Prediabetes: prediction and prevention trials

Different levels of physical activity and risk of developing type 2 diabetes among adults with prediabetes: a population-based cohort study

OBJECTIVES

This study aimed to evaluate the association between different levels of physical activity and risk of developing type 2 diabetes (T2D) mellitus among adults with prediabetes in Chinese population.

METHODS

This prospective population-based cohort study included 12,424 participants (mean [SD] age, 52.8 [16.8] years; 82.2% men) with prediabetes at 2014 survey of the Kailuan study. Physical activity information was collected through the International Physical Activity Questionnaire-Short Form and categorized by metabolic equivalent (MET) of task as low, moderate, and high. Cox regression models were built to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) for associations between physical activity levels and incident T2D.

RESULTS

During a median follow-up of 3.6 years, 2,207 (17.8%) participants developed T2D. The incident rate of T2D were 55.83/1000, 35.14/1000, and 39.61/1000 person-years in the low, moderate, and high physical activity level group, respectively. Both moderate (HR 0.57, 95% CI 0.49 to 0.67) and high (HR 0.76, 95% CI 0.66 to 0.89) physical activity levels were associated with lower risks of developing T2D compared to low physical activity level (P for trend < 0.001). The association between high physical activity level and T2D was primarily observed in participants without metabolic syndrome (P for interaction < 0.001). Moreover, participants with moderate or high levels of physical activity had significantly decreased fasting blood glucose levels during follow-up when compared to those with low level (P group*time < 0.001).

CONCLUSION

This study suggested that individuals with prediabetes might benefit from moderate and high levels of physical activity.

Systemic Stressors and Retinal Microvascular Alterations in People Without Diabetes: The Kailuan Eye Study

Purpose

The purpose of this study was to determine systemic stressors, including fasting plasma glucose (FPG), and other major atherosclerotic cardiovascular disease (ASCVD) risk factors of the retinal microvasculature in people without diabetes.

Methods

The Kailuan Eye Study enrolled applicants from the community-based longitudinal Kailuan Study. Applicants underwent optical coherence tomographic angiography (OCTA) and systemic examinations. Both the macula and optic disc were screened, whereas superficial capillary plexus (SCP), deep capillary plexus (DCP), foveal vessel density in the 300 µm ring (FD-300), and radial peripapillary capillaries (RPCs) density were measured in the study.

Results

This study included 353 eligible applicants (mean age = 49.86 ± 11.41 years; 47% men; FPG =5.32 ± 1.19 mmol/L). Lower DCP density was associated with elder age (P = 0.001), male gender (P < 0.001), and higher FPG (P = 0.008). Male gender (P < 0.001), axial length (P < 0.001), and FPG (P = 0.029) were inversely associated with RPC density. Meanwhile, a higher FPG concentration was significantly correlated with lower DCP density (P = 0.006) and higher intraocular pressure (P = 0.006), after adjusting mean arterial blood pressure (P = 0.001) and sex (P = 0.042).

Conclusions

DCP density showed a significantly negative correlation with FPG concentration in people without diabetes. These data suggest hyperglycemia could cause early retinal capillary alterations in patients without clinical signs of retinopathy and indicate the potential clinical applications of routine OCTA may be beneficial to screen for subclinical microvasculature and monitor patients with high risks of ASCVD.

The role of the gut microbiome and its metabolites in metabolic diseases

It is well known that an unhealthy lifestyle is a major risk factor for metabolic diseases, while in recent years, accumulating evidence has demonstrated that the gut microbiome and its metabolites also play a crucial role in the onset and development of many metabolic diseases, including obesity, type 2 diabetes, nonalcoholic fatty liver disease, cardiovascular disease and so on. Numerous microorganisms dwell in the gastrointestinal tract, which is a key interface for energy acquisition and can metabolize dietary nutrients into many bioactive substances, thus acting as a link between the gut microbiome and its host. The gut microbiome is shaped by host genetics, immune responses and dietary factors. The metabolic and immune potential of the gut microbiome determines its significance in host health and diseases. Therefore, targeting the gut microbiome and relevant metabolic pathways would be effective therapeutic treatments for many metabolic diseases in the near future. This review will summarize information about the role of the gut microbiome in organism metabolism and the relationship between gut microbiome-derived metabolites and the pathogenesis of many metabolic diseases. Furthermore, recent advances in improving metabolic diseases by regulating the gut microbiome will be discussed.

