Maternal health issues and cardio-metabolic outcomes in the offspring: a focus on Indigenous populations

Youth-onset type 2 diabetes mellitus: an urgent challenge

The incidence and prevalence of youth-onset type 2 diabetes mellitus (T2DM) and its complications are increasing worldwide. Youth-onset T2DM has been reported in all racial and ethnic groups, but Indigenous peoples and people of colour are disproportionately affected. People with youth-onset T2DM often have a more aggressive clinical course than those with adult-onset T2DM or those with type 1 diabetes mellitus. Moreover, the available treatment options for children and adolescents with T2DM are more limited than for adult patients. Intermediate complications of youth-onset T2DM, such as increased albuminuria, often develop in late childhood or early adulthood, and end-stage complications, including kidney failure, develop in mid-life. The increasing frequency, earlier onset and greater severity of childhood obesity in the past 50 years together with increasingly sedentary lifestyles and an increasing frequency of intrauterine exposure to diabetes are important drivers of the epidemic of youth-onset T2DM. The particularly high risk of the disease in historically disadvantaged populations suggests an important contribution of social and environmental factors, including limited access to high-quality health care, healthy food choices and opportunities for physical activity as well as exposure to stressors including systemic racism and environmental pollutants. Understanding the mechanisms that underlie the development and aggressive clinical course of youth-onset T2DM is key to identifying successful prevention and management strategies.

The Role of Maternal Vitamin D Deficiency in Offspring Obesity: A Narrative Review

Currently, vitamin D (VD) deficiency during pregnancy is widespread globally, causing unfavorable pregnancy outcomes for both mothers and infants for a longer time than expected, based on the Developmental Origins of Health and Disease (DOHaD) theory. As VD plays a key role in maintaining normal glucose and lipid metabolism, maternal VD deficiency may lead to obesity and other obesity-related diseases among offspring later in life. This review mainly focuses on the effect of maternal VD deficiency on offspring lipid metabolism, reviewing previous clinical and animal studies to determine the effects of maternal VD deficit on offspring obesity and potential mechanisms involved in the progression of offspring obesity. Emerging clinical evidence shows that a low VD level may lead to abnormal growth (either growth restriction or largeness for gestational age) and lipid and glucose metabolism disorders in offspring. Here, we also outline the link between maternal VD deficiency and life-long offspring effects, including the disorder of adipogenesis, the secretion of adipocytokines (including leptin, resistin, and adiponectin), activated systemic inflammation, increased oxidative reactions in adipose tissue, insulin resistance, and abnormal intestinal gut microbiota. Thus, there is an urgent need to take active steps to address maternal VD deficiency to relieve the global burden of obesity.

Epidemiology of Type 2 Diabetes in Indigenous Communities in the United States

PURPOSE OF REVIEW

The present review focuses on the epidemiology of type 2 diabetes (T2D) in Indigenous communities in the continental United States (U.S.)-including disease prevention and management-and discusses special considerations in conducting research with Indigenous communities.

RECENT FINDINGS

Previous studies have reported the disparately high prevalence of diabetes, especially T2D, among Indigenous peoples in the U.S. The high prevalence and incidence of early-onset T2D in Indigenous youth relative to that of all youth in the U.S. population pose challenges to the prevention of complications of diabetes. Behavioral, dietary, lifestyle, and genetic factors associated with T2D in Indigenous communities are often investigated. More limited is the discussion of the historical and ongoing consequences of colonization and displacement that impact the aforementioned risk factors. Future research is necessary to assess community-specific needs with respect to diabetes prevention and management across the diversity of Indigenous communities in the U.S.

Psychopathology in the Offspring of Indigenous Parents with Mental Health Challenges: A Systematic Review: Psychopathologie des descendants de parents autochtones ayant des problèmes de santé mentale: Une revue systématique

OBJECTIVE

Parental psychopathology is a significant risk factor for mental health challenges in offspring, but the nature and magnitude of this link in Indigenous Peoples is not well understood. This systematic review examined the emotional and behavioral functioning of the offspring of Indigenous parents with mental health challenges.

METHOD

We searched MEDLINE, EMBASE, PsycINFO, CINAHL, and Web of Science from their inceptions until April 2020. Studies were included if they included assessments of emotional, behavioral, or other psychological outcomes in the offspring of Indigenous parents with a mental health challenge.

RESULTS

The 14 studies eligible for review were focused on parental substance misuse (n = 8), maternal internalizing (i.e., depression, anxiety) issues (n = 5), and poor overall parental mental health (n = 4). In 11 studies, parental substance misuse, depression, and/or overall mental health challenges were associated with 2 to 4 times the odds of offspring externalizing and internalizing behaviors as compared to offspring of Indigenous parents without mental health challenges.

