Sex and Gender Differences in Prevention of Type 2 Diabetes

Exposure to maternal obesity programs sex differences in pancreatic islets of the offspring in mice

AIMS/HYPOTHESIS

Obesity during pregnancy increases offspring type 2 diabetes risk. Given that nearly half of women of child-bearing age in many populations are currently overweight/obese, it is key that we improve our understanding of the impact of the in utero/early life environment on offspring islet function. Whilst a number of experimental studies have examined the effect of maternal obesity on offspring islet architecture and/or function, it has not previously been delineated whether these changes are independent of other confounding risk factors such as obesity, postnatal high-fat-feeding and ageing. Thus, we aimed to study the impact of exposure to maternal obesity on offspring islets in young, glucose-tolerant male and female offspring.

METHODS

Female C57BL/6J mice were fed ad libitum either chow or obesogenic diet prior to and throughout pregnancy and lactation. Offspring were weaned onto a chow diet and remained on this diet until the end of the study. An IPGTT was performed on male and female offspring at 7 weeks of age. At 8 weeks of age, pancreatic islets were isolated from offspring for measurement of insulin secretion and content, mitochondrial respiration, ATP content, reactive oxygen species levels, beta and alpha cell mass, granule and mitochondrial density (by transmission electron microscopy), and mRNA and protein expression by real-time RT-PCR and Western blotting, respectively.

RESULTS

Glucose tolerance was similar irrespective of maternal diet and offspring sex. However, blood glucose was lower (p < 0.001) and plasma insulin higher (p < 0.05) in female offspring of obese dams 15 min after glucose administration. This was associated with higher glucose- (p < 0.01) and leucine/glutamine-stimulated (p < 0.05) insulin secretion in these offspring. Furthermore, there was increased mitochondrial respiration (p < 0.01) and density (p < 0.05) in female offspring of obese dams compared with same-sex controls. Expression of mitochondrial and nuclear-encoded components of the electron transport chain, L-type Ca²⁺ channel subtypes that play a key role in stimulus-secretion coupling [Cacna1d (p < 0.05)], and oestrogen receptor α (p < 0.05) was also increased in islets from these female offspring of obese dams. Moreover, cleaved caspase-3 expression and BAX:Bcl-2 were decreased (p < 0.05) reflecting reduced susceptibility to apoptosis. In contrast, in male offspring, glucose and leucine/glutamine-stimulated insulin secretion was comparable between treatment groups. There was, however, compromised mitochondrial respiration characterised by decreased ATP synthesis-driven respiration (p < 0.05) and increased uncoupled respiration (p < 0.01), reduced docked insulin granules (p < 0.001), decreased Cacna1c (p < 0.001) and Cacna1d (p < 0.001) and increased cleaved caspase-3 expression (p < 0.05).

CONCLUSIONS/INTERPRETATION

Maternal obesity programs sex differences in offspring islet function. Islets of female but not male offspring appear to be primed to cope with a nutritionally-rich postnatal environment, which may reflect differences in future type 2 diabetes risk.

Evaluating Ten Top Tips (10TT): Brief Dietary and Physical Activity Counseling in Rural Overweight and Obese Adults

Adults living in rural areas are at greater risk of becoming overweight and obese due to health care disparities. A pre-/postmatched cohort design was used to evaluate a brief weight-loss counseling intervention, Ten Top Tips (10TT), in a rural primary care setting. The rank sum scores for total weight-loss behaviors and the subscales for dietary changes, self-monitoring, physical activity, and psychological coping taken before and 12 weeks after the intervention differed significantly (P = .0001). Ten Top Tips offers rural community clinics an effective weight-loss intervention.

The Effects of Lifestyle and/or Vitamin D Supplementation Interventions on Pregnancy Outcomes: What Have We Learned from the DALI Studies?

PURPOSE OF REVIEW

The DALI (vitamin D and lifestyle intervention in the prevention of gestational diabetes mellitus (GDM)) study aimed to prevent GDM with lifestyle interventions or Vitamin D supplementation (1600 IU/day). This review summarizes the learnings from the DALI studies among pregnant women with a BMI ≥ 29 kg/m².

RECENT FINDINGS

Women diagnosed with GDM earlier in pregnancy had a worse metabolic profile than those diagnosed later. A combined physical activity (PA) and healthy eating (HE) lifestyle intervention improved both behaviours, limited gestational weight gain (GWG) and was cost-effective. Although GDM risk was unchanged, neonatal adiposity was reduced due to less sedentary time. Neither PA nor HE alone limited GWG or GDM risk. Fasting glucose was higher with HE only intervention, and lower with Vitamin D supplementation. Our combined intervention did not prevent GDM, but was cost-effective, limited GWG and reduced neonatal adiposity.

