Obesity and coronary artery calcium in diabetes: the Coronary Artery Calcification in Type 1 Diabetes (CACTI) study

Drawing lines in the sand: The growing threat of obesity in type 1 diabetes

In this editorial, we comment on the article by Zeng et al published in the recent issue of the World Journal of Diabetes in 2024. We focus on the epidemiological, pathophysiological, and clinical interplay between obesity and type 1 diabetes mellitus (T1DM). Overweight and obesity represent a growing threat for modern societies and people with T1DM could not be an exception to this rule. Chronic exogenous insulin administration, genetic and epigenetic factors, and psy-chosocial and behavioral parameters, along with the modern way of life that incorporates unhealthy eating patterns and physical inactivity, set the stage for the increasing obesity rates in T1DM. As our knowledge of the underlying mechanisms that lead to the development of obesity and hyperglycemia expands, it becomes clear that there are overlap zones in the pathophysiology of the two main types of diabetes. Stereotypes regarding strict dividing lines between "autoimmune" and "metabolic" phenotypes increase the risk of trapping physicians into ineffective therapeutic approaches, instead of individualized diabetes care. In this context, the use of adjuncts to insulin therapy that have the potential to alleviate cardiorenal risk and decrease body weight can reduce the burden of obesity in patients with T1DM.

Screening for Subclinical Atherosclerosis and the Prediction of Cardiovascular Events in People with Type 1 Diabetes

People with type 1 diabetes (T1D) have a high cardiovascular disease (CVD) risk, which remains the leading cause of death in this population. Despite the improved control of several classic risk factors, particularly better glycaemic control, cardiovascular morbidity and mortality continue to be significantly higher than in the general population. In routine clinical practice, estimating cardiovascular risk (CVR) in people with T1D using scales or equations is often imprecise because much of the evidence comes from pooled samples of people with type 2 diabetes (T2D) and T1D or from extrapolations of studies performed on people with T2D. Given that T1D onsets at a young age, prolonged exposure to the disease and its consequences (e.g., hyperglycaemia, changes in lipid metabolism or inflammation) have a detrimental impact on cardiovascular health. Therefore, it is critical to have tools that allow for the early identification of those individuals with a higher CVR and thus be able to make the most appropriate management decisions in each case. In this sense, atherosclerosis is the prelude to most cardiovascular events. People with diabetes present pathophysiological alterations that facilitate atherosclerosis development and that may imply a greater vulnerability of atheromatous plaques. Screening for subclinical atherosclerosis using various techniques, mainly imaging, has proven valuable in predicting cardiovascular events. Its use enables the reclassification of CVR and, therefore, an individualised adjustment of therapeutic management. However, the available evidence in people with T1D is scarce. This narrative review provides and updated overview of the main non-invasive tests for detecting atherosclerosis plaques and their association with CVD in people with T1D.

Treating obesity in type 1 diabetes mellitus - review of efficacy and safety

PURPOSE OF REVIEW

Obesity is an epidemic in the United States with serious concomitant co-morbid conditions; people living with type 1 diabetes mellitus (T1D) are not immune to the risk either. Weight gain in T1D is likely multifactorial, due to genetic, environmental and treatment-related factors. FDA-approved and other adjunctive weight loss therapies may benefit people living with T1D but there are risks to consider when providing recommendations or prescribing medications.

RECENT FINDINGS

We performed a PubMed search of studies assessing clinical outcomes of both approved and off-label medications used in the treatment of type 1 diabetes. Search terms included 'type 1 diabetes, obesity' and the following: (1) metformin, (2) pramlintide, (3) glucagon-like peptide-1 (GLP-1) receptor agonists, (4) dual GLP-1 and gastric inhibitory polypeptide (GIP) agonists, (5) sodium-glucose cotransporter-2 (SGLT-2) inhibitors, (6) surgical treatment of obesity, (7) insulin pump, (8) insulin, (9) medical nutrition therapy, (10) diabetes self-management education, (11) exercise, (12) naltrexone-buproprion, (13) orlistat, and (14) phentermine-topiramate.