Feasibility of procedures for a randomised pilot study of reduced exertion, high-intensity interval training (REHIT) with non-diabetic hyperglycaemia patients

Background

Physical activity and exercise interventions to improve health frequently bring about intended effects under ideal circumstances but often fail to demonstrate benefits in real-world contexts. The aim of this study was to describe the feasibility of an exercise intervention (reduced-exertion, high-intensity interval training) in non-diabetic hyperglycaemia patients delivered in a National Health Service setting to assess whether it would be appropriate to progress to a future large-scale study.

Methods

The intention was to recruit 40 participants from a single centre (specialist diabesity centre). Patients were eligible to take part if they were diagnostically defined as non-diabetic hyperglycaemic based on a glycated haemoglobin (HbA_1c) value of 42–46 mmol mol. Study procedures including recruitment, occurrence of adverse events, intervention acceptability, and intervention adherence were used to assess feasibility.

Results

Key criteria for progression to a larger study were not met. The study revealed several issues including patient eligibility, challenges to recruitment, patient consent, and poor clinician engagement. Furthermore, despite the simplicity and convenience of using HbA_1c to screen for diabetes risk, the process of accurately screening and case finding eligible patients was problematic. The small sample recruited for this trial (n = 6) also limits the interpretation of data, thus it is not possible to estimate the variability of intended outcomes to use in a formal sample size calculation for a full-scale trial. Some aspects of the intervention worked well. The acceptability of the exercise intervention and outcome measures met progression criteria thresholds and adherence was very high, with 97% of exercise sessions completed for participants that finished the study.

Conclusions

Given the issues, the trial is not feasible in its current form. Yet, this preparatory stage of trial design pre-empted problems with the intervention that could be changed to optimise the design and conduct of future studies. Solutions to the issues identified in this study revolve around using a dedicated local recruiter with a strong relationship among the healthcare team and patients, using participant incentives to take part, and allowing for a longer recruitment period.

Trial registration

ClinicalTrials.gov, NCT04011397. Registered 07 July 2019—retrospectively registered.

Association of Alcohol Drinking Patterns With Presence of Impaired Fasting Glucose and Diabetes Mellitus Among South Korean Adults

Background

We aimed to investigate the association between alcohol drinking patterns and the presence of impaired fasting glucose (IFG) and diabetes mellitus (DM).

Methods

We used data from the Korean National Health and Nutrition Examination Survey, 2010–2014. The participants were aged ≥30 years and had no previous diagnosis of DM. High-risk drinking was defined as alcohol consumption of ≥7 glasses at a sitting for men, and ≥5 glasses for women. After adjusting for confounding factors, a polychotomous logistic regression analysis was performed to assess the association of drinking patterns with IFG and DM.

Results

For men, high-risk drinking was associated with higher odds ratios (ORs) of IFG (2–4/month, OR 1.51; 95% confidence interval [CI], 1.13–2.04; 2–3/week, OR 1.79; 95% CI, 1.38–2.33; and ≥4/week, OR 2.24; 95% CI, 1.65–3.03) and of DM (2–4/month, OR 2.12; 95% CI, 1.20–3.77; 2–3/week, OR 1.78; 95% CI, 1.05–3.03; and ≥4/week, OR 2.98; 95% CI, 1.72–5.17). For women, high-risk drinking was associated with higher risk of IFG (2–4/month, OR 1.51; 95% CI, 1.04–2.21; 2–3/week, OR 3.19; 95% CI, 2.20–4.64; and ≥4/week, OR 2.23; 95% CI, 1.23–4.06), but not of DM, compared with non-high-risk drinkers who consumed alcohol ≤1 day/month. Non-high-risk drinkers who consumed alcohol ≥4 days/week had higher ORs of DM in men, but lower ORs of DM in women compared with non-high risk drinkers who consumed alcohol ≤1 day/month.

Conclusions

Compared with non-high-risk alcohol drinking, even occasional high-risk alcohol drinking was associated with a higher risk of IFG in men and women, and DM in men. Nearly daily non-high-risk alcohol drinking was associated with a higher risk of DM in men and lower risk of DM in women.

