Adiponectin trajectories before type 2 diabetes diagnosis: Whitehall II study

Type 2 diabetes mellitus in adults: pathogenesis, prevention and therapy

Type 2 diabetes (T2D) is a disease characterized by heterogeneously progressive loss of islet β cell insulin secretion usually occurring after the presence of insulin resistance (IR) and it is one component of metabolic syndrome (MS), and we named it metabolic dysfunction syndrome (MDS). The pathogenesis of T2D is not fully understood, with IR and β cell dysfunction playing central roles in its pathophysiology. Dyslipidemia, hyperglycemia, along with other metabolic disorders, results in IR and/or islet β cell dysfunction via some shared pathways, such as inflammation, endoplasmic reticulum stress (ERS), oxidative stress, and ectopic lipid deposition. There is currently no cure for T2D, but it can be prevented or in remission by lifestyle intervention and/or some medication. If prevention fails, holistic and personalized management should be taken as soon as possible through timely detection and diagnosis, considering target organ protection, comorbidities, treatment goals, and other factors in reality. T2D is often accompanied by other components of MDS, such as preobesity/obesity, metabolic dysfunction associated steatotic liver disease, dyslipidemia, which usually occurs before it, and they are considered as the upstream diseases of T2D. It is more appropriate to call "diabetic complications" as "MDS-related target organ damage (TOD)", since their development involves not only hyperglycemia but also other metabolic disorders of MDS, promoting an up-to-date management philosophy. In this review, we aim to summarize the underlying mechanism, screening, diagnosis, prevention, and treatment of T2D, especially regarding the personalized selection of hypoglycemic agents and holistic management based on the concept of "MDS-related TOD".

The Semmelweis Study: a longitudinal occupational cohort study within the framework of the Semmelweis Caring University Model Program for supporting healthy aging

The Semmelweis Study is a prospective occupational cohort study that seeks to enroll all employees of Semmelweis University (Budapest, Hungary) aged 25 years and older, with a population of 8866 people, 70.5% of whom are women. The study builds on the successful experiences of the Whitehall II study and aims to investigate the complex relationships between lifestyle, environmental, and occupational risk factors, and the development and progression of chronic age-associated diseases. An important goal of the Semmelweis Study is to identify groups of people who are aging unsuccessfully and therefore have an increased risk of developing age-associated diseases. To achieve this, the study takes a multidisciplinary approach, collecting economic, social, psychological, cognitive, health, and biological data. The Semmelweis Study comprises a baseline data collection with open healthcare data linkage, followed by repeated data collection waves every 5 years. Data are collected through computer-assisted self-completed questionnaires, followed by a physical health examination, physiological measurements, and the assessment of biomarkers. This article provides a comprehensive overview of the Semmelweis Study, including its origin, context, objectives, design, relevance, and expected contributions.

Characteristics of glucolipid metabolism and complications in novel cluster-based diabetes subgroups: a retrospective study

BACKGROUND

Glucolipid metabolism plays an important role in the occurrence and development of diabetes mellitus. However, there is limited research on the characteristics of glucolipid metabolism and complications in different subgroups of newly diagnosed diabetes. This study aimed to investigate the characteristics of glucolipid metabolism and complications in novel cluster-based diabetes subgroups and explore the contributions of different glucolipid metabolism indicators to the occurrence of complications and pancreatic function.

METHODS

This retrospective study included 547 newly diagnosed type 2 diabetes patients. Age, body mass index (BMI), glycated hemoglobin (HbA1C), homeostasis model assessment-2 beta-cell function (HOMA2-β), and homeostasis model assessment-2 insulin resistance (HOMA2-IR) were used as clustering variables. The participants were divided into 4 groups by k-means cluster analysis. The characteristics of glucolipid indicators and complications in each subgroup were analyzed. Regression analyses were used to evaluate the impact of glucolipid metabolism indicators on complications and pancreatic function.

RESULTS

Total cholesterol (TC), triglycerides (TG), triglyceride glucose index (TyG), HbA1C, fasting plasma glucose (FPG), and 2-h postprandial plasma glucose (2hPG) were higher in the severe insulin-resistant diabetes (SIRD) and severe insulin-deficient diabetes (SIDD) groups. Fasting insulin (FINS), fasting C-peptide (FCP), 2-h postprandial insulin (2hINS), 2-h postprandial C-peptide (2hCP), and the monocyte-to-high-density lipoprotein cholesterol ratio (MHR) were higher in mild obesity-related diabetes (MOD) and SIRD. 2hCP, FCP, and FINS were positively correlated with HOMA2-β, while FPG, TyG, HbA1C, and TG were negatively correlated with HOMA2-β. FINS, FPG, FCP, and HbA1C were positively correlated with HOMA2-IR, while high-density lipoprotein (HDL) was negatively correlated with HOMA2-IR. FINS (odds ratio (OR),1.043;95% confidence interval (CI) 1.006 ~ 1.081), FCP (OR,2.881;95%CI 2.041 ~ 4.066), and TyG (OR,1.649;95%CI 1.292 ~ 2.104) contributed to increase the risk of nonalcoholic fatty liver disease (NAFLD); 2hINS (OR,1.015;95%CI 1.008 ~ 1.022) contributed to increase the risk of atherosclerotic cardiovascular disease (ASCVD); FCP (OR,1.297;95%CI 1.027 ~ 1.637) significantly increased the risk of chronic kidney disease (CKD).

CONCLUSIONS

There were differences in the characteristics of glucolipid metabolism as well as complications among different subgroups of newly diagnosed type 2 diabetes. 2hCP, FCP, FINS, FPG, TyG, HbA1C, HDL and TG influenced the function of insulin. FINS, TyG, 2hINS, and FCP were associated with ASCVD, NAFLD, and CKD in newly diagnosed T2DM patients.

Association between adiponectin and newly diagnosed type 2 diabetes in population with the clustering of obesity, dyslipidaemia and hypertension: a cross-sectional study

OBJECTIVES

Adiponectin is closely related to glucose metabolism and traditional diabetes risk factors (obesity, hypertension and dyslipidaemia). We aimed to explore the association between adiponectin levels and newly diagnosed type 2 diabetes mellitus (T2DM) and pre-diabetes in subgroups classified according to T2DM risk factors.

SETTING

Sun Yat-sen Memorial Hospital of Sun Yat-sen University.

PARTICIPANTS

3680 individuals (1753 men and 1927 women) aged 18-70 years from Guangzhou and Dongguan, China, were enrolled from December 2018 to October 2019.

PRIMARY AND SECONDARY OUTCOME MEASURES

T2DM was defined as fasting plasma glucose (FPG)≥7.0 mmol/L or HbA1c≥6.5%, and pre-diabetes was defined as 6.1 mmol/L≤FPG<7.0 mmol/L or 5.7≤HbA1c<6.5%.

RESULTS

With the increasing number of T2DM risk factors, the proportion of the population with high-quartile adiponectin levels gradually decreased (p<0.001). A low level of adiponectin was significantly associated with diabetes and pre-diabetes in a population with ≥1 T2DM risk factor, whereas its association was not consistently significant in the population with all three T2DM risk factors. For instance, participants were more likely to have diabetes or prediabetes with low levels of adiponectin when they had ≥ one T2DM risk factor (quartile 2 vs. 1: OR 0.71 [95%CI: 0.56-0.89]; P=0.003; quartile 3 vs. 1: OR 0.57 [95%CIs: 0.44-0.72]; P<0.001; and quartile 4 vs. 1: OR 0.52 [95%CIs: 0.40-0.67]; P<0.001).

CONCLUSION

Adiponectin was negatively associated with diabetes and pre-diabetes in a population with few T2DM risk factors, while their relationship gradually attenuated with the accumulation of T2DM risk factors, especially in a population with coexisting diseases such as obesity, hypertension and dyslipidaemia.