SUMMARY

Weight loss treatments provide a wide-range of benefits in reducing both morbidity and mortality in those who are obese. Treatments also have varying adverse effect profiles which may impact T1D treatment. In this review, we aim to summarize study outcomes in people with T1D, including risks and benefits, of on- and off-label weight loss treatments.

Characteristics and outcomes of patients with type 1 diabetes admitted with acute coronary syndromes

AIMS

This study explored characteristics and outcomes of patients with type 1 diabetes mellitus (T1DM) and acute coronary syndromes (ACS).

METHODS

A retrospective analysis of patients with T1DM admitted with ACS to an Australian hospital was conducted. Risk factor targets were defined by 2021 European Society of Cardiology Guidelines. Outcomes were defined as an adverse cardiovascular event (ACS, unplanned revascularisation, heart failure, stroke, or cardiovascular death) or all-cause mortality within six-months after discharge.

RESULTS

61 patients were included [age 58.5 ± 12.8 years, 39 % female]. Dyslipidaemia (85 %), hypertension (75 %), smoking (28 %), prior coronary artery disease (CAD) (44 %), and microvascular complications (62 %) were common. HbA1c, low-density lipoprotein cholesterol, and blood pressure targets were attained in 12 %, 36 % and 47 %, respectively. ST-elevation myocardial infarction (65 % versus 7 %, p < 0.001) and revascularisation (77 % versus 41 %, p = 0.008) were more common in those without prior CAD. Peak inpatient blood glucose correlated directly with peak troponin (p = 0.011) and inversely with left ventricular ejection fraction (p = 0.027). Nineteen patients experienced an adverse six-month outcome, with peripheral neuropathy (p = 0.039) and in-hospital hypoglycaemia (p = 0.012) being independent predictors.

CONCLUSIONS

Patients with T1DM and ACS often do not meet guideline targets for cardiovascular risk factors, and frequently present with transmural infarctions. Dysglycemia and microvascular complications predict poorer outcomes.

The Relationship between Selected Inflammation and Oxidative Stress Biomarkers and Carotid Intima-Media Thickness (IMT) Value in Youth with Type 1 Diabetes Co-Existing with Early Microvascular Complications

Recent years have confirmed the importance of oxidative stress and biomarkers of inflammation in estimating the risk of cardiovascular disease (CVD) and explaining not fully understood pathogenesis of diabetic macroangiopathy. We aimed to analyze the relation between the intima-media thickness (IMT) of common carotid arteries and the occurrence of classical cardiovascular risk factors, together with the newly proposed biomarkers of CVD risk (high-sensitivity C-reactive protein (hsCRP), myeloperoxidase (MPO), adiponectin, N-terminal-pro B-type natriuretic peptide (NT-proBNP) and vitamin D) in youth with type 1 diabetes (T1D) recognized in screening tests to present early stages of microvascular complications (VC). The study group consisted of 50 adolescents and young adults with T1D, mean age 17.1 years (10–26 age range), including 20 patients with VC (+) and 30 VC (−). The control group (Control) consisted of 22 healthy volunteers, mean age 16.5 years (11–26 age range). In the VC (+) patients, we found a significantly higher concentration of HbA1c, lipid levels, hsCRP and NT-proBNP. BMI and blood pressure values were highest in the VC (+) group. Higher levels of MPO and lower levels of vitamin D were found in both diabetic groups vs. Control. IMT in VC (+) patients was significantly higher and correlated positively with HbA1c, hsCRP, NT-pro-BNP and negatively with vitamin D levels. In conclusion, youth with T1D and VC (+) present many abnormalities in the classical and new CVD biomarkers. hsCRP and MPO seem to be the most important markers for estimating the risk of macroangiopathy. NT-proBNP may present a possible marker of early myocardial injury in this population.

Cardiovascular disease risk profile of Indian young adults with type 1 diabetes compared to general population - A sub-study from the Young Diabetes Registry (YDR), India

OBJECTIVE

We estimated the prevalence of traditional CVD risk factors among young adults with type 1 diabetes and compared them with the general population without diabetes.

