Feasibility of prevention of type 2 diabetes in low- and middle-income countries.

Type 2 diabetes is a leading cause of global mortality and morbidity. Nearly 80% of individuals with diabetes live in low- and middle-income countries (LMICs), where nearly half of those with the condition remain undiagnosed. The majority of known cases have sub-optimal clinical outcomes. Moreover, large populations with impaired glucose tolerance and/or impaired fasting glucose contribute to the rapid increase in type 2 diabetes. Globally, priority should be given to limit the population with diabetes, especially in LMICs, alongside actions to optimise the care of people diagnosed with diabetes. Primary prevention studies in LMICs have generated evidence to show the efficacy and scalability of strategies to fully prevent or delay the development of diabetes in high-risk groups. However, these are mainly limited to certain countries in Asia, particularly China and India. The studies have indicated that prevention policies are effective in populations with a high risk of type 2 diabetes, and they also have long-term benefits, not only for the risk of type 2 diabetes but also for the risk of associated metabolic disorders, such as CVDs. For the effective conduct of national programmes, innovative mechanisms must be implemented, such as the use of information technology, joint efforts of multiple teams implementing similar programmes, and involvement of governmental and non-governmental partnerships. Continuous monitoring and long-term studies are required to assess the utility of these programmes. The effectiveness of such programmes in LMICs has not been proven over the longer term, except in China. Despite the available evidence, the feasibility of prevention strategies for type 2 diabetes in LMICs at population level remains an enigma. There remain challenges in the form of cultural, societal and economic constraints; insufficient infrastructure and healthcare capacity; and the non-fully elucidated natural history and determinants of type 2 diabetes in LMICs.

Synergistic effects of glucose tolerance and BMI on cardiovascular events and all-cause mortality in a healthy population: CA.ME.LI.A study 7 years follow-up.

The CA.ME.LI.A (CArdiovascular risks, MEtabolic syndrome, LIver and Autoimmune disease) epidemiological study was conducted in Abbiategrasso (Milan, Italy) to identify risk factors for metabolic and cardiovascular disease in an apparently healthy population of northern Italy. The population (n = 2,545, 1,251 men, 1,254 women) was stratified according to body mass index [normal body weight (NBW): <25 kg/m2; overweight-obese (OWO): ≥25 kg/m2] and according to fasting blood glucose [normal fasting glucose: <100 mg/dL; impaired fasting glucose (IFG): 100-125 mg/dL; diabetes mellitus (DM): ≥126 mg/dL]. The incidence of cardiovascular (CV) events and overall mortality were studied by the Kaplan-Meier method using the log rank test. Univariate analysis was conducted with time-dependent Cox models. During the 7-yr follow-up period, 80 deaths and 149 CV events occurred. IFG [hazard ratio (HR): 2.81; confidence interval (CI): 1.37-5.77; P = 0.005], DM (HR: 4.88; CI: 1.47-16; P = 0.010), or OWO (HR: 2.78; CI:1.68-4.59; P < 0.001) all produced significant increases in CV events and deaths. In the combination IFG/OWO (HR: 5.51; CI: 3.34-9.08; P < 0.001), there was an apparent additive effect of the two conditions, whereas in the combination DM/OWO (HR: 12.71; CI: 7.48-22; P < 0.001), there was an apparent multiplicative effect on the risk for CV events and deaths. In males, the DM/NBW group had a higher incidence of cardiovascular events and deaths than the IFG/OWO group. In contrast, in females, the IFG/OWO group had a higher incidence of cardiovascular events and deaths than the DM/NBW group. In women, there was a greater incidence of CV events in the IFG/OWO group (HR: 6.23; CI: 2.88-13; P < 0.001) than in men in the same group (HR: 4.27; CI: 2.15-8.47; P < 0.001). Consistent with these data, also all-cause mortality was progressively increased by IFG/DM and OWO, with an apparently exponential effect in the combination DM/OWO (HR: 11.78; CI: 6.11-23; P < 0.001). IFG/DM and OWO, alone or in combination, had major effects in increasing mortality for all causes and CV events. The relative contributions of hyperglycemia and overweight/obesity on cardiovascular events and deaths were apparently, to a certain extent, sex dependent. Females were more affected by overweight/obesity either alone or combined with IFG, as compared with males.NEW & NOTEWORTHY For the first time, the combined effects of glucose tolerance and BMI have been investigated in an apparently healthy large population sample of a city in the north of Italy. We found that there are synergistic effects of glucose levels with BMI to increase not only cardiovascular events and deaths but also cancer-related deaths and all-cause mortality.

