Estimating the Rates of Undiagnosed Prediabetes and Diabetes Among People Experiencing Homelessness

OBJECTIVES

The rising prevalence of type 2 diabetes (T2D) in Canada poses a significant health challenge. Despite the convenience of screening for diabetes with glycated hemoglobin concentration, people experiencing homelessness (PEH) often face barriers to accessing diabetes screening, potentially leading to underdiagnosis. In this study, we aim to assess the prevalence of undiagnosed diabetes among PEH in Calgary, Alberta, and contribute insights for planning healthcare services and public health initiatives.

METHODS

Four screening clinics were held, and participants were recruited through posters and word of mouth. Participants underwent point-of-care glycated hemoglobin (A1C) testing using the Siemens DCA Vantage point-of-care analyzer. Descriptive statistics were used to identify the proportions of prediabetes and diabetes, whereas CanRisk survey scores were used to identify the pre-test probability of diabetes.

RESULTS

The mean age of participants (n=102) was 47.6 years, and the self-reported causes of homelessness among the participants were diverse, including: housing and financial issues (n=53), interpersonal and family issues (n=35), and health or corrections-related factors (n=27). The average A1C was 5.60% (standard deviation 0.57%), with 5 values in the diabetes range and 12 in the prediabetes range, for a total of 17 participants found to have previously undiagnosed dysglycemia.

CONCLUSIONS

The high rate of undiagnosed prediabetes and diabetes among people experiencing homelessness reflects at least what is already seen in the general population in Canada. More resources are required to reduce the barriers to screening for diabetes among this population.

Changes in Prediabetes Status Among Adults During a 6-Month Randomized Placebo-controlled Supplement Trial With Nutrition and Lifestyle Counselling and 6-Month Follow-up

OBJECTIVES

In this work, we present an exploratory within-trial analysis of the changing prevalence of prediabetes in response to nutrition and lifestyle counselling provided as part of a randomized placebo-controlled supplement trial with follow-up. We aimed to identify factors associated with changing glycemia status.

METHODS

Participants (n=401) in this clinical trial were adults with a body mass index (BMI) of ≥25 kg/m2 and prediabetes (defined by the American Diabetes Association as a fasting plasma glucose [FPG] of 5.6 to 6.9 mmol/L or a glycated hemoglobin [A1C] of 5.7% to 6.4%) within 6 months before trial entry. The trial consisted of a 6-month randomized intervention with 2 dietary supplements and/or placebo. At the same time, all participants received nutrition and lifestyle counselling. This was followed by a 6-month follow-up. Glycemia status was assessed at baseline and at 6 and 12 months.

RESULTS

At baseline, 226 participants (56%) met a threshold for prediabetes, including 167 (42%) with elevated FPG and 155 (39%) with elevated A1C. After the 6-month intervention, the prevalence of prediabetes decreased to 46%, driven by a reduction in prevalence of elevated FPG to 29%. The prevalence of prediabetes then increased to 51% after follow-up. Risk of prediabetes was associated with older age (odds ratio [OR], 1.05; p<0.01), BMI (OR, 1.06; p<0.05), and male sex (OR, 1.81; p=0.01). Participants who reverted to normoglycemia had greater weight loss and lower baseline glycemia.

CONCLUSIONS

Glycemia status can fluctuate over time and improvements can be gained from lifestyle interventions, with certain factors associated with a higher likelihood of reverting to normoglycemia.

Predisposition to Type 2 Diabetes in Aspects of the Glycemic Curve and Glycated Hemoglobin in Healthy, Young Adults: A Cross-sectional Study

OBJECTIVES

Our aim in this study was to identify predictors for diabetes among the characteristics of the glycemic curve and glycated hemoglobin (A1C) in healthy, young adults.

METHODS

We used a cross-sectional study to establish predictors for diabetes based on earlier studies and evaluated occurrence of the condition in 81 healthy, young adult subjects. These volunteers underwent analysis of fasting plasma glucose, oral glucose tolerance test plasma glucose, A1C, and inflammatory markers (leukocytes, monocytes, and C-reactive protein). The nonparametric Mann-Whitney U test, Fisher's exact test, chi-square test, Kruskal-Wallis test, and multiple-comparisons test were used to analyze the data.

RESULTS

We studied 2 age groups, homogeneous in terms of family history of diabetes: one group ranged in age from ≥18 to <28 years (median 20 years; body mass index [BMI] 24 kg/m2) and the other group ranged in age from ≥28 to <45 years (median 35 years; BMI 24 kg/m2). The older group had a higher incidence of predictors (p=0.0005) and was associated with the predictors 30-minute blood glucose ≥164 mg/dL (p=0.0190), 60-minute blood glucose ≥125 mg/dL (p=0.0346), and A1C ≥5.5% (p=0.0162), with a monophasic glycemic curve (p=0.007). The younger group was associated with the 2-hour plasma glucose predictor ≥140 mg/dL (p=0.014). All subjects had fasting glucose in the normal range.

