Imbalance of APOB Lipoproteins and Large HDL in Type 1 Diabetes Drives Atherosclerosis.

BACKGROUND: Individuals with type 1 diabetes (T1D) generally have normal or even higher HDL (high-density lipoprotein)-cholesterol levels than people without diabetes yet are at increased risk for atherosclerotic cardiovascular disease (CVD). Human HDL is a complex mixture of particles that can vary in cholesterol content by >2-fold. To investigate if specific HDL subspecies contribute to the increased atherosclerosis associated with T1D, we created mouse models of T1D that exhibit human-like HDL subspecies. We also measured HDL subspecies and their association with incident CVD in a cohort of people with T1D. METHODS: We generated LDL receptor-deficient (Ldlr-/-) mouse models of T1D expressing human APOA1 (apolipoprotein A1). Ldlr-/-APOA1Tg mice exhibited the main human HDL subspecies. We also generated Ldlr-/-APOA1Tg T1D mice expressing CETP (cholesteryl ester transfer protein), which had lower concentrations of large HDL subspecies versus mice not expressing CETP. HDL particle concentrations and sizes and proteins involved in lipoprotein metabolism were measured by calibrated differential ion mobility analysis and targeted mass spectrometry in the mouse models of T1D and in a cohort of individuals with T1D. Endothelial transcytosis was analyzed by total internal reflection fluorescence microscopy. RESULTS: Diabetic Ldlr-/-APOA1Tg mice were severely hyperglycemic and hyperlipidemic and had markedly elevated plasma APOB levels versus nondiabetic littermates but were protected from the proatherogenic effects of diabetes. Diabetic Ldlr-/-APOA1Tg mice expressing CETP lost the atheroprotective effect and had increased lesion necrotic core areas and APOB accumulation, despite having lower plasma APOB levels. The detrimental effects of low concentrations of larger HDL particles in diabetic mice expressing CETP were not explained by reduced cholesterol efflux. Instead, large HDL was more effective than small HDL in preventing endothelial transcytosis of LDL mediated by scavenger receptor class B type 1. Finally, in humans with T1D, increased concentrations of larger HDL particles relative to APOB100 negatively predicted incident CVD independently of HDL-cholesterol levels. CONCLUSIONS: Our results suggest that the balance between APOB lipoproteins and the larger HDL subspecies contributes to atherosclerosis progression and incident CVD in the setting of T1D and that larger HDLs exert atheroprotective effects on endothelial cells rather than by promoting macrophage cholesterol efflux.

Intramuscular diacylglycerol accumulates with acute hyperinsulinemia in insulin-resistant phenotypes.

Elevated skeletal muscle diacylglycerols (DAGs) and ceramides can impair insulin signaling, and acylcarnitines (acylCNs) reflect impaired mitochondrial fatty acid oxidation, thus, the intramuscular lipid profile is indicative of insulin resistance. Acute (i.e., postprandial) hyperinsulinemia has been shown to elevate lipid concentrations in healthy muscle and is an independent risk factor for type 2 diabetes (T2D). However, it is unclear how the relationship between acute hyperinsulinemia and the muscle lipidome interacts across metabolic phenotypes, thus contributing to or exacerbating insulin resistance. We therefore investigated the impact of acute hyperinsulinemia on the skeletal muscle lipid profile to help characterize the physiological basis in which hyperinsulinemia elevates T2D risk. In a cross-sectional comparison, endurance athletes (n = 12), sedentary lean adults (n = 12), and individuals with obesity (n = 13) and T2D (n = 7) underwent a hyperinsulinemic-euglycemic clamp with muscle biopsies. Although there were no significant differences in total 1,2-DAG fluctuations, there was a 2% decrease in athletes versus a 53% increase in T2D during acute hyperinsulinemia (P = 0.087). Moreover, C18 1,2-DAG species increased during the clamp with T2D only, which negatively correlated with insulin sensitivity (P < 0.050). Basal muscle C18:0 total ceramides were elevated with T2D (P = 0.029), but not altered by clamp. Acylcarnitines were universally lowered during hyperinsulinemia, with more robust reductions of 80% in athletes compared with only 46% with T2D (albeit not statistically significant, main effect of group, P = 0.624). Similar fluctuations with acute hyperinsulinemia increasing 1,2 DAGs in insulin-resistant phenotypes and universally lowering acylcarnitines were observed in male mice. In conclusion, acute hyperinsulinemia elevates muscle 1,2-DAG levels with insulin-resistant phenotypes. This suggests a possible dysregulation of intramuscular lipid metabolism in the fed state in individuals with low insulin sensitivity, which may exacerbate insulin resistance.NEW & NOTEWORTHY Postprandial hyperinsulinemia is a risk factor for type 2 diabetes and may increase muscle lipids. However, it is unclear how the relationship between acute hyperinsulinemia and the muscle lipidome interacts across metabolic phenotypes, thus contributing to insulin resistance. We observed that acute hyperinsulinemia elevates muscle 1,2-DAGs in insulin-resistant phenotypes, whereas ceramides were unaltered. Insulin-mediated acylcarnitine reductions are also hindered with high-fat feeding. The postprandial period may exacerbate insulin resistance in metabolically unhealthy phenotypes.

