Definition and Classification of Diabetes and Prediabetes and Emerging Data on Phenotypes

Association between prediabetes and depression: A meta-analysis

BACKGROUND

Previous studies evaluating the association between prediabetes and depression have shown inconsistent results. Consequently, the aim of the systematic review and meta-analysis was to investigate whether prediabetes is associated with depression in the general population.

METHODS

Relevant observational studies were obtained by searching the Medline, Web of Science, and Embase databases. A random-effects model was utilized to pool the results by incorporating the influence of heterogeneity. Multiple subgroup analysis was performed to evaluate the influence of the study characteristics on the outcome.

RESULTS

Sixteen large-scale cross-sectional studies involving 322,863 participants were included. Among the total participants, 82,154 (25.4%) had prediabetes. The pooled results showed that prediabetes was associated with a higher prevalence of depression in this population (odds ratio [OR]: 1.16, 95% confidence interval [CI]: 1.05 to 1.28, p = 0.003; I2 = 58%). Subgroup analysis showed a stronger association between prediabetes and depression in younger subjects (<50 years old, OR: 1.25, 95% CI: 1.04 to 1.50) than that in older subjects (≥50 years old, OR: 1.05, 95% CI: 1.10 to 1.10; p for subgroup difference = 0.03). Other study characteristics, such as the study country, sex of the participants, definition of prediabetes, methods for the detection of depression, and study quality score, did not seem to significantly affect the results (p for subgroup difference all > 0.05).

CONCLUSIONS

Prediabetes may be associated with a slightly higher prevalence of depression in the general population, particularly in subjects aged <50 years old.

Influence of prediabetes on the prognosis of patients with myocardial infarction: a meta-analysis

BACKGROUND

Previous studies evaluating the association between prediabetes the prognosis of patients with acute myocardial infarction (AMI) showed inconsistent results. The aim of the meta-analysis was to compare the long-term incidence of major adverse cardiovascular events (MACEs) between AMI patients with prediabetes and normoglycemia.

METHODS

Relevant prospective cohort studies were obtained by searching Medline, Web of Science, and Embase databases. Only studies with follow-up duration of at least one year were included. A random-effects model was utilized to pool the results by incorporating the influence of heterogeneity.

RESULTS

Twelve studies with 6972 patients with AMI were included. Among them, 2998 were with prediabetes and 3974 were with normoglycemia. During a mean follow-up of 52.6 months, 2100 patients developed MACEs. Compared to those with normoglycemia, AMI patients with prediabetes were associated with a higher incidence of MACEs (risk ratio [RR]: 1.30, 95% confidence interval: 1.07 to 1.58, p = 0.008; I2 = 67%). Subgroup analysis showed a stronger association between prediabetes and MACEs in studies of patients with mean age ≥ 60 years compared to < 60 years (RR: 1.66 versus 1.10, p for subgroup difference = 0.04), with proportion of men < 75% compared to ≥ 75% (RR: 1.87 versus 1.08, p for subgroup difference = 0.01), and in prediabetes evaluated at or after discharge compared to that evaluated within three days of AMI onset (RR: 1.39 versus 0.78, p for subgroup difference = 0.01).

CONCLUSIONS

Prediabetes may be associated with a higher risk of MACEs in patients with AMI.

Pregestational Prediabetes Induces Maternal Hypothalamic-Pituitary-Adrenal (HPA) Axis Dysregulation and Results in Adverse Foetal Outcomes

Maternal type 2 diabetes mellitus (T2DM) has been shown to result in foetal programming of the hypothalamic-pituitary-adrenal (HPA) axis, leading to adverse foetal outcomes. T2DM is preceded by prediabetes and shares similar pathophysiological complications. However, no studies have investigated the effects of maternal prediabetes on foetal HPA axis function and postnatal offspring development. Hence, this study investigated the effects of pregestational prediabetes on maternal HPA axis function and postnatal offspring development. Pre-diabetic (PD) and non-pre-diabetic (NPD) female Sprague Dawley rats were mated with non-prediabetic males. After gestation, male pups born from the PD and NPD groups were collected. Markers of HPA axis function, adrenocorticotropin hormone (ACTH) and corticosterone, were measured in all dams and pups. Glucose tolerance, insulin and gene expressions of mineralocorticoid (MR) and glucocorticoid (GR) receptors were further measured in all pups at birth and their developmental milestones. The results demonstrated increased basal concentrations of ACTH and corticosterone in the dams from the PD group by comparison to NPD. Furthermore, the results show an increase basal ACTH and corticosterone concentrations, disturbed MR and GR gene expression, glucose intolerance and insulin resistance assessed via the Homeostasis Model Assessment (HOMA) indices in the pups born from the PD group compared to NPD group at all developmental milestones. These observations reveal that pregestational prediabetes is associated with maternal dysregulation of the HPA axis, impacting offspring HPA axis development along with impaired glucose handling.