CONCLUSIONS

Healthy, young adults may already have predictors of diabetes, identified mainly by aspects of the glycemic curve and A1C, but at more modest levels than those with prediabetes.

Effects of Prediabetes on Long-term Risk of Developing Cardiac Events in Patients Presenting With Acute Coronary Syndrome

OBJECTIVES

The aim of this work was to identify the long-term risk associated with prediabetes and developing subsequent cardiac events in patients presenting with acute coronary syndrome (ACS) at a tertiary health-care centre.

METHODS

In this retrospective cohort study, we analyzed patients admitted with ACS between January and December 2013. Two hundred thirty patients with prediabetes were matched to a comparison cohort of patients with no diabetes based on age, sex, and diagnosis code of the International Statistical Classification of Diseases and Related Health Problems---10th revision. The primary outcome was incidence of ACS readmission over a 5-year period.

RESULTS

There were 46 (20%) readmissions for ACS in the prediabetes cohort and 33 (14.3%) in the no-diabetes cohort. Univariable conditional logistic regression showed that prediabetes was not a significant risk factor for ACS readmission (odds ratio, 1.481; 95% confidence interval, 0.909 to 2.414; p=0.115). After accounting for other major risk factors for coronary disease, prediabetes was not shown to be a significant risk factor for ACS readmission (odds ratio, 1.333; 95% confidence interval, 0.795 to 2.233; p=0.276).

CONCLUSIONS

Among patients presenting with ACS, prediabetes was not associated with increased risk of readmission for subsequent cardiac events compared with patients with no diabetes after 5 years of follow-up. A longer follow-up duration is needed.

Changes in Cognition and Brain Function After 26 Weeks of Progressive Resistance Training in Older Adults at Risk for Diabetes: A Pilot Randomized Controlled Trial

OBJECTIVES

Type 2 diabetes is associated with deficits in cognition and brain health. Individuals with at least 1 risk factor for diabetes (i.e. obesity, prediabetes) already experience some neurocognitive impairment and are at risk for further decline. One way to combat these deficits is through exercise, but its is unknown whether resistance exercise can improve these functions in this at-risk group.

METHODS

This study was a pilot randomized controlled trial. Participants were 60 to 80 years of age and had prediabetes (fasting capillary glucose 6.1 to 6.9 mmol/L) and/or were overweight or obese (body mass index ≥25). Participants completed resistance training or balance and stretching exercise (control) thrice weekly for 6 months. Neuropsychological tests were used to assess cognitive ability, whereas functional magnetic resonance imaging was used to examine brain activation patterns.

RESULTS

Resistance training led to improvements in task-switching, attention and conflict resolution, as well as improved patterns of brain activation that may mimic healthy older adults.

CONCLUSIONS

Resistance exercise may serve as an effective behavioural strategy to improve neurocognition in older adults at risk for type 2 diabetes. A large-scale powered trial is needed to further explore these findings.

Interindividual variation in cardiometabolic health outcomes following 6 months of endurance training in youth at risk of type 2 diabetes mellitus

This study determined the interindividual variation in the cardiometabolic response to 6 months of moderate or vigorous intensity exercise training (ET) among youth at risk for type 2 diabetes mellitus. Youth were randomized to moderate intensity ET (45-55% heart rate reserve; n = 31), vigorous intensity ET (70-85% heart rate reserve; n = 37), or control (n = 36). Only those attending ≥70% of ET sessions were included. Cardiometabolic measures included insulin sensitivity, hepatic triglyceride content, visceral adipose area, and cardiorespiratory fitness. The contribution of ET to interindividual variation was determined using the standard deviation of individual responses (SD_IR) and considered meaningful if the SD_IR surpassed the smallest worthwhile difference (SWD), calculated as 0.2 × the standard deviation of the control group baseline values. ET meaningfully contributed to the interindividual variation among changes in peak oxygen uptake following moderate (SD_IR: 2.04) and vigorous (SD_IR: 3.43) ET (SWD: 1.17 mL·kg fat free mass^-1·min^-1), body fat percentage and hepatic triglyceride content following moderate-intensity ET (SD_IR: 1.64, SWD: 1.05%; SD_IR: 10.08, SWD: 1.06%, respectively), and visceral fat mass following vigorous ET (SD_IR: 11.06, SWD: 7.13 cm²). Variation in the changes in insulin sensitivity were not influenced by ET. The contribution of ET to interindividual variation appears to be influenced by the desired outcome and prescribed intensity. Trial registration at ClinicalTrials.gov (identifier no.: NCT00755547). Novelty: The contribution of exercise to interindividual variation following training depends on the outcome and exercise intensity. Increasing exercise intensity does not systematically reduce non-response among youth at risk for type 2 diabetes.

