Closed-loop insulin delivery in pregnant women with type 1 diabetes (CRISTAL): a multicentre randomized controlled trial - study protocol.

BACKGROUND: Despite increasing use of continuous glucose monitoring (CGM) and continuous subcutaneous insulin infusion (CSII, insulin pumps) in type 1 diabetes (T1D) in pregnancy, achieving recommended pregnancy glycaemic targets (3.5-7.8 mmol/L or 63-140 mg/dL) remains challenging. Consequently, the risk of adverse pregnancy outcomes remains high. Outside pregnancy, hybrid closed-loop (HCL) insulin delivery systems have led to a paradigm shift in the management of T1D, with 12% higher time in glucose target range (TIR) compared to conventional CSII. However, most commercially available HCL systems are currently not approved for use in pregnancy. This study aims to evaluate the efficacy, safety and cost-effectiveness of the MiniMed™ 780G HCL system (Medtronic) in T1D in pregnancy. METHODS: In this international, open-label, randomized controlled trial (RCT), we will compare the MiniMed™ 780G HCL system to standard of care (SoC) in T1D in pregnancy. Women aged 18-45 years with T1D diagnosis of at least one year, HbA1c ≤ 86 mmol/mol (≤ 10%), and confirmed singleton pregnancy up to 11 weeks 6 days will be eligible. After providing written informed consent, all participants will wear a similar CGM system (Guardian™ 3 or Guardian™ 4 CGM) during a 10-day run-in phase. After the run-in phase, participants will be randomised 1:1 to 780G HCL (intervention) or SoC [control, continuation of current T1D treatment with multiple daily injections (MDI) or CSII and any type of CGM] stratified according to centre, baseline HbA1c (< 53 vs. ≥ 53 mmol/mol or < 7 vs. ≥ 7%), and method of insulin delivery (MDI or CSII). The primary outcome will be the time spent within the pregnancy glucose target range, as measured by the CGM at four time points in pregnancy: 14-17, 20-23, 26-29, and 33-36 weeks. Prespecified secondary outcomes will be overnight TIR, time below range (TBR: <3.5 mmol/L or < 63 mg/dL), and overnight TBR. Other outcomes will be exploratory. The planned sample size is 92 participants. The study will end after postpartum discharge from hospital. Analyses will be performed according to intention-to-treat as well as per protocol. DISCUSSION: This large RCT will evaluate a widely used commercially available HCL system in T1D in pregnancy. Recruitment began in January 2021 and was completed in October 2022. Study completion is expected in May 2023. TRIAL REGISTRATION: ClinicalTrials.gov: NCT04520971. Registration date: August 20, 2020. https://clinicaltrials.gov/ct2/show/NCT04520971.

Identification of novel genetic Loci associated with thyroid peroxidase antibodies and clinical thyroid disease.

Autoimmune thyroid diseases (AITD) are common, affecting 2-5% of the general population. Individuals with positive thyroid peroxidase antibodies (TPOAbs) have an increased risk of autoimmune hypothyroidism (Hashimoto's thyroiditis), as well as autoimmune hyperthyroidism (Graves' disease). As the possible causative genes of TPOAbs and AITD remain largely unknown, we performed GWAS meta-analyses in 18,297 individuals for TPOAb-positivity (1769 TPOAb-positives and 16,528 TPOAb-negatives) and in 12,353 individuals for TPOAb serum levels, with replication in 8,990 individuals. Significant associations (P<5×10(-8)) were detected at TPO-rs11675434, ATXN2-rs653178, and BACH2-rs10944479 for TPOAb-positivity, and at TPO-rs11675434, MAGI3-rs1230666, and KALRN-rs2010099 for TPOAb levels. Individual and combined effects (genetic risk scores) of these variants on (subclinical) hypo- and hyperthyroidism, goiter and thyroid cancer were studied. Individuals with a high genetic risk score had, besides an increased risk of TPOAb-positivity (OR: 2.18, 95% CI 1.68-2.81, P = 8.1×10(-8)), a higher risk of increased thyroid-stimulating hormone levels (OR: 1.51, 95% CI 1.26-1.82, P = 2.9×10(-6)), as well as a decreased risk of goiter (OR: 0.77, 95% CI 0.66-0.89, P = 6.5×10(-4)). The MAGI3 and BACH2 variants were associated with an increased risk of hyperthyroidism, which was replicated in an independent cohort of patients with Graves' disease (OR: 1.37, 95% CI 1.22-1.54, P = 1.2×10(-7) and OR: 1.25, 95% CI 1.12-1.39, P = 6.2×10(-5)). The MAGI3 variant was also associated with an increased risk of hypothyroidism (OR: 1.57, 95% CI 1.18-2.10, P = 1.9×10(-3)). This first GWAS meta-analysis for TPOAbs identified five newly associated loci, three of which were also associated with clinical thyroid disease. With these markers we identified a large subgroup in the general population with a substantially increased risk of TPOAbs. The results provide insight into why individuals with thyroid autoimmunity do or do not eventually develop thyroid disease, and these markers may therefore predict which TPOAb-positives are particularly at risk of developing clinical thyroid dysfunction.

