Lipoprotein subfraction cholesterol distribution is more atherogenic in insulin resistant adolescents with type 1 diabetes

Heterogeneous response of estimated insulin sensitivity indices to metformin in young individuals with type 1 diabetes and different phenotypes

AIMS

This study aimed to investigate whether the response to adding metformin to insulin in young adults with type 1 diabetes (T1D) differs according to weight phenotype and insulin sensitivity index.

METHODS

A prospective pilot study was conducted over 26 weeks in which insulin plus metformin (2 g/day) was administered to 35 individuals, ranging from normal weight (NW) to overweight (OW) to obese (OB) T1D individuals, to correlate insulin sensitivity indices and other clinical variables.

RESULTS

At the end of the follow-up period, all groups showed an increase in the eGDR (NW: 7.37 vs 8.16, p = 0.002; OW: 7.28 vs 8.24, p < 0.001; OB: 6.33 vs 7.52 p < 0.001). KITT and SEARCH SCORE improved only in the OB group (2.15 vs 3.14, p < 0.001 and 5.26 vs 5.72, p = 0.007, respectively). Furthermore, HbA1c and BMI were significantly greater in the OB group (- 0.62%, p < 0.001; - 1.12 kg/m2, p = 0.031, respectively). Regression analysis revealed that the serum levels of triglycerides and uric acid were significantly (0.059, p = 0.013; 0.076, p = 0.001) associated with insulin sensitivity indices.

CONCLUSIONS

The study showed that eGDR improved independently of basal weight after metformin treatment. However, the KITT and SEARCH indices improved only in the obese group. Triglycerides and uric acid are associated with insulin sensitivity indices. These results highlight the heterogeneity of the mechanisms underlying insulin resistance and its response to metformin in individuals with T1D.

Hyperlipidemia and Cardiovascular Disease in People with Type 1 Diabetes: Review of Current Guidelines and Evidence

PURPOSE OF REVIEW

In this review, we discuss the prevalence of cardiovascular disease in people with type 1 diabetes. We outline key risk factors associated with increased cardiovascular event rates and discuss the prevalence and mechanisms underlying hyperlipidemia in people with type 1 diabetes. Finally, we summarize the evidence to support early and more aggressive lipid-lowering therapy in people with type 1 diabetes and review current guideline recommendations.

RECENT FINDINGS

Comprehensive treatment of hyperglycemia, hypertension, and hyperlipidemia reduces adverse cardiovascular outcomes in people with type 2 diabetes. In contrast, evidence to support a comparable benefit of intensive cardiovascular risk factor management in people with type 1 diabetes is lacking from prospective, randomized trials and has only been shown in registries. Therefore, current treatment guidelines extrapolate prospective clinical trial evidence obtained in people with type 2 diabetes to provide similar treatment recommendations for people with type 1 and type 2 diabetes. Evidence supports the more aggressive treatment of cardiovascular risk factors in people with type 1 diabetes, who would likely benefit from early risk stratification and comprehensive risk factor management, including aggressive lipid-lowering therapy.

Cardiovascular Disease in Adults with Type 1 Diabetes: Looking Beyond Glycemic Control

PURPOSE OF REVIEW

Despite improvements in treatment, people with type 1 diabetes continue to have increased cardiovascular disease (CVD) risk. Glycemic control does not fully explain this excess CVD risk, so a greater understanding of other risk factors is needed.

RECENT FINDINGS

The authors review the relationship between glycemia and CVD risk in adults with type 1 diabetes and summarize evidence regarding other factors that may explain risk beyond glycemia. Insulin resistance, weight gain, sex differences, genetics, inflammation, emerging markers of risk, including lipid subclasses and epigenetic modifications, and future directions are discussed. As glycemic control improves, an increased focus on other CVD risk factors is warranted in type 1 diabetes. Novel markers and precision medicine approaches may improve CVD prediction, but a lack of type 1 diabetes-specific guidelines for lipids, blood pressure, and physical activity are likely impediments to optimal CVD prevention in this high-risk population.

Protective effects of physical activity against health risks associated with type 1 diabetes: "Health benefits outweigh the risks"