A novel diabetes typology: towards precision diabetology from pathogenesis to treatment

The current classification of diabetes, based on hyperglycaemia, islet-directed antibodies and some insufficiently defined clinical features, does not reflect differences in aetiological mechanisms and in the clinical course of people with diabetes. This review discusses evidence from recent studies addressing the complexity of diabetes by proposing novel subgroups (subtypes) of diabetes. The most widely replicated and validated approach identified, in addition to severe autoimmune diabetes, four subgroups designated severe insulin-deficient diabetes, severe insulin-resistant diabetes, mild obesity-related diabetes and mild age-related diabetes subgroups. These subgroups display distinct patterns of clinical features, disease progression and onset of comorbidities and complications, with severe insulin-resistant diabetes showing the highest risk for cardiovascular, kidney and fatty liver diseases. While it has been suggested that people in these subgroups would benefit from stratified treatments, RCTs are required to assess the clinical utility of any reclassification effort. Several methodological and practical issues also need further study: the statistical approach used to define subgroups and derive recommendations for diabetes care; the stability of subgroups over time; the optimal dataset (e.g. phenotypic vs genotypic) for reclassification; the transethnic generalisability of findings; and the applicability in clinical routine care. Despite these open questions, the concept of a new classification of diabetes has already allowed researchers to gain more insight into the colourful picture of diabetes and has stimulated progress in this field so that precision diabetology may become reality in the future.

Prognostic significance of metabolomic biomarkers in patients with diabetes mellitus and coronary artery disease

Background

Diabetes mellitus (DM) and coronary artery disease (CAD) constitute inter-related clinical entities. Biomarker profiling emerges as a promising tool for the early diagnosis and risk stratification of either DM or CAD. However, studies assessing the predictive capacity of novel metabolomics biomarkers in coexistent CAD and DM are scarce.

Methods

This post-hoc analysis of the CorLipid trial (NCT04580173) included 316 patients with CAD and comorbid DM who underwent emergency or elective coronary angiography due to acute or chronic coronary syndrome. Cox regression analyses were performed to identify metabolomic predictors of the primary outcome, which was defined as the composite of major adverse cardiovascular or cerebrovascular events (MACCE: cardiovascular death, myocardial infarction, stroke, major bleeding), repeat unplanned revascularizations and cardiovascular hospitalizations. Linear regression analyses were also performed to detect significant predictors of CAD complexity, as assessed by the SYNTAX score.

Results

After a median 2-year follow up period (IQR = 0.7 years), the primary outcome occurred in 69 (21.8%) of patients. Acylcarnitine ratio C4/C18:2, apolipoprotein (apo) B, history of heart failure (HF), age > 65 years and presence of acute coronary syndrome were independent predictors of the primary outcome in diabetic patients with CAD (aHR = 1.89 [1.09, 3.29]; 1.02 [1.01, 1.04]; 1.28 [1.01, 1.41]; 1.04 [1.01, 1.05]; and 1.12 [1.05–1.21], respectively). Higher levels of ceramide ratio C24:1/C24:0, acylcarnitine ratio C4/C18:2, age > 65 and peripheral artery disease were independent predictors of higher CAD complexity (adjusted β = 7.36 [5.74, 20.47]; 3.02 [0.09 to 6.06]; 3.02 [0.09, 6.06], respectively), while higher levels of apoA1 were independent predictors of lower complexity (adjusted β= − 0.65 [− 1.31, − 0.02]).

Conclusions

In patients with comorbid DM and CAD, novel metabolomic biomarkers and metabolomics-based prediction models could be recruited to predict clinical outcomes and assess the complexity of CAD, thereby enabling the integration of personalized medicine into routine clinical practice. These associations should be interpreted taking into account the observational nature of this study, and thus, larger trials are needed to confirm its results and validate them in different and larger diabetic populations.

Trajectories of metabolic risk factors during the development of type 2 diabetes in Chinese adults

AIMS

China has the largest number of adults with diabetes. Although multiple metabolic risk factors (MRFs) are implicated in the development of diabetes, it remains unclear how they progress during the development of diabetes among Chinese. We examined trajectories of multiple MRFs among Chinese and identified the critical period when drastic changes occurred during the development of diabetes.

METHODS

This prospective cohort study included participants since 2006-2007 in the Kailuan study. People attended biennial examinations until 2017 with additions of new participants at each examination cycle. The time when a participant first completed the examination was designated as the baseline. A total of 122,659 participants without prevalent diabetes at baseline and with complete follow-up data were included. MRFs were collected via biennial physical examinations and laboratory measures. Incident diabetes cases were identified via biennial fasting glucose tests and self-reported physician-diagnosis.

RESULTS

During up to 12 years of follow-up, 14,922 incident diabetes cases were identified. Compared with participants who did not develop diabetes, those who developed diabetes had more adverse levels of most MRFs at baseline and during follow-up. Abrupt increases in multiple MRFs (including fasting glucose, surrogate insulin resistance indicators, lipids, systolic blood pressure, pulse pressure, heart rate, alanine aminotransferase, and C-reactive protein) were observed 3 years before the diagnosis of diabetes.

CONCLUSIONS

We identified 3 years before diabetes diagnosis as a critical period when multiple MRFs displayed drastic changes. This would have implications for early monitoring and timely prevention for individuals who experience sudden adverse progression of multiple MRFs.

Soluble LRIG2 is a potential biomarker for type 2 diabetes mellitus

Background

Early diagnosis and treatment of type 2 diabetes can delay the onset of microvascular and macrovascular complications. Therefore, the identification of a novel biomarker for diagnosing diabetes is necessary. In the present study, the role of serum soluble leucine-rich repeats and immunoglobulin like domains 2 (sLRIG2) was investigated as a diagnostic biomarker of type 2 diabetes.

Methods

A total of 240 subjects with newly diagnosed type 2 diabetes (n=80), prediabetes (n=80), or normal glucose tolerance (NGT; n=80) were included in this study. The fasting serum sLRIG2 level was measured using a quantitative sandwich enzyme immunoassay technique with an enzyme-linked immunosorbent assay (ELISA). Serum sLRIG2 levels were compared among the three groups, and the associations of serum sLRIG2 levels with clinical variables were investigated.

Results

Serum sLRIG2 levels were significantly higher in subjects with type 2 diabetes (16.7±8.0 ng/mL) than in subjects without diabetes (NGT group: 12.3±5.3 ng/mL, P<0.001; prediabetes group: 13.2±5.8 ng/mL, P=0.002). Glycosylated hemoglobin (HbA1c: r=0.378, P<0.001) and blood glucose (fasting: r=0.421, P<0.001; 2-hour postprandial: r=0.433, P<0.001) correlated more strongly with sLRIG2 than any other clinical variables.

Conclusions

The serum sLRIG2 levels correlated with glucose parameters; thus, sLRIG2 might be a novel diagnostic biomarker for type 2 diabetes.

Molecular Aspects of Lifestyle and Environmental Effects in Patients With Diabetes: JACC Focus Seminar

Diabetes is characterized as an integrated condition of dysregulated metabolism across multiple tissues, with well-established consequences on the cardiovascular system. Recent advances in precision phenotyping in biofluids and tissues in large human observational and interventional studies have afforded a unique opportunity to translate seminal findings in models and cellular systems to patients at risk for diabetes and its complications. Specifically, techniques to assay metabolites, proteins, and transcripts, alongside more recent assessment of the gut microbiome, underscore the complexity of diabetes in patients, suggesting avenues for precision phenotyping of risk, response to intervention, and potentially novel therapies. In addition, the influence of external factors and inputs (eg, activity, diet, medical therapies) on each domain of molecular characterization has gained prominence toward better understanding their role in prevention. Here, the authors provide a broad overview of the role of several of these molecular domains in human translational investigation in diabetes.