Protective effects and mechanisms of Momordica charantia polysaccharide on early-stage diabetic retinopathy in type 1 diabetes

Momordica charantia polysaccharide (MCP) is a potential drug for the prevention and alleviation of diabetes mellitus (DM) and diabetic retinopathy (DR). This study aimed to investigate the potential protective effects of MCP on early-stage DR and explore the underlying mechanisms. The model group (DM group) and treatment group (D+H group) were established by inducing type 1 DM using a single dose of streptozotocin (STZ) at 60 mg/kg. After modeling, the D+H group was orally administered a 500 mg/kg dose of MCP solution once daily for 12 weeks. Monitoring of systemic indicators (FBG, body weight, general condition) and retinal tissue inflammation and apoptosis (HE staining, IL-6, MCP-1, TNF-α, VEGF, NF-κB, Caspase-3) in this study demonstrated that MCP intervention alleviated both DM and DR. MCP improved the body weight and general condition of DM rats by reducing FBG levels. It also enhanced the anti-inflammatory and anti-apoptotic capabilities of retinal neurons and microvessels by modulating the actions of cytokines, thereby further regulating the inflammation and apoptosis of retinal neurons and microvessels. The underlying mechanisms may be associated with the downregulation of NF-κB and Caspase-3 pathway protein expression, as well as the downregulation of mRNA expression of NF-κB and Caspase-3 pathway genes. Further research is needed to elucidate the potential mechanisms underlying the protective effects of MCP on DR. MCP may emerge as a selective medication for the prevention and alleviation of DM and a novel natural medicine for the prevention and alleviation of DR.

Prevalence of undiagnosed diabetes and prediabetes related to periodontitis and its risk factors in elderly individuals

OBJECTIVE

The prevalence of undiagnosed diabetes was estimated to increase with age and can reach 3.5%. The purpose of the study was to evaluate the prevalence of undiagnosed diabetes and prediabetes in the elderly patients who attended a dental clinic and to find common risk factors.

METHODS

Male patients, older than 50 years, attended their first dental visit to the School of Dentistry for a period of two years, and it was proposed to evaluate undiagnosed type 2 diabetes mellitus. Periodontal, biochemical, microbiological examinations, nutritional profile, and physical activity were performed.

RESULTS

A total of 106 patients were examined, 6 (5.6%) had diabetes, and 37 (34.9%) had prediabetes without prior diagnosis. The severity of periodontitis was greater in patients with diabetes. Most of the patients were overweight and had increased systolic blood pressure. Patients with prediabetes and periodontitis had a low adherence to the Mediterranean diet. Tannerella forsythia was present in more patients with periodontitis, and the prevalence of Aggregatibacter actinomycetemcomitans is practically absent in groups with periodontitis, except for the group with diabetes.

CONCLUSIONS

In the population studied, the prevalence of patients without a diagnosis of diabetes and prediabetes was very high and underestimated. The increased severity of periodontitis in patients with diabetes and in conjunction with the high level of cortisol seen in patients with periodontitis, especially those with diabetes, emphasize the dysregulation of the immunoinflammatory system.

CLINICAL SIGNIFICANCE

It is essential to add all this data to our dental practice to cover patient health with a broader landscape.

Effects of somatostatin receptor type 2 antagonism during insulin-induced hypoglycaemia in male rats with prediabetes

AIMS

To examine if glucagon counterregulatory defects exist in a rat model of prediabetes (pre-T2D) and to assess if a selective somatostatin receptor 2 antagonist (SSTR2a), ZT-01, enhances the glucagon response to insulin-induced hypoglycaemia.