Body mass index moderates the association between diabetes distress and objective self-management behaviours in adolescents with type 1 diabetes and elevated A1Cs.

OBJECTIVE: To examine the cross-sectional associations between diabetes distress, BMI (zBMI; BMI z-score), objectively measured mean daily blood glucose readings and insulin boluses administered, and A1C in adolescents with type 1 diabetes (T1D) using insulin pumps. METHODS: T1D self-management behaviour data were downloaded from adolescents' (N = 79) devices and mean daily frequency of blood glucose readings and insulin boluses were calculated. Diabetes distress was measured (Problem Areas in Diabetes-Teen questionnaire [PAID-T]), A1C collected, and zBMI calculated from height and weight. Three multiple linear regressions were performed with blood glucose readings, insulin boluses, and A1C as the three dependent variables and covariates (age, T1D duration), zBMI, diabetes distress, and the diabetes distress x zBMI interaction as independent variables. RESULTS: Participants (55.7% female) were 14.9 ± 1.9 years old with T1D for 6.6 ± 3.4 years. zBMI moderated the relationship between diabetes distress and mean daily insulin boluses administered (b = -0.02, p = 0.02); those with higher zBMI and higher diabetes distress administered fewer daily insulin boluses. zBMI was not a moderator of the association between diabetes distress and blood glucose readings (b = -0.01, p = 0.29) or A1C (b = 0.002, p = 0.81). CONCLUSIONS: Using objective behavioural data is useful for identifying how adolescent diabetes distress and zBMI affect daily bolusing behaviour amongst adolescent insulin pump users. Although distinct interventions exist to improve T1D self-management or diabetes distress, none addresses them together while considering zBMI. Decreasing diabetes distress could be especially important for youth with high zBMI.

Social and Structural Determinants of Cardiovascular Complications of Diabetes.

PURPOSE OF REVIEW: Cardiovascular disease (CVD) is the leading cause of mortality in people who have diabetes. Racial and ethnic minorities with diabetes have suboptimal management of cardiovascular risk factors, leading to higher mortality. Social and structural determinants of health are external factors that influence an individual's ability to choose positive health behaviors. In this review, we will discuss cardiovascular complications in people who have diabetes and their relationship to social determinants of health (SDOH). RECENT FINDINGS: Recent innovations in diabetes treatment, including new devices and medications, have improved care and survival. However, disparities in the availability of these treatments to racial and ethnic minorities may contribute to continued inequities in CVD outcomes. Racial/ethnic disparities in CVD relate to inequities in economic opportunity, education and health literacy, neighborhoods and social cohesion, and health care access and quality driven by structural racism.

Sleep duration and association with cardiometabolic health in adolescents and adults with type 1 diabetes: Results from the BCQR-T1D study.

