Depression and type 2 diabetes: cortisol pathway implication and investigational needs

Combined association of abdominal obesity and depressive symptoms with risk of type 2 diabetes: A cohort study

OBJECTIVE

To explore the combined effect of abdominal obesity and depressive symptoms on the risk to type 2 diabetes, while also assessing the potential influence of various glycemic states and gender on this combined relationship.

METHODS

Data is acquired from the China Health and Retirement Longitudinal Study, and 5949 participants were included for analysis. Participants were divided into four groups: neither have abdominal obesity nor depressive symptoms (AO-/DS-), only have depressive symptoms (AO-/DS+), only have abdominal obesity (AO+/DS-), and have both abdominal obesity and depressive symptoms (AO+/DS+). Stratified analyses differentiating the glycemic statuses and sex of the participants were also carried out.

RESULTS

After adjusting for the confounders, the AO-/DS+, AO+/DS- and AO+/DS+ phenotypes were all discovered to be risk factors for type 2 diabetes (OR = 1.38, 95%CI: 1.06-1.79; OR = 2.07, 95%CI: 1.63-2.63; OR = 2.38, 95%CI: 1.83-3.11, respectively) compared with the AO-/DS- phenotype in the overall population. In further stratified analyses, we arrived at the same conclusion for normoglycemic individuals, especially in females. For prediabetes and males, the AO+/DS- and AO+/DS+ phenotypes are risk factors for type 2 diabetes compared with the AO-/DS- phenotype, but not with AO-/DS+.

CONCLUSION

Regardless of glycemic status and sex, the coexistence of abdominal obesity and depressive symptoms were associated with an increased risk of type 2 diabetes. Depressive symptoms were independent risk factors for type 2 diabetes only in normoglycemic individuals and females.

Review of the direct and indirect effects of hyperglycemia on the HPA axis in T2DM and the co-occurrence of depression

Type 2 diabetes mellitus (T2DM) is characterized by persistent hyperglycemia which is further associated with hyperactivity of the hypothalamic-pituitary-adrenal (HPA) axis. Several studies have shown that HPA axis hyperactivity is heightened in the chronic hyperglycemic state with severe hyperglycemic events more likely to result in a depressive disorder. The HPA axis is also regulated by the immune system. Upon stress, under homeostatic conditions, the immune system is activated via the sympatho-adrenal-medullary axis resulting in an immune response which secretes proinflammatory cytokines. These cytokines aid in the activation of the HPA axis during stress. However, in T2DM, where there is persistent hyperglycemia, the immune system is dysregulated resulting in the elevated concentrations of these cytokines. The HPA axis, already activated by the hyperglycemia, is further activated by the cytokines which all contribute to a diagnosis of depression in patients with T2DM. However, the onset of T2DM is often preceded by pre-diabetes, a reversible state of moderate hyperglycemia and insulin resistance. Complications often seen in T2DM have been reported to begin in the pre-diabetic state. While the current management strategies have been shown to ameliorate the moderate hyperglycemic state and decrease the risk of developing T2DM, research is necessary for clinical studies to profile these direct effects of moderate hyperglycemia in pre-diabetes on the HPA axis and the indirect effects moderate hyperglycemia may have on the HPA axis by investigating the components of the immune system that play a role in regulating this pathway.

The Role of the Adrenal-Gut-Brain Axis on Comorbid Depressive Disorder Development in Diabetes

Diabetic patients are more affected by depression than non-diabetics, and this is related to greater treatment resistance and associated with poorer outcomes. This increase in the prevalence of depression in diabetics is also related to hyperglycemia and hypercortisolism. In diabetics, the hyperactivity of the HPA axis occurs in parallel to gut dysbiosis, weakness of the intestinal permeability barrier, and high bacterial-product translocation into the bloodstream. Diabetes also induces an increase in the permeability of the blood-brain barrier (BBB) and Toll-like receptor 4 (TLR4) expression in the hippocampus. Furthermore, lipopolysaccharide (LPS)-induced depression behaviors and neuroinflammation are exacerbated in diabetic mice. In this context, we propose here that hypercortisolism, in association with gut dysbiosis, leads to an exacerbation of hippocampal neuroinflammation, glutamatergic transmission, and neuronal apoptosis, leading to the development and aggravation of depression and to resistance to treatment of this mood disorder in diabetic patients.