Dysglycemia and liver lipid content determine the relationship of insulin resistance with hepatic OXPHOS capacity in obesity.

BACKGROUND & AIMS: Hepatic mitochondrial respiration is higher in steatosis, but lower in overt type 2 diabetes. We hypothesized that hepatic OXPHOS capacity increases with a greater degree of insulin resistance in obesity, independent of other metabolic diseases. METHODS: We analysed 65 humans without diabetes (BMI 50±7 kg/m2, HbA1c 5.5±0.4%) undergoing bariatric surgery. MASLD stages were assessed by histology, whole-body insulin sensitivity (PREDIcted-M index) by oral glucose tolerance tests, and maximal ADP-stimulated mitochondrial OXPHOS capacity by high-resolution respirometry of liver samples. RESULTS: Prediabetes was present in 30 participants, and MASLD in 46 participants. Thereof, 25 had metabolic dysfunction-associated steatohepatitis (MASH), and seven had F2-F3 fibrosis. While simple regression did not detect an association of insulin sensitivity with hepatic OXPHOS capacity, interaction analyses revealed that the regression coefficient of OXPHOS capacity depended on fasting plasma glucose (FPG) and liver lipid content. Interestingly, the respective slopes were negative for FPG ≤100 mg/dl, but positive for FPG >100 mg/dl. Liver lipid content displayed similar behavior, with a threshold value of 24%. Post-challenge glycemia affected the association between insulin sensitivity and OXPHOS capacity normalized for citrate synthase activity. Presence of prediabetes affected hepatic insulin signaling, mitochondrial dynamics and fibrosis prevalence, while the presence of MASLD related to higher biomarkers of hepatic inflammation, cell damage and lipid peroxidation in people with normal glucose tolerance. CONCLUSIONS: Rising liver lipid contents and plasma glucose concentrations, even in the non-diabetic range, are associated with a progressive decline of hepatic mitochondrial adaptation in people with obesity and insulin resistance. CLINTRIALS. GOV IDENTIFIER: NCT01477957.

Test and Treat for Prediabetes: A Review of the Health Effects of Prediabetes and the Role of Screening and Prevention.

The term prediabetes describes blood glucose levels above the normal range but below the threshold to diagnose type 2 diabetes. Several population health initiatives encourage a test and treat approach for prediabetes. In this approach, screening and identification of individuals with prediabetes should be followed by prompt referral to structured lifestyle modification programs or pharmacologic interventions that have been shown to prevent or delay the progression to type 2 diabetes in clinical trials. Here we provide a critical review of evidence for this test and treat approach by examining health outcomes associated with prediabetes and the availability and effectiveness of lifestyle modification approaches that target prediabetes. We also describe current limitations to the reach and uptake of evidence-based treatment options for prediabetes. Finally, we highlight lessons learned from identifying and labeling other preconditions to consider challenges and opportunities that may arise with increasing awareness of prediabetes as part of routine preventive care.

Frequency of prediabetes in individuals with increased adiposity and metabolically healthy or unhealthy phenotypes.

AIMS: To utilize the estimated glucose disposal rate (eGDR) index of insulin sensitivity, which is based on readily available clinical variables, namely, waist circumference, hypertension and glycated haemoglobin, to discriminate between metabolically healthy and unhealthy phenotypes, and to determine the prevalence of prediabetic conditions. METHODS: Non-diabetic individuals (n = 2201) were stratified into quartiles of insulin sensitivity based on eGDR index. Individuals in the upper quartiles of eGDR were defined as having metabolically healthy normal weight (MHNW), metabolically healthy overweight (MHOW) or metabolically healthy obesity (MHO) according to their body mass index, while those in the lower quartiles were classified as having metabolically unhealthy normal weight (MUNW), metabolically unhealthy overweight (MUOW) and metabolically unhealthy obesity (MUO), respectively. RESULTS: The frequency of impaired fasting glucose (IFG), impaired glucose tolerance (IGT), and IFG + IGT status was comparable among the MHNW, MHOW and MHO groups, while it increased from those with MUNW status towards those with MUOW and MUO status. As compared with participants with MHNW, the odds ratio of having IFG, IGT, or IFG + IGT was significantly higher in participants with MUOW and MUO but not in those with MUNW, MHOW and MHO, respectively. CONCLUSIONS: A metabolically healthy phenotype is associated with lower frequency of IFG, IGT, and IFG + IGT status across all body weight categories.

Nonlinear association between remnant cholesterol and reversion from impaired fasting glucose to normoglycemia: a multicenter cohort study.