METHODS

Participants were young adults (aged 20 years and above) with type 1 diabetes, from the Delhi and Chennai sites of the ICMR -Young Diabetes Registry (YDR) and their age, gender and location matched controls, without diabetes from the CARRS (Cardio metabolic Risk Reduction in South Asia) cohort. YDR and CARRS used similar standard methodologies to quantify the CVD risk factors. Linear and logistic regression models were used to compare the adjusted means and proportions of risk factors.

RESULTS

Individuals with type 1 diabetes had lower levels of mean BMI (21.9 kg/m2 vs 24.3 kg/m2), waist circumference (76.8 cm vs 82.1 cm), favourable lipid profile (lower LDL and higher HDL), higher mean systolic blood pressure (122.1 mmHg vs 118.7 mmHg) and hypertension (29.2% vs 21.0%), compared to controls. The extent of clustering of two or more traditional CVD risk factors was higher among general population compared to people with type 1 diabetes.

CONCLUSION

We found that young adults with type 1 diabetes have relatively low prevalence and clustering of traditional CVD risk factors compared to general population.

Non-Insulin Antidiabetes Treatment in Type 1 Diabetes Mellitus: A Systematic Review and Meta-Analysis

In order to evaluate the efficacy and side effects of the non-insulin antidiabetes medications as an adjunct treatment in type 1 diabetes mellitus (T1DM), we conducted systematic searches in MEDLINE, Embase, and the Cochrane Central Register of Controlled Trials for randomized controlled trials published between the date of inception and March 2020 to produce a systematic review and meta-analysis. Overall, 57 studies were included. Compared with placebo, antidiabetes agents in adjunct to insulin treatment resulted in significant reduction in glycosylated hemoglobin (weighted mean difference [WMD], -0.30%; 95% confidence interval [CI], -0.34 to -0.25%; P<0.01) and body weight (WMD, -2.15 kg; 95% CI, -2.77 to -1.53 kg; P<0.01), and required a significantly lower dosage of insulin (WMD, -5.17 unit/day; 95% CI, -6.77 to -3.57 unit/day; P<0.01). Compared with placebo, antidiabetes agents in adjunct to insulin treatment increased the risk of hypoglycemia (relative risk [RR], 1.04; 95% CI, 1.01 to 1.08; P=0.02) and gastrointestinal side effects (RR, 1.99; 95% CI, 1.61 to 2.46; P<0.01) in patients with T1DM. Compared with placebo, the use of non-insulin antidiabetes agents in addition to insulin could lead to glycemic improvement, weight control and lower insulin dosage, while they might be associated with increased risks of hypoglycemia and gastrointestinal side effects in patients with T1DM.

Obesity in Patients with Type 1 Diabetes: Links, Risks and Management Challenges

Obesity affects large numbers of patients with type 1 diabetes (T1D) across their lifetime, with rates ranging between 2.8% and 37.1%. Patients with T1D and obesity are characterized by the presence of insulin resistance, of high insulin requirements, have a greater cardiometabolic risk and an enhanced risk of developing chronic complications when compared to normal-weight persons with T1D. Dual treatment of obesity and T1D is challenging and no specific guidelines for improving outcomes of both glycemic control and weight management have been established for this population. Nevertheless, although evidence is scarce, a comprehensive approach based on a balanced hypocaloric diet, physical activity and cognitive behavioral therapy by a multidisciplinary team, expert in both obesity and diabetes, remains as the best clinical practice. However, weight loss responses with lifestyle changes alone are limited, so in the "roadmap" of the treatment of obesity in T1D, it will be helpful to include anti-obesity pharmacotherapy despite at present there is a lack of evidence since T1D patients have been excluded from anti-obesity drug clinical trials. In case of severe obesity, bariatric surgery has proven to be of benefit in obtaining a substantial and long-term weight loss and reduction in cardiovascular risk. The near future looks promising with the development of new and more effective anti-obesity treatments and strategies to improve insulin resistance and oxidative stress. Advances in precision medicine may help individualize and optimize the medical management and care of these patients. This review, by gathering current evidence, highlights the need of solid knowledge in all facets of the treatment of patients with obesity and T1D that can only be obtained through high quality well-designed studies.