Serum high-sensitivity C-reactive protein as a biomarker in patients with metabolic syndrome: evidence-based study with 7284 subjects

BACKGROUND/OBJECTIVES

Metabolic syndrome (MetS) is characterized by abdominal obesity, dyslipidemia, hypertension and glucose intolerance, and is associated with an increased risk of developing cardiovascular disease (CVD), diabetes mellitus and related diseases. Circulating levels of inflammatory markers such as C-reactive-protein (CRP) have reported to be associated with CVD. Against this background, the prevalence of MetS is increasing globally, and thus predictive biomarkers are required for identification of MetS patients at an increased risk. Here we explored the value of CRP as a biomarker in 7284 subjects and also investigated which features of MetS have the greatest association with the hs-CRP level.

SUBJECTS/METHODS

The subjects were recruited from the Mashhad stroke and heart atherosclerotic disorder study. Anthropometric factors and biochemical parameters (for example, high-sensitivity CRP (hs-CRP), high-density lipoprotein/low-density lipoprotein, triglycerides (TGs) and fasting blood glucose (FBG)) were determined. Univariate and multivariate analyses were conducted to evaluate the association of hs-CRP and MetS.

RESULTS

Our results illustrated that the concentration of serum hs-CRP increased progressively with the number of MetS components, and subjects who fulfilled the criteria of MetS for waist circumference, TGs, blood pressure and FBG were found to have hs-CRP of 0.53, 0.38, 0.34 and 0.71 mg/l, respectively, higher than matched-subjects. Importantly, FBG had the greatest association with hs-CRP concentration.

CONCLUSIONS

Our data demonstrate the significant association between MetS components with hs-CRP, indicating that this association was cumulative by increasing the number of the defining features of MetS, supporting further studies to explore the value of emerging marker as a novel method for detecting individuals at high risk of developing MetS.

The effect of mosapride (5HT-4 receptor agonist) on insulin sensitivity and GLUT4 translocation

AIMS

We investigated the effect of mosapride, 5HT-4 (5-hydroxytryptamine) agonist, on blood glucose level and insulin sensitivity in subjects with impaired glucose tolerance (IGT) and conducted an in vitro study to evaluate the action mechanism.

METHODS

Thirty IGT patients were randomly assigned to receive either mosapride or placebo for 2 weeks. Biochemical profiles and insulin sensitivity index from euglycemic hyperinsulinemic clamp test were assessed before and after treatment. In cultured myotubes from human skeletal muscle cells, insulin- and mosapride-induced GLUT4 translocation and tyrosine phosphorylation of IRS-1 were determined.

RESULTS

After 2 weeks of treatment with mosapride, glucose disposal rates were significantly increased up to those of control (mosapride 5.47+/-1.72 vs 7.06+/-2.13, P=0.004, placebo 5.42+/-1.85 vs 5.23+/-1.53mgkg(-1)min(-1)). Fasting plasma glucose (FPG) and insulin levels were decreased. Mosapride increased the contents of GLUT4 in plasma membrane representing the increased recruitment of glucose transporters from intracellular pool. While insulin treatment on human skeletal muscle cell resulted in an increased tyrosine phosphorylation of IRS-1, mosapride did not have any effect.

CONCLUSIONS

Mosapride is effective in decreasing FPG without stimulating insulin secretion in IGT subjects, possibly by inducing GLUT4 translocation in skeletal muscles.

Cardiometabolic risk among African American women: a pilot study

OBJECTIVE

This study aimed to determine the associations of the Homeostatic Model of Assessment-insulin resistance (HOMA-ir), acanthosis nigricans, high-sensitivity C-reactive protein (hs-CRP), and plasminogen activator inhibitor-1 (PAI-1) with 2 of the commonly used definitions of metabolic syndrome (Adult Treatment Panel III [ATP III] and International Diabetes Federation [IDF]) among reproductive-age, healthy, free-living African American women.

METHODS

A pilot study with a cross-sectional design examined 33 African American women aged 20 to 46 years (mean [SD], 31.24 [7.25] years) for the presence of metabolic syndrome determined by ATP III and IDF criteria, insulin resistance (HOMA-ir and/or acanthosis nigricans), degree of inflammation (hs-CRP), and presence of dysfibrinolysis (PAI-1).

