Indigenous cultures in countries with similar colonisation histories share the challenge of intergenerational diabetes
Authors: Louise J Maple-Brown, Denella Hampton
Journal: The Lancet Global Health (2020)

In this issue of The Lancet Global Health, Britt Voaklander and colleagues1Voaklander B Rowe S Sanni O Campbell S Eurich D Ospina MB Prevalence of diabetes in pregnancy among Indigenous women in Australia, Canada, New Zealand, and the USA: a systematic review and meta-analysis.Lancet Glob Health. 2020; 8: e681-e698Summary Full Text Full Text PDF PubMed Scopus (21) Google Scholar report a systematic review and meta-analysis of the prevalence of pre-existing diabetes and gestational diabetes among Indigenous and non-Indigenous pregnant women in four countries with similar histories of colonisation: Australia, Canada, New Zealand, and the USA. The authors present the pooled unadjusted prevalence odds ratios (PORs) by country and by type of diabetes. Pre-existing diabetes was 1·8–3·6 times more prevalent in Indigenous compared with non-Indigenous pregnant women across each of the four countries, with the highest POR reported in Australia (3·63, 95% CI 2·35–5·62) and the lowest POR reported in the USA (1·81, 1·53–2·13). The POR of pre-existing diabetes in Indigenous compared with non-Indigenous pregnant women in New Zealand was not reported because the authors could not identify any studies that included these data.1Voaklander B Rowe S Sanni O Campbell S Eurich D Ospina MB Prevalence of diabetes in pregnancy among Indigenous women in Australia, Canada, New Zealand, and the USA: a systematic review and meta-analysis.Lancet Glob Health. 2020; 8: e681-e698Summary Full Text Full Text PDF PubMed Scopus (21) Google Scholar In the analyses, pre-existing diabetes consisted of both type 1 diabetes and type 2 diabetes, as further differentiation was not feasible with the available data.1Voaklander B Rowe S Sanni O Campbell S Eurich D Ospina MB Prevalence of diabetes in pregnancy among Indigenous women in Australia, Canada, New Zealand, and the USA: a systematic review and meta-analysis.Lancet Glob Health. 2020; 8: e681-e698Summary Full Text Full Text PDF PubMed Scopus (21) Google Scholar However, the authors appropriately noted that the disproportionately higher prevalence of diabetes among Indigenous women than non-Indigenous women was likely to be largely attributable to the high prevalence of type 2 diabetes in Indigenous populations worldwide, as reported by previous studies.2Harris SB Tompkins JW TeHiwi B Call to action: a new path for improving diabetes care for Indigenous peoples, a global review.Diab Res Clin Prac. 2017; 123: 120-133Summary Full Text Full Text PDF PubMed Scopus (33) Google Scholar Voaklander and colleagues1Voaklander B Rowe S Sanni O Campbell S Eurich D Ospina MB Prevalence of diabetes in pregnancy among Indigenous women in Australia, Canada, New Zealand, and the USA: a systematic review and meta-analysis.Lancet Glob Health. 2020; 8: e681-e698Summary Full Text Full Text PDF PubMed Scopus (21) Google Scholar report that the prevalence of gestational diabetes was 1·42–2·04 times higher in Indigenous women than in non-Indigenous women across each of the four countries. Despite identifying high heterogeneity between studies, the individual study PORs indicated a clear and consistent direction of a greater risk of diabetes in Indigenous pregnant women than in non-Indigenous pregnant women, and that this association was stronger and more consistent for pre-existing diabetes than it was for gestational diabetes. The degree of heterogeneity between studies could have been because of variation in the prevalence of type 2 diabetes in Indigenous peoples in the same country (as was previously reported in Australia3Minges KE Zimmet P Magliano DJ Dunstan DW Brown A Shaw JE Diabetes prevalence and determinants in Indigenous Australian populations: a systematic review.Diab Res Clin Prac. 2011; 93: 139-149Summary Full Text Full Text PDF PubMed Scopus (59) Google Scholar), and because of methodological differences between studies (ie, different diabetes risk profiles within non-Indigenous groups, and changes in gestational diabetes diagnostic criteria over time and in different countries). The important new contribution of this study1Voaklander B Rowe S Sanni O Campbell S Eurich D Ospina MB Prevalence of diabetes in pregnancy among Indigenous women in Australia, Canada, New Zealand, and the USA: a systematic review and meta-analysis.Lancet Glob Health. 2020; 8: e681-e698Summary Full Text Full Text PDF PubMed Scopus (21) Google Scholar is the separate reporting of the prevalence of pre-existing diabetes and gestational diabetes in Indigenous pregnant women compared with non-Indigenous pregnant women; previous systematic reviews4Porter C Skinner T Ellis I The current state of Indigenous and Aboriginal women with diabetes in pregnancy: a systematic review.Diab Res Clin Prac. 2012; 98: 209-225Summary Full Text Full Text PDF PubMed Scopus (33) Google Scholar of the prevalence of diabetes in these populations have combined all types together. The results of the study1Voaklander B Rowe S Sanni O Campbell S Eurich D Ospina MB Prevalence of diabetes in pregnancy among Indigenous women in Australia, Canada, New Zealand, and the USA: a systematic review and meta-analysis.Lancet Glob Health. 2020; 8: e681-e698Summary Full Text Full Text PDF PubMed Scopus (21) Google Scholar highlight the importance of health-care system changes and ongoing education for health practitioners regarding the prioritisation of screening for hyperglycaemia in Indigenous women early on in their pregnancies. The results also have implications for prenatal care services and birth outcomes in Indigenous women globally, and for the health of future generations. Children born to women with pre-pregnancy diabetes and gestational diabetes have an increased risk of youth-onset (ie, aged <25 years) obesity, type 2 diabetes, and premature cardiovascular disease5Dabelea D Knowler WC Pettitt DJ Effect of diabetes in pregnancy on offspring: follow-up research in the Pima Indians.J Matern Fetal Med. 2000; 9: 83-88Crossref PubMed Google Scholar. The disproportionately high prevalence of hyperglycaemia in Indigenous versus non-Indigenous pregnant women worldwide is contributing to an escalating epidemic of intergenerational type 2 diabetes in this population. The age of onset of type 2 diabetes continues to decrease with each generation, with Australian Aboriginal children as young as 5 years being diagnosed with the condition.6Kevat D Wilson D Sinha A A 5-year-old girl with type 2 diabetes.Lancet. 