BACKGROUND: Remnant cholesterol (RC), a potent atherogenic lipid, has been shown to be strongly correlated with insulin resistance and the pathogenesis of diabetes mellitus. However, the relationship between RC and normoglycemia reversal in individuals with impaired fasting glucose (IFG) is crucial and remains unclear. This investigation, which aimed to clarify this association, is important for understanding and potentially improving the management of diabetes. METHOD: This study, which included 15,019 IFG participants from 11 Chinese cities between 2010 and 2016, was conducted with a rigorous research process. Cox regression analysis revealed intriguing findings regarding the relationship between RC and normoglycemia reversal in individuals with IFG. Potential nonlinear associations were further explored via smooth curve-fitting techniques and 4-knot restricted cubic spline functions, ensuring a comprehensive analysis. To examine the validity of the results, an array of subgroup and sensitivity analyses were conducted, further bolstering the robustness of the findings. RESULTS: By the end of the 2.89-year median follow-up period, 6,483 of the 15,019 IFG participants (43.17%) had reverted to normoglycemia. The findings, which reveal that increased RC levels are inversely associated with the likelihood of normoglycemia reversal, are novel and significant. According to the fully adjusted Cox proportional hazards model analysis, an increase of one standard deviation in RC was associated with a 20% decrease in the likelihood of normoglycemia reversal among IFG participants (HR: 0.80, 95% CI: 0.77-0.82). A nonlinear association between RC and normoglycemia reversal was observed, with an inflection point at 41.37 mg/dL. This suggests that the growth rate of the likelihood of reversion decreased and stabilized after the inflection point was reached. Moreover, significant interactions were observed between the age groups, providing a more nuanced understanding of this complex relationship. CONCLUSION: Among Chinese adults with IFG, RC exhibited a negative nonlinear relationship with the probability of normoglycemia reversal. When RC levels reached or exceeded 41.38 mg/dL, the probability of achieving normoglycemia progressively diminished and subsequently stabilized. Maintaining RC levels below 41.38 mg/dL can significantly improve the probability of normoglycemia reversal among individuals with IFG, especially those aged 60 years or older.

Relationship between Marriage and Prediabetes among Healthcare Workers: Mediating Effect of Triglycerides.

Background and Objectives: In the literature, relationships between being married and having prediabetes or diabetes are inconsistent. We aimed to investigate whether marriage is a protective or risk factor for prediabetes and to uncover new insights into its impact on prediabetes. Materials and Methods: In this cross-sectional observational study, questionnaires were distributed by email to 1039 staff members who participated in an employee health check from a hospital affiliated with a medical university in Taiwan. Fasting blood glucose and triglyceride (TG) levels were checked and the questionnaires elicited basic demographic characteristics and included the Copenhagen Burnout Inventory and Nordic Musculoskeletal Questionnaire. The chi-square test or Fisher's exact test, logistic regression, and mediation analysis were conducted for statistical analysis. Results: Among the group aged 20-37 years, married (OR = 1.89, 95%CI: 1.08, 3.33), obesity (OR = 2.95, 95%CI: 1.49, 5.83), neck and shoulder pain (OR = 1.31, 95%CI: 1.01, 1.69), and elevated TG levels (OR = 1.01, 95%CI: 1.00, 1.01) were independent risk factors for prediabetes (impaired fasting glucose). For those >38 years old, overweight (OR = 2.08, 95%CI: 1.27, 3.43), obesity (OR = 4.30, 95%CI: 2.38, 7.79), and elevated triglyceride (TG) (OR = 1.003, 95%CI: 1.00, 1.01) were the independent risk factors for impaired fasting glucose. Increased TG levels serve as a mediating factor (Zm = 2.64, p < 0.01) linking marriage to an increased risk of prediabetes for the group aged 20-37 years. Conclusions: TGs play a significant role in the association between marriage and prediabetes among the group aged 20-37 years. Therefore, dietary habits, especially those of young adult couples should be considered. Our findings connect marital status to prediabetes, facilitating advances in diabetes prevention.

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.

Effects of acute changes in fasting glucose and free fatty acid concentrations on indices of ß-cell function and glucose metabolism in subjects without diabetes.