AIM: Type 1 diabetes (T1D) increases the risk of morbidity and mortality from cardiovascular disease, and insufficient sleep is prevalent. Emerging evidence suggests a link between sleep and cardiometabolic health, but this has not been examined across the lifespan in individuals with T1D. We aimed to examine associations between sleep and cardiometabolic health in adolescents and adults with T1D in a secondary analysis of data from a 4-week double-blind, random-order, placebo-controlled crossover trial of bromocriptine quick release (BCQR) therapy with a 4-week washout in between conditions. MATERIALS AND METHODS: Forty-two adults (19-60 years) and 42 adolescents (12-18 years) with T1D >9 months completed 1 week of home monitoring with wrist-worn actigraphy to estimate sleep duration and continuous glucose monitoring, anthropometrics, arterial stiffness, magnetic resonance imaging (adolescents only), and fasting laboratory testing at each treatment phase. RESULTS: Sixty-two per cent of adolescents and 74% of adults obtained <7 h of sleep per night at baseline. After adjustment for age, sex and diabetes duration, baseline sleep <7 h per night was associated with a higher body mass index, a higher waist circumference, a higher systolic blood pressure, worse arterial stiffness and a lower estimated insulin sensitivity (all p < .05). When examined by age group, associations between sleep duration and cardiometabolic health outcomes remained significant, predominantly for adolescents. In adolescents only, wake time was significantly later (p = .027) and time in bed was significantly longer with BCQR versus placebo (p = .049). CONCLUSIONS: Objectively measured sleep <7 h per night was prevalent in adolescents and adults with T1D and associated with poorer cardiometabolic health markers. Small changes in sleep were seen following BCQR treatment in adolescents only. Sleep may be an important and novel target for improving cardiometabolic health in individuals with T1D.

Longitudinal associations of the alternative healthy eating index with coronary artery calcification and pericardial adiposity in US adults with and without type 1 diabetes.

BACKGROUND AND AIM: Long-term associations between the alternative healthy eating index (AHEI) score and two predictive indicators for CVD, pericardial adipose tissue (PAT) and coronary artery calcification (CAC) volume, are lacking. Our study aims to investigate the longitudinal associations of the AHEI score with measures of CAC and PAT in adults with and without type 1 diabetes (T1D). METHODS AND RESULTS: The prospective Coronary Artery Calcification in T1D (CACTI) study included 652 people with T1D and 764 people without diabetes (non-DM) (19-56 years old) and was conducted in 2000-2002, 2003-2004, and 2006-2007. At each visit, food frequency questionnaires were collected and PAT and CAC were measured using electron beam computed tomography. Two variables were used for CAC analyses: a continuous variable for the square-root tranformed volume (SRV) for each visit and a second variable identified CAC progression from baseline to visit 3. Mixed effect models and a logistic regression model were used to conduct statistical analyses. A one-point increase in the AHEI score was significantly associated with a -0.12 cm3 (95% CI: -0.17, -0.08; p-value<0.0001) decrease in PAT volume in combined analyses, a -0.16 cm3 (95% CI: -0.22, -0.09; p-value<0.0001) decrease in the non-DM group, a marginally significant -0.07 cm3 (95% CI: -0.14, 0.002; p-value = 0.0571) decrease in the T1D group, and was not associated with either CAC outcome. CONCLUSION: The AHEI score is inversely associated with PAT; the association revealed greater magnitude of PAT reduction in the non-DM group. The AHEI score did not associate with CAC progression.

Longitudinal Associations of Healthy Dietary Pattern Scores with Coronary Artery Calcification and Pericardial Adiposity in United States Adults with and without Type 1 Diabetes.