Feasibility of a 26-Week Exercise Program to Improve Brain Health in Older Adults at Risk for Type 2 Diabetes: A Pilot Study

OBJECTIVES

Older adults at risk for type 2 diabetes (i.e. overweight individuals or those with prediabetes) experience accelerated cognitive and brain deficits. Aerobic training is known to improve these deficits, but the effects of resistance training are relatively unknown. Before conducting a large-scale, randomized, controlled trial to assess the effects of resistance training, we first conducted a pilot feasibility study to examine recruitment, attendance and retention rates in this population.

METHODS

Program participants (aged 60 to 80 years, mean age 68.7±5.7 years, 50% females) at risk for type 2 diabetes (body mass index of ≥25 or fasting blood glucose of 6.1 to <7 mmol/L) underwent 26 weeks of thrice-weekly progressive resistance training (n=13) or balance-and-tone exercises (control group, n=11). Recruitment, attendance and retention rates were recorded, and study feedback from program participants and research assistants was collected via questionnaires.

RESULTS

We recruited 72 older adults (total number enrolled = 24) over 17 months. Program retention and attendance were 95.8% and 84.4%, respectively. Program participants and research assistants expressed a high level of study enjoyment, and suggestions on how to improve study procedures were provided.

CONCLUSIONS

Based on our findings, a large-scale study in this at-risk group of older adults is feasible, and key strategies to improving future trials were identified.

Intricacies of the endothelin system in human obesity: role in the development of complications and potential as a therapeutic target

Activation of the vascular endothelin-1 (ET-1) system is a key abnormality in vascular dysfunction of human obesity, especially in patients developing complications, such as the metabolic syndrome, diabetes, and atherosclerosis. Vascular insulin resistance, an increased insulin-stimulated endothelial production of ET-1 combined with impaired nitric oxide availability, is the hallmark of obesity-related vasculopathy, but dysregulated adipokine release from obese adipose tissue may contribute to the predominance of ET-1-dependent vasoconstriction. ET-1, in turn, might determine unhealthy obese adipose tissue expansion, with visceral and perivascular adipose tissue changes driving the release of inflammatory cytokines and atherogenic chemokines. In addition, ET-1 might also play a role in the development of the metabolic complications of obesity. Studies have shown inhibition of lipoprotein lipase activity by ET-1, with consequent hypertriglyceridemia. Also, ET-1 in pancreatic islets seems to contribute to beta cell dysfunction, hence affecting insulin production and development of diabetes. Moreover, ET-1 may play a role in nonalcoholic steatohepatitis. Recent clinical trials using innovative design have demonstrated that antagonism of ET-type A receptors protects against some complications of obesity and diabetes, such as nephropathy. These findings encourage further investigation to evaluate whether targeting the ET-1 system could afford better protection against other consequences of the obesity epidemic.

Long-Term Physical Activity Levels After the End of a Structured Exercise Intervention in Adults With Type 2 Diabetes and Prediabetes: A Systematic Review

OBJECTIVES

Randomized, controlled trials have shown that exercise interventions reduce the incidence of type 2 diabetes in people with impaired glucose tolerance, and improve glycemic control, body composition and cardiorespiratory fitness in people with type 2 diabetes. We undertook the present systematic review to determine the extent to which participants in structured exercise trials continue to be physically active after the end of the interventions.

METHODS

We systematically searched MEDLINE, EMBASE, CINAHL, SPORTDiscus and Cochrane Central Register of Controlled Trials for randomized, controlled trials that reported objective or self-reported physical activity levels in people with type 2 diabetes or prediabetes a minimum of 3 months after the end of a structured exercise intervention. This systematic review was registered on PROSPERO (PROSPERO CRD42018089468).

RESULTS

Of 14,649 articles retrieved, 5 randomized, controlled trials (including 549 participants) were included in this systematic review. One study revealed significant improvements in self-reported physical activity levels in the intervention group compared with the control group 1, 3 and 5 years after baseline assessments, and decreased waist circumference, weight and body mass index at 1 year, but not 3 or 5 years. The 4 remaining studies did not find between-group differences at follow-up timepoints between 6 months and 3 years.

CONCLUSIONS

Future research should report physical activity levels at follow up to determine whether participation in a structured exercise intervention results in sustained increased physical activity levels. In addition, interventions should be evaluated for their effectiveness in improving adherence to long-term physical activity.

