Magnesium Intake Predicts Bone Turnover in Postmenopausal Black South African Women.

Hattie H Wright,Marlena C Kruger,Iolanthe M Kruger,Willem D Schutte,Herculina S Kruger,Edelweiss Wentzel-Viljoen

doi:10.3390/nu11102519

Hattie H Wright, Marlena C Kruger + Show 4 more

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https://doi.org/10.3390/nu11102519

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Abstract

This prospective study investigated the association between nutrient intake, dietary patterns, and changes in bone turnover and bone mineral density (BMD) in postmenopausal urban black South African women over two years. These women (n = 144) underwent BMD measurements at the distal radius, lumbar spine, femoral neck (FN), as well as a biochemical analysis which included the parathyroid hormone (PTH), 25-hydroxyvitamin D, C-Telopeptide of type I collagen (CTX-1) in 2010 and 2012. Their dietary intake was assessed in 2010 using a food frequency questionnaire, and sociodemographic and health information was collected. Four dietary patterns explained 54.4% of the variance of dietary intake, namely staple foods and processed meats, home cooking, snacking, and high sugar. Dietary magnesium negatively correlated with CTx-1 in 2012 (r = −0.21, p = 0.02), calcium correlated with distal radius BMD in 2010 (r = 0.22, p = 0.01) and 2012 (r = 0.24, p = 0.005), and the snacking dietary pattern score correlated with FN BMD in 2010 (r = 0.18, p = 0.03) and 2012 (r = 0.21, p = 0.02). The baseline CTx-1 and dietary magnesium intake predicted 22% of the variance in percentage change of CTx-1 over two years (p < 0.001).The magnesium intake predicted short-term bone resorption over two years.

Highlights

The ethnic differences in bone mineral density (BMD) and fracture risk have been described in both high-income [1,2], and low- and middle-income countries [3,4]
The South African Northwest Province (NWP) arm of the Prospective Urban and Rural Epidemiology (PURE) (PURE-SA-NWP) study commenced with a baseline data collection in 2005 [24]
Dietary magnesium intake was negatively associated with bone resorption

Summary

Introduction

The ethnic differences in bone mineral density (BMD) and fracture risk have been described in both high-income [1,2], and low- and middle-income countries [3,4]. In South Africa, black populations have been reported to have a higher overall BMD and a lower fracture risk compared to white populations [4]. Evidence point towards a lower than expected BMD in black South African women and an increased risk for poor bone health and fractures [5,6,7]. Reduced BMD among black South African women may be associated with the predominance of environmental exposures over genetic factors. Earlier studies [8,9] identified that the migration of black South Africans into urban areas significantly affects their health status with an increase in the incidence of obesity and non-communicable diseases related to urbanisation, the nutrition transition, and decreased physical activity.

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