BACKGROUND: Pericardial adipose tissue volume (PAT) and coronary artery calcification (CAC) are prognostic indicators for future cardiovascular events; however, no studies have assessed the long-term associations of adherence to dietary patterns (DPs) with PAT and CAC in adults with and without type 1 diabetes (T1D). OBJECTIVES: We investigated the longitudinal associations of the Mediterranean Diet (MedDiet) and Dietary Approaches to Stop Hypertension (DASH) diet with PAT and CAC progression in adults with and without T1D. METHODS: The Coronary Artery Calcification in Type 1 Diabetes (CACTI) study is a population-based, prospective study of 652 T1D and 764 nondiabetic mellitus (nonDM) (19-56 y) participants that began in 2000-2002 with follow-up visits in 2003-2004 and 2006-2007. At each visit, food frequency questionnaires were collected and used to develop adherence scores for the MedDiet and DASH diets. PAT and CAC were measured at each visit using electron beam computed tomography. CAC progression was defined as a ≥2.5 mm square root-transformed volume. Mixed effect models were used to conduct statistical analyses. RESULTS: Combined models found a significant-0.09 cm3 (95% CI: -0.14, -0.03; P = 0.0027) inverse association in PAT for every 1-point increase in the MedDiet score and a significant-0.26 cm3 (95% CI: -0.38, -0.14; P < 0.0001) inverse association in PAT for every 1-point increase in the DASH score. In combined models, the DPs were not significantly associated with lower odds of CAC progression; however, both DPs had significant interactions by diabetes status for CAC. Only the DASH diet was associated with lower odds of CAC progression in the nonDM group (OR: 0.96; 95% CI: 0.93, 0.99; P = 0.0224). CONCLUSIONS: These data suggest that the DPs are associated with lower PAT, which may reduce future cardiovascular events. The DASH diet may be beneficial for lower odds of CAC progression in those without T1D.

Assessing the relationship between low-calorie sweetener use and quality of life measures in adults with type 1 diabetes.

BACKGROUND: To evaluate use of low-calorie sweeteners (LCS) among adults with type 1 diabetes (T1D) and its impact on quality of life (QOL). METHODS: In this single center, cross-sectional survey study with 532 adults with T1D, Food related QOL (FRQOL), LCS specific questionnaire (LCSSQ), Diabetes Self-Management Questionnaire (DSMQ), Food Frequency Questionnaire (FFQ), Audit of Diabetes-Dependent QOL (AddQOL), Type 1 Diabetes and Life (T1DAL) questionnaires were administered through RedCAP, a secure, HIPAA-compliant web-based application. Demographics and scores of adults who used LCS in last month (recent users) and others (non-users) were compared. Results were adjusted for age, sex, diabetes duration and other parameters. RESULTS: Of 532 participants (mean age 36 ± 13, 69% female), 99% heard LCS before, 68% used them in the last month, 73% reported better glucose control with LCS use and 63% reported no health concerns about LCS use. Recent LCS users were older and had a longer diabetes duration and more complications (hypertension, or any complication) than non-users. However, A1c, AddQOL, T1DAL, FRQOL scores did not differ significantly between recent LCS users and non-users. DSMQ scores, DSMQ management, diet, health care scores did not differ between two groups; however, recent LCS users had lower physical activity score than non-users (p = 0.001). CONCLUSIONS: Most of the adults with T1D have used LCS and perceived that LCS use improved their QOL and glycemic control; however, these were not verified with questionnaires. There was no difference in QOL questionnaires except DSMQ physical activity between recent LCS users and not users with T1D. However, more patients in need to increase their QOL may be using LCS; therefore, associations between the exposure and outcome can be bi-directional.

Ultra-processed food consumption and obesity indicators in individuals with and without type 1 diabetes mellitus: a longitudinal analysis of the prospective Coronary Artery Calcification in Type 1 Diabetes (CACTI) cohort study.

OBJECTIVE: To evaluate the associations of ultra-processed food (UPF) consumption and obesity indicators among individuals with and without type 1 diabetes mellitus (T1DM) from the Coronary Artery Calcification in Type 1 Diabetes cohort study. DESIGN: A secondary analysis. The consumption of UPF was assessed using the dietary data collected with the Harvard FFQ, and each food item was categorised according to the NOVA food processing classification. Height, weight and waist circumference were measured at baseline and after a mean of 14·6-year follow-up. Generalised estimating equations stratified by diabetes status were used to assess the associations between UPF intake and obesity indicators over 14 years of follow-up. SETTING: USA. PARTICIPANTS: A total of 600 adults (256 T1DM and 344 non-diabetic controls) aged 39 ± 9·1 years at baseline and followed up for over 14 years were included. RESULTS: Participants with T1DM consumed significantly more UPF than non-diabetic controls at baseline: 7·6 ± 3·8 v. 6·6 ± 3·4 servings per day of UPF, respectively (P < 0·01). Participants with T1DM and with the highest UPF intake had the highest weight (ßQ4 v. Q1 = 3·07) and BMI (ßQ4 v. Q1 = 1·02, all P < 0·05) compared with those with the lowest UPF intake. Similar positive associations were observed in non-diabetic controls. CONCLUSIONS: Individuals with T1DM may consume more UPF than non-diabetic controls. Positive associations between UPF consumption and obesity indicators suggest that limiting UPF can be recommended for obesity prevention and management. Further research is needed to confirm these findings.