The magnitude of diabetes mellitus (DM) has increased in recent decades, where the number of cases and the proportion of the disease have been gradually increasing over the past few decades. The chronic complications of DM affect many organ systems and account for the majority of morbidity and mortality associated with the disease. The prevalence of type 1 DM (T1DM) is increasing globally, and it has a very significant burden on countries and at an individual level. T1DM is a chronic illness that requires ongoing medical care and patient self-management to prevent complications. This study aims to discuss the health benefits of physical activity (PA) in T1DM patients. The present review article was performed following a comprehensive literature search. The search was conducted using the following electronic databases: "Cochrane Library", Web of Science, PubMed, HINARI, EMBASE, Google for grey literature, Scopus, African journals Online, and Google Scholar for articles published up to June 21, 2021. The present review focused on the effects of PA on many outcomes such as blood glucose (BG) control, physical fitness, endothelial function, insulin sensitivity, well-being, the body defense system, blood lipid profile, insulin resistance, cardiovascular diseases (CVDs), insulin requirements, blood pressure (BP), and mortality. It was found that many studies recommended the use of PA for the effective management of T1DM. PA is a component of comprehensive lifestyle modifications, which is a significant approach for the management of T1DM. It provides several health benefits, such as improving BG control, physical fitness, endothelial function, insulin sensitivity, well-being, and the body defense system. Besides this, it reduces the blood lipid profile, insulin resistance, CVDs, insulin requirements, BP, and mortality. Overall, PA has significant and essential protective effects against the health risks associated with T1DM. Even though PA has several health benefits for patients with T1DM, these patients are not well engaged in PA due to barriers such as a fear of exercise-induced hypoglycemia in particular. However, several effective strategies have been identified to control exercise-induced hypoglycemia in these patients. Finally, the present review concludes that PA should be recommended for the management of patients with T1DM due to its significant health benefits and protective effects against associated health risks. It also provides suggestions for the future direction of research in this field.

Cardiovascular disease in diabetes, beyond glucose

Despite the decades-old knowledge that diabetes mellitus is a major risk factor for cardiovascular disease, the reasons for this association are only partially understood. While this association is true for both type 1 and type 2 diabetes, different pathophysiological processes may be responsible. Lipids and other risk factors are indeed important, whereas the role of glucose is less clear. This lack of clarity stems from clinical trials that do not unambiguously show that intensive glycemic control reduces cardiovascular events. Animal models have provided mechanisms that link diabetes to increased atherosclerosis, and evidence consistent with the importance of factors beyond hyperglycemia has emerged. We review clinical, pathological, and animal studies exploring the pathogenesis of atherosclerosis in humans living with diabetes and in mouse models of diabetes. An increased effort to identify risk factors beyond glucose is now needed to prevent the increased cardiovascular disease risk associated with diabetes.

Effect of metformin on the high-density lipoprotein proteome in youth with type 1 diabetes

Background

Youth with type 1 diabetes (T1D) have normal or elevated High‐Density Lipoprotein Cholesterol (HDL‐C), however, the function of HDL, partly mediated by the HDL proteome, may be impaired. Metformin can be used as an adjunct therapy in youth with T1D, but its effects on the HDL proteome are unknown.

Objective

To determine the effect of metformin on the HDL proteome.

Subjects

Youth (12–20 years old) with T1D who had a BMI > 90th percentile, HbA1c > 8.0% and Tanner stage 5.

Methods

Double‐blinded, placebo‐controlled randomized sub‐study. We examined the effects of metformin (n = 25) or placebo (n = 10) after 6 months on HDL proteome. Changes in HDL proteins were measured by data‐independent acquisition (DIA) mass spectrometry and compared between treatment groups. As a secondary outcome, associations between proteins of interest and the most studied function of HDL, the cholesterol efflux capacity (CEC), was examined.

Results

The relative abundance of 84 HDL‐associated proteins were measured. Two proteins were significantly affected by metformin treatment, peptidoglycan recognition protein 2 (PGRP2; +23.4%, p = .0058) and alpha‐2‐macroglobulin (A2MG; +29.8%, p = .049). Metformin did not significantly affect CEC. Changes in affected HDL proteins did not correlate with CEC.

Conclusions

Despite having little effect on HDL‐C, metformin increased PGRP2 and A2MG protein on HDL in youth with T1D, but had no significant effect on CEC. Further studies are needed to understand the impact of PGRP2 and A2MG on other HDL functions.

Vascular and metabolic effects of metformin added to insulin therapy in patients with type 1 diabetes: A systematic review and meta-analysis

BACKGROUND

The incidence of type 1 diabetes mellitus (T1DM) is increasing among youth worldwide, translating to an increased risk ofearly-onset cardiovascular disease (CVD). Mounting studies have shown that metformin may reduce maximal carotidintima-media thickness (cIMT), improve insulin resistance and metabolic control in subjects with T1DM, and thus, may extend cardioprotective benefits. This systematic review and meta-analysis was performed to assess the efficacy and safety of metformin added to insulin therapy on reducing CVD risks and improving metabolism in T1DM.

METHODS

PubMed, EMBASE, and the Cochrane Library were systematically searched for randomized controlled trials (RCTs) that compared metformin and insulin combination (duration ≥3 months) to insulin treatment alone in T1DM. Data were expressed as weighted/standardized mean differences (MDs/SMDs) for continuous outcomes and risk ratios (RRs) for dichotomous outcomes, along with 95% confidence intervals (CIs). The Grading of Recommendations Assessment, Development and Evaluation (GRADE) was used to evaluate the overall certainty of the evidence.