MATERIALS AND METHODS

Hyperglycaemia was induced in 8- to 9-week-old male, Sprague-Dawley rats via 7 weeks of high-fat diet followed by a single, low-dose intraperitoneal injection of streptozotocin (30 mg/kg). After 2 weeks of basal insulin therapy (0-4 U/d insulin glargine, administered subcutaneously [SC]) to facilitate partial glycaemic recovery and a pre-T2D phenotype, n = 17 pre-T2D and n = 10 normal chow-fed control rats underwent the first of two hypoglycaemic treatment-crossover experiments, separated by a 1-week washout period. On each experimental day, SSTR2a (3 mg/kg ZT-01, SC) or vehicle was administered 1 hour prior to insulin-induced hypoglycaemia (insulin aspart, 6 U/kg, SC).

RESULTS

Glucagon counterregulation was marginally reduced with the induction of pre-T2D. Treatment with SSTR2a raised peak plasma glucagon levels and glucagon area under the curve before and after insulin overdose in both and pre-T2D rats. Blood glucose concentration was elevated by 30 minutes after SSTR2a treatment in pre-T2D rats, and hypoglycaemia onset (≤3.9 mmol/L) was delayed by 15 ± 12 minutes compared with vehicle (P < 0.001), despite similar glucose nadirs in the two treatment groups (1.4 ± 0.3 mmol/L). SSTR2a treatment had no effect on blood glucose levels in the control group or on the hypoglycaemia-induced decline in plasma C-peptide levels in either group.

CONCLUSIONS

Treatment with an SSTR2a increases glucagon responsiveness and delays the onset of insulin-induced hypoglycaemia in this rat model of pre-T2D where only a modest deficiency in glucagon counterregulation exists.

Differential contribution of alpha and beta cell dysfunction to impaired fasting glucose and impaired glucose tolerance

AIMS/HYPOTHESIS

People with isolated impaired fasting glucose (IFG) have normal beta cell function. We hypothesised that an increased glucose threshold for beta cell secretion explains IFG.

METHODS

We used graded glucose infusion to examine the relationship of insulin secretion rate (ISR) and glucagon secretion rate (GSR) with rising glucose. We studied 39 non-diabetic individuals (53 ± 2 years, BMI 30 ± 1 kg/m2), categorised by fasting glucose and glucose tolerance status. After an overnight fast, a variable insulin infusion was used to maintain glucose at ~4.44 mmol/l (07:00 to 08:30 hours). At 09:00 hours, graded glucose infusion commenced at 1 mg kg-1 min-1 and doubled every 60 min until 13:00 hours. GSR and ISR were calculated by nonparametric deconvolution from concentrations of glucagon and C-peptide, respectively.

RESULTS

The relationship of ISR with glucose was linear and the threshold for insulin secretion in isolated IFG did not differ from that in people with normal fasting glucose and normal glucose tolerance. GSR exhibited a single-exponential relationship with glucose that could be characterised by G50, the change in glucose necessary to suppress GSR by 50%. G50 was increased in IFG compared with normal fasting glucose regardless of the presence of impaired or normal glucose tolerance.

CONCLUSIONS/INTERPRETATION

These data show that, in non-diabetic humans, alpha cell dysfunction contributes to the pathogenesis of IFG independently of defects in insulin secretion. We also describe a new index that quantifies the suppression of glucagon secretion by glucose.

Prevalence of diabetic nephropathy in the diabetes mellitus population: A protocol for systematic review and meta-analysis

BACKGROUND

Diabetic nephropathy (DN) is the leading cause of end-stage renal disease worldwide, placing enormous pressure on healthcare systems and creating a heavy socioeconomic burden. It is urgent to comprehensively study the epidemiological characteristics of DN in diabetic patients and to analyze the related factors to its incidence in order to implement effective prevention and control measures.

METHODS AND ANALYSIS

Computer-aided searches of the MEDLINE, EMBASE, Web of Science, PsycINFO, and CINAHL databases will be performed for prospective cohort studies reporting the prevalence of DN in diabetic populations. Studies will be pooled using a generalized linear mixed model, and a single proportion of included studies will be calculated to derive the overall incidence of DN in the diabetic population, and to analyze the effect of different factors on the incidence of DN. Publication bias will be assessed using a funnel plot combined with Begg test. Sensitivity analyses will be performed using the separation method, the exclusion of low-quality studies, and the trim and fill method.

