Studies /

The Gambian Bone Ageing Study

The GamBAS Study

GamBAS is a prospective study of musculoskeletal ageing in a rural, subsistence farming population from The Gambia, West Africa. It is the largest, most detailed study of musculoskeletal ageing in Sub-Saharan Africa. The GAMBAS cohort consists 488 males and females aged 40 and over, who have been measured three times.  In 2019-20 an Urban GAMBAS cohort was piloted, recruiting 102 individuals aged 60 years and over.

The primary objective is to measure within individual change BMD with ageing in men and women over the age of 40 years living in a rural area of The Gambia.  The secondary objectives are to (i) characterise  change in skeletal characteristics that influence fracture risk (BMC, areal and volumetric BMD, bone dimensions, geometry and strength); (ii) describe sarcopenia and vertebral fracture prevalence within the study population, (iii) investigate whether changes in muscle force and mass characterise change in bone strength; (iv) identify nutritional, hormonal and lifestyle determinants of bone loss and changes in muscle strength during ageing; (v) to understand whether seasonality alters the change in bone and muscle outcomes over follow-up.

Participant sampling and recruitment was through the Kiang West Demographic Surveillance Survey; initially in 4 cores study villages and then extended to 6 more sites within the region. Thirty males and thirty females in each of 8 age bands (40-45, 45-50, 50-55, 55-60, 60-65, 65-70, 75+) were recruited to the study and randomised at recruitment to follow-up at an interval of 1.5-2 years (2012-2015); mean time of follow-up was 1.7y. The second follow-up is ongoing (2018-).  A sample of 100 older, urban-dwelling adults (aged 60y and above) was recruited to pilot a larger, Urban GamBAS study.

The primary outcome is change in hip BMD by dual energy X-ray absorptiometry.  Secondary outcomes include bone and body composition measurements by DXA (spine, whole body); peripheral quantitative computed tomography;  grip strength and lower limb muscle force and power; short physical performance battery. A biobank of plasma, DNA and urine has been collated together with lifestyle and medical questionnaire data. In the Urban cohort collection of weight-bearing knee radiographs was piloted.

Research outputs: Five published papers and the creation of the Sub-Saharan Africa Musculoskeletal network (SAMSON) which Kate Ward leads together with Dr celia Gregson from Univeristy of Bristol.

SAMSON network: GamBAS led to the development of the Sub-Saharan Africa Musculoskeletal Network (SAMSON), an initiative led by myself and Dr Gregson. SAMSON provides a platform for collaborative research and capacity building across 9 partner institutions in the UK and SSA (Bristol, Oxford, The Gambia, Zimbabwe, South Africa, Uganda). Dr Gregson and I co-wrote the Lancet Global Health commentary calling for action on fragility fracture prevention in Sub-Saharan Africa.

Sarcopenia prevalence:  This study showed age related loss of muscle mass and strength in Gambian adults. Importantly showing that sarcopenia was prevalent but also that the currently accepted international definitions need refinement for application in this population. 

Cohort paper: Describes for the first time evidence of vertebral fractures and spine degeneration in ageing Gambians. Also showing age- and sex-related differences in bone and muscle mass, and evidence for peripheral vascular calcification.

Research Outputs

1. The prevalence of sarcopenia and relationships between muscle and bone in ageing West-African Gambian men and women

Zengin A, Jarjou LM, Prentice A, Cooper C, Ebeling PR, Ward KA.
J Cachexia Sarcopenia Muscle. 2018 Oct;9(5):920-928. doi: 10.1002/jcsm.12341. Epub 2018 Sep 16.

2. Corrigendum: The Gambian Bone and Muscle Ageing Study: Baseline Data From a Prospective Observational African Sub-Saharan Study

Zengin A, Fulford AJ, Sawo Y, Jarjou LM, Schoenmakers I, Goldberg G, Prentice A, Ward KA.
Front Endocrinol (Lausanne). 2018 Apr 16;9:160. doi: 10.3389/fendo.2018.00160. eCollection 2018.

3. The Gambian Bone and Muscle Ageing Study (GamBAS): baseline data from a prospective observational Sub-Saharan Africa study

Zengin A, Fulford AJ, Sawo Y, Jarjou LM, Schoenmakers I, Goldberg GR, Prentice A, Ward KA.
Front Endocrinol (Lausanne). 2017 Aug 31;8:219. doi: 10.3389/fendo.2017.00219. eCollection 2017.