RESULTS

Nineteen RCTs (n = 1540) met the eligibility criteria. Metformin treatment significantly reduced carotid artery intima-media thickness (MD -0.06 mm [95% CI -0.88, -0.28], P < .001). Though no significant difference was found in insulin sensitivity (SMD 2.21 [95% CI -1.88, 6.29], P = .29), the total daily insulin dosage (SMD -0.81 [95% CI -1.25, -0.36], P < .001) along with traditional CVD risk factors showed improvement by better glycaemic control, partial lipid profiles, diastolic blood pressure, and limited weight gain, with neutral effect on diabetic ketoacidosis, lactic acidosis, and hypoglycaemia. However, metformin therapy increased the incidence of gastrointestinal adverse events.

CONCLUSIONS

Metformin with insulin has the potential to retard the progression of atherosclerosis and provides better metabolic control in patients with T1DM, and thus, providing a potential therapeutic strategy for patients with T1DM on reducing CVD risks.

Lipid management for cardiovascular risk reduction in type 1 diabetes

PURPOSE OF REVIEW

To review the recent evidence for lipid management in type 1 diabetes (T1D) for cardiovascular risk reduction.

RECENT FINDINGS

Individuals with T1D are at increased risk for cardiovascular morbidity and mortality, with atherosclerosis beginning as early as adolescence. Elevated low-density lipoprotein cholesterol (LDL-C), triglycerides, and lipoprotein (a) are associated with increased cardiovascular risk in T1D. Although high-density lipoprotein cholesterol (HDL-C) in T1D is often normal or higher than in nondiabetic controls, HDL in T1D has structural alterations, which make it proatherogenic rather than cardioprotective. Similarly, although LDL-C is not particularly elevated in T1D, LDL still contributes to cardiovascular risk. Studies in individuals with diabetes have primarily included T2D participants, with a much smaller number of T1D participants; such studies have shown that lipid-lowering therapies, such as statins, ezetimibe, and proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibitors reduce LDL-C levels and cardiovascular events in both those with and without diabetes. Individuals with T1D have increased cholesterol absorption, suggesting that ezetimibe may be particularly effective in T1D. Results of the REDUCE-IT trial show cardiovascular risk reduction from high-dose omega-3 fatty acid (Icosapent Ethyl) therapy in patients with diabetes (primarily type 2 diabetes), independent of triglyceride lowering, but similar data in T1D are currently lacking.

SUMMARY

Individuals with T1D are at high risk of cardiovascular disease, necessitating close lipid monitoring and management from adolescence through adulthood.

The Impact of Diabetes Mellitus on Cardiovascular Risk Onset in Children and Adolescents

The prevalence of diabetes mellitus is rising among children and adolescents worldwide. Cardiovascular diseases are the main cause of morbidity and mortality in diabetic patients. We review the impact of diabetes on establishing, during childhood and adolescence, the premises for cardiovascular diseases later in life. Interestingly, it seems that hyperglycemia is not the only factor that establishes an increased cardiovascular risk in adolescence. Other factors have been recognized to play a role in triggering the onset of latent cardiovascular diseases in the pediatric population. Among these cardiovascular risk factors, some are modifiable: glucose variability, hypoglycemia, obesity, insulin resistance, waist circumference, hypertension, dyslipidemia, smoking alcohol, microalbuminuria and smoking. Others are unmodifiable, such as diabetes duration and family history. Among the etiological factors, subclinical endothelial dysfunction represents one of the earliest key players of atherosclerosis and it can be detected during early ages in patients with diabetes. A better assessment of cardiovascular risk in pediatric population still represents a challenge for clinicians, and thus further efforts are required to properly identify and treat pediatric patients who may suffer from cardiovascular disease later in early adulthood.

Comparison of mechanisms and transferability of outcomes of SGLT2 inhibition between type 1 and type 2 diabetes

Diabetes mellitus (DM) is a major chronic disease with ever-increasing prevalence and a variety of serious complications for persons with DM, such as cardiovascular and/or renal complications. New glucose-lowering therapies like DPP-4 inhibitors, GLP-1 receptor agonists, and SGLT-2 inhibitors have undergone cardiovascular outcome trials (CVOTs) for type 2 diabetes (T2DM), as by the guidance of the FDA. However, CVOTs for type 1 diabetes (T1DM) are generally lacking. Both, persons with T1DM and T2DM, are burdened with a high incidence of cardiovascular and renal disease such as atherosclerotic cardiovascular disease (ASCVD) and diabetic kidney disease (DKD). Although pathologies of the two types of diabetes cannot be compared, similar mechanisms and risk factors like sex, hyperglycaemia, hypertension, endothelial damage and (background) inflammation have been identified in the development of CVD and DKD in T1DM and T2DM. Recent CVOTs in T2DM demonstrated that SGLT-2 inhibitors, besides exerting a glucose-lowering effect, have beneficial effects on cardiovascular and renal mechanisms. These mechanisms are reviewed in detail in this manuscript and evaluated for possible transferability to, and thus efficacy in, T1DM. Our review of current literature suggests that SGLT-2 inhibitors have cardioprotective benefits beyond their glucose-lowering effects. As this mainly has been observed in CVOTs in T2DM, further investigation in the adjunctive therapy for type 1 diabetes is suggested.