Galectin-3/adiponectin as a new biological indicator for assessing the risk of type 2 diabetes: a cross-sectional study in a community population

OBJECTIVE

This study aimed to explore the association between the risk of newly diagnosed type 2 diabetes and galectin-3 and adiponectin and to investigate whether their joint action shows a favorable diabetes assessment performance.

METHODS

We conducted a community-based study in 135 newly diagnosed patients with type 2 diabetes and 270 age- and sex-matched nondiabetic patients. Odds ratios and 95% confidence intervals were determined using logistic regression analysis. Receiver operating characteristic curve, decision curve analysis and calibration plot were used to explore their efficacy and clinical utility for models.

RESULTS

High quartiles of galectin-3/adiponectin (quartile 4 vs 1: OR 2.43 [95% CIs: 1.21-5.00]) showed the strongest correlation with an increased risk of type 2 diabetes in the total population, which was consistent in the older population (age≥50 years old) in adjustment models. The combination + lipids + galectin-3/adiponectin model (AUC = 0.72 [95% CIs: 0.66-0.77]) displayed better diabetes assessment performance than the other two models.

CONCLUSIONS

High galectin-3 and low adiponectin levels were associated with the high risk of diabetes, and their joint action was a superior promising factor for evaluating diabetes risk. The diabetes discriminative strength of galectin-3/adiponectin was better in the older population than the younger.

Emerging Diabetic Novel Biomarkers of the 21st Century

Diabetes is a growing epidemic with estimated prevalence of infected to reach ~592 million by the year 2035. An effective way to approach is to detect the disease at a very early stage to reduce the complications and improve lifestyle management. Although several traditional biomarkers including glucated hemoglobin, glucated albumin, fructosamine, and 1,5-anhydroglucitol have helped in ease of diagnosis, there is lack of sensitivity and specificity and are inaccurate in certain clinical settings. Thus, search for new and effective biomarkers is a continuous process with an aim of accurate and timely diagnosis. Several novel biomarkers have surged in the present century that are helpful in timely detection of the disease condition. Although it is accepted that a single biomarker will have its inherent limitations, combining several markers will help to identify individuals at high risk of developing prediabetes and eventually its progression to frank diabetes. This review describes the novel biomarkers of the 21st century, both in type 1 and type 2 diabetes mellitus, and their present potential for assessing risk stratification due to insulin resistance that will pave the way for improved clinical outcome.

Sex Differences in Rates of Change and Burden of Metabolic Risk Factors Among Adults Who Did and Did Not Go On to Develop Diabetes: Two Decades of Follow-up From the Tehran Lipid and Glucose Study

OBJECTIVE

We investigated the cumulative burden and linear rates of change of major metabolic risk factors (MRFs) among Iranian adults in whom type 2 diabetes did and did not develop.

RESEARCH DESIGN AND METHODS

We included 7,163 participants (3,069 men) aged 20-70 years at baseline with at least three examinations during 1999-2018. Individual growth curve modeling was used for data analysis. Statistical interactions for sex by diabetes status were adjusted for age, family history of diabetes, smoking status, and physical activity level.

RESULTS

Study sample included 743 (316 men) new case subjects with diabetes. In both men and women, compared with individuals in whom diabetes did not develop, individuals in whom diabetes developed had a higher burden of all MRFs and a greater rate of change in BMI, fasting plasma glucose (FPG), systolic blood pressure (SBP), and diastolic blood pressure; however, the differences in burden and rate of change between those who did and did not develop diabetes were greater in women than in men. During the transition to diabetes, women experienced more adverse change in BMI, FPG, triglyceride, and HDL cholesterol (HDL-C) (diabetes-sex interaction P values <0.05) and faster rates of change in BMI, FPG, HDL-C, and total cholesterol (interaction P values <0.01) and SBP (interaction P = 0.055) than men.

CONCLUSIONS

The greater exposure of women to and burden of MRFs before onset of diabetes may have implications for implementing sex-specific strategies in order to prevent or delay diabetes complications.

All-source and source-specific air pollution and 10-year diabetes Incidence: Total effect and mediation analyses in the Heinz Nixdorf recall study

BACKGROUND

An increasing number of studies have been published recently on the association between ambient air pollution (AP) and incident diabetes mellitus (DM), but studies investigating source-specific AP toxicity and potential mediating pathways are rare. We investigated the associations of all-source, traffic-specific, and industry-specific outdoor AP exposure with 10-year incidence of DM and potential mediation via inflammation-associated biomarkers.

METHODS

Data from participants of the prospective Heinz Nixdorf Recall cohort study who attended the baseline (t₀; 2000-2003), 5-year follow-up (t₁; 2006-2008), and 10-year follow-up (t₂; 2011-2015) examinations was used. For participants without DM at baseline (determined using information on physician diagnosis and glucose-lowering medication), residential long-term exposure (total, traffic-specific, and industry-specific) to particulate matter (PM_2.5, PM₁₀), nitrogen dioxide (NO₂), and accumulation mode particle number concentration (PN_AM) were estimated using a chemistry transport model. Covariate-adjusted modified Poisson regression models with robust standard errors were applied to estimate relative risks (RR) for the associations between baseline AP and incident DM at t₂. Mediation analyses for adiponectin, high-sensitivity C-reactive protein (hsCRP), and interleukin-1 receptor antagonist (IL-1RA) were conducted to estimate natural direct and indirect effects.

RESULTS

Of the 4,814 participants at t₀, 2,451 participants (mean baseline age: 58.2 years) were included in the main analysis. Interquartile range (IQR) increases in total PM₁₀ and PN_AM were associated with increased risk of DM (e.g., RR: 1.25 [95% Confidence Interval (CI): 1.02, 1.53] per 3.8 µg/m³ PM₁₀). Whereas traffic-specific exposures were associated with DM risk for all air pollutants (e.g., RR: 1.24 [95% CI: 1.06, 1.46] per 0.3 µg/m³ PM₁₀), significant associations for industry exposures were limited to NO₂ and PN_AM (e.g., RR: 1.24 [95% CI: 1.03, 1.49] per 230 particles/mL PN_AM). Potential mediation of the association between AP and DM was observed for adiponectin but not for hsCRP and IL-1RA.

CONCLUSION

Our study shows that long-term exposure to total and source-specific ambient AP may increase DM risk, with consistent results observed across traffic-specific exposures. Decreases in adiponectin may play a potential role along the causal pathway.

Goat Milk Consumption Ameliorates Abnormalities in Glucose Metabolism and Enhances Hepatic and Skeletal Muscle AMP-Activated Protein Kinase Activation in Rats Fed with High-Fat Diets

SCOPE

Diabetes endangers health and causes serious economic impediment. The aim of this study is to identify the effects of goat milk consumption on glucose metabolism of rats with high-fat (HF) diet.

METHODS AND RESULTS

Sixty male Sprague Dawley rats are divided into five groups and fed with different diets for 24 weeks: goat-milk-based HF diet (GHF group; goat milk powder+HF diet), cow-milk-based HF diet (CHF group; cow milk powder+HF diet), HF diet, HF diet plus acarbose (HF+A group; acarbose+HF diet), and chow diet (CD group). Fasting glucose in GHF-fed rats are lower than HF-fed rats on weeks 16 and 20. GHF-fed rats display improved insulin sensitivity in oral glucose and insulin tolerance tests. Compared with HF-fed rats, glycated hemoglobin and triglycerides in GHF-fed rats are lower and high-density lipoprotein level is higher. AMP-activated protein kinase activation (AMPK) in the liver and skeletal muscle is higher in GHF rats than HF rats. Phosphoenolpyruvate carboxykinase and glucose 6-phosphatase protein levels in the liver are lower and hexokinase 2 protein level in the skeletal muscle is higher in GHF rats compared with HF rats.

CONCLUSION

Goat milk consumption can ameliorate abnormalities in glucose metabolism, and AMPK pathway in the liver and skeletal muscle plays an important role in the process.