RESULTS

The primary outcome will be the prevalence of DN in the diabetic population; secondary outcomes will be the influence of factors such as age, gender, region, ethnicity, duration of diabetes, type of diabetes, baseline body mass index, baseline glycated hemoglobin level, baseline blood pressure, quality of included studies, and follow-up time on the prevalence of DN in diabetic patients.

CONCLUSION

Through this systematic review and meta-analysis, the study will more comprehensively obtain the prevalence of DN in diabetic populations worldwide, and gain a deeper understanding of the differences in the prevalence of DN in diabetic populations with different characteristics, so as to provide evidence for the management of diabetes and the prevention of DN.

Ligament Alteration in Diabetes Mellitus

Connective tissue ageing is accelerated by the progressive accumulation of advanced glycation end products (AGEs). The formation of AGEs is characteristic for diabetes mellitus (DM) progression and affects only specific proteins with relatively long half-lives. This is the case of fibrillar collagens that are highly susceptible to glycation. While collagen provides a framework for plenty of organs, the local homeostasis of specific tissues is indirectly affected by glycation. Among the many age- and diabetes-related morphological changes affecting human connective tissues, there is concurrently reduced healing capacity, flexibility, and quality among ligaments, tendons, bones, and skin. Although DM provokes a wide range of known clinical disorders, the exact mechanisms of connective tissue alteration are still being investigated. Most of them rely on animal models in order to conclude the patterns of damage. Further research and more well-designed large-cohort studies need to be conducted in order to answer the issue concerning the involvement of ligaments in diabetes-related complications. In the following manuscript, we present the results from experiments discovering specific molecules that are engaged in the degenerative process of connective tissue alteration. This review is intended to provide the report and sum up the investigations described in the literature concerning the topic of ligament alteration in DM, which, even though significantly decreasing the quality of life, do not play a major role in research.

Cardiovascular risk, fatty liver disease, glucose and insulin curve among prediabetes phenotypes in Peruvian population

Aims

To describe the cardiovascular risks, fatty liver disease, and glucose and insulin curve among prediabetes phenotypes (PPh) in Peruvian population.

Methods

A study was carried out using a secondary database of a series of patients with identified risk factors for diabetes mellitus type 2 in one clinic in Lima, Peru. Patients were divided according with the OGTT in impaired glucose 2h or IGT(Pph1), impaired fasting glucose or IFG(Pph3) or both(Pph2).

Results

259 patients were identified for analysis, 149 of whom had normal OGTT, 94 had prediabetes (36.3%), and 16 diabetes (6.2%). We found that 37(39.4%), 37(39.4%) and 20(21.2%) presented Pph1, Pph-2 and Pph-3 respectively. Most of the cardiovascular risks and hepatic function comparison showed no difference in our study sample groups. However, we found that Pph2 showed significantly higher abnormalities in HDL-c, triglycerides, hepatic steatosis, and HOMA-IR compared with normal OGTT group (p < 0.05). Interestingly, this difference was not seen with the other phenotypes. Also, hepatic steatosis was higher in Pph2 compared to Pph3 (p < 0.05). HOMA-IR was high in Phenotype 2 compared with Phenotype 1. Regarding hepatic steatosis, this was high in all prediabetes phenotypes, however we found this to be of statistical significance in Pph2 compared to Pph3 (p < 0.01).

Conclusions

In general, prediabetes phenotypes show a similar association with cardiovascular risk factors and hepatic steatosis, however, Pph2 show more differences in specific comparisons. We believe that this study is a starting point for further investigation to understand prediabetes in Peruvian population and be able to improve disease risk stratification.

Population-Level Approaches to Preventing Type 2 Diabetes Globally

Type 2 diabetes (T2DM) is increasingly considered an epidemic rooted in modern society as much as in individual behavior. Addressing the T2DM burden thus involves a dual approach, simultaneously addressing high-risk individuals and whole populations. Within this context, this article summarizes the evidence base, in terms of effectiveness and cost-effectiveness, for population-level approaches to prevent T2DM: (1) modifications to the food environment; (2) modifications to the built environment and physical activity; and (3) programs and policies to address social and economic factors. Existing knowledge gaps are also discussed.