Validation of the FNIH sarcopenia criteria and SOF frailty index as predictors of long-term mortality in ambulatory older men.

OBJECTIVE: we aimed to evaluate the Foundation for the National Institutes of Health (FNIH) criteria for weakness and low muscle mass and the Study of Osteoporotic Fractures (SOF) frailty index for prediction of long-term, all-cause mortality. DESIGN: community-based cohort study. SETTING: semi-rural community of Merelbeke (Belgium). SUBJECTS: ambulatory men aged 74 and more (n = 191). METHODS: weakness was defined on previously established criteria as low grip strength (<26 kg) or low grip strength-to-body mass index (BMI) ratio (<1.00). Low muscle mass (dual-energy x-ray absorptiometry) was categorised as low appendicular lean mass (ALM; predefined <19.75 kg) or low ALM-to-BMI ratio (predefined <0.789). Frailty status was assessed using the components of weight loss, inability to rise from a chair and poor energy (SOF index). Survival time was calculated as the number of months from assessment in 2000 until death or up to 15 years of follow-up. RESULTS: mean age of the participants was 78.4 ± 3.5 years. Combined weakness and low muscle mass was present in 3-8% of men, depending on the criteria applied. Pre-frailty and frailty were present in 30 and 7% of men, respectively. After 15 years of follow-up, 165 men (86%) died. Both the presence of combined weakness and low ALM-to-BMI ratio (age-adjusted HR = 2.50, 95% CI = 1.30-4.79) and the presence of SOF frailty (age-adjusted HR = 2.64, 95% CI = 1.44-4.86) were associated with mortality. CONCLUSIONS: our findings confirm the predictive value for mortality of the non-distribution-based FNIH criteria and SOF index in older community-dwelling Belgian men.

Effects of tail suspension on serum testosterone and molecular targets regulating muscle mass.

INTRODUCTION: The contribution of reduced testosterone levels to tail suspension (TS)-induced muscle atrophy remains equivocal. The molecular mechanism by which testosterone regulates muscle mass during TS has not been investigated. METHODS: Effects of TS on serum testosterone levels, muscle mass, and expression of muscle atrophy- and hypertrophy-inducing targets were measured in soleus (SOL) and extensor digitorum longus (EDL) muscles after testosterone administration during 1, 5, and 14 days of TS in male mice. RESULTS: TS produced an increase followed by a transient drop in testosterone levels. Muscle atrophy was associated with downregulation of Igf1 and upregulation of Mstn, Redd1, Atrogin-1, and MuRF1 mRNA with clear differences in Igf1, Mstn, and MAFbx/Atrogin-1 gene expression between SOL and EDL. Testosterone supplementation did not affect muscle mass or protein expression levels during TS. Conclusions The known anabolic effects of testosterone are not sufficient to ameliorate loss of muscle mass during TS.

Glycated nail proteins: a new approach for detecting diabetes in developing countries.