Elevated fasting free fatty acids (FFAs) and fasting glucose are additively associated with impaired glucose tolerance (IGT) and decreased ß-cell function [quantified as disposition index (DI)]. We sought to examine how changes in fasting FFA and glucose alter islet function. We studied 10 subjects with normal fasting glucose (NFG) and normal glucose tolerance (NGT) on two occasions. On one occasion, Intralipid and glucose were infused overnight to mimic conditions present in IFG/IGT. In addition, we studied seven subjects with IFG/IGT on two occasions. On one occasion, insulin was infused to lower overnight FFA and glucose concentrations to those observed in people with NFG/NGT. The following morning, a labeled mixed meal was used to measure postprandial glucose metabolism and ß-cell function. Elevation of overnight fasting FFA and glucose in NFG/NGT did not alter peak or integrated glucose concentrations (2.0 ± 0.1 vs. 2.0 ± 0.1 Mol per 5 h, Saline vs. Intralipid/glucose, P = 0.55). Although overall ß-cell function quantified by the Disposition Index was unchanged, the dynamic component of ß-cell responsivity (ϕd) was decreased by Intralipid and glucose infusion (9 ± 1 vs. 16 ± 3 10-9, P = 0.02). In people with IFG/IGT, insulin did not alter postprandial glucose concentrations or indices of ß-cell function. Endogenous glucose production and glucose disappearance were also unchanged in both groups. We conclude that acute, overnight changes in FFA, and glucose concentrations do not alter islet function or glucose metabolism in prediabetes.NEW & NOTEWORTHY This experiment studied the effect of changes in overnight concentrations of free fatty acids (FFAs) and glucose on ß-cell function and glucose metabolism. In response to elevation of these metabolites, the dynamic component of the ß-cell response to glucose was impaired. This suggests that in health overnight hyperglycemia and FFA elevation can deplete preformed insulin granules in the ß-cell.

Neuropathy in prediabetes.

Diabetic neuropathies are the most frequent complications of diabetes, contributing to high morbidity, excess mortality, reduced quality of life, and increased healthcare costs. Prediabetes is characterised by glucose levels within an intermediate range above normoglycaemia yet below the diagnostic threshold for diabetes. In 2021, 10.6% and 6.2% of adults worldwide were estimated to have impaired glucose tolerance and impaired fasting glucose, respectively, the majority of whom are unaware of having prediabetes. Evidence has accumulated suggesting that prediabetes is a predictor of cardiovascular disease (CVD) and increased mortality. The past 2 decades have witnessed an extensive debate, particularly among diabetologists and neurologists, as to whether prediabetes is associated with peripheral neuropathy. In this review, we elaborate on the current evidence, particularly from population-based studies supporting an increased risk of distal sensorimotor polyneuropathy (DSPN) and cardiovascular autonomic neuropathy (CAN) in people with prediabetes. Moreover, we discuss whether lifestyle interventions showing efficacy in preventing or delaying the transition from prediabetes to diabetes in persons with prediabetes may also exert favourable effects on the development and progression of DSPN and CAN. This review should help in raising the awareness of and translating the current knowledge on neuropathies in people with prediabetes into clinical practice and public health. The current recommendation that adults who are overweight or obese should be screened for prediabetes and referred to or offered preventive interventions should ultimately culminate in preventing not only CVD but also prediabetic neuropathy.

Dairy Product Consumption and Incident Prediabetes in the Australian Diabetes, Obesity, and Lifestyle Study With 12 Years of Follow-Up.

BACKGROUND: Investigating modifiable risk factors for the early stages of the development of type 2 diabetes is essential for effective prevention. Some studies show protective associations between dairy and prediabetes; however, associations are heterogeneous by the type and fat content of dairy foods. OBJECTIVE: To examine the relationship between the consumption of dairy, including different types of dairy products and risk of prediabetes. METHODS: The study included 4891 participants with normal glucose tolerance (aged 49.0 ± 12.3 y, 57% female) of the Australian Diabetes, Obesity, and Lifestyle (AusDiab) study, a longitudinal population-based study. Dairy intake was measured at baseline using a food frequency questionnaire. Prediabetes at the 5-y and 12-y follow-ups was defined according to the WHO criteria as fasting plasma glucose levels of 110-125 mg/dL or 2-h plasma glucose levels of 140-199 mg/dL. Associations were analyzed using Poisson regression, adjusted for social demographics, lifestyle behaviors, a family history of diabetes, and food group intake. RESULTS: In total, 765 (15.6%) incident cases of prediabetes were observed. The mean intake of dairy foods was 2.4 ± 1.2 servings/d, mostly consisting of low-fat milk (0.70 ± 0.78 servings/d) and high-fat milk (0.47 ± 0.72 servings/d). A higher intake of high-fat dairy (RRservings/d: 0.92; 95% CI: 0.85, 1.00), high-fat milk (0.89; 95% CI: 0.80, 0.99), and total cheese (0.74; 95% CI: 0.56, 0.96) was associated with a lower risk of prediabetes. Low-fat milk intake was associated nonlinearly with prediabetes risk. Low-fat dairy foods, total milk, yogurt, low-fat cheese, and ice cream were not associated with prediabetes risk. CONCLUSION: In this large Australian cohort, protective associations were found for high-fat dairy types, whereas neutral associations were seen for low-fat dairy types. Studies with more detail on sugar content of types of dairy foods and products eaten with dairy foods (e.g., cereals or jam), and studies into potential causal mechanisms of the health effects of dairy intake are required.