Nutrition and Obesity in the Pathogenesis of Youth-Onset Type 1 Diabetes and Its Complications

Since the 1980s, there has been a dramatic rise in the prevalence of overweight and obesity in pediatric populations, in large part driven by sedentary lifestyles and changing dietary patterns with more processed foods. In parallel with the rise in pediatric obesity in the general population, the prevalence of overweight and obesity has increased among children and adolescents with type 1 diabetes. Adiposity has been implicated in a variety of mechanisms both potentiating the risk for type 1 diabetes as well as exacerbating long-term complications, particularly cardiovascular disease. Treatment options targeting the unique needs of obese pediatric patients, both before and after diagnosis of type 1 diabetes, are limited. In this review, we discuss the history of the epidemiology of the obesity epidemic in the context of pediatric type 1 diabetes, highlight the possible role of obesity in type 1 diabetes pathogenesis and review the concept of "double diabetes". The impact of obesity at and after diagnosis will be discussed, including noted differences in clinical and biochemical markers, lipid abnormalities, and long-term cardiovascular complications. Finally, we will review the existing literature on pharmacologic and nutritional interventions as potential treatment strategies for youth with coexisting type 1 diabetes and obesity.

Association of apolipoprotein C3 with insulin resistance and coronary artery calcium in patients with type 1 diabetes

BACKGROUND

Apolipoprotein C3 (APOC3) is a risk factor for incident coronary artery disease in people with type 1 diabetes (T1D). The pathways that link elevated APOC3 levels to an increased risk of incident cardiovascular disease in people with T1D are not understood.

OBJECTIVE

To explore potential mechanisms, we investigated the association of APOC3 with insulin resistance and coronary artery calcium (CAC).

METHODS

In a random subcohort of participants with T1D from Coronary Artery Calcification in Type 1 Diabetes (n = 134), serum APOC3, high-density lipoprotein (HDL)-associated APOC3, and retinol binding protein 4 (RBP4; a potential marker of insulin resistance) were measured by targeted mass spectrometry. We used linear regression to evaluate associations of serum APOC3 and HDL-APOC3 with APOB, non-HDL cholesterol, serum- and HDL-associated RBP4, and estimated insulin sensitivity and logistic regression to evaluate association with presence of CAC, adjusted for age, sex, and diabetes duration.

RESULTS

Serum APOC3 correlated positively with APOB and non-HDL cholesterol and was associated with increased odds of CAC (odds ratio: 1.68, P = .024). Estimated insulin sensitivity was not associated with serum- or HDL-RBP4 but was negatively associated with serum APOC3 in men (ß estimate: -0.318, P = .0040) and decreased odds of CAC (odds ratio: 0.434, P = .0023).

CONCLUSIONS

Serum APOC3 associates with increased insulin resistance and CAC in T1D.

Pharmacological therapies to address obesity in type 1 diabetes

PURPOSE OF REVIEW

Obesity is increasing in prevalence among patients with type 1 diabetes (T1D) and is associated with insulin resistance and increased cardiovascular risk. The management of obesity in this population is complicated by defects in pancreatic islet hormone secretion and the effects of exogenous insulin treatment. Here, we review the effects of antiobesity medications and adjunct-to-insulin medications on body weight in T1D.

RECENT FINDINGS

There is a profound evidence gap around the use of drugs for the treatment of obesity in T1D since systematic studies have not been performed in this population. Adjunctive-to-insulin therapy with certain antihyperglycemic agents leads to modest weight loss and reductions in insulin dose in T1D. However, only pramlintide has been approved in the United States for clinical use as adjunctive therapy in T1D.

SUMMARY

The growing prevalence of obesity in T1D has created an unmet need for safe and effective therapies to treat overweight and obesity in this population. Currently, antiobesity medications are used off-label for the treatment of patients with T1D. Additional studies are needed to understand the role of these medications in the management of obesity in patients with T1D.

Reducing Type 1 Diabetes Mortality: Role for Adjunctive Therapies?