[Diabetes mellitus-Definition, classification, diagnosis, screening and prevention (Update 2019)]

Diabetes mellitus comprises a group of heterogeneous disorders, which have an increase in blood glucose concentrations in common. The current classification for diabetes mellitus is presented and the main features of type 1 and type 2 diabetes are compared. Furthermore, the criteria for the correct biochemical diagnosis during fasting and oral glucose tolerance tests as well as the use of hemoglobin A1c (HbA1c) are summarized. The increasing prevalence of diabetes requires targeted screening for detecting diabetes and prediabetes in risk groups. This forms the basis for the early initiation of measures to prevent the onset of diabetes in these risk groups and to delay the progression of diabetes.

[Sex and gender-specific aspects in prediabetes and diabetes mellitus-clinical recommendations (Update 2019)]

Metabolic diseases dramatically affect the life of men and women from infancy up to old age in different and manifold ways and are a major challenge for the healthcare system. The treating physicians are confronted with the different needs of women and men in the clinical routine. Gender-specific differences affect screening, diagnostic and treatment strategies as well as the development of complications and mortality rates. Impairments in glucose and lipid metabolism, regulation of energy balance and body fat distribution and therefore the associated cardiovascular diseases, are greatly influenced by steroidal and sex hormones. Furthermore, education, income and psychosocial factors play an important role in the development of obesity and diabetes differently in men and women. Males appear to be at greater risk of diabetes at a younger age and at a lower body mass index (BMI) compared to women but women feature a dramatic increase in the risk of diabetes-associated cardiovascular diseases after the menopause. The estimated future years of life lost owing to diabetes is somewhat higher in women than men, with a higher increase in vascular complications in women but a higher increase of cancer deaths in men. In women prediabetes or diabetes are more distinctly associated with a higher number of vascular risk factors, such as inflammatory parameters, unfavorable changes in coagulation and higher blood pressure. Women with prediabetes and diabetes have a much higher relative risk for vascular diseases. Women are more often morbidly obese and less physically active but may have an even greater benefit in health and life expectation from increased physical activity than men. In weight loss studies men often showed a higher weight loss than women; however, diabetes prevention is similarly effective in men and women with prediabetes with a risk reduction of nearly 40%. Nevertheless, a long-term reduction in all cause and cardiovascular mortality was so far only observed in women. Men predominantly feature increased fasting blood glucose levels, women often show impaired glucose tolerance. A history of gestational diabetes or polycystic ovary syndrome (PCOS) as well as increased androgen levels in women and the presence of erectile dysfunction or decreased testosterone levels in men are important sex-specific risk factors for the development of diabetes. Many studies showed that women with diabetes reach their target values for HbA1c, blood pressure and low-density lipoprotein (LDL)-cholesterol less often than their male counterparts, although the reasons are unclear. Furthermore, sex differences in the effects, pharmacokinetics and side effects of pharmacological treatment should be taken more into consideration.

[Gestational diabetes mellitus (Update 2019)]

