants. Migrants spent more time engaged in moderate to heavy activity than did non-migrants (9.3h/24h versus 6.1 h/24h). Non-migrants slept or were inactive for a longer period than migrants (7.6 h/24h versus 6.3h/24h). They also rested for a longer period of the day (2.1h/24h versus 0.8h/24h). When examining the influence of maturational status on physical activity, there was a clear difference between the two groups: the less mature migrants were more active, whereas the reverse was true in villages, where girls at the end of puberty reached higher intensity indices. Conclusions and implications: In both situations, the activity level was high. The nutritional status of migrants was better despite a heavier work load. Differences could be explained by better living conditions and food intake in cities.

Assessment of physical activity among rural Senegalese adolescent girls: Influence of age, sexual maturation, and body composition

PURPOSE To analyze the level of habitual physical activity and its relationship with age, maturational stage, and growth status in a group of adolescent Senegalese girls. METHODS Physical activity was assessed for 3 consecutive years in a sample of 40 girls of rural origin. They were 13.3 +/- 0.5 years old at the beginning of the study and belonged to a Sereer community located in the center of Senegal. Minute-by-minute movement counts using accelerometers enabled quantification of levels of physical activity. The assessment was performed during a 4-day period in the first round (1997) and during a 3-day period in 1998 and 1999. Half of the girls were not yet pubescent during the first round, and the whole sample displayed growth retardation in weight and stature, compared with the World Health Organization/National Center for Health Statistics reference. RESULTS Estimated levels of activity were high, ranging from 1.80 to 1.85 multiples of basal metabolic rate. There was a clear decline in the activity level during the course of study. Schoolgirls were less active than the others. Mature adolescents showed more activity during the night. A weak, but significant and positive correlation existed between body mass index and activity during the day; during the night, there was a positive correlation with fat and lean body mass. CONCLUSION Factors determining the activity level were intricate but greater maturity and better nutritional status appeared to be positively related to the activity level.

Impact of the health and living conditions of migrant and non-migrant Senegalese adolescent girls on their nutritional status and growth

OBJECTIVE To describe the living conditions of Senegalese adolescent girls according to their migration status, and to define the main socio-economic and biological determinants of their nutritional and growth status. DESIGN Health and living conditions, sexual maturation, and nutritional and growth status of adolescent girls were determined within the framework of a longitudinal study on growth. SETTINGS The capital city of Senegal (Dakar) and a rural community (Niakhar), 120 km south-east of Dakar. SUBJECTS Three hundred and thirty-one girls, 14.5-16.6 years of age, were recruited from the same villages. Thirty-six per cent of the sample remained in the villages to attend school and/or to help with household subsistence tasks (non-migrants). The remaining (64%) migrated to cities to work as maids (migrants) and lived in two different socio-economic environments: at the home of a guardian during the night and in the house of the employer during the daytime. RESULTS Family rural environment and guardian and employer urban environments were socio-economically different (P < 0.001). Living conditions in urban areas were better than in rural areas and the employers environment was socio-economically more favourable. Migrants had more advanced sexual maturation and higher body mass index (BMI), fat mass index (FMI) and mid-upper arm circumference than non-migrants. However, migrants were smaller than non-migrants. BMI, FMI and weight-for-age were related to socio-economic levels and duration of migration. Schooling was positively related to height and negatively related to BMI. CONCLUSIONS Migrants enjoyed better living conditions than non-migrants. This could be partly due to the better socio-economic environment of the employer. It was associated with earlier puberty and better nutritional status, but not with a better growth.

Cross-cultural comparison of growth, maturation and adiposity indices of two contrasting adolescent populations in rural Senegal (West Africa) and Martinique (Caribbean).

OBJECTIVES To stress the importance of social and environment (nutritional) factors in determining the growth spurt during puberty and the risk of excessive adiposity, two contrasting adolescent populations, one from a rural area of Senegal (West Africa) and the other from Martinique (French West Indies), were compared. DESIGN Cross-cultural comparison of contrasting populations. Adolescents from Senegal belonged to a cohort followed up since 1995. Adolescents from Martinique participated in a cross-sectional nutritional survey that covered the entire island. SUBJECTS A total of 507 adolescents (mean age: 14.3+/-0.7 years) from Senegal (319 girls and 188 boys) and 703 adolescents from Martinique (351 boys and 352 girls) were surveyed. RESULTS Differences in growth and maturation were striking: boys in Martinique were 22.7 kg heavier and 20.1 cm taller than boys in Senegal. Differences were less important for girls but still evident: 12.6 kg in weight and 10.5 cm in stature. In Senegal, there were virtually no overweight adolescents, but 18% of girls and 50% of boys could be considered as malnourished. In Martinique, 19% of girls and 23% of boys were overweight or obese. Adolescent girls from Martinique were also sexually more mature than adolescent girls from Senegal. When comparisons were repeated after Senegalese girls reached menarche, differences in weight and body mass index disappeared, but Senegalese girls were still shorter than girls from Martinique. CONCLUSIONS Adolescents are extremely susceptible to nutritional changes and their particular situation needs to be incorporated into nutritional prevention programmes.