Individuals with type 1 diabetes (T1D) frequently fail to achieve glycemic goals and have excess cardiovascular risk and premature death. Adjunctive agents may play a role in reducing morbidity, mortality, and the adverse sequelae of insulin treatment. A surge in type 2 diabetes drug development has revealed agents with benefits beyond glucose lowering, including cardiovascular risk reduction. Could these benefits translate to T1D? Specific trials for T1D demonstrate substantial hemoglobin (Hb)A1c reductions with sodium glucose cotransporter inhibitors (SGLTis) and glucagon-like peptide (GLP)1 agonists, and modest improvements with metformin, dipeptidyl peptidase-4 inhibitor (DPP4i), and pramlintide. Studies exploring cardiovascular risk reduction are warranted. This review synthesizes the emerging literature for researchers and clinicians treating people with T1D. Challenges in T1D research are discussed.

Obesity in Type 1 Diabetes: Pathophysiology, Clinical Impact, and Mechanisms

There has been an alarming increase in the prevalence of obesity in people with type 1 diabetes in recent years. Although obesity has long been recognized as a major risk factor for the development of type 2 diabetes and a catalyst for complications, much less is known about the role of obesity in the initiation and pathogenesis of type 1 diabetes. Emerging evidence suggests that obesity contributes to insulin resistance, dyslipidemia, and cardiometabolic complications in type 1 diabetes. Unique therapeutic strategies may be required to address these comorbidities within the context of intensive insulin therapy, which promotes weight gain. There is an urgent need for clinical guidelines for the prevention and management of obesity in type 1 diabetes. The development of these recommendations will require a transdisciplinary research strategy addressing metabolism, molecular mechanisms, lifestyle, neuropsychology, and novel therapeutics. In this review, the prevalence, clinical impact, energy balance physiology, and potential mechanisms of obesity in type 1 diabetes are described, with a special focus on the substantial gaps in knowledge in this field. Our goal is to provide a framework for the evidence base needed to develop type 1 diabetes-specific weight management recommendations that account for the competing outcomes of glycemic control and weight management.

Possible early detection of coronary artery calcium progression in type 1 diabetes: A case-control study of normoalbuminuric type 1 diabetes patients and matched controls

AIMS

Coronary artery calcium (CAC) is associated with cardiovascular (CV) disease and progression of CAC is an independent predictor of mortality. Type 1 diabetes is associated with increased CV risk, especially in persons with cardiovascular autonomic neuropathy (CAN). This study aimed to examine whether short-term progression of CAC is increased in persons with type 1 diabetes compared to matched controls and if CAN increases risk of CAC progression.

METHODS

Fifty-three normoalbuminuric persons with long-term type 1 diabetes (20 with CAN) were matched in a 1:2 ratio with 106 controls without diabetes according to age, sex and baseline CAC. All were examined twice with cardiac computed tomography scans. Progression of CAC was defined as a value ≥2.5 between the square root-transformed values of follow-up and baseline CAC volume scores.

RESULTS

The participants were examined median (interquartile range) of 25 (23-27) months (type 1 diabetes) and 29 (25-33) months (controls) apart. In multivariable logistic regression, participants with type 1 diabetes had an odds ratio of 3.3 (95% CI 1.3-8.2, p = 0.01) for CAC progression. CAN did not increase progression of CAC (p = 0.64).

CONCLUSIONS

Progression of CAC was increased in well-treated, normoalbuminuric persons with type 1 diabetes compared to matched controls without diabetes, suggesting that type 1 diabetes is a risk factor for short-term progression. This finding could explain some of the increased morbidity and mortality observed in persons with type 1 diabetes, but it does not specifically explain the increased CV risk in persons with CAN.

Impact of Excessive Weight Gain on Cardiovascular Outcomes in Type 1 Diabetes: Results From the Diabetes Control and Complications Trial/Epidemiology of Diabetes Interventions and Complications (DCCT/EDIC) Study

OBJECTIVE

Intensive treatment (INT) of type 1 diabetes reduces the incidence of cardiovascular disease (CVD) events compared with conventional treatment (CONV), but it also results in more weight gain. Our objective was to examine whether excessive weight gain from INT of type 1 diabetes is independently associated with subsequent CVD events.

RESEARCH DESIGN AND METHODS

Quartiles (Q) of weight gain in 1,213 participants aged 18 years and older at enrollment in the Diabetes Control and Complications Trial (DCCT) were determined within randomized treatment groups (INT vs. CONV) using change in BMI from baseline to the closeout DCCT visits. Effects of this weight gain on CVD risk factors and outcomes during an additional 20 years of observational follow-up were then determined.