Investigating the Effects of Maternal Separation on Hypothalamic-Pituitary-Adrenal Axis and Glucose Homeostasis under Chronic Social Defeat Stress in Young Adult Male Rat Offspring

INTRODUCTION

Given the suggested metabolic regulatory effects of stress-responsive genes and based on the impacts of early-life stress on HPA axis development, this study aimed to characterize the maternal separation (MS) impact on the communication between glucose metabolism and HPA axis dysregulations under chronic social defeat stress (CSDS).

METHODS

During the first 2 weeks of life, male Wistar rats were either exposed to MS or left undisturbed with their mothers (Std). Starting on postnatal day 50, the animals of each group were either left undisturbed in the standard group housing (Con) or underwent CSDS for 3 weeks. There were four groups (n = 10/group): Std-Con, MS-Con, Std-CSDS, and MS-CSDS.

RESULTS

Early and/or adult life adversity reduced β-cell number, muscular FK506-binding protein 51 (FKBP51) content, and BMI in adulthood. The reduction of β-cell number and BMI in the MS-CSDS rats were more profound than MS-Con group. CSDS either alone or in combination with MS reduced locomotor activity and increased and decreased corticotropin-releasing factor type 1 receptor (CRFR1) content, respectively, in hypothalamus and pancreas. Although, under CSDS, MS intensified HPA axis overactivity and reduced isolated islets' insulin secretion, it could promote resilience to depression symptoms. No differences were observed in hypothalamic Fkbp5 gene DNA methylation and glucose tolerance among groups.

CONCLUSION

MS exacerbated HPA axis overactivity and the endocrine pancreas dysfunctions under CSDS. The intensified corticosterone secretion and the diminished content of pancreatic CRFR1 protein could be involved in the reduced β-cell number and islets' insulin secretion under CSDS. The decreased muscular FKBP51 content might be a homeostatic response to slow down insulin resistance development under chronic stress.

Depression, diabetes and immigration status: a retrospective cohort study using the Canadian Longitudinal Study on Aging

BACKGROUND

A bidirectional association between depression and diabetes exists, but has not been evaluated in the context of immigrant status. Given that social determinants of health differ between immigrants and nonimmigrants, we evaluated the association between diabetes and depression incidence, depression and diabetes incidence, and whether immigrant status modified this association, among immigrants and nonimmigrants in Canada.

METHODS

We employed a retrospective cohort design using data from the Canadian Longitudinal Study on Aging Comprehensive cohort (baseline [2012-2015] and 3-year follow-up [2015-2018]). We defined participants as having diabetes if they self-reported it or if their glycated hemoglobin A_1c level was 7% or more; we defined participants as having depression if their Center for Epidemiological Studies Depression score was 10 or higher or if they were currently undergoing depression treatment. We excluded those with baseline depression (Cohort 1) and baseline diabetes (Cohort 2) to evaluate the associations between diabetes and depression incidence, and between depression and diabetes incidence, respectively. We constructed logistic regression models with interaction by immigrant status.

RESULTS

Cohort 1 (n = 20 723; mean age 62.7 yr, standard deviation [SD] 10.1 yr; 47.6% female) included 3766 (18.2%) immigrants. Among immigrants, 16.4% had diabetes, compared with 15.6% among nonimmigrants. Diabetes was associated with an increased risk of depression in nonimmigrants (adjusted odds ratio [OR] 1.27, 95% confidence interval [CI] 1.08-1.49), but not in immigrants (adjusted OR 1.12, 95% CI 0.80-1.56). Younger age, female sex, weight change, poor sleep quality and pain increased depression risk. Cohort 2 (n = 22 054; mean age 62.1 yr, SD 10.1 yr; 52.2% female) included 3913 (17.7%) immigrants. Depression was associated with an increased risk of diabetes in both nonimmigrants (adjusted OR 1.39, 95% CI 1.16-1.68) and immigrants (adjusted OR 1.60, 95% CI 1.08-2.37). Younger age, male sex, waist circumference, weight change, hypertension and heart disease increased diabetes risk.

INTERPRETATION

We found an overall bidirectional association between diabetes and depression that was not significantly modified by immigrant status. Screening for diabetes for people with depression and screening for depression for those with diabetes should be considered.