OBJECTIVE: To assess glycation of nail proteins as a tool in the diagnosis of diabetes. METHODS: Glycation of nail proteins was assessed using a modified photometric nitroblue tetrazolium-based assay, which provides information about average glucose values of the last 6-9 months. Analysis is possible on 10 mg of nail clippings with a within-run coefficient of variation (CV) of 11%. The analyte is extremely stable. The reference range for glycated nail protein (0.55-3.60 µmol/g nail) increases upon ageing. RESULTS: In diabetics (n = 112), values for glycated nail protein are significantly higher (median: 4.07 µmol/g nail, IQR: 2.37-6.89 µmol/g nail, P < 0.0001) than in non-diabetics (n = 116). ROC analysis shows an AUC of 0.848 (specificity 93.1%; sensitivity 68.9%). CONCLUSION: This affordable method is a simple alternative for diagnosing diabetes in remote areas as the pre-analytical phase (including all processes from the time a laboratory request is made by a physician until the sample is ready for testing) is extremely robust.

The effect of magnesium supplements on early post-transplantation glucose metabolism: a randomized controlled trial.

Post-transplantation hypomagnesemia is common and predicts diabetes. Magnesium improves glycemic control in diabetics and insulin sensitivity in insulin resistant subjects. We aimed to assess the effectiveness of oral magnesium for improving glycemic control and insulin sensitivity at 3 months post-transplantation. We conducted a single-center, open-label, randomized parallel group study. We included adults with serum magnesium <1.7 mg/dl within 2 weeks after kidney transplantation. We randomized participants to 450 mg magnesium oxide up to three times daily or no treatment. The primary endpoint was the mean difference in fasting glycemia. Secondary endpoints were the mean difference in area under the curve (AUC) of glucose during an oral glucose tolerance test and insulin resistance measured by Homeostasis Model of Assessment-Insulin Resistance (HOMA-IR). Analyses were on intention-to-treat basis. In patients randomized to magnesium oxide (N = 27) versus no treatment (N = 27), fasting glycemia on average was 11.5 mg/dl lower (95% CI 1.7 to 21.3; P = 0.02). There was no difference between the two groups neither for 2 h AUC, where the mean value was 1164 mg/dl/min (95% CI -1884 to 4284; P = 0.45) lower in the treatment group nor for HOMA-IR. Magnesium supplements modestly improved fasting glycemia without effect on insulin resistance. Higher baseline glycemia among patients in the control group may have driven the positive outcome (ClinicalTrials.gov number: NCT01889576).

Comparing advanced hybrid closed loop therapy and standard insulin therapy in pregnant women with type 1 diabetes (CRISTAL): a parallel-group, open-label, randomised controlled trial.

BACKGROUND: Advanced hybrid closed loop (AHCL) therapy can improve glycaemic control in pregnant women with type 1 diabetes. However, data are needed on the efficacy and safety of AHCL systems as these systems, such as the MiniMed 780G, are not currently approved for use in pregnant women. We aimed to investigate whether the MiniMed 780G can improve glycaemic control with less hypoglycaemia in pregnant women with type 1 diabetes. METHODS: CRISTAL was a double-arm, parallel-group, open-label, randomised controlled trial conducted in secondary and tertiary care specialist endocrinology centres at 12 hospitals (11 in Belgium and one in the Netherlands). Pregnant women aged 18-45 years with type 1 diabetes were randomly assigned (1:1) to AHCL therapy (MiniMed 780G) or standard insulin therapy (standard of care) at a median of 10·1 (IQR 8·6-11·6) weeks of gestation. Randomisation was done centrally with minimisation dependent on baseline HbA1c, insulin administration method, and centre. Participants and study teams were not masked to group allocation. The primary outcome was proportion of time spent in the pregnancy-specific target glucose range (3·5-7·8 mmol/L), measured by continuous glucose monitoring (CGM) at 14-17 weeks, 20-23 weeks, 26-29 weeks, and 33-36 weeks. Key secondary outcomes were overnight time in target range, and time below glucose range (<3·5 mmol/L) overall and overnight. Analyses were conducted on an intention-to-treat basis. This trial is registered with ClinicalTrials.gov (NCT04520971). FINDINGS: Between Jan 15, 2021 and Sept 30, 2022, 101 participants were screened, and 95 were randomly assigned to AHCL therapy (n=46) or standard insulin therapy (n=49). 43 patients assigned to AHCL therapy and 46 assigned to standard insulin therapy completed the study. At baseline, 91 (95·8%) participants used insulin pumps, and the mean HbA1c was 6·5% (SD 0·6). The mean proportion of time spent in the target range (averaged over four time periods) was 66·5% (SD 10·0) in the AHCL therapy group compared with 63·2% (12·4) in the standard insulin therapy group (adjusted mean difference 1·88 percentage points [95% CI -0·82 to 4·58], p=0·17). Overnight time in the target range was higher (adjusted mean difference 6·58 percentage points [95% CI 2·31 to 10·85], p=0·0026), and time below range overall (adjusted mean difference -1·34 percentage points [95% CI, -2·19 to -0·49], p=0·0020) and overnight (adjusted mean difference -1·86 percentage points [95% CI -2·90 to -0·81], p=0·0005) were lower with AHCL therapy than with standard insulin therapy. Participants assigned to AHCL therapy reported higher treatment satisfaction. No unanticipated safety events occurred with AHCL therapy. INTERPRETATION: In pregnant women starting with tighter glycaemic control, AHCL therapy did not improve overall time in target range but improved overnight time in target range, reduced time below range, and improved treatment satisfaction. These data suggest that the MiniMed 780G can be safely used in pregnancy and provides some additional benefits compared with standard insulin therapy; however, it will be important to refine the algorithm to better align with pregnancy requirements. FUNDING: Diabetes Liga Research Fund and Medtronic.

