Population attributable fractions for Type 2 diabetes: an examination of multiple risk factors including symptoms of depression and anxiety

Intermittent hypoxia exacerbates anxiety in high-fat diet-induced diabetic mice by inhibiting TREM2-regulated IFNAR1 signaling

BACKGROUND

Type 2 diabetes mellitus (T2DM) and obstructive sleep apnea (OSA) are mutual risk factors, with both conditions inducing cognitive impairment and anxiety. However, whether OSA exacerbates cognitive impairment and anxiety in patients with T2DM remains unclear. Moreover, TREM2 upregulation has been suggested to play a protective role in attenuating microglia activation and improving synaptic function in T2DM mice. The aim of this study was to explore the regulatory mechanisms of TREM2 and the cognitive and anxiety-like behavioral changes in mice with OSA combined with T2DM.

METHODS

A T2DM with OSA model was developed by treating mice with a 60% kcal high-fat diet (HFD) combined with intermittent hypoxia (IH). Spatial learning memory capacity and anxiety in mice were investigated. Neuronal damage in the brain was determined by the quantity of synapses density, the number and morphology of brain microglia, and pro-inflammatory factors. For mechanism exploration, an in vitro model of T2DM combined with OSA was generated by co-treating microglia with high glucose (HG) and IH. Regulation of TREM2 on IFNAR1-STAT1 pathway was determined by RNA sequencing and qRT-PCR.

RESULTS

Our results showed that HFD mice exhibited significant cognitive dysfunction and anxiety-like behavior, accompanied by significant synaptic loss. Furthermore, significant activation of brain microglia and enhanced microglial phagocytosis of synapses were observed. Moreover, IH was found to significantly aggravate anxiety in the HFD mice. The mechanism of HG treatment may potentially involve the promotion of TREM2 upregulation, which in turn attenuates the proinflammatory microglia by inhibiting the IFNAR1-STAT1 pathway. Conversely, a significant reduction in TREM2 in IH-co-treated HFD mice and HG-treated microglia resulted in the further activation of the IFNAR1-STAT1 pathway and consequently increased proinflammatory microglial activation.

CONCLUSIONS

HFD upregulated the IFNAR1-STAT1 pathway and induced proinflammatory microglia, leading to synaptic damage and causing anxiety and cognitive deficits. The upregulated TREM2 inT2DM mice brain exerted a negative regulation of the IFNAR1-STAT1 pathway. Mice with T2DM combined with OSA exacerbated anxiety via the downregulation of TREM2, causing heightened IFNAR1-STAT1 pathway activation and consequently increasing proinflammatory microglia.

Glucagon-like Peptide 1 Receptor Activation Inhibits Microglial Pyroptosis via Promoting Mitophagy to Alleviate Depression-like Behaviors in Diabetic Mice

Depression is a frequent and serious comorbidity associated with diabetes which adversely affects prognosis and quality of life. Glucagon-like peptide-1 receptor (GLP-1R) agonists, widely used in the treatment of diabetes, are reported to exert neuroprotective effects in the central nervous system. Thus, we aim to evaluate whether GLP-1R agonist exendin-4 (EX-4) could alleviate depression-like behaviors in diabetic mice and to explore its underlying mechanism. The antidepressant effects of EX-4 were evaluated using behavioral tests in db/db mice. The effects of EX-4 on microglial pyroptosis and neuroinflammation were assessed in N9 microglial cells. EX-4 administration alleviated depression-like behaviors in diabetic db/db mice. GLP-1R activation by EX-4 significantly suppressed microglial pyroptosis and neuroinflammation by downregulation of gasdermin D (GSDMD) and interleukin (IL)-1β in diabetic mice and lipopolysaccharide (LPS)-primed N9 microglia. Mechanistically, GLP-1R activation improved mitochondrial function and promoted mitophagy by decreasing the accumulation of mitochondrial reactive oxygen species (mtROS) and intracellular ROS production. EX-4 exhibits antidepressant effects in depression associated with diabetes in diabetic mice, which may be mediated by inhibiting microglial pyroptisis via promoting mitophagy. It is supposed that GLP-1R agonists may be a promising therapy in depression associated with diabetes.

A bidirectional relationship between diabetes mellitus and anxiety: A systematic review and meta-analysis

BACKGROUND

Due to the existence of inconsistencies in the evidence regarding the direction and extent of association between diabetes and anxiety disorders, the anxiety-diabetes comorbidity remains an issue of debate.