The Relationship between Type 2 Diabetes, Differentiation of Self, and Emotional Distress: Jews and Arabs in Israel

Type 2 diabetes mellitus (T2DM) is considered a global epidemic, and is constantly on the rise. In Israel, the percentage of diabetics in the Arab population is twice that found in the Jewish population (12% and 6.2%, respectively). Findings suggest that low differentiation of self (DoS: emotional reactivity+ fusion with others, I-position, emotional cutoff) may raise vulnerability to certain physiological pathologies by increasing susceptibility to psychological distress. The major goal of this study was to test differences in DoS and emotional distress (anxiety and depressive symptoms) between diabetic and healthy participants. The second aim was to examine cultural differences within these metrics. Another purpose was to examine the relationship between DoS and emotional distress among healthy and diabetic participants. The sample included 261 participants, of whom 154 were healthy and 107 were diabetic. Diabetics reported more severe depressive symptoms, higher levels of anxiety and emotional cutoff and lower levels of I-position than healthy individuals. The groups did not differ in their levels of emotional reactivity + fusion with others. Arabs demonstrated higher levels of emotional cutoff, anxiety and depressive symptoms and lower levels of I-position than Jews. However, Arabs and Jews did not differ in their levels of emotional reactivity + fusion with others. Emotional reactivity + fusion with others contributed the most to diabetes among Arabs, while depressive symptoms contributed the most among Jews. Finally, among Jewish participants, age was positively correlated with emotional cutoff and depressive symptoms. Emotional cutoff was positively correlated with anxiety and depressive symptoms. Emotional reactivity + fusion with others was positively correlated with anxiety. Among Arab participants, age was positively correlated with emotional cutoff, anxiety and depressive symptoms. I-position was negatively correlated with all study variables. Emotional cutoff was positively correlated, anxiety and depressive symptoms. Emotional reactivity + fusion with others was positively correlated with anxiety and depressive symptoms.

Perceived stress, depressive symptoms, and cortisol-to-cortisone ratio in spot urine in 6878 older adults

BACKGROUND

Late life depression and perceived stress could influence disease pathways via reduced 11β-HSD2 activity, particularly given suggestions that reduced 11β-HSD2 activity, which is reflected in the cortisol-to-cortisone ratio, is a risk factor of disease. To date, however, examination of the relationship between the cortisol-to-cortisone ratio and perceived stress or depressive symptoms is insufficient.

METHODS

We examined the cross-sectional association of the cortisol-to-cortisone ratio with perceived stress and depressive symptoms, and analyzed whether cortisol levels modify this association, in 6878 participants aged 45-74 years. Cortisol and cortisone in spot urine were measured using liquid chromatography-mass spectrometry. Perceived stress during the past year was measured using a self-reported questionnaire. Depressive symptoms were evaluated using the Zung Self-Rating Depression Scale. Analyses were performed with adjustment for age, sex, lifestyle factors (smoking habit, alcohol consumption, physical activity, and sleeping hours), and physical health factors (body mass index [kg/m²] and medical history [diabetes, hypertension, and medication for hyperlipidemia or corticosteroids]).

RESULTS

Cortisol-to-cortisone ratio and cortisol were positively associated with perceived stress (% change: 2.33, P_trend = 0.003; and 4.74, P_trend = 0.001, respectively), but were not significantly associated with depressive symptoms. Further, the relationship between cortisol-to-cortisone ratio and perceived stress was modified by cortisol level and sex: the positive association between perceived stress and the cortisol-to-cortisone ratio was more evident in subjects with lower cortisol levels (P_interaction = 0.009) and in men (P_interaction = 0.026).

CONCLUSIONS

These findings suggest that the cortisol-to-cortisone ratio in spot urine may be a useful marker for non-acute perceived stress in daily life against a possible background of reduced 11β-HSD2 in older adults.

Interaction Mechanisms Between Major Depressive Disorder and Non-alcoholic Fatty Liver Disease

Major depressive disorder (MDD), which is highly associated with non-alcoholic fatty liver disease (NAFLD), has complex pathogenic mechanisms. However, a limited number of studies have evaluated the mutual pathomechanisms involved in MDD and NAFLD development. Chronic stress-mediated elevations in glucocorticoid (GC) levels play an important role in the development of MDD-related NAFLD. Elevated GC levels can induce the release of inflammatory factors and changes in gut permeability. Elevated levels of inflammatory factors activate the hypothalamic-pituitary-adrenal (HPA) axis, which further increases the release of GC. At the same time, changes in gut permeability promote the release of inflammatory factors, which results in a vicious circle among the three, causing disease outbreaks. Even though the specific role of the thyroid hormone (TH) in this pathogenesis has not been fully established, it is highly correlated with MDD and NAFLD. Therefore, changing lifestyles and reducing psychological stress levels are necessary measures for preventing MDD-related NAFLD. Among them, GC inhibitors and receptor antagonists may be key in the alleviation of early and mid-term disease progression. However, combination medications may be important in late-stage diseases, but they are associated with various side effects. Traditional Chinese medicines have been shown to be potential therapeutic alternatives for such complex diseases.