Effects of Metformin Added to Insulin in Adolescents with Type 1 Diabetes: An Exploratory Crossover Randomized Trial

BACKGROUND

To comprehensively assess the effects of metformin added to insulin on metabolic control, insulin sensitivity, and cardiovascular autonomic function in adolescents with type 1 diabetes.

MATERIALS AND METHODS

This was an exploratory, crossover, randomized trial conducted in adolescents with type 1 diabetes aged 12-18 years old. Participants were randomly received metformin (≤1000 mg/d) added to insulin for 24 weeks followed by insulin monotherapy for a subsequent 24 weeks or vice versa. Blood pressure, body mass index, insulin dose, estimated insulin sensitivity, glycated hemoglobin A1c (HbA1c), and lipid profiles were measured, with a 72-hour continuous glucose monitoring and 24-hour Holter monitoring performed at baseline, 24, and 50 weeks for the assessments of glucose variability and heart rate variability.

RESULTS

Seventeen patients with mean ± SD age 14.4 ± 2.3 years, body mass index 18.17 ± 1.81 kg/m², median (IQR) diabetes duration 4.50 (3.58, 6.92) years, and HbA1c 9.0% (8.5%, 9.4%) were enrolled. The between-group difference in HbA1c of 0.28% (95% CI -0.39 to 0.95%) was not significant (P = 0.40). Changes in body mass index, insulin dose, blood pressure, lipid profiles, and estimated insulin sensitivity were similar for metformin add-on vs. insulin monotherapy. Glucose variability also did not differ. Compared with insulin monotherapy, metformin add-on significantly increased multiple heart rate variability parameters.

CONCLUSIONS

Metformin added to insulin did not improve metabolic control or glucose variability in lean/normal-weight adolescents with type 1 diabetes. However, metformin added to insulin significantly increased heart rate variability, suggesting that metformin might improve cardiovascular autonomic function in this population.

Metformin Improves Insulin Sensitivity and Vascular Health in Youth With Type 1 Diabetes Mellitus

BACKGROUND

Cardiovascular disease is the leading cause of mortality in type 1 diabetes mellitus (T1DM) and relates strongly to insulin resistance (IR). Lean and obese adolescents with T1DM have marked IR. Metformin improves surrogate markers of IR in T1DM, but its effect on directly measured IR and vascular health in youth with T1DM is unclear. We hypothesized that adolescents with T1DM have impaired vascular function and that metformin improves this IR and vascular dysfunction.

METHODS

Adolescents with T1DM and control participants underwent magnetic resonance imaging of the ascending (AA) and descending aorta to assess pulse wave velocity, relative area change, and maximal (WSS_MAX) and time-averaged (WSS_TA) wall shear stress. Participants with T1DM also underwent assessment of carotid intima-media thickness by ultrasound, brachial distensibility by DynaPulse, fat and lean mass by dual-energy x-ray absorptiometry, fasting laboratories after overnight glycemic control, and insulin sensitivity by hyperinsulinemic-euglycemic clamp (glucose infusion rate/insulin). Adolescents with T1DM were randomized 1:1 to 3 months of 2000 mg metformin or placebo daily, after which baseline measures were repeated.