Peripheral quantitative computed tomography-derived bone parameters in men with impaired fasting glucose and diabetes.

INTRODUCTION: Individuals with type 2 diabetes mellitus (T2DM) are at higher risk of fracture, but paradoxically do not have reduced bone mineral density. We investigated associations between peripheral quantitative computed tomography (pQCT) and glycaemia status. MATERIALS AND METHODS: Participants were men (n = 354, age 33-92 year) from the Geelong Osteoporosis Study. Diabetes was defined by fasting plasma glucose (FPG) ≥ 7.0 mmol/L, self-report of diabetes and/or antihyperglycaemic medication use and impaired fasting glucose (IFG) as FPG 5.6-6.9 mmol/L. Bone measures were derived using pQCT (XCT2000) at 4% and 66% radial and tibial sites. Linear regression was used, adjusting for age, body mass index and socio-economic status. RESULTS: At the 4% site, men with T2DM had lower adjusted bone total area, trabecular area and cortical area at the radius (all - 6.2%) and tibia (all - 6.4%) compared to normoglycaemia. Cortical density was higher for T2DM at the radius (+ 5.8%) and tibia (+ 8.0%), as well as adjusted total bone density at the tibial site (+ 6.1%). At the 66% site, adjusted total bone area and polar stress strain index were lower for T2DM at the radius (- 4.3% and - 8.0%). Total density was also higher for T2DM (+ 1.2%). Only cortical density at the 4% tibial site was different between IFG and normoglycaemia in adjusted analyses (+ 4.5%). CONCLUSION: Men with T2DM had lower total bone area, trabecular area, cortical area and polar stress strain index than the other two groups; however, total density and cortical density were higher. Only one difference was observed between IFG and normoglycaemia; increased tibial cortical density.

Incidence and risk factors of fasting hyperglycaemia following first-attack acute pancreatitis before discharge: a retrospective study.

BACKGROUND: Pancreatic endocrine insufficiency is more likely to occur after acute pancreatitis (AP), but the risk factors affecting pancreatic endocrine function remain controversial. Therefore, exploring the incidence and risk factors of fasting hyperglycaemia following first-attack AP is important. METHODS: Data were collected from 311 individuals with first-attack AP without previous diabetes mellitus (DM) or impaired fasting glucose (IFG) history treated in the Renmin Hospital of Wuhan University. Relevant statistical tests were performed. A two-sided p-value < 0.05 was considered statistically significant. RESULTS: The incidence of fasting hyperglycaemia in individuals with first-attack AP was 45.3%. Univariate analysis showed that age (χ2 = 6.27, P = 0.012), aetiology (χ2 = 11.184, P = 0.004), serum total cholesterol (TC) (χ2 = 14.622, P < 0.001), and serum triglyceride (TG) (χ2 = 15.006, P < 0.001) were significantly different between the hyperglycaemia and non-hyperglycaemia groups (P < 0.05). The serum calcium concentration (Z=-2.480, P = 0.013) was significantly different between the two groups (P < 0.05). Multiple logistic regression analysis showed that age- ≥60 years (P < 0.001, OR = 2.631, 95%Cl = 1.529-4.527) and TG ≥ 5.65 mmol/L (P < 0.001, OR = 3.964, 95%Cl = 1.990-7.895) were independent risk factors for fasting hyperglycaemia in individuals with first-attack AP (P < 0.05). CONCLUSIONS: Old age, serum triglycerides, serum total cholesterol, hypocalcaemia, and aetiology are associated with fasting hyperglycaemia following first-attack AP. Age ≥ 60 years and TG ≥ 5.65 mmol/L are independent risk factors for fasting hyperglycaemia following first-attack AP.

Are HOMA-IR and HOMA-B good predictors for diabetes and pre-diabetes subtypes?

