Increased bone mineral density in Aboriginal and Torres Strait Islander Australians: impact of body composition differences

Minimal trauma hip fracture hospitalisations among older Indigenous and non-Indigenous Australians: A retrospective population-based cohort study

OBJECTIVES

To compare minimal trauma hip fractures (MTHF) between older Indigenous and non-Indigenous Australians.

METHODS

Epidemiological study of retrospective New South Wales hospitalisation data (2005-2016) for MTHF among Indigenous and non-Indigenous Australians over 40 years of age.

RESULTS

Estimated age-standardised rates of MTHF were lower among Indigenous Australians than non-Indigenous Australians (142.2 vs. 161.7 per 100,000) with a direct standardised rate ratio of 0.887 (95%CI 0.78-0.99, p = 0.031). However, for both male and female Indigenous Australians, MTHF occur at a younger age than in non-Indigenous Australians (age 40-74: 52% vs. 19%, p < 0.001). Proportions of MTHF are higher among women and were almost double among rural Indigenous Australians compared with rural non-Indigenous Australians (59% vs. 31%, p < 0.001).

CONCLUSIONS

New South Wales Hospitalisation data showed that estimated age-standardised rates of MTHF appear lower among Indigenous Australians than in non-Indigenous Australians but also occur at a younger age for Indigenous people. MTHF are more common among rural Indigenous Australians and women.

Why Aboriginal and Torres Strait Islander Australians fall and fracture: the codesigned Study of Indigenous Muscle and Bone Ageing (SIMBA) protocol

OBJECTIVES

Aboriginal and Torres Strait Islander Australians have a substantially greater fracture risk, where men are 50% and women are 26% more likely to experience a hip fracture compared with non-Indigenous Australians. Fall-related injuries in this population have also increased by 10%/year compared with 4.3%/year in non-Indigenous Australians. This study aims to determine why falls and fracture risk are higher in Aboriginal and Torres Strait Islander Australians.

SETTING

All clinical assessments will be performed at one centre in Melbourne, Australia. At baseline, participants will have clinical assessments, including questionnaires, anthropometry, bone structure, body composition and physical performance tests. These assessments will be repeated at follow-up 1 and follow-up 2, with an interval of 12 months between each clinical visit.

PARTICIPANTS

This codesigned prospective observational study aims to recruit a total of 298 adults who identify as Aboriginal and Torres Strait Islander and reside within Victoria, Australia. Stratified sampling by age and sex will be used to ensure equitable distribution of men and women across four age-bands (35-44, 45-54, 55-64 and 65+ years).

PRIMARY AND SECONDARY OUTCOME MEASURES

The primary outcome is within-individual yearly change in areal bone mineral density at the total hip, femoral neck and lumbar spine assessed by dual energy X-ray absorptiometry. Within-individual change in cortical and trabecular volumetric bone mineral density at the radius and tibia using high-resolution peripheral quantitative computed tomography will be determined. Secondary outcomes include yearly differences in physical performance and body composition.

ETHICAL APPROVAL

Ethics approval for this study has been granted by the Monash Health Human Research Ethics Committee (project number: RES-19-0000374A).

TRIAL REGISTRATION NUMBER

ACTRN12620000161921.

Effect of an ageing population on services for the elderly in the Northern Territory

Objective The aim of the present study was to describe the elderly population of the Northern Territory (NT), explore the challenges of delivering aged care services to this population and implications for the acute care sector. Methods Data gathered from a variety of sources were used to describe the demographic and health profile of elderly Territorians, the aged care structure and services in the NT, and admission trends of elderly patients in NT hospitals. Information regarding NT community and residential aged care services was sourced from government reports. NT public hospital admissions from 2001 to 2015 were adjusted by the estimated Aboriginal and non-Aboriginal populations. Results In 2015, elderly people constituted 9.2% of the NT population and this number is predicted to increase. Between 2001 and 2015, the number and rate of elderly admissions to NT public hospitals increased significantly. Compared with other jurisdictions, aged care in the NT is dominated by community services, which are of limited scope. Important geographical and economic factors affect the availability of residential aged care beds. This, in turn, affects the ability of elderly people to transition from hospital settings. Conclusions The NT has a relatively small but growing elderly population with increasing needs. This population is markedly different compared with its counterparts in other Australian states and territories, but receives aged care services based on national policies. Recent changes to community-based services and increases in residential beds should improve services and care, although remaining challenges and gaps need to be addressed. What is known about the topic? Increasing health and care needs of elderly people will place significant stress across the health and aged care system. In Australia, most aged care services are apportioned and funded under a national system. The NT has a markedly different population profile compared with the rest of Australia, which gives rise to unique considerations, but its aged care structure is based on nationally developed policies. What does this paper add? Elderly people in the NT are increasingly using acute care services. Aged care services in the NT have higher ratios of community-based services to residential aged care facilities (RACF) as a consequence of a 'younger' cohort of Aboriginal elderly people who live remotely. In addition, economic factors affect the low number of RACF places. As evidenced in past years, a small pool of beds can adversely affect the numbers and length of stay of elderly people waiting in hospitals. What are the implications for practitioners? The NT has a small but growing population of elderly people, which will place an increasing burden on acute care services that are ill equipped to manage their specific needs. Recent RACF and flexible care bed approvals may alleviate past difficulties to transition hospital patients awaiting RACF placement. Significant changes at the national level to community-based care services that increase flexibility for providers may bring about better outcomes for remote elderly recipients. However, high costs and issues with remote servicing will remain. Psychogeriatrics remains a major underserviced area in the NT with no prospective solution.