RESULTS

The Q4 INT group experienced greater proportional weight gain (median change in BMI, 6.08 kg/m2), increases in CVD risk factors, and need for medications for hypertension and lipids compared with the Q1-3 INT and comparable CONV groups. Over a mean of 26 years of follow-up, the numbers of major and total CVD events were not statistically different in Q4 compared with Q1-3 of either the INT or CONV group. By year 14, however, the incident CVD event curve became significantly higher in the Q4 INT group than in the Q1-3 INT groups (P = 0.024) and was similar to that for the CONV group.

CONCLUSIONS

For the first 13 years after DCCT, INT for type 1 diabetes reduced macrovascular events compared with CONV, even when excessive weight gain occurred. After this, total CVD events significantly increased in the Q4 INT group, becoming equivalent to those in the CONV group. Longer follow-up is needed to determine whether this trend continues and results in more major CVD events.

Management of Asymptomatic Patients With Positive Coronary Artery Calcium Scans

Background

The widespread availability of the coronary artery calcium scan to diagnose coronary artery atheroma semiquantitatively and its prognostic significance has frequently resulted in a difficult therapeutic decision for physicians caring for asymptomatic patients.

Patients and Risk Factors

Of particular concern are patients over 40 years of age and young adults characterized by multiple cardiovascular risk factors. The correct prognostic interpretation of coronary artery calcium scores and the potential benefits and risks of various therapeutic modalities need to be understood.

Conclusion

This review describes the therapeutic choices available to endocrinologists and provides recommendations for various treatment options.

Myostatin inhibition therapy for insulin-deficient type 1 diabetes

While Type 1 Diabetes Mellitus (T1DM) is characterized by hypoinsulinemia and hyperglycemia, persons with T1DM also develop insulin resistance. Recent studies have demonstrated that insulin resistance in T1DM is a primary mediator of the micro and macrovascular complications that invariably develop in this chronic disease. Myostatin acts to attenuate muscle growth and has been demonstrated to be elevated in streptozotocin-induced diabetic models. We hypothesized that a reduction in mRNA expression of myostatin within a genetic T1DM mouse model would improve skeletal muscle health, resulting in a larger, more insulin sensitive muscle mass. To that end, Akita diabetic mice were crossed with Myostatin^Ln/Ln mice to ultimately generate a novel mouse line. Our data support the hypothesis that decreased skeletal muscle expression of myostatin mRNA prevented the loss of muscle mass observed in T1DM. Furthermore, reductions in myostatin mRNA increased Glut1 and Glut4 protein expression and glucose uptake in response to an insulin tolerance test (ITT). These positive changes lead to significant reductions in resting blood glucose levels as well as pronounced reductions in associated diabetic symptoms, even in the absence of exogenous insulin. Taken together, this study provides a foundation for considering myostatin inhibition as an adjuvant therapy in T1DM as a means to improve insulin sensitivity and blood glucose management.

The Role of a Coronary Artery Calcium Scan in Type 1 Diabetes

The coronary artery calcium (CAC) scan has recently emerged as a reproducible noninvasive test to detect asymptomatic atherosclerotic coronary artery disease. It has several advantages over the traditional cardiac stress testing modalities, including lower cost, greater sensitivity for nonobstructing coronary artery lesions, and excellent prognostic value when combined with the Framingham risk parameters. Its chief disadvantage is that it does not identify obstructing coronary artery lesions or noncalcified coronary artery plaque. A CAC scan utilizes a chest computed tomogram and computer software to calculate the amount of calcium in the four main coronary vessels. Calcium is deposited in coronary plaques so that the greater the calcium score, the greater the plaque burden. This, in turn, is the basis for predicting a 10-15-year risk of a cardiovascular event. Individuals with a zero calcium score have a very low 10-year risk of a cardiovascular event. Obtaining a calcium score in a diabetic patient permits rational decisions for prescribing statin therapy. In patients with a zero score, the initiation of statin therapy is not recommended because the 5-year incidence of atherosclerotic cardiovascular disease is so low. In patients with diabetes, it is recommended to repeat the calcium scan in 4-5 years to permit timely therapy in the event that the score becomes positive. Since statins mildly increase coronary calcium as part of the stabilization of plaque, a reduction in the calcium score should not be anticipated. However, progression of the calcium score by more than 15%/year (calculated from a repeat CAC scan) provides additional prognostic information of an indication of progression of atherosclerosis. In summary, the coronary calcium score is a major clinical advance for noninvasively detecting coronary artery disease and managing antiatherosclerotic therapy in type 1 diabetes.