Pulmonary surfactant protein B carried by HDL predicts incident CVD in patients with type 1 diabetes.

Atherosclerotic CVD is the major cause of death in patients with type 1 diabetes mellitus (T1DM). Alterations in the HDL proteome have been shown to associate with prevalent CVD in T1DM. We therefore sought to determine which proteins carried by HDL might predict incident CVD in patients with T1DM. Using targeted MS/MS, we quantified 50 proteins in HDL from 181 T1DM subjects enrolled in the prospective Coronary Artery Calcification in Type 1 Diabetes study. We used Cox proportional regression analysis and a case-cohort design to test associations of HDL proteins with incident CVD (myocardial infarction, coronary artery bypass grafting, angioplasty, or death from coronary heart disease). We found that only one HDL protein-SFTPB (pulmonary surfactant protein B)-predicted incident CVD in all the models tested. In a fully adjusted model that controlled for lipids and other risk factors, the hazard ratio was 2.17 per SD increase of SFTPB (95% confidence interval, 1.12-4.21, P = 0.022). In addition, plasma fractionation demonstrated that SFTPB is nearly entirely bound to HDL. Although previous studies have shown that high plasma levels of SFTPB associate with prevalent atherosclerosis only in smokers, we found that SFTPB predicted incident CVD in T1DM independently of smoking status and a wide range of confounding factors, including HDL-C, LDL-C, and triglyceride levels. Because SFTPB is almost entirely bound to plasma HDL, our observations support the proposal that SFTPB carried by HDL is a marker-and perhaps mediator-of CVD risk in patients with T1DM.

Bromocriptine quick-release as adjunct therapy in youth and adults with type 1 diabetes: A randomized, placebo-controlled crossover study.

AIM: To evaluate the potential for glycaemic, renal and vascular benefits of bromocriptine quick release (BCQR) in adolescents and adults with type 1 diabetes. MATERIALS AND METHODS: Forty adolescents and 40 adults with type 1 diabetes aged 12-60 years old were enrolled in a double-blind, placebo-controlled, random order crossover study of 4 weeks of treatment in the morning with BCQR (titrated weekly from 0.8 mg to 1.6 mg to 3.2 mg, minimum dose 1.6 mg). Study assessments after each phase included blood pressure (BP), lipids, peripheral arterial stiffness and autonomic function, mixed meal tolerance test, continuous glucose monitoring (CGM), creatinine, estimated glomerular filtration rate, estimated insulin sensitivity, insulin dose and indirect calorimetry. RESULTS: Adolescents displayed baseline hyperglycaemia, insulin resistance, metabolic dysfunction and increased renal filtration compared with adults. In both age groups, continuous glucose monitoring measures, estimated insulin sensitivity and insulin dose did not differ with BCQR treatment. In adolescents, BCQR decreased systolic BP, diastolic BP and triangular index and increased serum creatinine. In adults, systolic BP, mean arterial pressure, systemic vascular resistance, and mixed meal tolerance test glucose and glucagon-like peptide 1 areas under the curve were lower, and the orthostatic drop in systolic BP was greater with BCQR. CONCLUSIONS: Greater hyperglycaemia, insulin resistance, metabolic dysfunction and renal hyperfiltration in adolescents argues for increased attention during this high-risk age period. Although BCQR had little impact on glycaemia or insulin sensitivity, initial vascular and renal responses suggest potential benefits of BCQR in adolescents and adults with type 1 diabetes requiring further study.

Physical activity and progression to type 1 diabetes in children and youth with islet autoimmunity: The diabetes autoimmunity study in the young.