Self-Compassion, Adaptive Reactions and Health Behaviours Among Adults With Prediabetes and Type 1, Type 2 and Gestational Diabetes: A Scoping Review

Engaging in health-promoting behaviours has health benefits for people with prediabetes or diabetes. People experience negative affect after diagnoses, which can impede self-regulation of health behaviours. Self-compassion, extending care to oneself in difficult times, can mitigate negative affect and promote self-regulation. This scoping review explored the relationship between self-compassion and adaptive affect, self-regulation and engagement in health-promoting/management behaviours among people with prediabetes or diabetes. We conducted a scoping literature search from 6 databases for studies and conference abstracts. Randomized controlled trials and cross-sectional, longitudinal, observational and qualitative designs focused on self-compassion were included. Eligible studies included adults with diabetes (prediabetes, type 1, type 2 and gestational), measured self-compassion using a validated Self-Compassion Scale (quantitative) or included the 3 components (qualitative) and investigated: negative affect, health promoting/management behaviours and/or self-regulation. After deduplication, 5,338 quantitative and 953 qualitative abstracts, and 18 conference proceedings were screened leaving 35 articles. Full-text screening retained 11 eligible studies (6 cross-sectional studies, 2 randomized controlled trials, 2 longitudinal studies and 1 qualitative study). Higher self-compassion was associated with decreased negative affect in 9 studies and was positively associated with well-being in 1 cross-sectional study. Self-compassion led to decreased negative affect and improved blood glucose in 2 interventions. Five studies found positive associations between self-compassion and health-promoting/management behaviours. One qualitative study found self-compassion to benefit affective reactions, health-promoting behaviours and self-regulation. This review shows that self-compassion is linked to adaptive behavioural and affective responding among people with prediabetes and diabetes, and the need for more research on self-compassion and self-regulation in these populations.

Hypoglycaemic effect of catalpol in a mouse model of high-fat diet-induced prediabetes

Type 2 diabetes mellitus is a major health problem and a societal burden. Individuals with prediabetes are at increased risk of type 2 diabetes mellitus. Catalpol, an iridoid glycoside, has been reported to exert a hypoglycaemic effect in db/db mice, but its effect on the progression of prediabetes is unclear. In this study, we established a mouse model of prediabetes and examined the hypoglycaemic effect, and the mechanism of any such effect, of catalpol. Catalpol (200 mg/(kg·day)) had no effect on glucose tolerance or the serum lipid level in a mouse model of impaired glucose tolerance-stage prediabetes. However, catalpol (200 mg/(kg·day)) increased insulin sensitivity and decreased the fasting glucose level in a mouse model of impaired fasting glucose/impaired glucose tolerance-stage prediabetes. Moreover, catalpol increased the mitochondrial membrane potential (1.52-fold) and adenosine triphosphate content (1.87-fold) in skeletal muscle and improved skeletal muscle function. These effects were mediated by activation of the insulin receptor-1/glucose transporter type 4 (IRS-1/GLUT4) signalling pathway in skeletal muscle. Our findings will facilitate the development of a novel approach to suppressing the progression of diabetes at an early stage. Novelty Catalpol prevents the progression of prediabetes in a mouse model of prediabetes. Catalpol improves insulin sensitivity in skeletal muscle. The effects of catalpol are mediated by activation of the IRS-1/GLUT4 signalling pathway.

The contribution of phosphodiesterases to cardiac dysfunction in rats with metabolic syndrome induced by a high-carbohydrate diet

Metabolic syndrome (MetS) is a cluster of risk factors, including insulin resistance among others, underlying the development of diabetes and (or) cardiovascular diseases. Studies show a close relationship between cardiac dysfunction and abnormal cAMP catabolism, which contributes to pathological remodelling. Stimulating the synthesis of cAMP via suppression of phosphodiesterases (PDEs) has positive therapeutic effects. Therefore, we examined the role of PDEs on cardiac dysfunction in high-carbohydrate diet-induced MetS rats. We first demonstrated significantly high expression levels of PDE3 and PDE4, the most highly expressed subtypes, together with depressed cAMP levels in heart tissue from MetS rats. Second, we demonstrated the activity of these PDEs by using either their basal or PDE inhibitor-induced intracellular levels of cAMP and Ca²⁺, the transient intracellular Ca²⁺ changes under electrical stimulation, isometric contractions in papillary muscle strips and some key signalling proteins (such as RyR2, PLN, PP1A, and PKA) are responsible for the Ca²⁺ homeostasis in isolated cardiomyocytes from MetS rats. The clear recovery in decreased basal cAMP levels, increased protein expression levels of PDE3 and PDE4, and positive responses in the altered Ca²⁺ homeostasis to PDE inhibitors as seen in our study can provide important insights about the roles of activated PDEs in depressed contractile activity in hearts from MetS rats.

Do Cultural and Psychosocial Factors Contribute to Type 2 Diabetes Risk? A Look Into Vancouver's South Asian Community

OBJECTIVES

South Asian immigrants are generally healthy upon arrival, but precipitously develop diabetes after immigration. Whether cultural and psychosocial factors contribute to diabetes risk in this ethnic minority group remains unclear. Existing prediction models focus primarily on clinical and lifestyle factors. This study explored whether nontraditional risk factors are incrementally predictive beyond traditional risk factors in this South Asian community.