CONCLUSION

The findings suggest higher risks of mental health challenges among offspring of Indigenous parents with psychiatric difficulties than among Indigenous children of parents without similar difficulties. Knowledge of these phenomena would be improved by the use of larger, more representative samples, culturally appropriate measures, and the engagement of Indigenous communities. Future studies should be focused on both risk and resilience mechanisms so that cycles of transmission can be interrupted and resources aimed at detection, prevention, and treatment optimally allocated.

Roles of Epigenetic Modifications in the Differentiation and Function of Pancreatic β-Cells

Diabetes, a metabolic disease with multiple causes characterized by high blood sugar, has become a public health problem. Hyperglycaemia is caused by deficiencies in insulin secretion, impairment of insulin function, or both. The insulin secreted by pancreatic β cells is the only hormone in the body that lowers blood glucose levels and plays vital roles in maintaining glucose homeostasis. Therefore, investigation of the molecular mechanisms of pancreatic β cell differentiation and function is necessary to elucidate the processes involved in the onset of diabetes. Although numerous studies have shown that transcriptional regulation is essential for the differentiation and function of pancreatic β cells, increasing evidence indicates that epigenetic mechanisms participate in controlling the fate and regulation of these cells. Epigenetics involves heritable alterations in gene expression caused by DNA methylation, histone modification and non-coding RNA activity that does not result in DNA nucleotide sequence alterations. Recent research has revealed that a variety of epigenetic modifications play an important role in the development of diabetes. Here, we review the mechanisms by which epigenetic regulation affects β cell differentiation and function.

A Scoping Review of Obesity among Indigenous Peoples in Canada

Indigenous populations in Canada are heavily affected by the burden of obesity, and certain communities, such as First Nations on reserve, are not included in the sampling framework of large national health surveys. A scoping review of ever published original research reporting obesity rates (body mass index ≥ 30), among adult Indigenous peoples in Canada, was conducted to identify studies that help close the Canadian Community Health Survey (CCHS) data gap for obesity prevalence in Indigenous populations in Canada and to make comparisons based on ethnicity, sex, time, and geography. First Nations on reserve with self-reported height and weight had higher rates of obesity (30%-51%) than First Nations off reserve (21%-42%) and non-Indigenous populations (12%-31%) in their respective province or territory, with the exception of Alberta, where rates in First Nations on reserve (30% and 36%) were lower or similar to those reported in First Nations off reserve (38%). First Nations on reserve with predominantly measured height and weight (42%-66%) had higher rates of obesity compared to Inuit in Quebec (28%), Nunavut (33%), and Newfoundland and Labrador (41%), while the rates were similar to those in Inuit in Northwest Territories (49%). Obesity in these large studies conducted among Inuit was based solely on measured height and weight. Studies in First Nations and Inuit alike showed higher prevalence of obesity in women, as well as an increase with time. No recent studies measured the obesity rates for First Nations in Yukon and Northwest Territories and for Métis living in settlements of Northern Alberta. Researchers are encouraged to conduct total diet studies in these regions, and to use existing data to analyze the associations between obesity, road access, latitude, food environment, and traditional food intake, to further inform community planning and development.

Association of Gestational Diabetes and Type 2 Diabetes Exposure In Utero With the Development of Type 2 Diabetes in First Nations and Non-First Nations Offspring

IMPORTANCE

Type 2 diabetes is increasing worldwide, disproportionately affecting First Nations (FN) people. Identifying early-life determinants of type 2 diabetes is important to address the intergenerational burden of illness.

OBJECTIVE

To investigate the association of in utero exposure to gestational diabetes and type 2 diabetes, stratified by FN status, with the development of type 2 diabetes in offspring.

DESIGN, SETTING, AND PARTICIPANTS

This cohort study was derived from the linkage of a pediatric diabetes clinical database and a population-based research data repository in Manitoba, Canada. Mother-infant dyads with a hospital birth or midwifery report in the data repository between April 1, 1984, and April 1, 2008, were identified. The dates of analysis were August through December 2017. Children identified with type 1 diabetes, monogenic diabetes, or secondary diabetes were excluded.

EXPOSURES

Primary exposures included maternal gestational diabetes or type 2 diabetes and FN status.

MAIN OUTCOMES AND MEASURES

The primary outcome was incident type 2 diabetes in offspring by age 30 years.