AIMS/HYPOTHESES: Physical inactivity may contribute to islet autoimmunity and progression to clinical type 1 diabetes. To test this hypothesis, we evaluated physical activity, assessed by accelerometer, as an independent risk factor for progression to clinical diabetes among genetically at risk for type 1 diabetes children and youth with islet autoimmunity. METHODS: Accelerometer data were obtained for 95 children and youth participating in the diabetes autoimmunity study in the young who had islet autoimmunity. Islet autoimmunity was defined as the presence of islet autoantibodies to insulin, glutamic acid decarboxylase, tyrosine phosphatase-like protein IA-2, or zinc transporter 8. RESULTS: During prospective follow-up for up to 7 years, 13 of the 95 participants progressed to clinical diabetes. In multivariable survival analysis, none of the physical activity parameters examined predicted a higher risk of developing diabetes. In survival analysis with time-varying physical activity parameters, none of the physical activity parameters over time were associated with the risk of developing type 1 diabetes. CONCLUSIONS/INTERPRETATION: It does not appear that low-physical activity is a risk factor for progression from islet autoantibodies to diabetes in children and youth at high-genetic risk for type 1 diabetes.

Continuous Glucose Monitor, Insulin Pump, and Automated Insulin Delivery Therapies for Type 1 Diabetes: An Update on Potential for Cardiovascular Benefits.

PURPOSE OF REVIEW: The incidence of type 1 diabetes (T1D) is rising in all age groups. T1D is associated with chronic microvascular and macrovascular complications but improving glycemic trends can delay the onset and slow the progression of these complications. Utilization of technological devices for diabetes management, such as continuous glucose monitors (CGM) and insulin pumps, is increasing, and these devices are associated with improvements in glycemic trends. Thus, device use may be associated with long-term prevention of T1D complications, yet few studies have investigated the direct impacts of devices on chronic complications in T1D. This review will describe common diabetes devices and combination systems, as well as review relationships between device use and cardiovascular outcomes in T1D. RECENT FINDINGS: Findings from existing cohort and national registry studies suggest that pump use may aid in improving cardiovascular risk factors such as hypertension and dyslipidemia. Furthermore, pump users have been shown to have lower arterial stiffness and better measures of myocardial function. In registry and case-control longitudinal data, pump use has been associated with fewer cardiovascular events and reduction of cardiovascular disease (CVD) and all-cause mortality. CVD is the leading cause of morbidity and mortality in T1D. Consistent use of diabetes devices may protect against the development and progression of macrovascular complications such as CVD through improvement in glycemic trends. Existing literature is limited, but findings suggest that pump use may reduce acute cardiovascular risk factors as well as chronic cardiovascular complications and overall mortality in T1D.

Follow-Up Mental Health Care in Youth and Young Adults With Type 1 Diabetes After Positive Depression Screen and/or Suicidal Ideation.

Individuals with type 1 diabetes have higher rates of depression and suicidal ideation than the general population, and symptoms of depression are often associated with higher A1C levels and complications. This study evaluated mental health follow-up rates in youth and young adults with type 1 diabetes who screened positive for depressive symptoms or suicidal ideation and identified differences between those who obtained follow-up mental health care and those who did not. Specifically, males were less likely to obtain follow-up, and those who had mental health follow-up had decreasing A1C over the following year. These findings suggest increased assistance and monitoring are needed to ensure follow-up mental health care is obtained.

Subcellular localisation and composition of intramuscular triacylglycerol influence insulin sensitivity in humans.