Prospective Study of Sex-Specific Adiponectin Changes and Incident Metabolic Syndrome: The ARIRANG Study

We investigated whether changes in adiponectin levels over time predict incident metabolic syndrome (MetS) in a population-based prospective study. In total, 1110 subjects were categorized into four groups according to their sex-specific median baseline adiponectin levels and the change in adiponectin levels at follow-up: low baseline adiponectin and decreased adiponectin during follow-up (LB&DF), low baseline adiponectin and increased adiponectin during follow-up (LB&IF), high baseline adiponectin and decreased adiponectin during follow-up (HB&DF), and high baseline adiponectin and increased adiponectin during follow-up (HB&IF). During the median 2.4-year follow-up period, 180 (16.2%) subjects developed MetS. Compared to the LB&DF group, the fully adjusted hazard ratio (95% confidence interval) for incident MS was the lowest in the HB&IF group (0.33, (0.17–0.63)), followed by the HB&DF group (0.58, (0.40–0.84)) and LB&IF group (0.63, (0.41–0.93)). This phenomenon was more prominent in men than in women. Among the individual MetS components, increased adiponectin levels during follow-up were significantly associated with lower risks of incident low high density lipoprotein (HDL) cholesterol and incident high blood pressure. This finding suggests that a change in adiponectin level, as well as the baseline adiponectin level, might have a clinical role in the development of MetS among men.

Three-year renal function trajectory and its association with adverse renal event in patients with type 2 diabetes

AIMS

The study evaluated associations between 3-year eGFR trajectory patterns and adverse renal event in diabetic patients.

METHODS

Adverse renal event was defined as sustained eGFR <60 or one ACR >300 mg/g creatinine. Cox proportional hazards models evaluated association between eGFR trajectory patterns and adverse renal event.

RESULTS

We detected six clusters. Cluster 1 had a stable but relatively low baseline eGFR level (n = 823, 20.52%), cluster 2 had a high baseline eGFR level, but slightly decreased afterwards (n = 1708, 42.59%), cluster 3 had an increasing eGFR during the first 15-month follow-up and then a decline rate (n = 505, 12.59%), cluster 4 decreased during the first 9-month follow-up and then remained stable (n = 774, 19.30%), cluster 5 had a sharp decline and then was elevated after 21 months until the end of follow-up (n = 135, 3.37%), and cluster 6 had an extremely fluctuating eGFR and then a sharp increase at the last 12-month period (n = 65, 1.62%). Clusters 1, 3, and 4 show increased adverse renal risks compared with cluster 2 (2.24, 1.69-2.97; 2.70, 2.02-3.61; and 2.15, 1.64-2.83, respectively).

CONCLUSIONS

Patients with sustained low-level renal function, renal decline, or increasing trend in eGFR trajectory encountered an increased CKD risk.

Role of Adiponectin in Central Nervous System Disorders

Adiponectin, the most abundant plasma adipokine, plays an important role in the regulation of glucose and lipid metabolism. Adiponectin also possesses insulin-sensitizing, anti-inflammatory, angiogenic, and vasodilatory properties which may influence central nervous system (CNS) disorders. Although initially not thought to cross the blood-brain barrier, adiponectin enters the brain through peripheral circulation. In the brain, adiponectin signaling through its receptors, AdipoR1 and AdipoR2, directly influences important brain functions such as energy homeostasis, hippocampal neurogenesis, and synaptic plasticity. Overall, based on its central and peripheral actions, recent evidence indicates that adiponectin has neuroprotective, antiatherogenic, and antidepressant effects. However, these findings are not without controversy as human observational studies report differing correlations between plasma adiponectin levels and incidence of CNS disorders. Despite these controversies, adiponectin is gaining attention as a potential therapeutic target for diverse CNS disorders, such as stroke, Alzheimer's disease, anxiety, and depression. Evidence regarding the emerging role for adiponectin in these disorders is discussed in the current review.

The Emerging Role of Biomarkers in the Diagnosis of Gestational Diabetes Mellitus

Gestational diabetes mellitus (GDM) is a common complication of pregnancy; its rising incidence is a result of increased maternal obesity and older maternal age together with altered diagnostic criteria identifying a greater proportion of pregnant women with GDM. Its consequences are far-reaching, associated with poorer maternal and neonatal outcomes compared to non-GDM pregnancies, and GDM has implications for metabolic health in both mother and offspring. Objective markers to identify women at high risk for the development of GDM are useful to target therapy and potentially prevent its development. Established clinical risk factors for GDM include overweight/obesity, age, ethnicity, and family history of diabetes, though they lack specificity for its development. The addition of biomarkers to predictive models of GDM may improve the ability to identify women at risk of GDM prior to its development. These biomarkers reflect the pathophysiologic mechanisms of GDM involving insulin resistance, chronic inflammation, and altered placental function. In addition, the role of epigenetic changes in GDM pathogenesis highlights the complex interplay between genetic and environmental factors, potentially offering further refinement of the prediction of GDM risk. In this review, we will discuss the clinical challenges associated with the diagnosis of GDM and its current pathophysiologic basis, giving rise to potential biomarkers that may aid in its identification. While not yet validated for clinical use, we explore the possible clinical role of biomarkers in the future. We also explore novel diagnostic tools, including high throughput methodologies, that may have potential future application in the identification of women with GDM.

Circulating triacylglycerols but not pancreatic fat associate with insulin secretion in healthy humans

BACKGROUND

Loss of adequate insulin secretion for the prevailing insulin resistance is critical for the development of type 2 diabetes and has been suggested to result from circulating lipids (triacylglycerols [TG] or free fatty acids) and/or adipocytokines or from ectopic lipid storage in the pancreas. This study aimed to address whether circulating lipids, adipocytokines or pancreatic fat primarily associates with lower insulin secretion.

SUBJECTS/METHODS

Nondiabetic persons (n=73), recruited from the general population, underwent clinical examinations, fasting blood drawing to measure TG and adipocytokines and oral glucose tolerance testing (OGTT) to assess basal and dynamic insulin secretion and sensitivity indices. Magnetic resonance imaging and ¹H-magnetic resonance spectroscopy were used to measure body fat distribution and ectopic fat content in liver and pancreas.

RESULTS

In age-, sex- and BMI-adjusted analyses, total and high-molecular-weight adiponectin were the strongest negative predictors of fasting beta-cell function (BCF; β=-0.403, p=0.0003 and β=-0.237, p=0.01, respectively) and adaptation index (AI; β=-0.210, p=0.006 and β=-0.133, p=0.02, respectively). Circulating TG, but not pancreatic fat content, related positively to BCF (β=0.375, p<0.0001) and AI (β=0.192, p=0.003). Similar results were obtained for the disposition index (DI).

CONCLUSIONS

The association of serum lipids and adiponectin with beta-cell function may represent a compensatory response to adapt for lower insulin sensitivity in nondiabetic humans.

Adiponectin and Its Isoforms in Pathophysiology

Adiponectin circulates in blood in multiple isoforms. High molecular weight (HMW) adiponectin is thought to be most biologically active and promotes glucose uptake, insulin sensitivity, and fatty acid oxidation. In obesity, adiponectin isoform formation is disrupted, leading to an inverse association between metabolic disease and HMW and total adiponectin. Adiponectin isoforms also function as acute-phase reactants influencing inflammation in acute and chronic disease. Interestingly, adiponectin and mortality have a U-shaped association. Unfortunately, data concerning adiponectin and its pathophysiologic function conflict. This is predominantly due to difficulties in adequate measurement of adiponectin isoforms and lack of a gold standard. In this review we provide a general overview of the formation and function of adiponectin and its isoforms under physiologic conditions. We highlight the ways adiponectin isoform formation is disrupted in obesity and its ensuing pathologic conditions. Furthermore, we will elaborate on the role of adiponectin isoforms as inflammatory proteins with respect to cardiac and kidney disease and discuss the association of adiponectin with mortality. Finally, we will provide a historical perspective on the measurement of adiponectin isoforms, current limitations, and future challenges.