METHODS

In this cross-sectional study, we recruited 425 South Asian adults attending Sikh and Hindu temples in Metro Vancouver between July 2013 and June 2014. We measured traditional risk factors, including glycated hemoglobin (A1C), apolipoprotein B, systolic and diastolic blood pressure (BP), waist circumference, weight, body mass index (BMI), dietary patterns and physical activity level. Self-report questionnaires assessed cultural and psychosocial factors, including acculturation, dinnertime (timing of the evening meal), religion and depressive symptoms. We constructed a penalized multivariable linear model with A1C level using the least absolute shrinkage and selection operator (LASSO) approach to overcome issues of overfitting and reduce prediction error of previous diabetes prediction models.

RESULTS

The LASSO model selected 24 risk factors for the optimal model to predict glycemic control. Results revealed that higher degree of acculturation (p=0.007), later dinnertime (p=0.01) and greater depressive symptoms (p=0.038) are important factors in diabetes risk in addition to traditional risk factors (fruit/vegetable/fibre intake, BMI and systolic BP).

CONCLUSIONS

Nontraditional factors, such as cultural practices and emotional functioning, are also important predictors of diabetes risk and should be considered when culturally tailoring diabetes prevention programs.

Effect of Acute Aerobic Exercise and Rapamycin Treatment on Autophagy in Peripheral Blood Mononuclear Cells of Adults With Prediabetes

OBJECTIVES

Recently, a malfunction of the autophagic pathway has been implicated with impaired glucose metabolism and progression from prediabetes to type 2 diabetes. The aims of this study were to investigate the effect of exercise and rapamycin (RAPA) treatment on the autophagic process in peripheral blood mononuclear cells (PBMCs) from people with prediabetes compared with control subjects.

METHODS

Two groups matched for age and sex served as participants and included 6 participants with prediabetes (42.4±11.7 years) and 6 control subjects (44.4±11.9 years). Participants exercised at 50% of maximal oxygen consumption for 60 min with 5 min of rest interspersed every 20 min. PBMCs were isolated pre-exercise, immediately postexercise and 4 h after exercise recovery. Additional PBMCs were incubated for 24 h and either exposed to bafilomycin, rapamycin with bafilomycin (RAPA), or no treatment with vehicle (dimethyl sulfoxide). Proteins and mRNA were analyzed via western blot and quantitative real-time polymerase chain reaction, respectively.

RESULTS

Exercise increased autophagy immediately postexercise and recovered 4 h after exercise in control participants but not in participants with prediabetes. Autophagy increased in PBMCs from people with prediabetes and control participants after RAPA treatment; however, a significantly impaired autophagic response was observed in people with prediabetes when compared with control subjects.

CONCLUSIONS

Our results indicate an impairment in autophagic flux in PBMCs from people with prediabetes when compared with control subjects in response to both exercise and RAPA treatment. Future methods of autophagic upregulation should be investigated to spare malfunctions in autophagy in people with prediabetes.

Associations Between Depressive Symptoms and Indices of Obesity in Adults With Prediabetes and Normal Blood Glucose Levels: Results From the Emotional Health and Wellbeing Study

OBJECTIVES

This study describes associations between depressive symptoms and indices of obesity in a community sample of adults with prediabetes. The strengths of these associations were compared to those observed in individuals with normal blood glucose levels.

METHODS

Cross-sectional data came from the baseline assessment of the Emotional Health and Wellbeing Study. Participants were classified as meeting the American Diabetes Association criteria for prediabetes (n=1,152) or normal blood glucose levels (n=1,567). Indices of obesity included body mass index, waist circumference and fat mass index.

RESULTS

After adjusting for sociodemographic covariates, greater depressive symptoms were associated with greater body mass index, waist circumference and fat mass index. These associations were stronger in participants with prediabetes compared to participants with normal blood glucose levels. The pattern of results observed for body mass index and waist circumference held after controlling for self-reported fruit and vegetable consumption, physical activity and sedentary time, but the strength of the interaction was attenuated for fat mass index.

CONCLUSIONS

Depressive symptoms were more strongly associated with indices of obesity in people with prediabetes than in people with normal blood glucose levels. Depressive symptoms may be a barrier to weight management in people with prediabetes.

Optimal Glycated Hemoglobin Cutoff Point for Diagnosis of Type 2 Diabetes in Iranian Adults

OBJECTIVES

The aim of this study was to evaluate the capability of glycated hemoglobin (A1C) levels to be a tool for identifying Iranian adults with diabetes and prediabetes.