AIMS/HYPOTHESIS: Subcellular localisation is an important factor in the known impact of bioactive lipids, such as diacylglycerol and sphingolipids, on insulin sensitivity in skeletal muscle; yet, the role of localised intramuscular triacylglycerol (IMTG) is yet to be described. Excess accumulation of IMTG in skeletal muscle is associated with insulin resistance, and we hypothesised that differences in subcellular localisation and composition of IMTG would relate to metabolic health status in humans. METHODS: We evaluated subcellular localisation of IMTG in lean participants, endurance-trained athletes, individuals with obesity and individuals with type 2 diabetes using LC-MS/MS of fractionated muscle biopsies and insulin clamps. RESULTS: Insulin sensitivity was significantly different between each group (athletes>lean>obese>type 2 diabetes; p < 0.001). Sarcolemmal IMTG was significantly greater in individuals with obesity and type 2 diabetes compared with lean control participants and athletes, but individuals with type 2 diabetes were the only group with significantly increased saturated IMTG. Sarcolemmal IMTG was inversely related to insulin sensitivity. Nuclear IMTG was significantly greater in individuals with type 2 diabetes compared with lean control participants and athletes, and total and saturated IMTG localised in the nucleus had a significant inverse relationship with insulin sensitivity. Total cytosolic IMTG was not different between groups, but saturated cytosolic IMTG species were significantly increased in individuals with type 2 diabetes compared with all other groups. There were no significant differences between groups for IMTG concentration in the mitochondria/endoplasmic reticulum. CONCLUSIONS/INTERPRETATION: These data reveal previously unknown differences in subcellular IMTG localisation based on metabolic health status and indicate the influence of sarcolemmal and nuclear IMTG on insulin sensitivity. Additionally, these studies suggest saturated IMTG may be uniquely deleterious for muscle insulin sensitivity. Graphical abstract.

A randomized controlled trial of transition from insulin pump to multiple daily injections using insulin degludec.

AIM: To evaluate two methods of transition from an insulin pump to multiple daily injections (MDI) using long-acting insulin degludec (IDeg). MATERIALS AND METHODS: After a 1-week run-in period, adults with type 1 diabetes for longer than 1 year and HbA1c 48-69 mmol/mol (6.5%-8.5%), who had been using an insulin pump at least for 6 months, were randomly transitioned to either standard of care (discontinued insulin pump and started IDeg in 1:1 dose) or overlap (IDeg 1:1 at pump basal dose, but pump continued for the first 48 hours with a gradual basal reduction; 50% from 0-24 hours, 75% from 24-48 hours and then pump discontinued). Participants used blinded Dexcom G6 and the IDeg dose was not changed during the trial. Primary (% time above 180 mg/dL) and secondary (% time in 70-180 mg/dL and below 70 mg/dL) outcomes were compared between the two groups during 7 days of randomization. RESULTS: Age, gender, diabetes duration and basal/bolus insulin doses were similar between patients randomized to standard of care (n = 17) or overlap (n = 13) transition. Compared with overlap transition, the standard of care group spent 4.8% more time in hyperglycaemia (least square mean 4.8% [95% CI -3.3%, 12.9%]) and 5.3% less time in range (-5.3% [-12.6%, -2.0%]), without a significant difference in hypoglycaemia (0.5% [-2.3%,3.4%]). No treatment-related adverse events were noted in either group. CONCLUSION: The overlap transition method may result in a significant improvement in time-in-range without increasing hypoglycaemia during the first week of transition from an insulin pump to MDI using IDeg in adults with type 1 diabetes.

Real-world performance of hybrid closed loop in youth, young adults, adults and older adults with type 1 diabetes: Identifying a clinical target for hybrid closed-loop use.

AIM: To describe real-world hybrid closed loop (HCL) use and glycaemic outcomes across the lifespan and identify a clinical threshold for HCL use associated with meeting the internationally recommended target of 70% sensor glucose time in range (TIR; 70-180 mg/dL). MATERIALS AND METHODS: Mixed models examined MiniMed 670G HCL use and glycaemic outcomes in 276 people with type 1 diabetes from four age groups: youth (aged <18 years), young adults (18-25 years), adults (26-49 years) and older adults (≥50 years) for 1 year. ROC analysis identified the minimum percentage HCL use associated with meeting the TIR goal of 70%. RESULTS: HCL use at month 1 was 70.7% ± 2.9% for youth, 71.0% ± 3.8% for young adults, 78.9% ± 2.1% for adults and 84.7% ± 3.8% in older adults. HCL use declined significantly at 12 months to 49.3% ± 3.2% in youth (P < .001) and 55.7% ± 4.3% in young adults (P = .002). HCL use was sustained at 12 months in adults (76.4% ± 2.2%, P = .36) and older adults (80.4% ± 3.9%, P = .36). HCL use of 70.6% was associated with 70% TIR (sensitivity 58.3%, specificity 85%, AUC 0.77). Older age, 80% or higher continuous glucose monitor use and four or more blood glucose checks per day were associated with attaining the HCL-use threshold. CONCLUSIONS: HCL use of 70% or higher may be a useful target for clinicians to use to assist people with diabetes in attaining glycaemic goals. Youth may struggle with HCL use more than adults and require clinical intervention to help sustain HCL use across time.