2014; 3831268Summary Full Text Full Text PDF PubMed Scopus (8) Google Scholar Of great concern is the strikingly high mortality and number of complications associated with youth-onset diabetes in Indigenous peoples in these same countries.7Reynolds K Saydah SH Isom S et al.Mortality in youth-onset type 1 and type 2 diabetes: The SEARCH for Diabetes in Youth study.J Diabetes Complications. 2018; 32: 545-549Crossref PubMed Scopus (30) Google Scholar Further research is needed to understand the reasons for this intergenerational epidemic, with epigenetics likely playing a role.8Hjort L Novakovic B Grunnet LG et al.Diabetes in pregnancy and epigenetic mechanisms-how the first 9 months from conception might affect the child's epigenome and later risk of disease.Lancet Diabetes Endocrinol. 2019; 7: 796-806Summary Full Text Full Text PDF PubMed Scopus (31) Google Scholar Although not assessed by Voaklander and colleagues,1Voaklander B Rowe S Sanni O Campbell S Eurich D Ospina MB Prevalence of diabetes in pregnancy among Indigenous women in Australia, Canada, New Zealand, and the USA: a systematic review and meta-analysis.Lancet Glob Health. 2020; 8: e681-e698Summary Full Text Full Text PDF PubMed Scopus (21) Google Scholar recognising the important contribution of the social determinants of health and the effect of colonisation on the increased prevalence of diabetes in Indigenous women compared with non-Indigenous women is key when considering further strategies to improve outcomes in Indigenous populations. With similar histories of colonisation, Indigenous peoples in Australia, Canada, New Zealand, and the USA have all experienced a loss of land, culture, and language, and have experienced racism, poverty, and discrimination. Further research to inform the design of appropriate strategies that address the problem of intergenerational diabetes should also include a systematic review of programmes that aim to reduce and prevent intergenerational diabetes, including those that work in partnership with Indigenous populations. Pregnant Indigenous women with diabetes face many challenges, including prioritising one's own health in the context of other family or carer responsibilities, food insecurity, the high cost of fresh food, limited access to transport to medical appointments, difficultes in the timing of blood glucose profiling, and the absence of appropriate household hardware to store food or medications and prepare food. The burden of this condition in women facing these challenges is amplified by the effect of the social determinants of health. Programmes of care for the management of diabetes must be culturally safe and should be designed and implemented in conjunction with Indigenous women. Cultural safety is determined by Indigenous individuals, families, and communities, and requires health professionals to develop skills to critically reflect on their attitudes, power differentials, and practising behaviours, and to deliver accessible and responsive health care that is free of racism.9Australian Health Practitioner Regulation AgencyAustralian National Scheme's Aboriginal and Torres Strait Islander Health and Cultural Safety Strategy 2020-2025.https://nacchocommunique.files.wordpress.com/2020/02/aboriginal-and-torres-strait-islander-cultural-health-and-safety-strategy-2020-2025-1.pdfDate accessed: March 25, 2020Google Scholar Community-based care encourages the formation of strong partnering relationships between clinicians and consumers and enables diabetes care to be offered in a culturally safe manner, in which women are empowered to make their own health-care decisions. Outreach programmes are important and should be included in the suite of health-care programmes to support Indigenous women and communities overcome the challenges associated with diabetes. Increasing the number of Indigenous health-care workers and the capacity building of this workforce, together with training non-Indigenous clinicians in how to provide culturally safe care and in understanding the social determinants of health, are key. Diabetes prevention programmes tailored to all age groups are needed, commencing as early as possible in life, from preconception, to pregnancy, to early childhood. Such programmes should be designed and led by the community, thus ensuring that Indigenous knowledge, cultures, and practices are at the centre of all diabetes prevention strategies.10Titmuss A Davis EA Brown A Maple-Brown LJ Emerging diabetes and metabolic conditions among Aboriginal and Torres Strait Islander young people.Med J Aust. 2019; 210: 111-113Crossref PubMed Scopus (24) Google Scholar System-wide action is required urgently to address the intergenerational diabetes epidemic in Indigenous populations worldwide. Collaboration across governmental, non-governmental, and Indigenous-led sectors, both within and beyond health care (including education, housing, and food retail) is critical for achieving improved outcomes. Empowering Indigenous communities to lead changes, such that Indigenous women, people, and communities worldwide are at the centre of their design and implementation, is fundamental. We declare no competing interests. Prevalence of diabetes in pregnancy among Indigenous women in Australia, Canada, New Zealand, and the USA: a systematic review and meta-analysisThe prevalence of pre-existing diabetes and gestational diabetes was higher in Indigenous pregnant women than in non-Indigenous pregnant women in four countries (Australia, Canada, New Zealand and the USA) with similar histories of colonialism. These findings have implications for prenatal care services and the monitoring of Indigenous women in industrialised countries. Full-Text PDF Open Access