METHODS

In a cross-sectional population-based study, 1,813 adults, men and women 35 to 75 years of age and without a history of diabetes and hemoglobinopathies, were included. Fasting blood glucose and A1C levels were obtained. According to the criteria of the American Diabetes Association, participants were categorized into 3 groups: newly diagnosed diabetes, prediabetes and healthy subjects. The optimal cutoff point for A1C in diabetes and prediabetes diagnosis was determined by studying the sensitivity and specificity of different cutoff points for A1C, while using different levels of fasting blood glucose as the gold standard.

RESULTS

Participants with newly diagnosed diabetes were significantly older than subjects with prediabetes and healthy subjects (mean [± SD] 47.3±12.9, 44.6±13.0 and 39.2±14.1 years, respectively) and also had higher body mass indexes. As expected, the levels of fasting blood glucose (8.79±2.24, 6.01±0.38 and 4.97±0.4 mmol/L) and A1C (6.55±1.4%, 5.61±0.61% and 5.28±0.59%) were significantly different in the groups (p<0.001). The optimal cutoff point for A1C to predict prediabetes was 5.5% (sensitivity of 60.5% and specificity of 63.1%) and for diabetes was 5.9% (sensitivity of 66.7% and specificity of 81.2%). ADA cutoff points for prediabetes and diabetes detection yielded a sensitivity of 45.2% and 39.8%, respectively.

CONCLUSIONS

The findings suggest the necessity of determining the A1C cutoffs for detecting diabetes or prediabetes in each region's population. They also suggest that the combination of these A1C cutoffs with fasting blood glucose levels are required to determine diabetes and prediabetes more accurately.

Plasma Palmitoyl-Carnitine (AC16:0) Is a Marker of Increased Postprandial Nonesterified Incomplete Fatty Acid Oxidation Rate in Adults With Type 2 Diabetes

OBJECTIVES

Enhanced mitochondrial fatty acid utilization is known to increase radical oxidative stress and induce insulin resistance. An increased level of plasma acylcarnitine (AC) has been proposed to indicate mitochondrial energy substrate overload, a possible mechanism leading to insulin resistance. The aim of our study was to determine fasting and postprandial plasma acetyl-carnitine (AC2:0), palmitoyl-carnitine (AC16:0), oleoyl-carnitine (AC18:1) and linoleoyl-carnitine (AC18:2) levels and their relationships with plasma nonesterified fatty acid appearance and oxidation rates and insulin sensitivity in participants with type 2 diabetes and normoglycemic offspring of 2 parents with type 2 diabetes (FH+) compared to healthy participants without family histories of type 2 diabetes (FH-).

METHODS

All participants underwent 3 metabolic protocols: 1) a euglycemic hyperinsulinemic clamp at fasting; 2) a 6-hour steady-state oral standard liquid meal and 3) an identical 6-hour steady-state meal intake study with a euglycemic hyperinsulinemic clamp. AC levels were measured by liquid chromatography with tandem mass spectrometry, and fatty acid oxidation (FAO) rates were measured by stable isotopic tracer techniques with indirect respiratory calorimetry.

RESULTS

During the insulin clamp at fasting, AC16:0 was significantly higher in the group with type 2 diabetes vs. FH- (p<0.05). In the postprandial state, AC2:0, AC16:0 and AC18:1 decreased significantly, but this reduction was blunted in type 2 diabetes, even during normalization of postprandial glucose levels during the insulin clamp. Fasting AC16:0 correlated with FAO (ρ=+0.604; p=0.0002); triacylglycerol (ρ=+0.427; p<0.02) and waist circumference (ρ=+0.416; p=0.02).

CONCLUSIONS

Spillover of AC occurs in type 2 diabetes but is not fully established in FH+. AC16:0 can be a useful biomarker of excessive FAO.

Glycated Hemoglobin, Albuminuria and Surrogate Markers of Macrovascular Disease in Adults Without Diabetes: The Guangzhou Biobank Cohort Study, Cardiovascular Disease Subcohort

OBJECTIVES

To explore the clinical utility of glycated hemoglobin (A1C) levels as an early marker of albuminuria, macrovascular disease and subclinical cardiovascular disease in comparison to fasting and postprandial glucose levels in a well-characterized Chinese population with no history of diabetes.

METHODS

The study population consisted of 1223 individuals who were enrolled in the Guangzhou Biobank Cohort Study, Cardiovascular Disease Subcohort, and who had undergone oral glucose tolerance tests. The associations between each glycemic measure and albuminuria, carotid intima-media thickness (CIMT) and CIMT-based presence of carotid plaques and aortic arch calcification were assessed by chest radiographs.