Gestational diabetes mellitus (GDM) is defined as a glucose tolerance disorder with onset during pregnancy and is associated with increased feto-maternal morbidity as well as long-term complications in mother and child. Women who fulfil the criteria of a manifest diabetes in early pregnancy (fasting plasma glucose >126 mg/dl, spontaneous glucose level >200 mg/dl or HbA1c > 6.5% before 20 weeks of gestation) should be classified as having manifest diabetes in pregnancy and treated as such. Screening for undiagnosed type 2 diabetes at the first prenatal visit (evidence level B) is particularly recommended in women at increased risk (history of GDM or prediabetes, malformation, stillbirth, successive abortions or birth weight >4500 g in previous pregnancies, obesity, metabolic syndrome, age >35 years, vascular disease, clinical symptoms of diabetes, e. g. glucosuria, or ethnic groups with increased risk for GDM/T2DM, e.g. Arabian countries, south and southeast Asia and Latin America). A GDM is diagnosed by an oral glucose tolerance test (OGTT) or a fasting glucose concentration ≥92 mg/dl. Performance of the OGTT (120 min, 75 g glucose) may already be indicated in the first trimester in high risk women but is mandatory between 24-28 gestational weeks in all pregnant women with previous non-pathological glucose metabolism (evidence level B). Based on the results of the Hyperglycemia and Adverse Pregnancy Outcome (HAPO) study and following the recent WHO recommendations, GDM is present if the fasting plasma glucose level exceeds 92 mg/dl, the 1 h level exceeds 180 mg/dl or the 2 h level exceeds 153 mg/dl after glucose loading (OGTT international consensus criteria). A single increased value is sufficient for the diagnosis and a strict metabolic control is mandatory. After bariatric surgery an OGTT is not recommended due to the risk of postprandial hypoglycemia. All women with GDM should receive nutritional counselling, be instructed in self-monitoring of blood glucose and to increase physical activity to moderate intensity levels, if not contraindicated. If blood glucose levels cannot be maintained in the therapeutic range (fasting <95 mg/dl and 1 h postprandial <140 mg/dl) insulin therapy should be initiated as first choice. Maternal and fetal monitoring is required in order to minimize maternal and fetal/neonatal morbidity and perinatal mortality. After delivery all women with GDM have to be re-evaluated by a 75 g OGTT (WHO criteria) 4-12 weeks postpartum to reclassify the glucose tolerance and every 2 years in cases of normal glucose tolerance (evidence level B). All women have to be informed about their (sevenfold increased relative) risk of developing type 2 diabetes (T2DM) at follow-up and possible preventive measures, in particular weight management, healthy diet and maintenance/increase of physical activity. Monitoring of the development of children and recommendations for a healthy lifestyle are necessary for the whole family. Regular obstetric examinations including ultrasound examinations are recommended. Within the framework of neonatal care, neonates of GDM mothers should undergo blood glucose measurements and if necessary appropriate measures should be initiated.

Interdisciplinary Weight Loss and Lifestyle Intervention for Obstructive Sleep Apnoea in Adults: Rationale, Design and Methodology of the INTERAPNEA Study

Obesity is a major risk factor for obstructive sleep apnoea (OSA), the most common sleep-disordered breathing related to neurocognitive and metabolic syndromes, type II diabetes, and cardiovascular diseases. Although strongly recommended for this condition, there are no studies on the effectiveness of an interdisciplinary weight loss and lifestyle intervention including nutrition, exercise, sleep hygiene, and smoking and alcohol cessation. INTERAPNEA is a randomised controlled trial with a two-arm parallel design aimed at determining the effects of an interdisciplinary tailored weight loss and lifestyle intervention on OSA outcomes. The study will include 84 males aged 18–65 with a body mass index of ≥25 kg/m² and severe to moderate OSA randomly assigned to usual care (i.e., continuous positive airway pressure), or interdisciplinary weight loss and lifestyle intervention combined with usual care. Outcomes will be measured at baseline, intervention end-point, and six-month post-intervention, including apnoea-hypopnoea index (primary outcome), other neurophysical and cardiorespiratory polysomnographic outcomes, sleep quality, daily functioning and mood, body weight and composition, physical fitness, blood biomarkers, health-related quality of life, and cost-effectiveness. INTERAPNEA may serve to establish a cost-effective treatment not only for the improvement of OSA and its vast and severe comorbidities, but also for a potential remission of this condition.

Weight loss and lifestyle interventions for obstructive sleep apnoea in adults: Systematic review and meta-analysis

Lifestyle interventions addressing diet, exercise-training, sleep hygiene, and/or tobacco/alcohol cessation are recommended in the management of obstructive sleep apnoea (OSA). Yet their effectiveness on this condition still requires further research. This systematic review and meta-analysis was aimed at establishing (a) the effectiveness of lifestyle interventions on apnoea-hypopnoea index (AHI), oxygen desaturation index (ODI), excessive daytime sleepiness (EDS), and secondary OSA measures among adults, and (b) which intervention characteristics may drive the greatest improvements. A systematic search of studies was conducted using CINAHL, ProQuest, Psicodoc, Scopus, and Web of Science, from inception to April 2018. Standardized mean differences were calculated using the inverse variance method and random-effects models. The meta-analyses of 13 randomized controlled trials and 22 uncontrolled before-and-after studies (1420 participants) revealed significant reductions on AHI (d = -0.61 and -0.46, respectively), ODI (d = -0.61 and -0.46) and EDS (d = -0.41 and -0.49). Secondary OSA outcomes were also improved after interventions. However, effectiveness of interventions differed depending on their components, OSA severity, and gender. Thus, until future research further supports the differential effectiveness among lifestyle interventions on OSA, those addressing weight loss through diet and exercise-training may be the most effective treatments for male patients with moderate-severe OSA.