Physical function measurements predict mortality in ambulatory older men.

BACKGROUND: To assess and compare the predictive value of physical function measurements (PFMs) for all-cause mortality in older men and to evaluate the Timed Up and Go test (TUG) as a predictor in subjects with underlying comorbidity. DESIGN: Observational study of a population-based sample of 352 ambulatory older men aged 71-86 at study baseline. The Rapid disability rating scale-2, 36-Item short form health survey, Grip strength, Five times sit-to-stand test, Standing balance, and TUG were determined at baseline. Associations with all-cause mortality were assessed using Cox proportional hazard analyses. Age, Body mass index (BMI), smoking status, education, physical activity and cognitive status were included as confounders. Follow-up exceeded 15 years. Comorbidity status was categorized into cardiovascular disease, chronic obstructive pulmonary disease (COPD) and diabetes mellitus. RESULTS: All examined PFMs were associated with all-cause mortality. TUG was the best predictor (adjusted HR per SD increase = 1·58, 95% CI = 1·40-1·79, P < 0·001) for global mortality and continued to be predictive in subjects with cardiovascular disease (adjusted HR per SD increase = 1·80, 95% CI = 1·40-2·33, P < 0·001). CONCLUSIONS: The assessment of physical functioning is important in the evaluation of older persons. We encourage the use of the TUG as a reliable, quick and feasible screening tool in clinical settings.

Prenatal lipid-based nutrient supplements increase cord leptin concentration in pregnant women from rural Burkina Faso.

In developing countries, prenatal lipid-based nutrient supplements (LNSs) were shown to increase birth size; however, the mechanism of this effect remains unknown. Cord blood hormone concentrations are strongly associated with birth size. Therefore, we hypothesize that LNSs increase birth size through a change in the endocrine regulation of fetal development. We compared the effect of daily prenatal LNSs with multiple micronutrient tablets on cord blood hormone concentrations using a randomized, controlled design including 197 pregnant women from rural Burkina Faso. Insulin-like growth factors (IGF) I and II, their binding proteins IGFBP-1 and IGFBP-3, leptin, cortisol, and insulin were quantified in cord sera using immunoassays. LNS was associated with higher cord blood leptin mainly in primigravidae (+57%; P = 0.02) and women from the highest tertile of BMI at study inclusion (+41%; P = 0.02). We did not find any significant LNS effects on other measured cord hormones. The observed increase in cord leptin was associated with a significantly higher birth weight. Cord sera from small-for-gestational age newborns had lower median IGF-I (-9 µg/L; P = 0.003), IGF-II (-79 µg/L; P = 0.003), IGFBP-3 (-0.7 µg/L; P = 0.007), and leptin (-1.0 µg/L; P = 0.016) concentrations but higher median cortisol (+18 µg/L; P = 0.037) concentrations compared with normally grown newborns. Prenatal LNS resulted in increased cord leptin concentrations in primigravidae and mothers with higher BMI at study inclusion. The elevated leptin concentrations could point toward a higher neonatal fat mass.

Long-term evaluation of donor-site morbidity after radial forearm flap phalloplasty for transsexual men.