AIM

To estimate the proportion and risk of diabetes among individuals with anxiety disorder and vice versa.

METHODS

A systematic review was conducted using studies retrieved from databases and grey literature, with the last database search being conducted on April 15, 2021. The methodological rigor of studies was assessed using the National Institute of Health quality assessment tool. Prevalence and effect size (ES) estimates were pooled using a random effect model. Heterogeneity was assessed using the Higgins' I² statistical test, and subgroup analysis conducted.

RESULTS

We included 68 studies presenting data from 2,128,029 participants. The prevalence of anxiety disorders in diabetic patients was 28% (95% CI: 26%, 31%); however, subgroup analysis showed significant differences based on type of anxiety assessment scales, study location, and type of diabetes. The prevalence of diabetes among patients with anxiety disorders was 12% (95% CI: 9%, 16%). Patients with anxiety disorders were found to have a 19% higher risk of diabetes (pooled effect size (ES) = 1.19, 95% CI: 1.13, 1.26). Diabetic patients were found to have a 41% higher risk of developing anxiety disorders (ES = 1.41, 95% CI: 1.19, 1.62).

CONCLUSIONS

There is a higher risk of anxiety disorders in patients with diabetes mellitus and vice versa. It is recommended to screen diabetic patients for anxiety at initial diagnosis and follow-up visits. Similarly, patients with anxiety disorders should have regular screening for diabetes.

REVIEW REGISTRATION

PROSPERO registration number CRD42021252475.

The prevalence and related factors of metabolic syndrome in outpatients with first-episode drug-naive major depression comorbid with anxiety

Metabolic syndrome (MetS) is associated with depression, but its role in major depressive disorder comorbid with anxiety (AMD) is unclear. This study aimed to investigate the prevalence and clinical correlates of MetS in first-episode drug-naive (FEDN) patients with AMD in a Chinese Han population. In total, 1380 FEDN outpatients with AMD were recruited in this cross-sectional study. The sociodemographic features, clinical characteristics, history of suicide attempts, thyroid-stimulating hormone (TSH) levels, and MetS parameters of each subject were evaluated. All subjects were rated on the Hamilton Depression Rating Scale (HAM-D), Hamilton Anxiety Rating Scale (HAM-A), and the Positive and Negative Syndrome Scale positive symptom subscale. The prevalence of MetS among AMD patients was 8.04%. Compared to the non-MetS group, age, age of onset, TSH level, HAM-A and HAM-D scores, history of attempted suicide, and comorbid psychiatric symptoms were higher in the MetS group. Those in this group were also more likely to be married, and they had a lower educational level. Furthermore, age, psychiatric symptoms, suicide attempts, and higher TSH levels were independently associated with MetS in AMD patients. This study suggests a lower prevalence of MetS in FEDN patients with AMD in a Chinese Han population. Older age, comorbid psychiatric symptoms, history of attempted suicide, and higher TSH levels are related factors for MetS in AMD patients.

Anxiety boosts progression of prediabetes to type 2 diabetes: findings from the prospective Cooperative Health Research in the Region of Augsburg F4 and FF4 studies

AIM

To investigate the association between anxiety symptoms and the progression from prediabetes to type 2 diabetes.

METHODS

A sample of 1708 participants aged 31-82 years from the population-based Cooperative Health Research in the Region of Augsburg F4 and the follow-up Cooperative Health Research in the Region of Augsburg FF4 studies was included. Prediabetes was defined as impaired fasting glucose and/or impaired glucose tolerance, and anxiety status was measured by the generalized anxiety disorder-7 questionnaire. Newly diagnosed type 2 diabetes cases were identified after 6.5 years (11 102 person-years) and confirmed by medical records. Multivariate logistic regression analyses were employed to estimate the effect of prediabetes and anxiety on the incidence of type 2 diabetes with different levels of adjustments for potential confounders. The population attributable risk of type 2 diabetes in participants with prediabetes and anxiety was estimated.

RESULTS

Prediabetes at baseline was prevalent in 247 participants, of whom 77 developed diabetes after follow-up, accounting for a progression rate of 31%. In participants with prediabetes, high anxiety was associated with a 3-fold increased risk of progression to type 2 diabetes in comparison with low anxiety, even after accounting for socio-demographic, lifestyle and metabolic risk factors (OR = 2.82, 95% CI = 0.95-8.37, P = 0.06). A significant proportion of incident type 2 diabetes was attributed to having anxiety in addition to prediabetes (attributable risk proportion: 0.52; 95% CI = 0.004-1.04, P = 0.05).