The Glucose-Lowering Effect of Foxtail Millet in Subjects with Impaired Glucose Tolerance: A Self-Controlled Clinical Trial

Foxtail millet has relatively low starch digestibility and moderate glycemic index compared to other grains. Since there are still no clinical researches regarding its long-term effect on blood glucose, this self-controlled study was conducted to investigate the glucose-lowering effect of foxtail millet in free-living subjects with impaired glucose tolerance (IGT). Fifty g/day of foxtail millet was provided to enrolled subjects throughout 12 weeks and the related clinical parameters were investigated at week 0, 6 and 12, respectively. After 12 weeks of foxtail millet intervention, the mean fasting blood glucose of the subjects decreased from 5.7 ± 0.9 mmol/L to 5.3 ± 0.7 mmol/L (p < 0.001) and the mean 2 h-glucose decreased from 10.2 ± 2.6 mmol/L to 9.4 ± 2.3 mmol/L (p = 0.003). The intake of foxtail millet caused a significant increase of serum leptin (p = 0.012), decrease of insulin resistance (p = 0.007), and marginal reduction of inflammation. Furthermore, a sex-dependent difference in glucose-lowering effect of foxtail millet was observed in this study. Foxtail millet could improve the glycemic control in free-living subjects with IGT, suggesting that increasing the consumption of foxtail millet might be beneficial to individuals suffering from type 2 diabetes mellitus.

Male Patients with Longstanding Type 2 Diabetes Have a Higher Incidence of Hypoglycemia Compared with Female Patients

INTRODUCTION

To explore whether there was a gender difference in the risk of hypoglycemia during intensive insulin therapy in patients with longstanding type 2 diabetes (T2D). This was a post hoc analysis of a single-center, open-label and prospective trial.

METHODS

All subjects were admitted as inpatients, underwent a standard bread meal test at baseline and received a 7-day continuous subcutaneous insulin infusion (CSII) therapy for achieving glycemic control. Patients then were randomized 1:1 to two groups receiving (1) 4 days of Novo Mix 30 followed by 2 days of Humalog Mix 50; (2) 4 days of Humalog Mix 50 followed by 2 days of Novo Mix 30. All patients were subjected to 4-day retrospective continuous glucose monitoring (CGM) during the last 4 days in this study. The primary outcome was the incidences of hypoglycemia monitored by CGM at the end point.

RESULTS

A total of 102 patients met the inclusion criteria and completed the study. Our data revealed that 29 patients (28%) experienced hypoglycemia as detected by CGM at the end point. Binary logistic stepwise regression analysis showed that only gender significantly correlated with hypoglycemia (B = 1.17, p = 0.017). Importantly, male patients had a significantly higher incidence of hypoglycemia than female patients (male = 20/52, female = 9/50, p = 0.022), although male patients required significantly lower insulin doses to maintain glycemic control than female patient (p = 0.00).

CONCLUSION

Male patients with longstanding T2D had a higher incidence of hypoglycemia than female patients during intensive insulin therapy.

TRIAL REGISTRATION

ClinicalTrials.gov identifier, ChiCTR-IPR-15007340.

Sex Differences in Cardiac Mitochondria in the New Zealand Obese Mouse

Background: Obesity is a risk factor for diseases including type 2 diabetes mellitus (T2DM) and cardiovascular disorders. Diabetes itself contributes to cardiac damage. Thus, studying cardiovascular events and establishing therapeutic intervention in the period of type T2DM onset and manifestation are of highest importance. Mitochondrial dysfunction is one of the pathophysiological mechanisms leading to impaired cardiac function. Methods: An adequate animal model for studying pathophysiology of T2DM is the New Zealand Obese (NZO) mouse. These mice were maintained on a high-fat diet (HFD) without carbohydrates for 13 weeks followed by 4 week HFD with carbohydrates. NZO mice developed severe obesity and only male mice developed manifest T2DM. We determined cardiac phenotypes and mitochondrial function as well as cardiomyocyte signaling in this model. Results: The development of an obese phenotype and T2DM in male mice was accompanied by an impaired systolic function as judged by echocardiography and MyH6/7 expression. Moreover, the mitochondrial function only in male NZO hearts was significantly reduced and ERK1/2 and AMPK protein levels were altered. Conclusions: This is the first report demonstrating that the cardiac phenotype in male diabetic NZO mice is associated with impaired cardiac energy function and signaling events.