Musculoskeletal health of Indigenous Australians

INTRODUCTION

Research on non-communicable diseases (NCD) in Indigenous Australians has mostly focused on diabetes mellitus and chronic kidney or cardiovascular disease. Osteoporosis, characterised by low bone mass and structural deterioration of bone tissue, and sarcopenia, the age-related loss of muscle mass and strength, often co-exist with these common NCDs-the combination of which will disproportionately increase bone fragility and fracture risk and negatively influence cortical and trabecular bone. Furthermore, the social gradient of NCDs, including osteoporosis and fracture, is well-documented, meaning that specific population groups are likely to be at greater risk of poorer health outcomes: Indigenous Australians are one such group.

PURPOSE

This review summarises the findings reported in the literature regarding the muscle and bone health of Indigenous Australians.

FINDINGS

There are limited data regarding the musculoskeletal health of Indigenous Australians; however, areal bone mineral density (aBMD) measured by dual-energy X-ray absorptiometry (DXA) is reported to be greater at the hip compared to non-Indigenous Australians. Falls are the leading cause of injury-related hospitalisations in older Australians, particularly Indigenous Australians, with a great proportion suffering from fall-related fractures. Despite sparse data, it appears that Indigenous men and women have a substantially higher risk of hip fracture at a much younger age compared to non-Indigenous Australians.

CONCLUSION

Data on more detailed musculoskeletal health outcomes are required in Indigenous Australians to better understand fracture risk and to formulate evidence-based strategies for fracture prevention and to minimise the risk of falls.

Development of a single-frequency bioimpedance prediction equation for fat-free mass in an adult Indigenous Australian population

BACKGROUND/OBJECTIVES

To describe the development of a single-frequency bioimpedance prediction equation for fat-free mass (FFM) suitable for adult Aboriginal and Torres Strait Islander peoples with and without diabetes or indicators of chronic kidney disease (CKD).

SUBJECTS/METHODS

FFM was measured by whole-body dual-energy X-ray absorptiometry in 147 adult Indigenous Australians. Height, weight, body circumference and resistance were also measured. Adults with and without diabetes and indicators of CKD were examined. A random split sample with internal cross-validation approach was used to predict and subsequently validate FFM using resistance, height, weight, age and gender against measured FFM.

RESULTS

Among 147 adults with a median body mass index of 31 kg/m(2), the final model of FFM was FFM (kg)=0.432 (height, cm(2)/resistance, ohm)-0.086 (age, years)+0.269 (weight, kg)-6.422 (if female)+16.429. Adjusted R(2) was 0.94 and the root mean square error was 3.33 kg. The concordance was high (rc=0.97) between measured and predicted FFM across a wide range of FFM (31-85 kg).

CONCLUSIONS

In the context of the high burden of diabetes and CKD among adult Indigenous Australians, this new equation for FFM was both accurate and precise and based on easily acquired variables (height, weight, age, gender and resistance) among a heterogeneous adult cohort.

Lean body mass: the development and validation of prediction equations in healthy adults

Background

There is a loss of lean body mass (LBM) with increasing age. A low LBM has been associated with increased adverse effects from prescribed medications such as chemotherapy. Accurate assessment of LBM may allow for more accurate drug prescribing. The aims of this study were to develop new prediction equations (PEs) for LBM with anthropometric and biochemical variables from a development cohort and then validate the best performing PEs in validation cohorts.

Methods

PEs were developed in a cohort of 188 healthy subjects and then validated in a convenience cohort of 52 healthy subjects. The best performing anthropometric PE was then compared to published anthropometric PEs in an older (age ≥ 50 years) cohort of 2287 people. Best subset regression analysis was used to derive PEs. Correlation, Bland-Altman and Sheiner & Beal methods were used to validate and compare the PEs against dual X-ray absorptiometry (DXA)-derived LBM.

Results

The PE which included biochemistry variables performed only marginally better than the anthropometric PE. The anthropometric PE on average over-estimated LBM by 0.74 kg in the combined cohort. Across gender (male vs. female), body mass index (< 22, 22- < 27, 27- < 30 and ≥30 kg/m²) and age groups (50–64, 65–79 and ≥80 years), the maximum mean over-estimation of the anthropometric PE was 1.36 kg.

Conclusions

A new anthropometric PE has been developed that offers an alternative for clinicians when access to DXA is limited. Further research is required to determine the clinical utility and if it will improve the safety of medication use.