RESULTS

HOMA-ir identified insulin resistance in 27 (81.8%) women, whereas the presence of acanthosis nigricans indicated that 16 (48%) of these women manifested insulin resistance. Metabolic syndrome was found in 7 women (21.2%) by ATP III or in 9 (27.3%) women by IDF criteria. Bivariate correlations showed associations between HOMA-ir and waist circumference, body mass index (BMI), acanthosis nigricans, and the ATP III and IDF definitions for metabolic syndrome. Plasminogen activator inhibitor-1 was significantly correlated with waist circumference, BMI, fasting glucose, HOMA-ir, and ATP III. Both HOMA-ir and PAI-1 were significantly and negatively correlated with high-density lipoprotein cholesterol. High-sensitivity CRP was significantly correlated with BMI and 2-hour postglucose.

CONCLUSION

Both dysfibrinolysis (PAI-1 levels) and insulin resistance (HOMA-ir), when individually regressed on the ATP III definition of metabolic syndrome, explained 32% and 29% of the respective variance. The addition of HOMA-ir measurement may significantly improve early recognition of cardiometabolic risk among reproductive-age African American women who have not yet met the criteria for the ATP III or IDF definitions of metabolic syndrome. Likewise, acanthosis nigricans is potentially a clinically significant screening tool when used to determine early recognition of insulin resistance and/or cardiometabolic risk among this population. African American women's risk for cardiovascular disease is likely underestimated based on the sole use of ATP III criteria for diagnosis of metabolic syndrome. Clinicians should consider a broader definition of risk than that contained within ATP III. Inclusion of biomarkers of inflammation and dysfibrinolysis, along with measures of insulin resistance, may add to early detection of cardiometabolic risk and ultimate reduction in cardiovascular health disparities among African American women.

Glucoregulatory physiology in subjects with low-normal, high-normal, or impaired fasting glucose

OBJECTIVE

We determined whether variations in fasting plasma glucose (FPG) within the nondiabetic range represent differences in insulin action or secretion.

SUBJECTS AND METHODS

Using results of the 75-g oral glucose tolerance test, we classified 39 adults (body mass index range 20-56 kg/m2) as having normal fasting glucose (NFG, <100 mg/dl, n = 24) or impaired fasting glucose (IFG, 100-125 mg/dl, n = 15). The NFG group was subdivided into low-NFG (<90 mg/dl, n = 11) and high-NFG (90-99 mg/dl, n = 13). The 2-h oral glucose tolerance test plasma glucose value was used to assign normal or impaired glucose tolerance (IGT) status. Insulin sensitivity was assessed by hyperinsulinemic euglycemic clamp, quantitative insulin sensitivity check index, and homeostasis model assessment of insulin resistance; beta-cell function was assessed by calculating the insulinogenic index, homeostasis model assessment, and the disposition index.

RESULTS

Compared with low-NFG subjects, insulin sensitivity and glucose tolerance were lower among persons with isolated IFG and combined IFG-IGT. The hyperinsulinemic euglycemic clamp (micromol/kg x min(-1)/pmol/liter) was 0.109 +/- 0.011 in low-NFG subjects, 0.088 +/- 0.009 in IFG subjects (P = 0.04), and 0.022 +/- 0.003 in IFG-IGT subjects (P = 0.0014). The spread in FPG from 70-125 mg/dl was associated with a greater than 3-fold difference in insulin sensitivity. Compared with low-NFG subjects, the disposition index decreased by 32.8% in high-NFG subjects (P = 0.08), by 45.6% in subjects with isolated IFG (P < 0.02), and by 49.8% (P < 0.02) in those with combined IFG-IGT.

CONCLUSION

Compared with persons with low-NFG, those with IFG or combined IFG-IGT have significant alteration of glucoregulatory physiology, whereas high-NFG (pre-prediabetes) status might portend nascent glucoregulatory perturbations.