Development of type 2 diabetes in adolescent girls with polycystic ovary syndrome and obesity.

OBJECTIVE: Adult women with polycystic ovary syndrome (PCOS) and obesity have an 8-fold increased risk of developing type 2 diabetes (T2D). Our goal was to determine the incidence and risk factors for T2D in adolescents with PCOS and obesity. RESEARCH DESIGN AND METHODS: Retrospective chart review of girls aged 11-21 years with confirmed PCOS (oligomenorrhea and hyperandrogenism) diagnosis between July 2013 and Aug 2018 and at least one follow-up visit and BMI >85%ile. T2D incidence, defined with an HbA1c ≥6.5%, was calculated. A nested case-control study with 1:3 matching by race, ethnicity, and BMI was performed to determine predictors of T2D diagnosis. RESULTS: Four hundred ninety-three patients with PCOS (age 15.6 ± 1.9 years, BMI 36.2 ± 6.3 kg/m2 ) were identified with a follow-up of 1018 person-years. Twenty-three developed T2D (incidence 22.6/1000 person-years) with diagnosis a median of 1.8 years (2 months-5.5 years) after PCOS diagnosis. T2D risk was higher in girls with a prediabetes HbA1c (5.7%-6.4%) (HR 14.6 [4.8-44.5]) and among Hispanic girls with an elevated HbA1c and alanine aminotransferase (HR 19.0 [3.7-97.2]) at the time of PCOS diagnosis. In the 1:3 matched cohort, T2D risk was 18.7 times higher (OR 18.66 [2.27-153.24]) for every 0.1% increase in HbA1c at the time of PCOS diagnoses. CONCLUSIONS: Girls with PCOS and obesity have an 18-fold increase in T2D incidence compared to published rates in non-PCOS youth. Hispanic girls with elevated HbA1c and ALT are at particular risk. Due to the morbidity associated with youth onset T2D, these findings argue for better screening and prevention approaches in this population.

Associations of dietary patterns and nutrients with coronary artery calcification and pericardial adiposity in a longitudinal study of adults with and without type 1 diabetes.

PURPOSE: To examine the associations of dietary patterns and nutrients with coronary artery calcification (CAC) and pericardial adiposity (PAT) in adults with and without type 1 diabetes. METHODS: We conducted a six-year longitudinal analysis of data from Coronary Artery Calcification in Type 1 Diabetes study [n = 1255; T1D: n = 563; non-DM: n = 692] collected at baseline, year 3 and year 6. Participants completed a validated food frequency questionnaire, a physical examination, and fasting (12 h overnight fast) biochemical analyses. CAC and PAT were measured using electron beam computed tomography. Dietary patterns were identified using factor analysis. Generalized estimating equations were used to examine associations of dietary patterns and nutrients with CAC and PAT in models adjusted for traditional cardiovascular risks. RESULTS: The 'starchy veggies, meats and alcohol pattern' was associated with significantly increased risk of CAC presence in all adjusted models; an increasing trend was observed with CAC progression. Increasing intake of dietary proteins and total fats were also associated with higher risk of the presence and/or progression of CAC in adjusted models (all p < 0.05). PAT was positively associated with dietary total fats, and inversely associated with dietary intakes of saturated fats, omega-3 fats and fiber in models adjusted for age, sex, total calories, time, diabetes status, systolic blood pressure, serum lipids and physical activity. CONCLUSION: Diets high in total fats and proteins, and in meats (processed and red) and alcohol may increase risks of CAC, while saturated fats, omega-3-fats and fiber may be protective against pericardial adiposity as a risk factor for coronary artery disease. ClinicalTrials.gov Identifier: NCT00005754.