INTRODUCTION: Phalloplasty using the radial forearm flap is currently the most frequently used technique to create the neophallus in transsexual men (formerly described as female-to-male transsexual persons). Although it is considered the gold standard, its main disadvantage is the eventual donor-site morbidity in a young, healthy patient population. AIM: The study aims to examine the long-term effects of radial forearm flap phalloplasty in transsexual men and to evaluate aesthetic outcome, scar acceptance, bone health, and daily functioning. MAIN OUTCOME MEASURES: Scars were evaluated with the patient and observer scar assessment scale, the Vancouver Scar Scale, and self-reported satisfaction. Bone health was assessed using dual X-ray absorptiometry and peripheral quantitative computed tomography, and daily functioning using a physical activity questionnaire (Baecke). These measurements were compared with 44 age-matched control women. METHODS: This is a cross-sectional study of 44 transsexual, a median of 7 years after radial forearm flap phalloplasty, recruited from the Center for Sexology and Gender Problems at the Ghent University Hospital, Belgium. RESULTS: We observed no functional limitations on daily life activities, a pain-free and rather aesthetic scar, and unaffected bone health a median of 7 years after radial foreram flap phalloplasty. Over 75% of transsexual men were either satisfied or neutral with the appearance of the scar. CONCLUSIONS: Transsexual men, despite scarring the forearm, consider the radial forearm flap phalloplasty as worthwhile.

Gene expression of carnosine-related enzymes and transporters in skeletal muscle.

Chronic oral beta-alanine supplementation can elevate muscle carnosine (beta-alanyl-L-histidine) content and improve high-intensity exercise performance. However, the regulation of muscle carnosine levels is poorly understood. The uptake of the rate-limiting precursor beta-alanine and the enzyme catalyzing the dipeptide synthesis are thought to be key steps. The aims of this study were to investigate the expression of possible carnosine-related enzymes and transporters in both human and mouse skeletal muscle in response to carnosine-altering stimuli. Human gastrocnemius lateralis and mouse tibialis anterior muscle samples were subjected to HPLC and qPCR analysis. Mice were subjected to chronic oral supplementation of beta-alanine and carnosine or to orchidectomy (7 and 30 days, with or without testosterone replacement), stimuli known to, respectively, increase and decrease muscle carnosine and anserine. The following carnosine-related enzymes and transporters were expressed in human and/or mouse muscles: carnosine synthase (CARNS), carnosinase-2 (CNDP2), the carnosine/histidine transporters PHT1 and PHT2, the beta-alanine transporters TauT and PAT1, beta-alanine transaminase (ABAT) and histidine decarboxylase (HDC). Six of these genes showed altered expression in the investigated interventions. Orchidectomy led to decreased muscle carnosine content, which was paralleled with decreased TauT expression, whereas CARNS expression was surprisingly increased. Beta-alanine supplementation increased both muscle carnosine content and TauT, CARNS and ABAT expression, suggesting that muscles increase beta-alanine utilization through both dipeptide synthesis (CARNS) and deamination (ABAT) and further oxidation, in conditions of excess availability. Collectively, these data show that muscle carnosine homeostasis is regulated by nutritional and hormonal stimuli in a complex interplay between related transporters and enzymes.

Low plasma carnosinase activity promotes carnosinemia after carnosine ingestion in humans.

A polymorphism in the carnosine dipeptidase-1 gene (CNDP1), resulting in decreased plasma carnosinase activity, is associated with a reduced risk for diabetic nephropathy. Because carnosine, a natural scavenger/suppressor of ROS, advanced glycation end products, and reactive aldehydes, is readily degraded in blood by the highly active carnosinase enzyme, it has been postulated that low serum carnosinase activity might be advantageous to reduce diabetic complications. The aim of this study was to examine whether low carnosinase activity promotes circulating carnosine levels after carnosine supplementation in humans. Blood and urine were sampled in 25 healthy subjects after acute supplementation with 60 mg/kg body wt carnosine. Precooled EDTA-containing tubes were used for blood withdrawal, and plasma samples were immediately deproteinized and analyzed for carnosine and ß-alanine by HPLC. CNDP1 genotype, baseline plasma carnosinase activity, and protein content were assessed. Upon carnosine ingestion, 8 of the 25 subjects (responders) displayed a measurable increase in plasma carnosine up to 1 h after supplementation. Subjects with no measurable increment in plasma carnosine (nonresponders) had ∼2-fold higher plasma carnosinase protein content and ∼1.5-fold higher activity compared with responders. Urinary carnosine recovery was 2.6-fold higher in responders versus nonresponders and was negatively dependent on both the activity and protein content of the plasma carnosinase enzyme. In conclusion, low plasma carnosinase activity promotes the presence of circulating carnosine upon an oral challenge. These data may further clarify the link among CNDP1 genotype, carnosinase, and diabetic nephropathy.