Approach to patients with pseudo-Cushing's states

The distinction between pseudo-Cushing's states (PCS) and Cushing's syndrome (CS) poses a significant clinical challenge even for expert endocrinologists. A patient's clinical history can sometimes help to distinguish between them (as in the case of alcoholic individuals), but the overlap in clinical and laboratory findings makes it difficult to arrive at a definitive diagnosis. We aim to describe the most common situations that can give rise to a condition resembling overt endogenous hypercortisolism and try to answer questions that physicians often face in clinical practice. It is important to know the relative prevalence of these different situations, bearing in mind that most of the conditions generating PCS are relatively common (such as metabolic syndrome and polycystic ovary syndrome), while CS is rare in the general population. Physicians should consider CS in the presence of additional features. Appropriate treatment of underlying conditions is essential as it can reverse the hormonal abnormalities associated with PCS. Close surveillance and a thorough assessment of a patient's hormone status will ultimately orient the diagnosis and treatment options over time.

Depressive Symptoms Mediate the Relationship between Emotional Cutoff and Type 2 Diabetes Mellitus

BACKGROUND

Differentiation of self is a family systems construct defined as the ability to balance intimacy and autonomy and to separate instinctually driven emotional reactions and thoughtfully considered goal-directed functioning. In theory, low differentiation of self is reflected by four components: a low tendency to take an I-position in relationships (i.e., to own one's thoughts and feelings); emotional cutoff from others; a greater tendency to fuse with others; and a tendency towards emotional reactivity. Low differentiation of self is associated with anxiety and depression, which are risk factors for type 2 diabetes mellitus. The current study examines the relationship between differentiation of self and type 2 diabetes mellitus.

METHOD

Individuals with type 2 diabetes mellitus (N = 107) and healthy individuals (N = 145) completed the Differentiation of Self Inventory-Revised (DSI-R), the State-Trait Anxiety Inventory (STAI), and the Beck Depression Inventory (BDI-II).

RESULTS

Compared with healthy individuals, participants with type 2 diabetes had more severe depressive symptoms, higher levels of emotional cutoff, and a lower tendency to take an I-position, but had similar levels of trait anxiety, emotional reactivity, and fusion with others (factor analysis revealed these factors were not separable in the current sample and thus were merged into a single construct). Importantly, the severity of depressive symptoms mediated the relationship between emotional cutoff and being in the type 2 diabetes study group rather than the healthy group.

CONCLUSION

These findings suggest a new perspective on the role of psychological patterns in type 2 diabetes mellitus development and progression.

Co-shared genetics and possible risk gene pathway partially explain the comorbidity of schizophrenia, major depressive disorder, type 2 diabetes, and metabolic syndrome

Schizophrenia (SCZ) and major depressive disorder (MDD) in treatment-naive patients are associated with increased risk for type 2 diabetes (T2D) and metabolic syndrome (MetS). SCZ, MDD, T2D, and MetS are often comorbid and their comorbidity increases cardiovascular risk: Some risk genes are likely co-shared by them. For instance, transcription factor 7-like 2 (TCF7L2) and proteasome 26S subunit, non-ATPase 9 (PSMD9) are two genes independently reported as contributing to T2D and SCZ, and PSMD9 to MDD as well. However, there are scarce data on the shared genetic risk among SCZ, MDD, T2D, and/or MetS. Here, we briefly describe T2D, MetS, SCZ, and MDD and their genetic architecture. Next, we report separately about the comorbidity of SCZ and MDD with T2D and MetS, and their respective genetic overlap. We propose a novel hypothesis that genes of the prolactin (PRL)-pathway may be implicated in the comorbidity of these disorders. The inherited predisposition of patients with SCZ and MDD to psychoneuroendocrine dysfunction may confer increased risk of T2D and MetS. We illustrate a strategy to identify risk variants in each disorder and in their comorbid psychoneuroendocrine and mental-metabolic dysfunctions, advocating for studies of genetically homogeneous and phenotype-rich families. The results will guide future studies of the shared predisposition and molecular genetics of new homogeneous endophenotypes of SCZ, MDD, and metabolic impairment.