RESULTS

Forty-eight adolescents with T1DM who were 12 to 21 years of age (40% body mass index [BMI] ≥90th percentile; 56% female) and 24 nondiabetic control participants of similar age, BMI, and sex distribution were enrolled. Adolescents with T1DM demonstrated impaired aortic health compared with control participants, including elevated AA and descending aorta pulse wave velocity, reduced AA and descending aorta relative area change, and elevated AA and descending aorta WSS_MAX and WSS_TA. Adolescents with T1DM in the metformin versus placebo group had improved glucose infusion rate/insulin (12.2±3.2 [mg·kg^-1·min^-1]/μIU/μL versus -2.4±3.6 [mg·kg^-1·min^-1]/μIU/μL, P=0.005; 18.6±4.8 [mg·lean kg^-1·min^-1]/μIU/μL versus -3.4±5.6 [mg·lean kg^-1·min^-1]/μIU/μL, P=0.005) and reduced weight (-0.5±0.5 kg versus 1.6±0.5 kg; P=0.004), BMI (-0.2±0.15 kg/m² versus 0.4±0.15 kg/m²; P=0.005), and fat mass (-0.7±0.3 kg versus 0.6±0.4 kg; P=0.01). Glucose infusion rate/insulin also improved in normal-weight participants (11.8±4.4 [mg·kg^-1·min^-1]/μIU/μL versus -4.5±4.4 [mg·kg^-1·min^-1]/μIU/μL, P=0.02; 17.6±6.7 [mg·lean kg^-1·min^-1]/μIU/μL versus -7.0±6.7 [mg·lean kg^-1·min^-1]/μIU/μL, P=0.02). The metformin group had reduced AA WSS_MAX (-0.3±0.4 dyne/cm² versus 1.5±0.5 dyne/cm²; P=0.03), AA pulse wave velocity (-1.1±1.20 m/s versus 4.1±1.6 m/s; P=0.04), and far-wall diastolic carotid intima-media thickness (-0.04±0.01 mm versus -0.00±0.01 mm; P=0.049) versus placebo.

CONCLUSIONS

Adolescents with T1DM demonstrate IR and impaired vascular health compared with control participants. Metformin improves IR, regardless of baseline BMI, and BMI, weight, fat mass, insulin dose, and aortic and carotid health in adolescents with T1DM. Metformin may hold promise as a cardioprotective intervention in T1DM.

CLINICAL TRIAL REGISTRATION

URL: https://www.clinicaltrials.gov . Unique identifier: NCT01808690.

Association of metformin and statin medications with surrogate measures of cardiovascular disease in youth with type 1 diabetes: the SEARCH for diabetes in youth study

PURPOSE

Youth with type 1 diabetes mellitus (T1DM) are at risk of cardiovascular disease (CVD). We evaluated if metformin or statin use was associated with surrogate measures of improved CVD.

METHODS

We included participants from the SEARCH observational study. Participants treated with insulin plus metformin (n=42) or insulin plus statin (n=39) were matched with 84 and 78 participants, respectively, treated with insulin alone. Measures of arterial stiffness obtained were pulse wave velocity (PWV), augmentation index (AI75), and heart rate variability as standard deviation of the normal-to-normal interval (SDNN) and root mean square differences of successive NN intervals (RMSSD).

RESULTS

CVD measures were not significantly different among participants on insulin plus metformin versus those on insulin alone: PWV (5.9±1.0 m/sec vs. 5.8±1.5 m/sec, P=0.730), AI75 (1.8 [-6.0 to 8.0] vs. -2.4 [-10.7 to 3.8], P=0.157), SDNN (52.4 [36.8-71.1] m/sec vs. 51.8 [40.1-74.9] m/sec, P=0.592), and RMSSD (43.2 [29.4-67.6] vs. 47.4 [28.0-76.3], P=0.952). CVD measures were not different for statin users versus nonusers: PWV (5.7±0.8 m/sec vs. 5.9 ±1.1 m/sec, P=0.184), AI75 ( -4.0 [-9.5 to 1.7] vs. -6.7 [-11.3 to 5.7], P=0.998), SDNN (54.6 [43.5-77.2] m/sec vs. 63.1 [44.2-86.6] m/sec, P=0.369), and RMSSD (49.5 [31.2-74.8] vs. 59.2 [38.3-86.3], P=0.430).

CONCLUSION

We found no associations of statin or metformin use with surrogate measures of CVD. Future prospective pediatric clinical trials could address this issue.

Metformin Improves Peripheral Insulin Sensitivity in Youth With Type 1 Diabetes

CONTEXT

Type 1 diabetes in adolescence is characterized by insulin deficiency and insulin resistance (IR), both thought to increase cardiovascular disease risk. We previously demonstrated that adolescents with type 1 diabetes have adipose, hepatic, and muscle IR, and that metformin lowers daily insulin dose, suggesting improved IR. However, whether metformin improves IR in muscle, hepatic, or adipose tissues in type 1 diabetes was unknown.

OBJECTIVE

Measure peripheral, hepatic, and adipose insulin sensitivity before and after metformin or placebo therapy in youth with obesity with type 1 diabetes.

DESIGN

Double-blind, placebo-controlled clinical trial.

SETTING

Multi-center at eight sites of the T1D Exchange Clinic Network.

PARTICIPANTS

A subset of 12- to 19-year-olds with type 1 diabetes (inclusion criteria: body mass index ≥85th percentile, HbA1c 7.5% to 9.9%, insulin dosing ≥0.8 U/kg/d) from a larger trial (NCT02045290) were enrolled.

INTERVENTION

Participants were randomized to 3 months of metformin (N = 19) or placebo (N = 18) and underwent a three-phase hyperinsulinemic euglycemic clamp with glucose and glycerol isotope tracers to assess tissue-specific IR before and after treatment.