CONCLUSIONS

Anxiety symptoms independently increase the progression risk of prediabetes to type 2 diabetes and should be routinely considered alongside the traditional risk factors in people with prediabetes.

Risk and population attributable fraction of metabolic syndrome and impaired fasting glucose for the incidence of type 2 diabetes mellitus among middle-aged Japanese individuals: Aichi Worker's Cohort Study

AIMS/INTRODUCTION

The Japanese government started a nationwide screening program for metabolic syndrome (MetS) to prevent cardiovascular diseases and diabetes in 2008. Although impaired fasting glucose (IFG) is a strong predictor for type 2 diabetes mellitus, the program does not follow up IFG in non-MetS individuals. This study aimed to examine the risk and the population attributable fraction (PAF) of MetS and IFG for incidence of type 2 diabetes mellitus.

MATERIALS AND METHODS

Japanese workers (3,417 men and 714 women) aged 40-64 years without a history of diabetes were prospectively followed. MetS was defined as either abdominal obesity plus two or more metabolic risk factors, or being overweight in the case of normal waist circumference plus three or more metabolic risk factors. IFG was defined as fasting blood glucose 100-125 mg/dL.

RESULTS

During a mean 6.3 years, 240 type 2 diabetes mellitus cases were identified. Compared with those without MetS and IFG, the multivariable-adjusted hazard ratios (95% confidence interval) of non-MetS individuals with IFG, MetS individuals without IFG and MetS individuals with IFG for type 2 diabetes mellitus were 4.9 (3.4-7.1), 2.4 (1.6-3.5) and 8.3 (5.9-11.5), respectively. The corresponding PAFs for type 2 diabetes mellitus incidence were 15.6, 9.1 and 29.7%, respectively.

CONCLUSIONS

IFG represented a higher risk and PAF than MetS for type 2 diabetes mellitus incidence in middle-aged Japanese individuals. The coexistence of MetS and IFG showed the highest risk and PAF for type 2 diabetes mellitus incidence. The current Japanese MetS screening program should be reconsidered to follow up non-MetS individuals with IFG.

Strain and sex-based glucocentric & behavioral differences between KK/HlJ and C57BL/6J mice

INTRODUCTION

Small-animal models are the most widely used preclinical model for studying the etiology, pathology and treatment of diabetes, prediabetes and diabetic comorbidities. Diabetic patients are burdened with higher rates of depression, anxiety and cognitive decline due to inadequate control of blood glucose levels, vascular damage and aberrant CNS insulin signaling. The C57BL/6J model is amongst the most widely used mouse model due to its susceptibility to diet-induced obesity (DIO). This strain has also been well-characterized in behavioral research studies. However the C57BL/6J model has a number of limitations: [1] overt fasting hyperglycemia can only be induced by dietary manipulation and/or chemical ablation of the pancreatic beta cells. [2] There is heterogeneity in the obesogenic response to hypercaloric feeding as well as sex-dependent differences, with males being more responsive. The KK inbred strain has been used to study aspects of the metabolic syndrome and prediabetes due to inherent glucose intolerance, hyperinsulinemia and insulin resistance. However KK/HlJ mice are less well-characterized and there have been fewer behavioral studies reported. The aim of this study was to examine differences in male and female glucocentric parameters between KK/HlJ and C57BL/6J mice, and to compare their performance in a variety of standard behavioral tests relating to general, anxiogenic and cognitive paradigms.

METHODS

Strain differences in male and female KK/HlJ and C57BL/6J mouse adiposity, glucose and insulin parameters were studied together with group differences in standard Open Field, Object Recognition, Elevated Plus Maze, Light-Dark Transition, Porsolt test, Marble Burying, Social Recognition and Morris Water Maze tests. Correlations between behavioral variables were analyzed.

RESULTS AND CONCLUSION

In addition to being uniformly larger, hyperinsulinemic and more insulin intolerant than C57BL/6J mice, we observed marked strain and sex-differences in KK/HlJ behavior. KK/HlJ mice exhibited less locomotor and vertical exploratory behavior in comparison to C57BL/6J, whereas object exploration and novel object discrimination were superior in KK/HlJ mice. Female KK/HlJ mice were faster swimmers, whereas the males exhibited greater spatial cognition and place-learning during the MWM test.