Single nucleotide polymorphisms in sFRP4 are associated with bone and body composition related parameters in Danish but not in Belgian men.

The senescence accelerated mouse P6 (SAMP6) has a low bone mass and has previously shown to be a good model for senile osteoporosis in humans. In addition to a reduced bone mass, SAMP6 mice are obese and have hyperlipidemia. Using positional cloning and expression studies, an increased expression of sfrp4 was found in these mice. SFRP4 is a modulator of the Wnt signalling pathway. This pathway has been previously shown to be involved in regulating bone mass. Additional evidence that sFRP4 has an influence on BMD was delivered by linkage and association studies mostly performed in Asian populations. Based on these data we decided to perform an association study between common variants in sFRP4, BMD, hip geometry parameters and body composition parameters in a population consisting of 1383 Danish men (783 aged 20-29 years; 600 aged 60-74 years). Afterwards we tried to replicate the significant results in a population of 994 Belgian men. In the Danish population we found 6 SNPs associated with BMD at the hip and/or femoral neck. Furthermore, all 6 SNPs were associated with several hip geometry parameters. The homozygous presence of the minor allele resulted for all SNPs (except rs4720265) in a decrease in bone density and bone strength. Finally, we observed in the Danish population age specific associations with height and fat mass. In the Belgian population we tried to replicate the results of three SNPs with BMD and body composition parameters. Unfortunately, we were not able to replicate the results found in the Danish cohort but we found one SNP (rs2598116) associated with height. In conclusion, genetic variation in sFRP4 has an influence on hip fracture risk, percentage body fat and height in a Danish male population. However, we were unable to replicate these results in an independent Belgian population.

Association study of common variants in the sFRP1 gene region and parameters of bone strength and body composition in two independent healthy Caucasian male cohorts.

Bone mineral density (BMD) and bone strength are predictive parameters for the development of osteoporosis and related fracture later in life. Although it is well known that BMD and bone strength have a high heritability, not much of the variation is already explained. Mice models showed that sFRP1 has an influence on bone formation. Therefore this study aimed to investigate the effect of common genetic variation on BMD and bone strength in Caucasian men of different ages. Using HapMap we selected 13 tagSNPs which tag most common genetic variation in and around sFRP1 and we genotyped these SNPs in the young cohort of the Odense Androgen Study (OAS). The OAS includes a total of 1383 Danish men from two different age groups ([20-29 years]: N=783; [60-74 years]: N=600) and is well characterised. The subjects were phenotyped for BMD at several sites, and additionally for body composition and hip geometry parameters. Based on the results of the young cohort we selected three SNPs for further analysis in the complete OAS population. To conclude we tried to replicate the results of two SNPs in an independent population of 994 Belgian men. We found a strong association for rs9694405 with BMI as well in both cohorts separately as in the whole OAS population. Further we found rs4736965 associated with several hip geometry parameters in the same population. However we were not able to replicate those results in the Belgian population. At last we found in the OAS population age specific effects for rs10106678 with whole body BMD and waist to hip ratio.

Sex hormone-binding globulin at the crossroad of body composition, somatotropic axis and insulin/glucose homeostasis in young healthy men.