MAIN OUTCOME MEASURES

Peripheral insulin sensitivity, endogenous glucose release, rate of lipolysis.

RESULTS

Between-group differences in change in insulin sensitivity favored metformin regarding whole-body IR [change in glucose infusion rate 1.3 (0.1, 2.4) mg/kg/min, P = 0.03] and peripheral IR [change in metabolic clearance rate 0.923 (-0.002, 1.867) dL/kg/min, P = 0.05]. Metformin did not impact insulin suppression of endogenous glucose release (P = 0.12). Adipose IR was not assessable with traditional methods in this highly IR population.

CONCLUSIONS

Metformin appears to improve whole-body and peripheral IR in youth who are overweight/obese with type 1 diabetes.

Low cholesterol efflux capacity and abnormal lipoprotein particles in youth with type 1 diabetes: a case control study

Background

Patients with type 1 diabetes (T1DM) have increased mortality from cardiovascular disease (CVD). Risk factors for CVD include an elevation of LDL (LDLp) and small HDL (sHDLp) particles, and a decrease in reverse cholesterol transport i.e. HDL-cholesterol efflux capacity (CEC). Our objective was to compare lipoprotein particles and CEC between T1DM and healthy controls (HC) and to explore the associations between NMR lipid particles and cholesterol efflux.

Methods

78 patients with T1DM and 59 HC underwent fasting lipoprotein profile testing by NMR and measurements of CEC by cell-based method. The associations between NMR lipid particles with CEC were analyzed using multivariable linear regression models.

Results

Youth with T1DM had higher total LDLp 724 [(563–985) vs 622 (476–794) nmol/L (P = 0.011)] (Maahs et al. in Circulation 130(17):1532–58, 2014; Shah et al. in Pediatr Diabetes 16(5):367–74, 2015), sHDLp [11.20 (5.7–15.3) vs 7.0 (3.2–13.1) μmol/L (P = 0.021)], and lower medium HDLp [11.20 (8.5–14.5) vs 12.3 (9–19.4), (P = 0.049)] and lower CEC (0.98 ± 0.11% vs 1.05 ± 0.15%, P = 0.003) compared to HC. Moreover, CEC correlated with sHDLp (β = − 0.28, P = 0.045) and large HDLp (β = 0.46, P < 0.001) independent of age, sex, ethnicity, BMIz, HbA1c, hsCRP and total HDLp in the diabetic cohort.

Conclusions

Youth with T1DM demonstrated a more atherogenic profile including higher sHDL and LDLp and lower CEC. Future efforts should focus on considering adding lipoprotein particles and CEC in CVD risk stratification of youth with T1DM.

Trial registration Clinical Trials Registration Number NCT02275091

Pathogenesis of Lipid Disorders in Insulin Resistance: a Brief Review

PURPOSE OF REVIEW

Insulin resistance (IR) is recognized to play an important role in the pathogenesis of dyslipidemia. This review summarizes the complex interplay between IR and dyslipidemia in people with and without diabetes.

RECENT FINDINGS

IR impacts the metabolism of triglycerides, high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), and very low-density lipoprotein cholesterol (VLDL-C) by several mechanisms. Trials with insulin sensitizing therapies, including biguanides and thiazolidinediones, have provided inconsistent results on lipid lowering in people with and without diabetes. In this review, we focus on the pathophysiological interplay between IR and dyslipidemia and recapitulate lipid and lipoprotein data from insulin-sensitizing trials. Further research elucidating the reciprocal relationship between IR and dyslipidemia is needed to better target these important risk factors for cardiovascular disease.

Gender differences in diabetes self-care in adults with type 1 diabetes: Findings from the T1D Exchange clinic registry

AIMS

To evaluate gender differences in diabetes self-care components including glycemic, blood pressure and lipid control, utilization of diabetes technologies and acute diabetes complications in adults with type 1 diabetes.

METHODS

A total of 9,481 participants >18 years were included in the analysis, 53% were female. Variables of interest included glycemic control measured by HbA1c, systolic/diastolic blood pressures, presence of dyslipidemia, insulin delivery modality, and rates of acute complications.

RESULTS

Glycemic control was similar in women and men (mean HbA1c in both groups: 8.1% ± 1.6% (64 ± 16 mmol/mol), (p = 0.54). More women used insulin pump therapy (66% vs. 59%, p < 0.001) but use of sensor technology was similar (p < = 0.42). Women had higher rates of diabetic ketoacidosis (DKA) (5% vs. 3%, p < 0.001) and eating disorders (1.7% vs. 0.1%, p < 0.001). Severe hypoglycemia rates were not different between men and women (p = 0.42). Smoking (6% vs 4%, p < 0.001), systolic (125 ± 14.2 vs. 121 ± 14.4, p < 0.001) and diastolic blood pressure (73.3 ± 9.5 vs. 72.2 ± 9.3, p < 0.001) and rate of dyslipidemia (28% vs. 23%, p < 0.001) were higher in men.