RESULTS

The overall prevalence of albuminuria, carotid plaque and any aortic arch calcification was 20.6%, 22.8% and 25.8%, respectively. All 3 glycemia indices were significantly associated with albuminuria, but only 1 (fasting glucose) was associated with carotid plaques. No significant difference was detected among them in the area under the curve for albuminuria (chi-square test; p=0.84), carotid plaques (p=0.28) or calcifications (p=0.29). In sensitivity analysis, adjusted for age and sex, the above findings remained unchanged.

CONCLUSIONS

Although there was evidence suggesting differential associations, the performance of the glycemic indices was similar, and their association with macrovascular disease and albuminuria was modest.

Role of Serum Adiponectin and Vitamin D in Prediabetes and Diabetes Mellitus

OBJECTIVES

The roles of deficient or deranged insulin, adiponectin and 25 hydroxy vitamin D (25[OH]D) levels regulating food intake, energy metabolism, glucose and lipid metabolism and body weight have been reported in the pathogenesis of prediabetes and type 2 diabetes mellitus. However, their congruity in the etiology of diabetes mellitus is unknown. Thus, the aim of the study was to investigate the roles of these parameters together and to establish their interrelationship in patients with prediabetes and diabetes.

METHODS

The preliminary cross-sectional study included 77 persons with type 2 diabetes who were matched for age, sex and body mass index (BMI); 73 persons with prediabetes; and 52 healthy control subjects. Fasting serum levels of adiponectin, insulin and 25(OH)D were measured by commercially available immune assay kits, and routine biochemical parameters were analyzed in all study groups.

RESULTS

The results show statistically significant lower levels of serum adiponectin and serum 25(OH)D and higher serum insulin levels in persons with prediabetes or type 2 diabetes with respect to controls. The changes in the serum adiponectin or serum 25(OH)D in persons with prediabetes and type 2 diabetes were found to be inversely correlated with the serum levels of insulin. Moreover, multiple linear regression analysis, with 25(OH)D, insulin and homeostatic model assessment-insulin resistance (HOMA-IR) as the variables, revealed that serum adiponectin levels might be an independent risk factor for the progression of prediabetes and type 2 diabetes in subjects.

CONCLUSIONS

The association of these hormones might act as a significant predictor of progression of prediabetes to type 2 diabetes. Decreased serum adiponectin levels might be an independent risk factor for progression to prediabetes and type 2 diabetes, which may help in developing experimental models of the disease or in identifying biomarkers or disease-modifying drugs.

Community-Based Culturally Preferred Physical Activity Intervention Targeting Populations at High Risk for Type 2 Diabetes: Results and Implications

OBJECTIVES

In Canada, an ageing population, obesity rates and high risk among certain ethnocultural populations are driving diabetes prevalence. Given the burden associated with type 2 diabetes and its link to modifiable risk factors, this study aimed to implement culturally preferred physical activities at the community level, targeting individuals at high risk for type 2 diabetes. Glycated hemoglobin (A1C) levels were used to detect potential improvements in glycemic control.

METHODS

Participants were screened for diabetes risk using a questionnaire and capillary point-of-care A1C blood testing. Participants were offered community-based physical activity classes 2 to 3 times per week for 6 months. A subset of participants (n=84) provided additional measurements.

RESULTS

In total, 718 subjects were reached during recruitment. Substantial participant dropout took place, and 487 participants were exposed to the intervention. Among those who participated in the physical activity and provided follow up, mean A1C levels were reduced by 0.17 (p=0.002) after 3 months (n=84) and by 0.06 (p=0.35; n=49) after 6 months. The homeostatic model assessment (HOMA-beta) showed a significant improvement of 23.6% after 3 months (n=20; p=0.03) and 45.2% after 6 months (n=12; p=0.02). Resting systolic blood pressure and diastolic blood pressure plus combined hand-grip strength improved after 6 months (n=12).

CONCLUSIONS

Implementation of this community-based, culturally preferred physical activity program presented several challenges and was associated with significant participant dropout. After considering participant dropout, the relatively small group who participated and provided follow-up measures showed improvements various physiologic measures. Despite efforts to enhance accessibility, it appears that several barriers to physical activity participation remain and need to be explored to enhance the success of future programs.

A Simple Score Model to Assess Prediabetes Risk Status Based on the Medical Examination Data

OBJECTIVES

We aimed to build a risk score model to screen out the patients at high-risk status so as to prevent or delay the conversion of prediabetes to diabetes.

METHODS

The population were divided into 2 groups: 1 was an exploratory population, and the other was a validation population. All the data were extracted from the electronic medical examination datasets in the School Hospital of Harbin Institute of Technology, Harbin, China. A binary logistic regression model was used to screen out the risk factors, and the associated risk factors were categorized into 3 levels to create the prediabetes score model. We divided the total score into 4 risk categories: low, middle, high and extremely high risk. We also tested the performance of our prediabetes risk score model.