Adiponectin, biomarkers of inflammation and changes in cardiac autonomic function: Whitehall II study

BACKGROUND

Biomarkers of inflammation and adiponectin are associated with cardiovascular autonomic neuropathy (CAN) in cross-sectional studies, but prospective data are scarce. This study aimed to assess the associations of biomarkers of subclinical inflammation and adiponectin with subsequent changes in heart rate (HR) and heart rate variability (HRV) in non-diabetic and diabetic individuals.

METHODS

Data are based on up to 25,050 person-examinations for 8469 study participants of the Whitehall II cohort study. Measures of CAN included HR and several HRV indices. Associations between baseline serum levels of high-sensitivity C-reactive protein (hsCRP), interleukin (IL)-6, IL-1 receptor antagonist (IL-1Ra) and adiponectin and 5-year changes in HR and six HRV indices were estimated using mixed-effects models adjusting for age, sex, ethnicity, body mass index (BMI), metabolic covariates and medication. A modifying effect of diabetes was tested.

RESULTS

Higher levels of IL-1Ra were associated with higher increases in HR. Additional associations with measures of HRV were observed for hsCRP, IL-6 and IL-1Ra, but these associations were explained by BMI and other confounders. Associations between adiponectin, HR and HRV differed depending on diabetes status. Higher adiponectin levels were associated with more pronounced decreases in HR and increases in three measures of HRV reflecting both sympathetic and vagal activity, but these findings were limited to individuals with type 2 diabetes.

CONCLUSIONS

Higher IL-1Ra levels appeared as novel risk marker for increases in HR. Higher adiponectin levels were associated with a more favourable development of cardiovascular autonomic function in individuals with type 2 diabetes independently of multiple confounders.

In vivo ROS production and use of oxidative stress-derived biomarkers to detect the onset of diseases such as Alzheimer's disease, Parkinson's disease, and diabetes

Breakthroughs in biochemistry have furthered our understanding of the onset and progression of various diseases, and have advanced the development of new therapeutics. Oxidative stress and reactive oxygen species (ROS) are ubiquitous in biological systems. ROS can be formed non-enzymatically by chemical, photochemical and electron transfer reactions, or as the byproducts of endogenous enzymatic reactions, phagocytosis, and inflammation. Imbalances in ROS homeostasis, caused by impairments in antioxidant enzymes or non-enzymatic antioxidant networks, increase oxidative stress, leading to the deleterious oxidation and chemical modification of biomacromolecules such as lipids, DNA, and proteins. While many ROS are intracellular signaling messengers and most products of oxidative metabolisms are beneficial for normal cellular function, the elevation of ROS levels by light, hyperglycemia, peroxisomes, and certain enzymes causes oxidative stress-sensitive signaling, toxicity, oncogenesis, neurodegenerative diseases, and diabetes. Although the underlying mechanisms of these diseases are manifold, oxidative stress caused by ROS is a major contributing factor in their onset. This review summarizes the relationship between ROS and oxidative stress, with special reference to recent advancements in the detection of biomarkers related to oxidative stress. Further, we will introduce biomarkers for the early detection of neurodegenerative diseases and diabetes, with a focus on our recent work.

Ten-year alcohol consumption typologies and trajectories of C-reactive protein, interleukin-6 and interleukin-1 receptor antagonist over the following 12 years: a prospective cohort study

BACKGROUND

Moderate alcohol consumption is thought to confer cardiometabolic protective effects. Inflammatory pathways are hypothesized to partly underlie this association.

OBJECTIVES

The aim of this study was to examine the association between typologies of alcohol consumption and markers of inflammation, and their rate of change over time.

METHODS

Data were collected from 8209 participants [69% men; mean age, 50 years (SD 6.1)] of the British Whitehall II study. Alcohol consumption typologies were defined using up to three measures during an approximately 10-year period spanning from 1985 to 1994 as (i) stable nondrinkers, (ii) stable moderate drinkers (referent), (iii) stable heavy drinkers, (iv) nonstable drinkers and (v) former drinkers. C-reactive protein (CRP), interleukin (IL)-6 and IL-1 receptor antagonist (IL-1 RA) were measured up to three times in the following 12 years.

RESULTS

Stable moderate drinkers had lower levels of CRP than stable nondrinkers, stable heavy drinkers, former drinkers and nonstable drinkers, but there were no differences in the rate of change in CRP over time between groups. Stable nondrinkers had higher levels of IL-6 as did stable heavy drinkers; rates of change in IL-6 over time were also increased in the latter group. Stable nondrinkers also had higher levels of IL-1 RA. These associations were robust to adjustment for confounding factors.

CONCLUSION

Our novel investigation of 10-year drinking typologies shows that stable moderate alcohol consumption is associated with a long-term inflammatory marker profile that is consistent with conferring a reduced risk of developing coronary heart disease.

Novel biomarkers for prediabetes, diabetes, and associated complications

The number of individuals with prediabetes is expected to grow substantially and estimated to globally affect 482 million people by 2040. Therefore, effective methods for diagnosing prediabetes will be required to reduce the risk of progressing to diabetes and its complications. The current biomarkers, glycated hemoglobin (HbA1c), fructosamine, and glycated albumin have limitations including moderate sensitivity and specificity and are inaccurate in certain clinical conditions. Therefore, identification of additional biomarkers is being explored recognizing that any single biomarker will also likely have inherent limitations. Therefore, combining several biomarkers may more precisely identify those at high risk for developing prediabetes and subsequent progression to diabetes. This review describes recently identified biomarkers and their potential utility for addressing the burgeoning epidemic of dysglycemic disorders.

Biomarkers of subclinical inflammation and increases in glycaemia, insulin resistance and beta-cell function in non-diabetic individuals: the Whitehall II study

OBJECTIVE

Higher systemic levels of pro-inflammatory biomarkers and low adiponectin are associated with increased risk of type 2 diabetes, but their associations with changes in glycaemic deterioration before onset of diabetes are poorly understood. We aimed to study whether inflammation-related biomarkers are associated with 5-year changes in glucose and insulin, HbA1c, insulin sensitivity and beta-cell function before the diagnosis of type 2 diabetes and whether these associations may be bidirectional.

DESIGN AND METHODS

We used multiple repeat measures (17 891 person-examinations from 7683 non-diabetic participants) from the Whitehall II study to assess whether circulating high-sensitivity C-reactive protein (hsCRP), interleukin-6 (IL6), IL1 receptor antagonist (IL1Ra) and adiponectin are associated with subsequent changes in glycaemia, insulin, insulin resistance and beta-cell function (based on oral glucose tolerance tests). We examined bidirectionality by testing if parameters of glucose metabolism at baseline are associated with changes in inflammation-related biomarkers.

RESULTS

Higher hsCRP and IL6 were associated with increases in fasting insulin, insulin resistance and, for IL6, with beta-cell function after adjustment for confounders. Higher adiponectin was associated with decreases in fasting glucose, HbA1c, fasting insulin, insulin resistance and beta-cell function. The reverse approach showed that 2-h glucose and insulin sensitivity were associated with changes in IL1Ra. Fasting insulin and insulin resistance showed inverse associations with changes in adiponectin.

CONCLUSIONS

Subclinical inflammation is associated with development of increased glycaemia, insulin resistance and beta-cell function in non-diabetic individuals. These findings are consistent with the hypothesis that inflammation-related processes may increase insulin resistance and lead to a compensatory upregulation of beta-cell function.

Low adiponectin levels at baseline and decreasing adiponectin levels over 10 years of follow-up predict risk of the metabolic syndrome

AIM

Adiponectin is the most abundant adipokine and may play a key role in the interplay between obesity, inflammation, insulin resistance and the metabolic syndrome (MetS). Thus, this large population-based cohort investigated whether adiponectin at baseline and/or a decrease in adiponectin during follow-up is associated prospectively with the risk of incident MetS.

