Diabetes and related conditions in Australia: recognising the heterogeneity

1
Diabetes and related conditions in
Australiarecognising the heterogeneity

• Kerin ODea
• Menzies School of Health Research
• Darwin, NT

2
Critical role of population based data

• Identify undiagnosed burden of disease
• Identify predictors of disease and associated
  conditions
• Overweight and obesity
• Sedentariness and physical activity
• Over consumption of energy dense foods
• Identify trends
• Sharp increase in obesity in children

3
AUSTRALIAN DIABETES, OBESITY LIFESTYLE STUDY
(AusDiab)

• Population-based study (1999-2000) to estimate
  national prevalence of diabetes and its
  precursors in Australian adults 25 years.

4
(No Transcript)
5
Average meal sizes of take away foods
have doubled in the US over the past 20 years
SUPER-SIZE ME
6
Sharp recent increase in prevalence of overweight
and obesity in Australian children since mid
1980s

Booth et al, AJCN, 7729-36, 2003
7
A steady increase in diabetes prevalence or an
accelerating epidemic??

• Trends in obesity in children suggest
• Younger age of onset
• Accelerating increase in prevalence
• Inactivity appears to confer additional risk
• Diet trends may exacerbate insulin resistance
• Refined, energy dense
• Monitoring trends in body weight appears to be
  the simplest and strongest indicator

8
Australian Aborigines as hunter gatherers
9
Australian Aborigines as hunter gatherers
10
Australian Aborigines as hunter gatherers

• Physically fit
• Lean - BMI lt 20 kg/m2
• Low blood pressure
• No rise of body weight or BP with age
• Low fasting glucose (lt 4mmol/L)
• Low fasting cholesterol (lt 4mmol/L)
• ? Insulin resistance?

11
Aborigines after westernisation

• Extreme social disadvantage
• high unemployment
• welfare dependency
• poor education
• overcrowded living conditions
• Poor health
• heavy burden of infectious diseases, particularly
  among children
• heavy burden of lifestyle-related chronic
  diseases among adults
• Poor quality diet
• high cost and limited availability of fresh
  vegetables and fruit in rural and remote Australia

12
Aborigines after westernisation

• Obesity
• centralised fat distribution in both men and
  women
• Early onset type 2 diabetes
• Premature cardiovascular disease
• dyslipidemia (high TG, low HDL-chol)
• hypertension
• microalbuminuria
• Renal disease
• Hyperinsulinemia
• The metabolic syndrome
• Low birthweight, diabetes in pregnancy/GDM

13
Diabetes in Australian populations

Diabetes prevalence

• from Glatthaar C et al., Diabetes and impaired
  glucose tolerance a prevalence estimate based on
  the Busselton 1981 survey. Med J Aust 1985 143
  436-40.
• Central Aust 1 Gault A et al, Diabetes Care 19
  1269-1273, 1996.
• Central Aust 2 O'Dea K et al, Diabetes Care 16
  1004-1010, 1993.

14
Diabetes incidence and BMI in Central Australian
Aborigines 1987/88 - 1995
Body mass index (kg/m2)
Daniel et al., Diabetes Care, 1999, 221993-8b
15
Diabetes risk in Indigenous populations in
Australia

• Different patterns of risk between Aboriginal and
  Torres Strait Islander populations
• Weight gain (even in the healthy weight range)
  is a particularly strong risk factor for diabetes
  among Aborigines
• How does this differ between different groups?
• What is the influence of early life events and
  social disadvantage generally?

16
Renal disease in Indigenous Australian populations

• Studies in the NT (Top end) - Hoy et al.
• rising prevalence
• link with risk factors throughout the life course
• socio economic factors
• intervention with ACE inhibitor
• Studies in other populations (Kimberley, Central
  Australia, North Queensland
• similar patterns

17
Indigenous ESRD incidence 1993-98
18
Recognise the heterogeneity in Australias
Indigenous peoples

• Renal disease is an excellent example of why it
  is misleading to generalise
• Avoid burying serious health disadvantage in
  averages
• Direct services to those sectors of the
  population most disadvantaged
• Develop better indices of disadvantage to apply
  to Indigenous populations

19
What are the data needs in relation to the
accelerating epidemic of diabetes in Australia?

• Regular monitoring (such as AusDiab)
• Including critical biological data
• Longitudinal data (Australia_at_risk)
• To follow trends in incidence of new cases and
  progression of complications
• Implications for policy and service provision
• Routine data collection
• Gestational diabetes monitoring and follow up
  of cases and offspring
• Trends in childhood and adolescent obesity

20
Additional data needs for Indigenous Australian
populations

• High risk generally but great heterogeneity
• How can the differences be better documented?
• Gaps in information
• Population-based data for urban communities
• What data could be routinely collected?
• Consider sentinel sites for 5-yearly monitoring
  of chronic diseases and their risk factors
• Urban, rural and remote
• Biomedical and social demographic data

21
The case for a regular biomedical risk factor
survey in Australia

• If practical, should be linked in some way to the
  National Health Survey
• Do not be too ambitious in terms of what is
  measured
• Possibility of sub studies for areas of special
  interest
• Consider a CRC to run a regular biomedical survey
  a broad partnership of researchers and the
  public and private sector
• Include a nutrition survey
• A survey of Australias children
• Less invasive urine, anthropometry, blood
  pressure