RESULTS

Age, body mass indexes, histories of hypertension, family histories of diabetes, diastolic blood pressure levels and triglyceride levels were screened out as independent risk factors in order to build the risk score model. The area under the curve (AUC) of the prediabetes risk score model was 0.748 (95% CI, 0.720 to 0.777), and the AUC for the validation population reached 0.713 (95% CI, 0.686 to 0.740). Low, middle, high and extremely high risk statuses for prediabetes were associated with a total score of 0 to 3, 4 to 6, 7 to 10 and 11 to 12.

CONCLUSIONS

Our prediabetes score model can be used easily and understood by doctors and other related users to assess prediabetes risk status. The intervention program, designed based on our prediabetes score model, is likely to prevent or delay the conversion of prediabetes to diabetes.

Diet, inflammation and prediabetes-impact of quality of diet

Low grade inflammation has been linked to risk of type 2 diabetes and atherosclerotic vascular diseases. Obesity and, in particular, abdominal obesity increase the risk of diabetes and atherosclerotic vascular diseases. One of the mechanisms could be low grade inflammation and vascular endothelial dysfunction. Permanent weight reduction is the first line of treatment both for obese individuals at increased risk of diabetes and for newly onset type 2 diabetes. Weight reduction lowers the level of several inflammatory factors in the body while increasing the level of adiponectin. Besides weight reduction the quality of diet and physical activity also modifies low grade inflammation. Based on the literature survey and our own studies in humans, it is possible to have dietary patterns that reduce inflammatory stress in the body and improves vascular endothelial dysfunction. There is strong evidence to suggest that IL-1 Ra is a very sensitive marker of low grade inflammation in obesity and related phenotypes; however, its level is markedly lowered by weight reduction and by choosing foods that have been shown to reduce inflammatory stress in the body.

Evaluating the performance of the Framingham Diabetes Risk Scoring Model in Canadian electronic medical records

OBJECTIVE

The objective of this study was to evaluate the performance of the Framingham Diabetes Risk Scoring Model (FDRSM) in a Canadian population, using the Canadian Primary Care Sentinel Surveillance Network (CPCSSN) database.

METHODS

We analyzed the records of 571 631 patients, between the ages of 45 and 64, between 2002 and 2005, by extracting the most recent laboratory and examination results, including age, sex, body mass index, fasting blood glucose, high-density lipoprotein, triglycerides and blood pressure. We calculated the risk scores of these patients based on the FDRSM. We tracked these patients for 8 years to find out whether or not they were diagnosed with diabetes. We used the area under the receiver operating characteristics curve (AROC) to estimate the discrimination capability of the FDRSM on our study sample and compared it with the AROC reported in the original Framingham diabetes study.

RESULTS

The AROC for our main research sample of 1970 patients for whom all risk factors and follow-up data were available was 78.6% compared to the AROC of 85% reported in the FDRSM. We found that 70.1% of our main sample had risks lower than 3%; 16.3% had risks between 3% and 10%; and 13.6% had risks greater than 10% for diabetes over the following 8-year period.

CONCLUSIONS

The discrimination capability of the FDRSM Canadian electronic medical records is fair. However, building a more accurate model for predicting diabetes based on the characteristics of Canadian patients is highly recommended.

Food and physical activity behaviours of adults attending a prediabetes education class

OBJECTIVES

The primary objective of this study was to examine food and physical activity behaviours of adults with prediabetes.

METHODS

For this cross-sectional study, adults (aged >17 years) with prediabetes (n=1228) who attended a prediabetes education class were recruited. Participants self-administered an assessment of food and physical activity behaviours using the Food Behaviour Checklist and the Godin Leisure Time Exercise Questionnaire. Linear regression models were performed to identify significant relationships between food, physical activity, age, body mass index and food access variables.

RESULTS

Participants were 35.8% men with a mean age of 57.7 years (SD 11.6) and 64.2% women with a mean age of 55.2 years (13.9). Neither group was consuming adequate fruits and vegetables (17.1% for men and 29.2% for women eating 5 or more servings a day) or meeting physical activity guidelines of 150 minutes (29.5% for men and 26.2% for women). Approximately 29.0% of the entire sample "always" consumed milk or soy products. Men reported higher saturated fat intakes than women. For the entire sample, 83.4% rated their diet quality as needing improvement, and most consumed sweetened beverages (71.1% of men and 50.9% of women). Many participants (88.5%) used nutrition facts panels to choose foods. Food behaviour subscales and physical activity were significantly associated with each other and with age, body mass index and food access (p<0.05).

CONCLUSIONS

Overall, adults with prediabetes reported less than optimal food and physical activity behaviours. Evaluation of lifestyle behaviours using simple tools like the Food Behaviour Checklist and Godin Leisure Time Exercise Questionnaire can be helpful for program design, evaluation and delivery.