METHODS

Using a prospective study design, the development of MetS was examined in 1134 healthy participants from the community. Plasma adiponectin was measured at study entry and again after a median follow-up of 9.4 years (IQR: 9.2-9.7). During follow-up, 187 participants developed MetS, and 439 presented with at least two components of MetS.

RESULTS

During follow-up, adiponectin decreased in participants who developed MetS, whereas adiponectin was increased in those who did not develop MetS (P<0.001). Those with low adiponectin levels (quartile 1) at baseline had an increased risk of developing MetS (OR: 2.92, 2.08-6.97; P<0.001) compared with those with high levels (quartile 4). After adjusting for confounding variables, low adiponectin levels at baseline remained independently associated with MetS (OR: 2.24, 1.11-4.52; P=0.017). Similarly, participants with a decrease in adiponectin during follow-up also had an increased risk of MetS (OR: 2.96, 2.09-4.18; P<0.001). This association persisted after multivariable adjustments, including for baseline adiponectin (OR: 4.37, 2.77-6.97; P<0.001). Finally, adiponectin levels at follow-up were inversely associated with an increase in the number of components of MetS (P<0.001); geometric mean adiponectin levels were 9.5mg/L (95% CI: 9.0-10.0) for participants with no components vs 7.0mg/L (95% CI: 6.3-7.9) for those with four to five components.

CONCLUSIONS/INTERPRETATION

Low plasma adiponectin levels at baseline and decreasing adiponectin levels during follow-up are both associated with an increased risk of MetS.

The Role of Alcohol Consumption in Regulating Circulating Levels of Adiponectin: A Prospective Cohort Study

CONTEXT

The role of alcohol intake in influencing longitudinal trajectories of adiponectin is unclear.

OBJECTIVE

The objective of the study was to examine the association between alcohol intake and changes in the circulating levels of adiponectin over repeat measures.

DESIGN, SETTING, AND PARTICIPANTS

A prospective cohort study of 2855 men and women (74% men with a mean age of 50 y at baseline) drawn from the Whitehall II study. Data from study phases 3 (1991-1993), 5 (1997-1999), and 7 (2002-2004) were used.

MAIN OUTCOME MEASURE

Adiponectin serum concentrations (nanograms per milliliter) were measured, and alcohol intake was defined in terms of number of UK units (1 U = 8 g ethanol) consumed in the previous 7 days on three occasions. Cross-sectional associations between alcohol and adiponectin levels were calculated using linear regression. A bivariate dual-change score model was used to estimate the effect of alcohol intake on upcoming change in adiponectin. Models were adjusted for age, sex, ethnicity, and smoking status.

RESULTS

Alcohol consumption was cross-sectionally associated with (log transformed) adiponectin levels (β ranging from .001 to .004, depending on phase and level of adjustment) but was not associated with changes in adiponectin levels over time [γ = -0.002 (SE 0.002), P = 0.246].

CONCLUSION

Alcohol intake is not associated with changes in circulating adiponectin levels in this cohort. This finding provides evidence that adiponectin levels are unlikely to mediate the relationship between moderate alcohol consumption and reduced risk of type 2 diabetes. It is important to consider dynamic longitudinal relationships rather than cross-sectional associations.

Prediabetes and associated disorders

Prediabetes represents an elevation of plasma glucose above the normal range but below that of clinical diabetes. Prediabetes includes individuals with IFG, IGT, IFG with IGT and elevated HbA1c levels. Insulin resistance and β-cell dysfunction are characteristic of this disorder. The diagnosis of prediabetesis is vital as both IFG and IGT are indeed well-known risk factors for type 2 diabetes with a greater risk in the presence of combined IFG and IGT. Furthermore, as will be illustrated in this review, prediabetes is associated with associated disorders typically only considered in with established diabetes. These include cardiovascular disease, periodontal disease, cognitive dysfunction, microvascular disease, blood pressure abnormalities, obstructive sleep apnea, low testosterone, metabolic syndrome, various biomarkers, fatty liver disease, and cancer. As the vast majority of individuals with prediabetes are unaware of their diagnosis, it is therefore vital that the associated conditions are identified, particularly in the presence of mild hyperglycemia, so they may benefit from early intervention.

Genetic determinants of circulating interleukin-1 receptor antagonist levels and their association with glycemic traits

The proinflammatory cytokine interleukin (IL)-1β is implicated in the development of insulin resistance and β-cell dysfunction, whereas higher circulating levels of IL-1 receptor antagonist (IL-1RA), an endogenous inhibitor of IL-1β, has been suggested to improve glycemia and β-cell function in patients with type 2 diabetes. To elucidate the protective role of IL-1RA, this study aimed to identify genetic determinants of circulating IL-1RA concentration and to investigate their associations with immunological and metabolic variables related to cardiometabolic risk. In the analysis of seven discovery and four replication cohort studies, two single nucleotide polymorphisms (SNPs) were independently associated with circulating IL-1RA concentration (rs4251961 at the IL1RN locus [n = 13,955, P = 2.76 × 10(-21)] and rs6759676, closest gene locus IL1F10 [n = 13,994, P = 1.73 × 10(-17)]). The proportion of the variance in IL-1RA explained by both SNPs combined was 2.0%. IL-1RA-raising alleles of both SNPs were associated with lower circulating C-reactive protein concentration. The IL-1RA-raising allele of rs6759676 was also associated with lower fasting insulin levels and lower HOMA insulin resistance. In conclusion, we show that circulating IL-1RA levels are predicted by two independent SNPs at the IL1RN and IL1F10 loci and that genetically raised IL-1RA may be protective against the development of insulin resistance.

Low adiponectin levels and increased risk of type 2 diabetes in patients with myocardial infarction

OBJECTIVE

Patients with acute myocardial infarction (MI) have increased risk of developing type 2 diabetes mellitus (T2DM). Adiponectin is an insulin-sensitizing hormone produced in adipose tissue, directly suppressing hepatic gluconeogenesis, stimulating fatty acid oxidation and glucose uptake in skeletal muscle and insulin secretion. In healthy humans, low plasma adiponectin levels associate with increased risk of T2DM; however, the relationship between adiponectin and T2DM in patients with MI has never been investigated.

RESEARCH DESIGN AND METHODS

We prospectively included 666 patients with ST-segment elevation MI, without diabetes, treated with percutaneous coronary intervention, from September 2006 to December 2008 at a tertiary cardiac center. Blood samples were drawn before intervention, and total plasma adiponectin was measured in all samples. During follow-up (median 5.7 years [interquartile range 5.3-6.1]) 6% (n = 38) developed T2DM. Risk of T2DM was analyzed using a competing risk analysis.

RESULTS

Low adiponectin levels were associated with increased risk of T2DM (P < 0.001). Even after adjustment for confounding risk factors (age, sex, hypertension, hypercholesterolemia, current smoking, previous MI, BMI, blood glucose, total cholesterol, HDL, LDL, triglyceride, estimated glomerular filtration rate, C-reactive protein, peak troponin I, and proatrial natriuretic peptide), low adiponectin levels remained an independent predictor of T2DM (hazard ratio [HR] 5.8 [2.3-15.0]; P < 0.001). Importantly, plasma adiponectin added to the predictive value of blood glucose, with the combination of high blood glucose and low plasma adiponectin, vastly increasing the risk of developing T2DM (HR 9.6 [3.7-25.3]; P < 0.001).

CONCLUSIONS

Low plasma adiponectin levels are independently associated with increased risk of T2DM in patients with MI and added significantly to the predictive value of blood glucose.

The Early Diabetes Intervention Program--is early actually late?

This Commentary briefly reviews the background of prediabetes including its definition and pathophysiology and describes as well the natural course of glycemic deterioration as it follows a continuum. Research efforts in identifying glucose and other biomarkers for the early detection of high-risk individuals are summarized.

