The Gambia is a West African country in nutritional, demographic and epidemiological transition. The climate is sub-tropical with both wet and dry seasons impacting food availability and nutritional status. The nutrition transition is associated with shifts from traditional to Western patterns of food consumption and physical activity; i.e. reduced intakes of fruit and vegetables, increased consumption of oil and sugar, and a more sedentary lifestyle.Nutrition research in the rural district of Kiang West in The Gambia has enabled characterisation of food and nutrient intakes of a rural population. Most people are subsistence farmers, spending significant time outdoors exposed to UVB sunshine. The diet consists of cereals, predominantly rice, combined with sauces, typically composed of groundnuts or leaves, depending on the season. Due to limited consumption of animal products e.g. dairy and meat, intakes of important minerals are low, particularly calcium. Despite the habitually low calcium, reported incidence of fragility fracture is low (1) . The aim of this study was to investigate whether migrating to an urban environment impacted dietary intakes of bone forming minerals. This research formed part of a larger study investigating the impact of nutrition transition on bone health in Gambian women living in rural and urban areas of The Gambia. As part of this study we conducted a 2 day prospective weighed diet record. Data were collected for two groups of pre-menopausal Gambian women: urban migrant (n = 59) and rural (n = 75). Both groups spent their formative years in the same rural setting, selected urban women were known to have migrated when aged ≥16 years. Food and nutrient intakes were calculated using Gambian food composition tables and Diet in Nutrients out (DINO), a programme which enables both coding of dietary data and export of nutrient intakes (2) . Mean age and height of rural and urban groups were not significantly different (p > 0·05). Urban migrant women were significantly heavier: urban 69·2 ± 15·6 kg and rural 60·5 ± 12·2 kg (p < 0·01). There were no significant differences in energy intake or macronutrient composition of the diet; approximately 65 % of energy came from carbohydrates. Calcium intakes were low in both groups, urban migrant 294 mg/d (IQR: 235 to 385) and rural 305 mg/d (IQR: 222 to 420). Urban women had significantly lower intakes of potassium, magnesium and dietary fibre (p < 0·01), related to lower consumption of fruit, green leafy vegetables and groundnuts. These differences reflect the early stages of the nutrition transition; implications for bone health and other non-communicable diseases requires further research.
Urbanisation and the associated nutrition transition have been linked with the rapid and recent rise in osteoporotic fragility fracture incidence in many countries (1) . Predictions indicate that hip fracture incidence will increase 6-fold in Africa and Asia by 2050, partially attributed to demographic transition and population ageing (2) . Differences in areal bone mineral density (aBMD) between rural and urban locations indicate that urban regions of high income countries (HIC) have lower aBMD and a higher incidence of hip fracture (3) . The few studies conducted in low and middle income countries (LMIC) provide inconsistent results; in contrast to HIC, most have found higher aBMD in urban populations (4) . In order to investigate the impact of migrating to an urban environment, we have conducted detailed studies of bone phenotype and factors affecting bone health in two groups of pre-menopausal Gambian women: urban migrant (n = 58) and rural (n = 81). Both groups spent their formative years in the same rural setting, urban women were known to have migrated when aged ≥16 years. Bone phenotype (bone mineral content (BMC); bone area (BA); areal bone mineral density (aBMD), and size-adjusted BMC (height, weight and BA) of the whole-body, lumbar spine and hip) was measured by dual energy x-ray absorptiometry (DXA) with further characterisation of bone phenotype by peripheral quantitative CT (pQCT). Data were also collected on anthropometry, body composition, food and nutrient intakes, physical activity, socio-demographic characteristics, vitamin D status and 24hr urinary mineral outputs (Na, K, P and Ca).Mean age and height of rural and urban migrant groups were not significantly different (p > 0·05). Urban migrant women were significantly heavier (p < 0·01). Significant differences in BMC and aBMD were found between groups at all skeletal sites, with urban women having higher BMC and aBMD; BA was not significantly different. The greatest difference in BMC was found at the lumbar spine (8·5 % ± SE 3·0, p < 0·01). After adjusting for size, the differences between urban and rural spine BMC remained significant (6·2 % ± SE 2·1, p < 0·01). These results indicate that rural-to-urban migration is associated with higher BMC, with differences mostly attenuated by adjusting for body size, particularly weight. In this African population, higher SA-BMC may affect future fracture risk.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.