Is There a Relationship Between Gestational Diabetes and Perinatal Depression?

Perinatal depression (PND) is one of the leading complications associated with childbirth. Early detection and treatment of depression, particularly during the perinatal period, is essential for the promotion of positive maternal-child outcomes. Gestational diabetes mellitus (GDM) has been suggested as a confounding factor associated with PND. Concerns associated with PND include interference with maternal-newborn bonding and long-term effects of neurobehavioral consequences. An exemplar case describing one woman's experience with GDM and her subsequent complications associated with PND is presented to discuss maternal depression and its plausible association with GDM. Recommendations include universal screening with the validated Edinburgh Postnatal Depression Scale screening tool during the early perinatal period to reduce incidence of maternal-newborn complications associated with PND and promote underpinnings for best practice.

Quantitative assessment of the bidirectional relationships between diabetes and depression

Diabetes and depression impose an enormous public health burden and the present study aimed to assess quantitatively the bidirectional relationships between the two disorders. We searched databases for eligible articles published until October 2016. A total of 51 studies were finally included in the present bidirectional meta-analysis, among which, 32 studies were about the direction of depression leading to diabetes, and 24 studies about the direction of diabetes leading to depression. Pooled results of the 32 eligible studies covering 1274337 subjects showed that depression patients were at higher risk for diabetes (odds ratio (OR) = 1.34, 95% confidence intervals (CI) = [1.23, 1.46]) than non-depressive subjects. Further gender-subgroup analysis found that the strength of this relationship was stronger in men (OR = 1.63, 95%CI = [1.48, 1.78]) than in women (OR = 1.29, 95%CI = [1.07, 1.51]). For the direction of diabetes leading to depression, pooled data of 24 articles containing 329658 subjects showed that patients with diabetes were at higher risk for diabetes (OR = 1.28, 95%CI = [1.15, 1.42]) than non-diabetic subjects. The available data supports that the relationships between diabetes and depression are bidirectional and the overall strengths are similar in both directions. More mechanistic studies are encouraged to explore the molecular mechanisms underlying the relationships between the two diseases.

Banxia-houpu decoction restores glucose intolerance in CUMS rats through improvement of insulin signaling and suppression of NLRP3 inflammasome activation in liver and brain

ETHNOPHARMACOLOGICAL RELEVANCE

Banxia-houpu decoction is a famous formula in traditional Chinese medicine (TCM) with the powerful anti-depressant activity.

AIM OF THE STUDY

This study aimed to investigate the effect of Banxia-houpu decoction on glucose intolerance associated with anhedonia in chronic unpredictable mild stress (CUMS) rats, then to explore its underlying pharmacological mechanisms.

MATERIALS AND METHODS

After 6-week CUMS procedure, male Wistar rats were given Banxia-houpu decoction (3.29 and 6.58g/kg, intragastrically) for 6 weeks. Sucrose solution consumption test was employed to evaluate the anhedonia behavior. Oral glucose tolerance test (OGTT) was used to determine glucose tolerance. Serum levels of corticosterone, corticotropin-releasing factor (CRF), insulin and interleukin-1 beta (IL-1β) were measured by commercial enzyme-linked immunosorbent assay kits, respectively. Furthermore, the key proteins for insulin signaling, as well as nod-like receptor family pyrin domain containing 3 (NLRP3) inflammasome, were analyzed by Western blot in periphery liver and brain regions hypothalamus, hippocampus and prefrontal cortex, respectively.

RESULTS

Banxia-houpu decoction significantly increased sucrose solution consumption and decreased serum corticosterone and CRF levels in CUMS rats, further demonstrating its antidepressant activity. More importantly, Banxia-houpu decoction improved glucose tolerance in OGTT in this animal model. Furthermore, it protected against CUMS-induced insulin signaling impairment in the liver, as well as hypothalamus and prefrontal cortex in rats. Although without significant effect on serum IL-1β levels, Banxia-houpu decoction inhibited NLRP3 inflammasome activation in the liver, hypothalamus, hippocampus and prefrontal cortex of CUMS rats, respectively.