Circulating adiponectin and cardiovascular mortality in patients with type 2 diabetes mellitus: evidence of sexual dimorphism

BACKGROUND

The pathogenesis of cardiovascular (CV) mortality, whose rate is increased in type 2 diabetes, is poorly understood.

METHODS

Three prospective cohorts were analyzed: 1) Gargano Heart Study (GHS; 359 patients, 58 events/1,934 person-years; py); 2) Health Professional Follow-up Study (HPFS; 833 men, 146 events/10,024 py); 3) Nurses' Health Study (NHS; 902 women, 144 events/15,074 py).

RESULTS

In GHS serum adiponectin predicted CV mortality in men (hazard ratio, HR, and 95% CI per standard deviation, SD, increment = 1.54, 1.19-2.01), but not women (HR = 0.98, 0.48-2.01).

CONCLUSIONS

This is the first report showing that high circulating adiponectin predicts increased CV mortality in men, but not in women with type 2 diabetes. Further studies are necessary to unravel the mechanisms through which adiponectin influences CV mortality in a sex-specific manner.

Adiponectin and bariatric surgery: associations with diabetes and cardiovascular disease in the Swedish Obese Subjects Study

OBJECTIVE

Adiponectin has been implicated in the pathogenesis of type 2 diabetes, but its role for incident diabetes, myocardial infarction, or stroke in obesity is unclear. The aim of this study was to analyze the associations between systemic levels of adiponectin and the aforementioned outcomes in a population with severe obesity at high risk of diabetes and cardiovascular events.

RESEARCH DESIGN AND METHODS

We measured serum concentrations of total adiponectin in 3,299 participants of the prospective controlled Swedish Obese Subjects (SOS) Study (bariatric surgery group, n = 1,570; control group given usual care, n = 1,729). Median follow-up periods ranged between 10 and 13 years for different outcomes.

RESULTS

In models containing both baseline adiponectin and 2-year changes in adiponectin, high baseline adiponectin and 2-year increases in adiponectin were associated with decreased risk of diabetes and myocardial infarction among controls. In the surgery group, the 2-year weight loss was paralleled by substantial increase in circulating adiponectin (1,807-1,958 ng/mL per 10-kg weight loss). However, neither baseline adiponectin nor 2-year increases in adiponectin were associated with risk of diabetes or myocardial infarction in the fully adjusted models in the surgery group. No associations were found for stroke in either group.

CONCLUSIONS

Taken together, baseline adiponectin and 2-year changes were associated with incident diabetes and myocardial infarction in the control group but not in the surgery group. Baseline adiponectin did not predict treatment benefit of bariatric surgery.

Patterns of obesity development before the diagnosis of type 2 diabetes: the Whitehall II cohort study

BACKGROUND

Patients with type 2 diabetes vary greatly with respect to degree of obesity at time of diagnosis. To address the heterogeneity of type 2 diabetes, we characterised patterns of change in body mass index (BMI) and other cardiometabolic risk factors before type 2 diabetes diagnosis.

METHODS AND FINDINGS

We studied 6,705 participants from the Whitehall II study, an observational prospective cohort study of civil servants based in London. White men and women, initially free of diabetes, were followed with 5-yearly clinical examinations from 1991-2009 for a median of 14.1 years (interquartile range [IQR]: 8.7-16.2 years). Type 2 diabetes developed in 645 (1,209 person-examinations) and 6,060 remained free of diabetes during follow-up (14,060 person-examinations). Latent class trajectory analysis of incident diabetes cases was used to identify patterns of pre-disease BMI. Associated trajectories of cardiometabolic risk factors were studied using adjusted mixed-effects models. Three patterns of BMI changes were identified. Most participants belonged to the "stable overweight" group (n = 604, 94%) with a relatively constant BMI level within the overweight category throughout follow-up. They experienced slightly worsening of beta cell function and insulin sensitivity from 5 years prior to diagnosis. A small group of "progressive weight gainers" (n = 15) exhibited a pattern of consistent weight gain before diagnosis. Linear increases in blood pressure and an exponential increase in insulin resistance a few years before diagnosis accompanied the weight gain. The "persistently obese" (n = 26) were severely obese throughout the whole 18 years before diabetes diagnosis. They experienced an initial beta cell compensation followed by loss of beta cell function, whereas insulin sensitivity was relatively stable. Since the generalizability of these findings is limited, the results need confirmation in other study populations.

CONCLUSIONS

Three patterns of obesity changes prior to diabetes diagnosis were accompanied by distinct trajectories of insulin resistance and other cardiometabolic risk factors in a white, British population. While these results should be verified independently, the great majority of patients had modest weight gain prior to diagnosis. These results suggest that strategies focusing on small weight reductions for the entire population may be more beneficial than predominantly focusing on weight loss for high-risk individuals.

The potential of novel biomarkers to improve risk prediction of type 2 diabetes

The incidence of type 2 diabetes can be reduced substantially by implementing preventive measures in high-risk individuals, but this requires prior knowledge of disease risk in the individual. Various diabetes risk models have been designed, and these have all included a similar combination of factors, such as age, sex, obesity, hypertension, lifestyle factors, family history of diabetes and metabolic traits. The accuracy of prediction models is often assessed by the area under the receiver operating characteristic curve (AROC) as a measure of discrimination, but AROCs should be complemented by measures of calibration and reclassification to estimate the incremental value of novel biomarkers. This review discusses the potential of novel biomarkers to improve model accuracy. The range of molecules that serve as potential predictors of type 2 diabetes includes genetic variants, RNA transcripts, peptides and proteins, lipids and small metabolites. Some of these biomarkers lead to a statistically significant increase of model accuracy, but their incremental value currently seems too small for routine clinical use. However, only a fraction of potentially relevant biomarkers have been assessed with regard to their predictive value. Moreover, serial measurements of biomarkers may help determine individual risk. In conclusion, current risk models provide valuable tools of risk estimation, but perform suboptimally in the prediction of individual diabetes risk. Novel biomarkers still fail to have a clinically applicable impact. However, more efficient use of biomarker data and technological advances in their measurement in clinical settings may allow the development of more accurate predictive models in the future.

Adiponectin, type 2 diabetes and cardiovascular risk

BACKGROUND

Adiponectin is viewed as an insulin-sensitizing hormone with anti-inflammatory effects. In accordance, plasma adiponectin is decreased in metabolic disorders including type 2 diabetes mellitus (T2DM). However, in spite of the apparently beneficially effects, recent data from large prospective studies have consistently linked high adiponectin levels with increased cardiovascular (CV) disease and mortality, thus questioning the positive view on adiponectin. Accordingly, we investigated the relationship between adiponectin, incident T2DM and subsequently CV events.

METHODS

We prospectively followed 5349 randomly selected men and women from the community, without T2DM or CV disease. Plasma adiponectin was measured at study entry. Median follow-up time was 8.5 years (IQR 8.0-9.1 years). During follow up, 136 participants developed T2DM. Following their diagnosis, 36 of the 136 participants experienced a CV event (myocardial infarction, ischaemic stroke, or CV death).

RESULTS

Participants with increasing adiponectin had reduced risk of developing T2DM (p < 0.001). After adjustment for confounding risk factors (including age, gender, body mass index, physical activity, alcohol consumption, blood glucose, HbA1c, blood pressure, lipids, high-sensitivity C-reactive protein, estimated glomerular filtration rate, and plasma N-terminal pro-brain natriuretic peptide, competing risk Cox-regression analysis identified adiponectin as an independent predictor of T2DM: hazard ratio (HR) for each doubling of adiponectin 0.55 (95% CI 0.41-0.74; p < 0.001). After development of T2DM, the risk of a CV event more than doubled. Increasing adiponectin (adjusted for the confounding risk factors mentioned) was associated with reduced risk of CV events: HR 0.34 (95% CI 0.16-0.72; p = 0.005) for each doubling in plasma adiponectin.