The role of mineral and bone disorders in the development and progression of cardiac and renal pathology in patients with type 1 diabetes mellitus of long duration

AIMS

The objective of our study was to evaluate the role of mineral and bone metabolism disorders associated with chronic kidney disease (MBD-CKD) in the development and progression of cardiac and renal pathology in patients with type 1 diabetes mellitus (T1DM) of long duration.

METHODS

We investigated 96 patients with T1DM of long duration, with CKD at different stages (0-5), including patients on hemodialysis (HD) and with kidney transplantation (KT). Along with overall clinical examination, we assessed markers of MBD (calcium, phosphorus, parathormone, vitamin D, fibroblast growth factor (FGF) 23) and levels of cardiac injury marker (atrial natriuretic peptide, NT-proBNP). Multispiral computer tomography with Agatston index calculation was also included.

RESULTS

Decreased kidney function was associated with increased of levels phosphorus, parathormone, FGF 23, and vitamin D deficiency, with the highest deviation from the reference ranges seen in patients on HD with a very high risk of cardiovascular events. In KT patients with satisfactory graft function, these parameters were at the same levels as in patients with CKD stages 0-4. Progression of cardiovascular pathology was accompanied by elevation of NT-proBNP levels as CKD duration increased, decreased glomerular filtration rate, and were correlated with the main parameters of mineral homeostasis. The severity of coronary arteries calcification was associated with patient age and duration of T1DM and arterial hypertension.

CONCLUSIONS

Development and progression of kidney dysfunction is accompanied by MBD, a significant factor in progression of cardiac pathology, which remains a major cause of mortality in this patient population.

Body mass index changes in youth in the first year after type 1 diabetes diagnosis

OBJECTIVES

To describe changes in weight and body mass index (BMI) during the first year following diagnosis of type 1 diabetes (T1D) and associations with demographic and clinical characteristics.

STUDY DESIGN

The Pediatric Diabetes Consortium includes 7 US centers with prospective longitudinal data from initial T1D diagnosis. This analysis includes 530 youth with diabetes duration of ≥1 year and measures of BMI at 3 and 12 months after diagnosis. BMI trajectory of participants and relationships between the change in BMI z-score from baseline (3 months) to 12 months with demographic characteristics, hemoglobin A1c at baseline, and insulin delivery mode at baseline were evaluated.

RESULTS

As a group, BMI z-scores increased sharply from diagnosis for 1-3 months but remained relatively stable from +0.51 at 3 months to +0.48 at 12 months. Children aged 2-<5 years experienced a significant positive change in BMI z-score between 3 and 12 months, and there was a similar trend among girls that did not reach statistical significance. No significant differences were found for race, socioeconomic status, or insulin delivery mode.

CONCLUSIONS

These data suggest that increased BMI during the first year of treatment of most youth with T1D reflects regain of weight lost before diagnosis. There is, however, a propensity toward additional weight gain in younger children and girls.

Early diabetic nephropathy: a complication of reduced insulin sensitivity in type 1 diabetes

OBJECTIVE

Diabetic nephropathy (DN) is a major cause of mortality in type 1 diabetes. Reduced insulin sensitivity is a well-documented component of type 1 diabetes. We hypothesized that baseline insulin sensitivity would predict development of DN over 6 years.