CONCLUSIONS

The present study demonstrates that Banxia-houpu decoction suppresses NLRP3 inflammasome activation and improves insulin signaling impairment in both periphery liver and brain regions in CUMS rats, possibly contributing to its anti-depressive effect with glucose tolerance improvement. These results may provide the evidence that Banxia-houpu decoction is a potential antidepressant with the advantage to reduce the risk of comorbid depression with type 2 diabetes mellitus.

Inside the Diabetic Brain: Role of Different Players Involved in Cognitive Decline

Diabetes mellitus is the most common metabolic disease, and its prevalence is increasing. A growing body of evidence, both in animal models and epidemiological studies, has demonstrated that metabolic diseases like obesity, insulin resistance, and diabetes are associated with alterations in the central nervous system (CNS), being linked with development of cognitive and memory impairments and presenting a higher risk for dementia and Alzheimer's disease. The rising prevalence of diabetes together with its increasing earlier onset suggests that diabetes-related cognitive dysfunction will increase in the near future, causing substantial socioeconomic impact. Decreased insulin secretion or action, dysregulation of glucose homeostasis, impairment in the hypothalamic-pituitary-adrenal axis, obesity, hyperleptinemia, and inflammation may act independently or synergistically to disrupt neuronal homeostasis and cause diabetes-associated cognitive decline. However, the crosstalk between those factors and the mechanisms underlying the diabetes-related CNS complications is still elusive. During the past few years, different strategies (neuroprotective and antioxidant drugs) have emerged as promising therapies for this complication, which still remains to be preventable or treatable. This Review summarizes fundamental past and ongoing research on diabetes-associated cognitive decline, highlighting potential contributors, mechanistic mediators, and new pharmacological approaches to prevent and/or delay this complication.

Depression in Mexican Americans with diagnosed and undiagnosed diabetes

BACKGROUND

Depression and diabetes commonly co-occur; however, the strength of the physiological effects of diabetes as mediating factors towards depression is uncertain.

METHOD

We analyzed extensive clinical, epidemiological and laboratory data from n = 2081 Mexican Americans aged 35-64 years, recruited from the community as part of the Cameron County Hispanic Cohort (CCHC) divided into three groups: Diagnosed (self-reported) diabetes (DD, n = 335), Undiagnosed diabetes (UD, n = 227) and No diabetes (ND, n = 1519). UD participants denied being diagnosed with diabetes, but on testing met the 2010 American Diabetes Association and World Health Organization definitions of diabetes. Depression was measured using the Center for Epidemiological Studies - Depression (CES-D) scale. Weighted data were analyzed using dimensional and categorical outcomes using univariate and multivariate models.

RESULTS

The DD group had significantly higher CES-D scores than both the ND and UD (p ⩽ 0.001) groups, whereas the ND and UD groups did not significantly differ from each other. The DD subjects were more likely to meet the CES-D cut-off score for depression compared to both the ND and UD groups (p = 0.001), respectively. The UD group was also less likely to meet the cut-off score for depression than the ND group (p = 0.003). Our main findings remained significant in models that controlled for socio-demographic and clinical confounders.

CONCLUSIONS

Meeting clinical criteria for diabetes was not sufficient for increased depressive symptoms. Our findings suggest that the 'knowing that one is ill' is associated with depressive symptoms in diabetic subjects.

The Risk of Gestational Diabetes Mellitus Following Bereavement: A Cohort Study from Denmark and Sweden

BACKGROUND

We investigated whether bereavement of a close family member - a source of severe psychological stress exposure - the year before pregnancy is associated with gestational diabetes mellitus (GDM).

METHODS

We studied pregnant women with livebirths in Denmark during 1994-2008 and with births in Sweden during 1987-2006 (n = 2,569,446). We obtained data on death of women's parents, siblings, and older children, and on demographic and health- and pregnancy-related factors through linkage between nationwide registers.

RESULTS

In multivariable models, death of a close relative the year before pregnancy was associated with a 14% increased odds of GDM [95% confidence intervals (CIs) 1.03, 1.26]. The odds ratios corresponding to the loss of a child, parent, and sibling were 1.51 (95% CI: 1.17, 1.95), 1.12 (95% CI: 1.00, 1.25), and 0.68 (95% CI: 0.40, 1.25), respectively. Deaths due to cardiovascular diseases or diabetes were more closely related to the risk of GDM than other types of deaths. We found no association between unnatural deaths and the risk of GDM.