Insulin sensitivity and first-phase insulin secretion in obese Chinese with hyperglycemia in 30 and/or 60 min during glucose tolerance tests

The purpose of this study was to investigate insulin sensitivity and first-phase insulin secretion in obesity with hyperglycemia in 30 and/or 60 min during oral glucose tolerance (OGTT, glucose > or = 11.1 mmol/l, post-loading hyperglycemia, PLH) in Chinese population. A total of 196 nondiabetic subjects were included in the present study, among them 99 had normal glucose tolerance (NGT, subdivided into 32 lean NGT and 67 obese NGT), 74 had obesity with impaired glucose tolerance (IGT) and 23 had obesity with PLH. A standard 75-g oral glucose tolerance test was performed after fasting and at 30 min, 1, 2 and 3 h. Insulin sensitivity index (S(I)) was assessed by the Bergman's minimal model method with frequently sampled intravenous glucose tolerance test (FSIGTT), insulin secretion was determined by acute insulin response to glucose (AIRg). The disposition index (DI), the product of AIRg and S(I) was used to determine whether AIRg was adequate to compensate for insulin resistance. S(I) was significantly equally lower in three obese subgroups. AIRg was significantly increased in obese NGT as compared with lean NGT controls, and reduced to the same extent in IGT and PLH subjects. There was no significant difference among lean NGT, IGT and PLH subjects. DI value was reduced from obese NGT individuals, IGT and PLH subjects had a similar lower level of DI. In conclusion, our present results demonstrated that the pathophysiological basis of obese subjects with PLH were clearly insulin resistance and defective in first-phase insulin secretion as that in IGT subjects in Chinese population.

The effect of lowering the threshold for diagnosis of impaired fasting glucose

PURPOSE

The aim of this study was to evaluate the effect of lowering the fasting plasma glucose (FPG) criteria for impaired fasting glucose (IFG) on the prevalence of IFG and the risk for the development of diabetes associated with IFG in Koreans.

MATERIALS AND METHODS

A total of 7,211 subjects who had normal glucose tolerance (NGT) or IFG were recruited. Subjects were evaluated at baseline and after two years follow up. Clinical data including total cholesterol, FPG and blood pressure were examined.

RESULTS

Lowering the criteria for IFG from 6.1 mmol/L (110 mg/dL) to 5.6 mmol/L (100 mg/dL) increased the prevalence of IFG from 6.6% (494 subjects) to 24.4% (1829 subjects). After the 2 years follow up period, 91 subjects (1.3%) developed diabetes. Twenty one (0.3%) subjects developed diabetes among 5,382 NGT subjects and 70 (3.8%) subjects developed diabetes among 1,829 IFG (5.6-7.0 mmol/L) subjects. Lowering the IFG threshold from 6.1 mmol/L to 5.6 mmol/L resulted in a 18.4% decrease in specificity and 23.9% increase in sensitivity for predicting diabetes. The baseline FPG for predicting the development of diabetes after 2 years at a point on the receiver operating characteristic curve that was closest to the ideal 100% sensitivity and 100% specificity was 5.7 mmol/L (103 mg/dL).

CONCLUSION

Lowering the FPG criterion of IFG should have benefits in predicting new onset type 2 diabetes mellitus in Koreans. The economic and health benefits of applying the new IFG criteria should be evaluated in future studies.

Contributions of beta-cell dysfunction and insulin resistance to the pathogenesis of impaired glucose tolerance and impaired fasting glucose

Impaired glucose tolerance (IGT) and impaired fasting glucose (IFG) are intermediate states in glucose metabolism that exist between normal glucose tolerance and overt diabetes. Epidemiological studies demonstrate that the two categories describe distinct populations with only partial overlap, suggesting that different metabolic abnormalities characterize IGT and IFG. Insulin resistance and impaired beta-cell function, the primary defects observed in type 2 diabetes, both can be detected in subjects with IGT and IFG. However, clinical studies suggest that the site of insulin resistance varies between the two disorders. While subjects with IGT have marked muscle insulin resistance with only mild hepatic insulin resistance, subjects with IFG have severe hepatic insulin resistance with normal or near-normal muscle insulin sensitivity. Both IFG and IGT are characterized by a reduction in early-phase insulin secretion, while subjects with IGT also have impaired late-phase insulin secretion. The distinct metabolic features present in subjects with IFG and IGT may require different therapeutic interventions to prevent their progression to type 2 diabetes.