CONCLUSIONS

In conclusion, increasing plasma adiponectin is associated with decreased risk of T2DM and subsequently reduced risk of CV events.

Adiponectin as predictor for diabetes among pre-diabetic groups

Adiponectin is found to associate with diabetes in studies apart from cohort studies. This prospective cohort study is to evaluate the predictive role of adiponectin in diabetes among participants with impaired fasting glucose (IFG). A total of 42,845 participants who visited 7 health examination centers located in Seoul and Kyunggi province, South Korea, during 2004-2008 were first included. Of the 42,845 participants, 5,085 participants had IFG. IFG was categorized as stage 1 (fasting glucose 100-109 mg/dL) or stage 2 (110-125 mg/dL). The incidence rates of diabetes were followed up to December, 2011. Hazard ratios (HRs) and 95 % confidence intervals (CI) were performed by Cox proportional hazard model. Of the 5,085 participants, 652 participants developed diabetes during a mean follow-up of 4.4 years. Low adiponectin was associated with diabetes among men with stage 2 IFG (HR, 1.78; 95 %CI, 1.33-2.38) while it was associated with diabetes among women with stage 1 IFG (HR, 2.64; 95 %CI, 1.38-5.03) and stage 2 IFG (HR, 2.17; 95 %CI, 1.07-4.42). When combined men and women, the association between adiponectin and diabetes was statistically significant in stage 2 IFG with an increase of about 82 % (HR, 1.82; 95 %CI, 1.40-2.39) after adjusting for age, sex, body mass index, waist circumference, and fasting serum glucose. There was an interaction by sex and stage 1 IFG in the association between adiponectin and risk of diabetes (P < 0.001). Adiponectin was independently associated with diabetes among participants with IFG. This association was apparent in stage 2 IFG. Adiponectin may be used as a predictor of diabetes in patients having IFG.

Trajectories of cardiometabolic risk factors before diagnosis of three subtypes of type 2 diabetes: a post-hoc analysis of the longitudinal Whitehall II cohort study

BACKGROUND

Most clinicians acknowledge that type 2 diabetes is multifactorial and has heterogeneous characteristics, but neither prevention nor treatment is systematically stratified. To address the heterogeneity of the disease, we examined whether patients diagnosed on the basis of fasting glucose concentrations, those diagnosed on the basis of 2 h concentrations, and those diagnosed on the basis of both criteria differed in terms of pathogenesis or cardiovascular risks.

METHODS

Retrospectively, we analysed trajectories of cardiometabolic risk factors and 10 year cardiovascular risks in the prospective Whitehall II study cohort by use of multilevel longitudinal modelling. Participants were diagnosed by 75 g oral glucose-tolerance tests. We classified those diagnosed with type 2 diabetes into three subgroups: diagnosed on the basis of fasting glucose concentrations, diagnosed on the basis of 2 h glucose concentrations, and diagnosed on the basis of both concentrations. We also developed a classification tree for identification of individuals who are likely to have high fasting and 2 h glucose concentrations, but for whom only fasting concentrations are available.

RESULTS

Median follow-up was 14·2 years with 15,826 person-examinations (1991-2009). Of 10,308 individuals, 6843 were included and 6569 remained diabetes free. 274 cases of type 2 diabetes were identified: 55 had high fasting glucose concentrations only, 148 had high 2 h concentrations only, and 71 had high fasting and 2 h concentrations. At diagnosis, participants with high fasting and 2 h glucose concentrations had higher mean body-mass indices (30·9 kg/m(2) [SD 5·7]) than did those with high fasting concentrations (28·4 kg/m(2) [4·4]; p=0·0009) or 2 h concentrations (27·9 kg/m(2) [4·9]; <0·0001). Mean glycated haemoglobin A1c concentrations were also higher in the fasting and 2 h subgroup (7·4% [1·6]) than in the fasting (5·9% [0·5]; <0·0001) or 2 h (5·9% [0·6]; <0·0001) sugroups. Additionally, the fasting and 2 h subgroup had a higher proportion of individuals with moderate or high risk of cardiovascular disease than did the fasting subgroup (p=0·02). A classic pattern of β-cell decompensation before diagnosis was noted only in the fasting and 2 h subgroup. Additionally, glucose concentrations and insulin resistance accelerated more substantially before diagnosis in the fasting and 2 h subgroup than in the fasting subgroup or the 2 h subgroup.

INTERPRETATION

Patients with type 2 diabetes diagnosed on the basis of increased fasting glucose concentrations or 2 h glucose concentrations, or both, have distinct cardiometabolic risk development before diagnosis.

FUNDING

UK Medical Research Council, UK Economic and Social Research Council, British Heart Foundation, UK Health and Safety Executive, UK Department of Health, US National Heart Lung and Blood Institute, US National Institute on Aging, US Agency for Health Care Policy Research, and John D and Catherine T MacArthur Foundation.

Anti-inflammatory cytokines and risk of type 2 diabetes

Proinflammatory processes have been investigated extensively in the development of type 2 diabetes, but our knowledge on anti-inflammatory proteins is rather limited. This article summarizes studies that investigated associations between circulating levels of anti-inflammatory cytokines and incident type 2 diabetes preferably in prospective epidemiological studies. Adiponectin is the only known anti-inflammatory protein whose circulating levels are decreased before type 2 diabetes. In contrast, concentrations of interleukin-1 receptor antagonist (IL-1RA), transforming growth factor-β1 (TGF-β1) and growth differentiation factor-15 (GDF-15) are increased and indicate the presence of a compensatory, but eventually futile, counter-regulation of proinflammatory stimuli. Importantly, a proof-of-principle study using recombinant IL-1RA to improve metabolic control in patients with type 2 diabetes demonstrated that a more pronounced upregulation of this protein than that found in the natural course of diabetes development may have clinical relevance. Other interesting candidates like omentin (which shows similar associations with metabolic parameters as adiponectin), interleukin-10 (IL-10) and secreted frizzled-related protein-5 (Sfrp5) are currently less well studied with sometimes conflicting results regarding their association with type 2 diabetes. Thus, further research is required to better understand the causal role of proinflammatory cytokines, hypoadiponectinaemia and the upregulation of anti-inflammatory proteins before the onset of type 2 diabetes.

Are current diagnostic guidelines delaying early detection of dysglycemic states? Time for new approaches

Diagnosis of dysglycemic states is likely delayed as current diagnostic criteria apply absolute threshold values to a process that is continuous. The importance of this relates to forestalling opportunities for earlier diagnosis when prevention and reversibility are more likely to occur by preventing further β cell dysfunction. Although the optimal method for earlier identification of individuals at risk remains uncertain, the paper suggests novel approaches.

Obesity as the common soil of non-alcoholic fatty liver disease and diabetes: Role of adipokines

Non‐alcoholic fatty liver disease (NAFLD) describes a spectrum of liver conditions from simple steatosis, steatohepatitis to end‐stage liver disease. The prevalence of NAFLD has been on the rise in many parts of the world, including Asia, and NAFLD is now the liver disease associated with the highest mortality, consequent to the increased risk of cardiovascular diseases and hepatocellular carcinoma. Whereas NAFLD is an independent risk factor for type 2 diabetes, increased hepatic and peripheral insulin resistance contribute to the pathogenesis of both NAFLD and diabetes, which are associated with enhanced cardiovascular risk. Studies in humans and animal models have suggested obesity as the common link of these two diseases, likely mediated by adipose tissue inflammation and dysregulated adipokine production in obesity. In the present review, we discuss recent advances in our understanding of the role of several novel adipokines (adiponectin, adipocyte fatty acid binding protein and fibroblast growth factor‐21) in the pathophysiology of NAFLD and diabetes, as well as their use as potential biomarkers and therapeutic targets for dysglycemia in NAFLD patients.