CONCLUSIONS

Death of a close relative the year before pregnancy was associated with a modestly increased GDM risk. Our findings according to the relative's cause of death suggest that differences in screening for GDM among exposure groups and residual confounding by familial factors related to metabolic and cardiovascular diseases may have contributed to this association. If there is a causal stress effect on GDM in this predominantly Nordic population, it is most likely small.

Cortisol, platelet serotonin content, and platelet activity in patients with major depression and type 2 diabetes: an exploratory investigation

OBJECTIVE

Hypothalamic-pituitary-adrenal system dysfunction, serotonergic system alterations, and enhanced platelet activity may contribute to the increased cardiac risk in depression. This exploratory study examined associations between cortisol parameters, platelet serotonin (5-HT) content, and platelet activity markers in patients with newly diagnosed major depression (MD) and/or Type 2 diabetes (T2DM) compared with healthy controls.

METHODS

We compared cortisol awakening response (CAR), diurnal decrease in salivary cortisol concentrations (slope), platelet 5-HT, and platelet markers (CD40, CD40 ligand [CD40L], soluble CD40L, CD62P, β-thromboglobulin, and platelet factor-4) in 22 T2DM patients, 20 MD patients, 18 T2DM patients with MD, and 24 healthy controls.

RESULTS

Platelet markers were elevated in MD (F(6,60) = 11.14, p < .001) and T2DM (F(6,60) = 13.07, p < .001). Subgroups did not differ in 5-HT or cortisol slope, whereas T2DM patients without depression had significantly lower CAR than did healthy controls (F(1,61) = 7.46, p = .008). In healthy controls, cortisol slope correlated with platelet activity for CD40 (r = -0.43, p = .048) and 5-HT was correlated with CD40L (r = 0.53, p = .007). In patients with both T2DM and MD, 5-HT and CD62P were correlated (r = 0.52, p = .033).

CONCLUSIONS

Increased platelet activity in T2DM and MD may play a role in the association between diabetes, depression, and coronary artery disease. The present data suggest that group differences in cortisol or 5-HT as well as group-specific associations of cortisol or 5-HT with platelet markers might be of limited importance in the shared pathways of T2DM and depression in the pathophysiology of coronary artery disease.

Diabetes in China: a societal solution for a personal challenge

China has a large burden of diabetes: in 2013, one in four people with diabetes worldwide were in China, where 11·6% of adults had diabetes and 50·1% had prediabetes. Many were undiagnosed, untreated, or uncontrolled. This epidemic is the result of rapid societal transition that has led to an obesogenic environment against a backdrop of traditional lifestyle and periods of famine, which together puts Chinese people at high risk of diabetes and multiple morbidities. Societal determinants including social disparity and psychosocial stress interact with factors such as low-grade infection, environmental pollution, care fragmentation, health illiteracy, suboptimal self-care, and insufficient community support to give rise to diverse subphenotypes and consequences, notably renal dysfunction and cancer. In the China National Plan for Non-Communicable Disease Prevention and Treatment (2012-15), the Chinese Government proposed use of public measures, multisectoral collaborations, and social mobilisation to create a health-enabling environment and to reform the health-care system. While awaiting results from these long-term strategies, we advocate the use of a targeted and proactive approach to identify people at high risk of diabetes for prevention, and of private-public-community partnerships that make integrated care more accessible and sustainable, focusing on registry, empowerment, and community support. The multifaceted nature of the societal and personal challenge of diabetes requires a multidimensional solution for prevention in order to reduce the growing disease burden.

Meta-analysis of genome-wide association studies in East Asian-ancestry populations identifies four new loci for body mass index

Recent genetic association studies have identified 55 genetic loci associated with obesity or body mass index (BMI). The vast majority, 51 loci, however, were identified in European-ancestry populations. We conducted a meta-analysis of associations between BMI and ∼2.5 million genotyped or imputed single nucleotide polymorphisms among 86 757 individuals of Asian ancestry, followed by in silico and de novo replication among 7488-47 352 additional Asian-ancestry individuals. We identified four novel BMI-associated loci near the KCNQ1 (rs2237892, P = 9.29 × 10(-13)), ALDH2/MYL2 (rs671, P = 3.40 × 10(-11); rs12229654, P = 4.56 × 10(-9)), ITIH4 (rs2535633, P = 1.77 × 10(-10)) and NT5C2 (rs11191580, P = 3.83 × 10(-8)) genes. The association of BMI with rs2237892, rs671 and rs12229654 was significantly stronger among men than among women. Of the 51 BMI-associated loci initially identified in European-ancestry populations, we confirmed eight loci at the genome-wide significance level (P < 5.0 × 10(-8)) and an additional 14 at P < 1.0 × 10(-3) with the same direction of effect as reported previously. Findings from this analysis expand our knowledge of the genetic basis of obesity.