RESEARCH DESIGN AND METHODS

We assessed the relationship between insulin sensitivity at baseline and development of early phenotypes of DN-microalbuminuria (albumin-creatinine ratio [ACR] ≥30 mg/g) and rapid renal function decline (glomerular filtration rate [GFR] loss >3 mL/min/1.73 m2 per year)-with three Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equations over 6 years. Subjects with diabetes (n = 449) and without diabetes (n = 565) in the Coronary Artery Calcification in Type 1 Diabetes study had an estimated insulin sensitivity index (ISI) at baseline and 6-year follow-up.

RESULTS

The ISI was lower in subjects with diabetes than in those without diabetes (P < 0.0001). A higher ISI at baseline predicted a lower odds of developing an ACR ≥30 mg/g (odds ratio 0.65 [95% CI 0.49-0.85], P = 0.003) univariately and after adjusting for HbA1c (0.69 [0.51-0.93], P = 0.01). A higher ISI at baseline conferred protection from a rapid decline of GFR as assessed by CKD-EPI cystatin C (0.77 [0.64-0.92], P = 0.004) and remained significant after adjusting for HbA1c and age (0.80 [0.67-0.97], P = 0.02). We found no relation between ISI and rapid GFR decline estimated by CKD-EPI creatinine (P = 0.38) or CKD-EPI combined cystatin C and creatinine (P = 0.50).

CONCLUSIONS

Over 6 years, a higher ISI independently predicts a lower odds of developing microalbuminuria and rapid GFR decline as estimated with cystatin C, suggesting a relationship between insulin sensitivity and early phenotypes of DN.

Vascular calcification in diabetes: mechanisms and implications

Cardiovascular disease (CVD) remains the leading cause of death among adults with diabetes, and CVD prevention remains a major challenge. Coronary artery calcium (CAC) score measured by electron beam tomography (EBT) or multi-slice detector computed tomography correlates closely with plaque burden and coronary angiography, and predicts coronary events independently of other risk factors. Further, progression of CAC over several years has been shown to predict increased mortality. Coronary calcification is an active process strongly associated with atherosclerotic plaque evolution and is an accepted surrogate endpoint in studies of patients with diabetes older than 30. In this review, recent findings regarding the mechanisms and implications of vascular calcification in diabetes will be discussed.

Is the risk and nature of CVD the same in type 1 and type 2 diabetes?

The incidence of both type 1 and type 2 diabetes is increasing globally, most likely explained by environmental changes, such as changing exposures to foods, viruses, and toxins, and by increasing obesity. While cardiovascular disease (CVD) mortality has been declining recently, this global epidemic of diabetes threatens to stall this trend. CVD is the leading cause of death in both type 1 and type 2 diabetes, with at least a two- to fourfold increased risk in patients with diabetes. In this review, the risk factors for CVD are discussed in the context of type 1 and type 2 diabetes. While traditional risk factors such as dyslipidemia, hypertension, and obesity are greater in type 2 patients than in type 1 diabetes, they explain only about half of the increased CVD risk. The role for diabetes-specific risk factors, including hyperglycemia and kidney complications, is discussed in the context of new study findings.

The interplay of autoimmunity and insulin resistance in type 1 diabetes

Type 1 diabetes (T1D) is a common chronic disease characterized by selective autoimmune destruction of the pancreatic islet beta cells and subsequent dependence on exogenous insulin. Certain alleles including the high-risk HLA genotype, HLA-DR3-DQ2/DR4-DQ8, place individuals at increased risk of developing T1D. Autoantibodies to beta cell antigens are used in the diagnosis of T1D, and studies have shown that they can be used to predict risk of developing T1D in first degree relatives of probands. The annual global incidence of T1D is increasing by 3-5% per year. Many environmental factors have been implicated in the rising incidence of T1D. Proponents of the accelerator hypothesis argue that T1D and type 2 diabetes (T2D) are the same disorder of insulin resistance, although with different genetic backgrounds. While insulin resistance is a recognized hallmark of T2D, it also appears to play a significant role in the pathogenesis of T1D and its vascular complications. In this article, we will review: 1) immunogenetics of T1D, 2) risk factors for the development of islet autoimmunity and T1D, 3) mechanisms of insulin resistance in T1D, and 4) links between insulin resistance and complications in T1D. Further studies are needed to define environmental factors causing T1D as well as the role of insulin resistance in the pathogenesis of T1D and its complications.