Determinants of Bone Strength Estimated by Calcaneal Ultrasonography in Inuit Women from Nuuk (Greenland)

Alexandra-Cristina Paunescu,Pierre Ayotte,Gert Mulvad,Sylvie Dodin,Suzanne Côté,Henning S Pedersen,Éric Dewailly

doi:10.1155/2014/408316

Abstract

This study was conducted to identify determinants of bone strength estimated by quantitative ultrasonography (QUS) at the calcaneus of Greenlandic Inuit women. A total of 153 Inuit women from Nuuk, aged from 49 to 64 years, participated in the first QUS measurement (year 2000) with an Achilles Lunar instrument (speed of sound (SOS); broadband ultrasound attenuation (BUA); stiffness index (SI)). A second measurement was performed two years later (year 2002) in 121 participants. Several factors known to be associated with bone strength were recorded at baseline for 118 of them. Determinants of QUS parameters were identified using an automatic (stepwise) selection of variables in linear regression. Significant determinants of baseline QUS measurements were age and body weight for all QUS parameters, height for BUA and SI, and hormone replacement therapy (HRT) use for SI. Significant predictors of follow-up QUS measurements were baseline QUS values, the smoking status and HRT use for all QUS parameters, omega-3/omega-6 PUFA content ratio of erythrocytes membrane phospholipids (BUA and SI), and menopausal status (BUA). Several modifiable dietary factors, such as a diet rich in omega-3 PUFAs and lifestyle factors (i.e., smoking, taking HRT), were shown to determine QUS parameters after a follow-up of two years.

Highlights

Inuit populations live in extreme climatic conditions and exhibit specific lifestyle and dietary habits, in particular their traditional diet that comprises large amounts of fish and marine mammal meat and fat [1]
We found that after a two-year follow-up, lower quantitative ultrasonography (QUS) measures were predicted by smoking and postmenopausal status, whereas past hormone replacement therapy (HRT) use and an elevated omega-3/omega-6 polyunsaturated fatty acids (PUFAs) content ratio in erythrocyte membranes is predictive of higher QUS values
Baseline QUS measures, the strongest determinants of QUS measures after a two-year follow-up, were themselves determined by age, past HRT use, body weight, and height

Summary

Introduction

Inuit populations live in extreme climatic conditions and exhibit specific lifestyle and dietary habits, in particular their traditional diet that comprises large amounts of fish and marine mammal meat and fat [1]. Studies conducted during the 70’s reported that Inuit experience an earlier onset and a greater bone loss with age, compared to U.S Caucasians [3,4,5,6]. Cortical bone thickness in Inuit was reported to be lower than in Caucasians [5,6,7,8]. Reported lower values of bone parameters measured by quantitative ultrasonography (QUS) at the right calcaneus compared to values obtained in southern Quebec women. Mean values for broadband ultrasound attenuation (BUA), Epidemiology Research International speed of sound (SOS), and the stiffness index (SI) were, respectively, 4%, 1.4%, and 9.5% lower in Greenlandic Inuit women compared to the southern Quebec women [12]

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