CONCLUSION

While glycemic control in type 1 diabetes was similar regardless of gender, rates of DKA and eating disorders were higher in women while rates of smoking, hypertension and dyslipidemia were higher in men.

Youth With Type 1 Diabetes Have Adipose, Hepatic, and Peripheral Insulin Resistance

CONTEXT

Adolescents with type 1 diabetes (T1D) have difficulty obtaining optimal glucose control, which may relate to insulin resistance (IR), especially during puberty. Moreover, IR increases the risk for cardiovascular disease, the leading cause of death in T1D. However, the tissue specificity of IR in adolescents with T1D has not been fully phenotyped.

OBJECTIVE

To assess adipose, hepatic, and peripheral insulin sensitivity in adolescents with and without T1D.

DESIGN AND SETTING

Thirty-five youth with T1D [median age, 16 (first and third quartiles, 14, 17) years; 53% female; median body mass index (BMI) percentile, 82nd (55th, 96th); late puberty; median hemoglobin A1c, 8.3% (7.3%, 9.4%)] and 22 nondiabetic youth of similar age, BMI, pubertal stage, and level of habitual physical activity were enrolled. Insulin action was measured with a four-phase hyperinsulinemic euglycemic clamp (basal and 10, 16, and 80 mU/m2/min) with glucose and glycerol isotope tracers.

RESULTS

Adolescents with T1D had a significantly higher rate of lipolysis (P < 0.0001) and endogenous glucose production (P < 0.001) and lower peripheral glucose uptake (glucose rate of disappearance, 6.9 ± 2.9 mg/kg/min for patients with T1D vs 11.3 ± 3.3 for controls; P < 0.0001) during hyperinsulinemia compared with controls. In youth with T1D, glucose rate of disappearance correlated with free fatty acid at the 80-mU/m2/min phase (P = 0.005), markers of inflammation (IL-6; P = 0.012), high-sensitivity C-reactive protein (P = 0.001), and leptin (P = 0.008)], but not hemoglobin A1c.

CONCLUSIONS

Adolescents with T1D have adipose, hepatic and peripheral IR. This IR occurs regardless of obesity and metabolic syndrome features. Youth with T1D may benefit from interventions directed at improving IR in these tissues, and this area requires further research.

Modifiable Risk Factors for Cardiovascular Disease in Children with Type 1 Diabetes: Can Early Intervention Prevent Future Cardiovascular Events?

PURPOSE OF REVIEW

Patients with type 1 diabetes have increased risk for cardiovascular disease. The purpose of this review is to examine the following: i) current evidence for subclinical cardiovascular disease (CVD) in children with type 1 diabetes (T1DM) ii) known modifiable risk factors for CVD and their relationship to subclinical CVD in this population iii) studies that have addressed these risk factors in order to improve CVD outcomes in children with T1DM RECENT FINDINGS: Subclinical CVD presents in children as increased carotid intima-media thickness, increased arterial stiffness, and endothelial and myocardial dysfunction. Modifiable risk factors for CVD include hyperglycemia, hyperlipidemia, obesity, hypertension, depression, and autonomic dysfunction. Very few randomized controlled studies have been done in children with T1DM to examine how modification of these risk factors can affect their CVD. Children with T1DM have subclinical CVD and multiple modifiable risk factors for CVD. More research is needed to define how modification of these factors affects the progression of CVD.

The role and function of HDL in patients with diabetes mellitus and the related cardiovascular risk

BACKGROUND

Diabetes mellitus (DM) is a major public health problem which prevalence is constantly raising, particularly in low- and middle-income countries. Both diabetes mellitus types (DMT1 and DMT2) are associated with high risk of developing chronic complications, such as retinopathy, nephropathy, neuropathy, endothelial dysfunction, and atherosclerosis.

METHODS

This is a review of available articles concerning HDL subfractions profile in diabetes mellitus and the related cardiovascular risk. In this review, HDL dysfunction in diabetes, the impact of HDL alterations on the risk diabetes development as well as the association between disturbed HDL particle in DM and cardiovascular risk is discussed.

RESULTS

Changes in the amount of circulation lipids, including triglycerides and LDL cholesterol as well as the HDL are frequent also in the course of DMT1 and DMT2. In normal state HDL exerts various antiatherogenic properties, including reverse cholesterol transport, antioxidative and anti-inflammatory capacities. However, it has been suggested that in pathological state HDL becomes "dysfunctional" which means that relative composition of lipids and proteins in HDL, as well as enzymatic activities associated to HDL, such as paraoxonase 1 (PON1) and lipoprotein-associated phospholipase 11 (Lp-PLA2) are altered. HDL properties are compromised in patients with diabetes mellitus (DM), due to oxidative modification and glycation of the HDL protein as well as the transformation of the HDL proteome into a proinflammatory protein. Numerous studies confirm that the ability of HDL to suppress inflammatory signals is significantly reduced in this group of patients. However, the exact underlying mechanisms remains to be unravelled in vivo.