BACKGROUND: To investigate the association between the Homeostasis Model Assessment of Insulin Resistance (HOMA-IR) and Homeostasis Model Assessment of Beta-cell function (HOMA-B) with the incidence of diabetes and pre-diabetes subtypes. METHODS: A total of 3101 normoglycemic people aged 20-70 years were included in the 6-year follow-up study. Multinomial logistic regression was used to calculate the incidence possibility of isolated Impaired Fasting Glucose (iIFG), isolated Impaired Glucose Tolerance (iIGT), Combined impaired fasting glucose & impaired glucose tolerance (CGI), and Diabetes Mellitus (DM) per standard deviation (SD) increment in HOMA-IR and HOMA-B in the crude and multivariable model. RESULTS: In the multivariate model, an increase in one SD change in HOMA-IR was associated with a 43, 42, 75, and 92% increased risk of iIFG, iIGT, CGI, and DM, respectively. There was a positive correlation between the increase in HOMA-B and the incidence of iIGT; however, after adjusting the results for metabolic syndrome components, it was inversely correlated with the incidence of iIFG [Odds Ratio = 0.86(0.75-0.99)]. CONCLUSIONS: HOMA-IR is positively correlated with diabetes and pre-diabetes subtypes' incidence, and HOMA-B is inversely correlated with the incidence of iIFG but positively correlated with iIGT incidence. However, none of these alone is a good criterion for predicting diabetes and pre-diabetes.

NMR derived changes of lipoprotein particle concentrations related to impaired fasting glucose, impaired glucose tolerance, or manifest type 2 diabetes mellitus.

BACKGROUND: Type 2 diabetes mellitus (T2D) and corresponding borderline states, impaired fasting glucose (IFG) and/or glucose tolerance (IGT), are associated with dyslipoproteinemia. It is important to distinguish between factors that cause T2D and that are the direct result of T2D. METHODS: The lipoprotein subclass patterns of blood donors with IFG, IGT, with IFG combined with IGT, and T2D are analyzed by nuclear magnetic resonance (NMR) spectroscopy. The development of lipoprotein patterns with time is investigated by using samples retained for an average period of 6 years. In total 595 blood donors are classified by oral glucose tolerance test (oGTT) and their glycosylated hemoglobin (HbA1c) concentrations. Concentrations of lipoprotein particles of 15 different subclasses are analyzed in the 10,921 NMR spectra recorded under fasting and non-fasting conditions. The subjects are assumed healthy according to the strict regulations for blood donors before performing the oGTT. RESULTS: Under fasting conditions manifest T2D exhibits a significant concentration increase of the smallest HDL particles (HDL A) combined with a decrease in all other HDL subclasses. In contrast to other studies reviewed in this paper, a general concentration decrease of all LDL particles is observed that is most prominent for the smallest LDL particles (LDL A). Under normal nutritional conditions a large, significant increase of the concentrations of VLDL and chylomicrons is observed for all groups with IFG and/or IGT and most prominently for manifest T2D. As we show it is possible to obtain an estimate of the concentrations of the apolipoproteins Apo-A1, Apo-B100, and Apo-B48 from the NMR data. In the actual study cohort, under fasting conditions the concentrations of the lipoproteins are not increased significantly in T2D, under non-fasting conditions only Apo-B48 increases significantly. CONCLUSION: In contrast to other studies, in our cohort of "healthy" blood donors the T2D associated dyslipoproteinemia does not change the total concentrations of the lipoprotein particles produced in the liver under fasting and non-fasting conditions significantly but only their subclass distributions. Compared to the control group, under non-fasting conditions participants with IGT and IFG or T2D show a substantial increase of plasma concentrations of those lipoproteins that are produced in the intestinal tract. The intestinal insulin resistance becomes strongly observable.

Obesity as a mediator linking sleep-disordered breathing to both impaired fasting glucose and type 2 diabetes.

PURPOSE: To examine whether or not associations between sleep-disordered breathing (SDB) and impaired fasting glucose and type 2 diabetes are mediated by obesity. METHODS: We used cross-sectional data including participants from the Multi-Ethnic Study of Atherosclerosis (MESA). SDB, including obstructive sleep apnea (OSA), hypoxia and sleep fragmentation, was evaluated by polysomnography. Further, five obesity measures related to overall obesity and central obesity were assessed. Mediation analysis was conducted to explore the mediating effect of obesity on these relationships between SDB and impaired fasting glucose and type 2 diabetes. RESULTS: Among 1615 participants, OSA and hypoxia, including apnea hypopnea index (AHI) ≥ 15, percent of total sleep time (TST) with SaO2 < 90% (TST90), oxygen desaturation index (ODI), and lowest oxygen saturation (SaO2), were significantly associated with impaired fasting glucose and type 2 diabetes. In addition, mean SaO2 was also associated with impaired fasting glucose. Mediation analysis showed that these relationships were significantly mediated by all five obesity measures, where central obesity had greater mediating effect than overall obesity. Proportion of mediation of obesity ranged from 21.5 to 62.5% for impaired fasting glucose and 25.85 to 71.6% for type 2 diabetes, with substantial differences found in the subgroup analysis by gender or race/ethnicity. The consistency of the mediating effect was demonstrated across multiple measures of SDB, obesity, and glucose metabolism. CONCLUSION: Obesity, especially central obesity, may play a critical role in the pathway where SDB, including OSA and hypoxia, increases the occurrence of impaired fasting glucose and type 2 diabetes. Weight management is important for patients with SDB to prevent type 2 diabetes.