Harmful effects of functional hypercortisolism: a working hypothesis

Functional hypercortisolism (FH) is caused by conditions able to chronically activate hypothalamic-pituitary-adrenal axis and usually occurs in cases of major depression, anorexia nervosa, bulimia nervosa, alcoholism, diabetes mellitus, simple obesity, polycystic ovary syndrome, obstructive sleep apnea syndrome, panic disorder, generalized anxiety disorder, shift work, and end-stage renal disease. Most of these states belong to pseudo-Cushing disease, a condition which is difficult to distinguish from Cushing's syndrome and characterized not only by biochemical findings but also by objective ones that can be attributed to hypercortisolism (e.g., striae rubrae, central obesity, skin atrophy, easy bruising, etc.). This hormonal imbalance, although reversible and generally mild, could mediate some systemic complications, mainly but not only of a metabolic/cardiovascular nature, which are present in these states and are largely the same as those present in Cushing's syndrome. In this review we aim to discuss the evidence suggesting the emerging negative role for FH.

Phobic anxiety symptom scores and incidence of type 2 diabetes in US men and women

CONTEXT

Emotional stress may be a risk factor for type 2 diabetes (T2D), but the relation between phobic anxiety symptoms and risk of T2D is uncertain.

OBJECTIVE

To evaluate prospectively the association between phobic anxiety symptoms and incident T2D in three cohorts of US men and women.

DESIGN, SETTING AND PATIENTS

We followed 30,791 men in the Health Professional's Follow-Up Study (HPFS) (1988-2008), 68,904 women in the Nurses' Health Study (NHS) (1988-2008), and 79,960 women in the Nurses' Health Study II (NHS II) (1993-2011). Phobic anxiety symptom scores, as measured by the Crown-Crisp index (CCI), calculated from 8 questions, were administered at baseline and updated in 2004 for NHS, in 2005 for NHS II, and in 2000 for HPFS. Incident T2D was confirmed by a validated supplementary questionnaire. We used Cox proportional hazards analysis to evaluate associations with incident T2D.

RESULTS

During 3,099,651 person-years of follow-up, we documented 12,831 incident T2D cases. In multivariate Cox proportional-hazards models with adjustment for major lifestyle and dietary risk factors, the hazard ratios (HRs) of T2D across categories of increasing levels of CCI (scores=2 to <3, 3 to <4, 4 to <6, ⩾6), compared with a score of <2, were increased significantly by 6%, 10%, 10% and 13% (Ptrend=0.001) for NHS; and by 19%, 11%, 21%, and 29% (Ptrend<0.0001) for NHS II. Each score increment in CCI was associated with 2% higher risk of T2D in NHS (HRs, 1.02, 95% confidence intervals: 1.01-1.03) and 4% higher risk of T2D in NHS II (HRs, 1.04, 95% confidence intervals: 1.02-1.05). Further adjustment for depression did not change the results. In HPFS, the association between CCI and T2D was not significant after adjusting for lifestyle variables.

CONCLUSION

Our results suggest that higher phobic anxiety symptoms are associated with an increased risk of T2D in women.

The comorbidity between depression and diabetes

Comorbidity of depression and diabetes is common, and each disorder has a negative impact on the outcome of the other. The direction of causality is not certain as each disorder seems to act as both a risk factor and consequence for the other in longitudinal studies. This bidirectional association is possibly mediated by shared environmental and genetic risk factors. Comorbid depression is associated with reduced adherence to medication and self-care management, poor glycaemic control, increased health care utilization, increased costs and elevated risk of complications, as well as mortality in patients with diabetes. Psychological and pharmacological interventions are shown to be effective in improving depression symptoms; however, collaborative care programs that simultaneously manage both disorders seem to be most effective in improving diabetes-related outcomes.