CONCLUSIONS

The understanding of pathological mechanisms underlying HDL dysfunction may enable the development of therapies targeted at specific subpopulations and focusing at the diminishing of cardiovascular risk.

Obese adolescents with polycystic ovarian syndrome have elevated cardiovascular disease risk markers

Women with polycystic ovarian syndrome (PCOS) have evidence of subclinical cardiovascular disease (CVD). However, insulin resistance, an important factor in the development of CVD in adults, is common in adolescents with PCOS, yet data in adolescents are limited. Therefore, we sought to measure insulin resistance and CVD markers in obese youth with and without PCOS. Thirty-six PCOS and 17 non-PCOS adolescent girls who were obese, sedentary, and non-hypertensive were recruited from clinics located within the Children's Hospital Colorado. Following 3 days of controlled diet and restricted exercise, fasting plasma samples were obtained prior to a hyperinsulinemic euglycemic clamp. PCOS girls were more insulin resistant than controls (glucose infusion rate 5.24±1.86 mg/kg/min vs 9.10±2.69; p<0.001). Girls with PCOS had blood pressure in the normal range, but had greater carotid intima-media thickness (cIMT) (0.49±0.07 mm vs 0.44±0.06; p=0.038), beta stiffness index (5.1±1.3 U vs 4.4±0.9; p=0.037), and reduced arterial compliance (1.95±0.47 mm²/mmHg × 10^-1 vs 2.13±0.43; p=0.047). PCOS girls had a normal mean lipid profile, yet had a more atherogenic lipoprotein cholesterol distribution and had persistent elevations of free fatty acids despite hyperinsulinemia (68±28 μmol/mL vs 41±10; p=0.001), both potential contributors to CVD. Free fatty acid concentrations correlated best with all CVD markers. In summary, adolescent girls with PCOS have greater cIMT and stiffer arteries than girls without PCOS, perhaps related to altered lipid metabolism, even when clinical measures of blood pressure and cholesterol profiles are 'normal'. Therefore, management of adolescent PCOS should include assessment of CVD risk factor development.

Influences of gender on cardiovascular disease risk factors in adolescents with and without type 1 diabetes

Background

Women with type 1 diabetes (T1D) have a four-fold increased risk for cardiovascular disease (CVD) compared to non-diabetic (non-DM) women, as opposed to double the risk in T1D men compared to non-DM men. It is unclear how early in life CVD risk differences begin in T1D females. Therefore, our objective was to compare CVD risk factors in adolescents with and without T1D to determine the effects of gender on CVD risk factors.

Methods

The study included 300 subjects with T1D (age 15.4±2.1 years, 50 % male, 80 % non-Hispanic White (NHW), glycated hemoglobin (A1c) 8.9±1.6 %, diabetes duration 8.8±3.0 years, BMI Z-score 0.62±0.77) and 100non-DM controls (age 15.4±2.1 years, 47 % male, 69 % NHW, BMI Z-score 0.29±1.04). CVD risk factors were compared by diabetes status and gender. Multivariate linear regression analyses were used to determine if relationships between diabetes status and CVD risk factors differed by gender independent of differences in A1c and BMI.

Results

Differences in CVD risk factors between T1D subjects and non-DM controls were more pronounced in girls. Compared to boys with T1D and non-DM girls, T1D girls had higher A1c (9.0 % vs. 8.6 % and 5.1 %, respectively), BMI Z-score (0.70 vs. 0.47 and 0.27), LDL-c (95 vs. 82 and 81 mg/dL), total cholesterol (171 vs. 153 and 150 mg/dL), DBP (68 vs. 67 and 63 mmHg), and hs-CRP (1.15 vs. 0.57 and 0.54 mg/dL) after adjusting for Tanner stage, smoking status, and race/ethnicity (p <0.05 for all). In T1D girls, differences in lipids, DBP, and hs-CRP persisted even after adjusting for centered A1c and BMI Z-score.

Testing interactions between gender and T1D with CVD risk factors indicated that differences were greater between girls with T1D and non-DM compared to differences between boys with T1D and non-DM. Overall, observed increases in CVD risk factors in T1D girls remained after further adjustment for centered A1c or BMI Z-score.

Conclusions

Interventions targeting CVD risk factors in addition to lowering HbA1c and maintaining healthy BMI are needed for youth with T1D. The increased CVD risk factors seen in adolescent girls with T1D in particular argues for earlier intervention to prevent later increased risk of CVD in women with T1D.