Relationship between BMI and risk of impaired glucose tolerance and impaired fasting glucose in Chinese adults: a prospective study.

BACKGROUND: Current studies in most Western countries have largely focused on body mass index (BMI) as an important risk factor for impaired glucose tolerance (IGT) and impaired fasting glucose (IFG), which have different pathophysiological bases. In people with obesity, the prevalence of IGT is higher and the prevalence of IFG is lower. The prevalence of IGT in the Asian population is higher than that in the white population, and the obesity rate in China is still increasing. However, few cohort studies explore the relationship between BMI and the incidence of IGT and IFG in China. We aimed to explore the relationship between BMI and the risk of IGT and IFG in Chinese adults and analyze the differences between them. METHODS: The baseline data were obtained from the 2010 China Chronic Disease and Risk Factor Surveillance, of which 20 surveillance sites were followed up from 2016 to 2017. Finally, in this study, a total of 5,578 studies were grouped into BMI categories of underweight (BMI < 18.5 kg/m2), normal weight (18.5-23.9 kg/m2), overweight (24.0-27.9 kg/m2), and obesity (≥ 28.0 kg/m2). We used the unconditional logistic regression model to analyze the relationship between BMI and the risk of IGT and IFG. RESULTS: During an average follow-up of 6.4 years, 562 developed IGT and 257 developed IFG. After age, gender, urban and rural areas, physical activity, family history of diabetes, hypertension, abdominal obesity, dyslipidemia, and other factors were adjusted, overweight increased the risk of IGT by 35% [odds ratio (OR) 1.35, 95% confidence interval (CI) 1.08-1.70], and obesity increased the risk of IGT by 77% (OR 1.77, 95% CI 1.27-1.47). After the factors consistent with the above were adjusted, only obesity increased the risk of IFG by 122% (OR 2.22, 95% CI 1.39-3.54). CONCLUSIONS: In China, obesity is an important risk factor for IGT and IFG, and the risk of IGT increases during the overweight stage.

Higher HDL-C levels attenuated the association of plasma polybrominated diphenyl ethers with prediabetes and type 2 diabetes mellitus in rural Chinese adults.

BACKGROUND: Plasma polybrominated diphenyl ethers (PBDE) were used as flame retardants widely, however, epidemiological evidence for the association between PBDEs and type 2 diabetes mellitus (T2DM) is inconsistent. Moreover, the combined effects of PBDEs and blood lipid indicators on impaired fasting glucose (IFG) and T2DM remains largely unknown in rural areas lacking good waste recycling infrastructure. METHODS: In this study, a total of 2607 subjects aged 18-79 years were included from the Henan Rural Cohort. Generalized linear and logistic regression models were applied to evaluate the associations of various PBDE pollutants on IFG and T2DM. Quantile g-computation regression and PBDE pollution score created by the adaptive elastic net were applied to evaluate the impact of PBDEs mixtures on IFG and T2DM. Interaction effects of individual PBDE pollutants and blood lipid indicators on IFG and T2DM were assessed by using Interaction plots. RESULTS: The geometric mean concentrations (detection rates) were 0.09 ng/mL (100.0%), 0.12 ng/mL (97.8%), 0.22 ng/mL (94.7%), 0.16 ng/mL (99.2%) and 0.28 ng/mL (100.0%) for PBDE-28, PBDE-47, PBDE-99, and PBDE-153 respectively. However, PBDE-28, PBDE-99, PBDE-100, and ΣPBDEs were positively associated with IFG (odds ratios (ORs) (95% confidence intervals (CIs)): 1.14 (1.06, 1.23), 1.16 (1.04, 1.29), 1.25 (1.14, 1.37), and 1.27 (1.08, 1.50)). Similarly, PBDE-28, PBDE-47, PBDE-99, PBDE-100, and ΣPBDEs were positively associated with T2DM (ORs (95% CIs): 1.30 (1.10, 1.54), 1.13 (1.06, 1.22), 1.27 (1.13, 1.43), 1.27 (1.15, 1.40), and 1.30 (1.10, 1.54)). Moreover, five PBDE mixtures or jointly as PBDE pollution score, were significantly associated with an increased risk of T2DM (P < 0.05 for all). In addition, the harmful effect of PBDE exposure on T2DM was decreased with accompanying high-density lipoprotein cholesterol (HDL-C) levels increased. CONCLUSIONS: Our findings highlight the importance of managing PBDEs contamination and suggest that HDL-C may be a novel way to prevent T2DM.