RESULTS

In this cohort study of 467 850 offspring (mean follow-up, 17.7 years; 51.2% male), FN status and diabetes exposure were associated with incident type 2 diabetes in offspring after adjustment for sex, maternal age, socioeconomic status, birth size, and gestational age. Type 2 diabetes exposure conferred a greater risk to offspring compared with gestational diabetes exposure (3.19 vs 0.80 cases per 1000 person-years, P < .001). Compared with no diabetes exposure, any diabetes exposure accelerated the time to the development of type 2 diabetes in offspring by a factor of 0.74 (95% CI, 0.62-0.90) for gestational diabetes and a factor of 0.50 (95% CI, 0.45-0.57) for type 2 diabetes. First Nations offspring had a higher risk compared with non-FN offspring (0.96 vs 0.14 cases per 1000 person-years, P < .001). First Nations offspring had accelerated type 2 diabetes onset by a factor of 0.52 (95% CI, 0.49-0.55) compared with non-FN offspring. Neither interaction between FN and type 2 diabetes (0.92; 95% CI, 0.80-1.05) nor interaction between FN and gestational diabetes (0.97; 95% CI, 0.77-1.20) was significant (P = .21 and P = .75, respectively).

CONCLUSIONS AND RELEVANCE

Important differences exist in offspring risk based on type of diabetes exposure in utero. These findings have implications for future research and clinical practice guidelines, including early pregnancy screening and follow-up of the offspring.

Call to action: A new path for improving diabetes care for Indigenous peoples, a global review

Diabetes has reached epidemic proportions in Indigenous populations around the globe, and there is an urgent need to improve the health and health equity of Indigenous peoples with diabetes through timely and appropriate diabetes prevention and management strategies. This review describes the evolution of the diabetes epidemic in Indigenous populations and associated risk factors, highlighting gestational diabetes and intergenerational risk, lifestyle risk factors and social determinants as having particular importance and impact on Indigenous peoples. This review further describes the impact of chronic disease and diabetes on Indigenous peoples and communities, specifically diabetes-related comorbidities and complications. This review provides continued evidence that dramatic changes are necessary to reduce diabetes-related inequities in Indigenous populations, with a call to action to support programmatic primary healthcare transformation capable of empowering Indigenous peoples and communities and improving chronic disease prevention and management. Promising strategies for transforming health services and care for Indigenous peoples include quality improvement initiatives, facilitating diabetes and chronic disease registry and surveillance systems to identify care gaps, and prioritizing evaluation to build the evidence-base necessary to guide future health policy and planning locally and on a global scale.

Early Life Predictors of Increased Body Mass Index among Indigenous Australian Children

Aboriginal and Torres Strait Islander Australians are more likely than non-Indigenous Australians to be obese and experience chronic disease in adulthood--conditions linked to being overweight in childhood. Birthweight and prenatal exposures are associated with increased Body Mass Index (BMI) in other populations, but the relationship is unclear for Indigenous children. The Longitudinal Study of Indigenous Children is an ongoing cohort study of up to 1,759 children across Australia. We used a multilevel model to examine the association between children's birthweight and BMI z-score in 2011, at age 3-9 years, adjusted for sociodemographic and maternal factors. Complete data were available for 682 of the 1,264 children participating in the 2011 survey; we repeated the analyses in the full sample with BMI recorded (n=1,152) after multilevel multiple imputation. One in ten children were born large for gestational age, and 17% were born small for gestational age. Increasing birthweight predicted increasing BMI; a 1-unit increase in birthweight z-score was associated with a 0.22-unit (95% CI:0.13, 0.31) increase in childhood BMI z-score. Maternal smoking during pregnancy was associated with a significant increase (0.25; 95% CI:0.05, 0.45) in BMI z-score. The multiple imputation analysis indicated that our findings were not distorted by biases in the missing data. High birthweight may be a risk indicator for overweight and obesity among Indigenous children. National targets to reduce the incidence of low birthweight which measure progress by an increase in the population's average birthweight may be ignoring a significant health risk; both ends of the spectrum must be considered. Interventions to improve maternal health during pregnancy are the first step to decreasing the prevalence of high BMI among the next generation of Indigenous children.

Cardiovascular complications of type 2 diabetes in youth

The prevalence of type 2 diabetes mellitus (T2DM) in youth has increased dramatically over the past decades. The literature also suggests that the progression from an impaired glucose tolerance state to established T2DM is more rapid in youth, compared to adults. The presence of significant cardiovascular complications in youth with T2DM, including cardiac, macrovascular, and microvascular remodeling, is another major issue in this younger cohort and poses a significant threat to the healthcare system. However, this issue is only now emerging as a major public health concern, with few data to support optimal treatment targets and strategies to reduce cardiovascular disease (CVD) risk in youth with T2DM. Accordingly, the purpose of this minireview is to better understand the cardiovascular complications in youth with T2DM. We briefly describe the pathophysiology from youth studies, including oxidative stress, inflammation, renin-angiotensin aldosterone system, and epigenetics, which link T2DM and CVD. We also describe the literature concerning the early signs of CVD in youth and potential treatment options to reduce cardiovascular risk.