Associations of Glucometabolic Indices with Aortic Stiffness in Patients Undergoing Peritoneal Dialysis with and without Diabetes Mellitus.

Disruptions in glucose metabolism are frequently observed among patients undergoing peritoneal dialysis (PD) who utilize glucose-containing dialysis solutions. We aimed to investigate the relationship between glucometabolic indices, including fasting glucose, insulin resistance, advanced glycation end products (AGEs), PD-related glucose load, and icodextrin usage, and aortic stiffness in PD patients with and without diabetic mellitus (DM). This study involved 172 PD patients (mean age 58.3 ± 13.5 years), consisting of 110 patients without DM and 62 patients with DM. Aortic stiffness was assessed using the carotid-femoral pulse wave velocity (cfPWV). Impaired fasting glucose was defined as a fasting glucose level ≥ 100 mg/dL. Homeostatic model assessment for insulin resistance (HOMA-IR) scores, serum AGEs, dialysate glucose load, and icodextrin usage were assessed. Patients with DM exhibited the highest cfPWV (9.9 ± 1.9 m/s), followed by those with impaired fasting glucose (9.1 ± 1.4 m/s), whereas patients with normal fasting glucose had the lowest cfPWV (8.3 ± 1.3 m/s), which demonstrated a significant trend. In non-DM patients, impaired fasting glucose (ß = 0.52, 95% confidence interval [CI] = 0.01-1.03, p = 0.046), high HOMA-IR (ß = 0.60, 95% CI = 0.12-1.08, p = 0.015), and a high PD glucose load (ß = 0.58, 95% CI = 0.08-1.08, p = 0.023) were independently associated with increased cfPWV. In contrast, none of the glucometabolic factors contributed to differences in cfPWV in DM patients. In conclusion, among PD patients without DM, impaired fasting glucose, insulin resistance, and PD glucose load were closely associated with aortic stiffness.

Association of alcohol drinking with incident type 2 diabetes and pre-diabetes: The Guangzhou Biobank Cohort Study.

AIMS: We examined associations of baseline alcohol drinking with incident type 2 diabetes (T2D) or impaired fasting glucose (IFG), and explore whether the associations were modified by genetic polymorphisms of aldehyde dehydrogenase-2 (ALDH2) and alcohol dehydrogenase-1B (ADH1B). MATERIALS AND METHODS: All participants were aged 50+ (mean = 60.45; standard deviation = 6.88) years. Information of alcohol consumption was collected at baseline from 2003 to 2008. Incident T2D was defined as fasting glucose ≥7.0 mmol/L or post-load glucose ≥11.1 mmol/L at follow-up examination (2008-2012), self-reported T2D and/or initiation of hypoglycaemia medication or insulin during follow-up. Impaired fasting glucose was defined as fasting glucose ≥5.6 mmol/L and <7 mmol/L. RESULTS: Of 15,716 participants without diabetes and 11,232 participants without diabetes and IFG at baseline, 1624 (10.33%) developed incident T2D and 1004 (8.94%) developed incident IFG during an average 4 years of follow-up. After multivariable adjustments, compared with never drinking, occasional or moderate alcohol drinking was not associated with risk of incident hyperglycaemia (T2D + IFG) (odds ratio (OR) = 1.10, 95% confidence interval (CI) 0.95-1.27, and 0.90 (0.69-1.18), respectively), whereas heavy alcohol drinking was associated with a higher risk of incident hyperglycaemia (T2D + IFG) (OR = 1.82, 95% CI 1.24-2.68). No interactions of sex, overweight/obesity and genetic polymorphisms of ADH1B/ALDH2 genes with alcohol drinking on incident T2D and/or IFG were found (P for interaction from 0.12 to 0.85). CONCLUSIONS: Our results support a detrimental effect of heavy alcohol use on IFG and T2D. No protective effect was found for those carrying lower risk alleles for ADH1B/ALDH2 genes.