OBJECTIVES: Sex hormone-binding globulin (SHBG) modulates the bioavailability of sex steroids at tissue level. Genetic, hormonal and lifestyle-related factors determine the SHBG levels, and low SHBG levels are a known risk factor for the development of the metabolic syndrome, diabetes and cardiovascular diseases. We investigated to what extent different determinants contribute to the variation in SHBG levels in healthy young men. DESIGN AND PATIENTS: Healthy male siblings (n = 677) aged 25-45 year were recruited in a cross-sectional, population-based study. MEASUREMENTS: Lean and fat mass were measured using dual-energy X-ray absorptiometry (DXA), and immunoassays were used to determine the serum hormonal levels. Additional information about smoking and physical activity was obtained using questionnaires. Carriers of two SHBG polymorphisms, the Asp327Asn polymorphism and the (TAAAA)(n) repeat polymorphism, were identified. RESULTS: Weight, BMI, whole body fat mass and truncal fat mass were negatively associated with SHBG levels. Body composition characteristics did not differ between SHBG genotype groups, indicating that body composition controls SHBG levels rather than the other way around. The associations may be mediated by adipokines because leptin and adiponectin were, respectively, inversely and positively associated with SHBG levels. Insulin and glucose were negatively associated with SHBG levels, as well as IGF-1 and IGF-BP3, while no associations were found with free thyroid hormone status. CONCLUSIONS: In conclusion, we found that fat mass, insulin and IGF-1 levels are important negative determinants of SHBG levels in young healthy men. The association with fat mass could be mediated by the effects of adiponectin and/or leptin on SHBG synthesis.

Reduced muscle carnosine content in type 2, but not in type 1 diabetic patients.

Carnosine is present in high concentrations in skeletal muscle where it contributes to acid buffering and functions also as a natural protector against oxidative and carbonyl stress. Animal studies have shown an anti-diabetic effect of carnosine supplementation. High carnosinase activity, the carnosine degrading enzyme in serum, is a risk factor for diabetic complications in humans. The aim of the present study was to compare the muscle carnosine concentration in diabetic subjects to the level in non-diabetics. Type 1 and 2 diabetic patients and matched healthy controls (total n=58) were included in the study. Muscle carnosine content was evaluated by proton magnetic resonance spectroscopy (3 Tesla) in soleus and gastrocnemius. Significantly lower carnosine content (-45%) in gastrocnemius muscle, but not in soleus, was shown in type 2 diabetic patients compared with controls. No differences were observed in type 1 diabetic patients. Type II diabetic patients display a reduced muscular carnosine content. A reduction in muscle carnosine concentration may be partially associated with defective mechanisms against oxidative, glycative and carbonyl stress in muscle.

Relationship Between Time in Range, Glycemic Variability, HbA1c, and Complications in Adults With Type 1 Diabetes Mellitus.

PURPOSE: Real-time continuous glucose monitoring (RT-CGM) provides information on glycemic variability (GV), time in range (TIR), and guidance to avoid hypoglycemia, thereby complimenting HbA1c for diabetes management. We investigated whether GV and TIR were independently associated with chronic and acute diabetes complications. METHODS: Between September 2014 and January 2017, 515 subjects with type 1 diabetes using sensor-augmented pump therapy were followed for 24 months. The link between baseline HbA1c and CGM-derived glucometrics (TIR [70-180 mg/dL], coefficient of variation [CV], and SD) obtained from the first 2 weeks of RT-CGM use and the presence of complications was investigated. Complications were defined as: composite microvascular complications (presence of neuropathy, retinopathy, or nephropathy), macrovascular complications, and hospitalization for hypoglycemia and/or ketoacidosis. RESULTS: Individuals with microvascular complications were older (P < 0.001), had a longer diabetes duration (P < 0.001), a higher HbA1c (7.8 ± 0.9 vs 7.5 ± 0.9%, P < 0.001), and spent less time in range (60.4 ± 12.2 vs 63.9 ± 13.8%, P = 0.022) compared with those without microvascular complication. Diabetes duration (odds ratio [OR] = 1.12 [1.09-1.15], P < 0.001) and TIR (OR = 0.97 [0.95-0.99], P = 0.005) were independent risk factors for composite microvascular complications, whereas SD and CV were not. Age (OR = 1.08 [1.03-1.14], P = 0.003) and HbA1c (OR = 1.80 [1.02-3.14], P = 0.044) were risk factors for macrovascular complications. TIR (OR = 0.97 [0.95-0.99], P = 0.021) was the only independent risk factor for hospitalizations for hypoglycemia or ketoacidosis. CONCLUSIONS: Lower TIR was associated with the presence of composite microvascular complications and with hospitalization for hypoglycemia or ketoacidosis. TIR, SD, and CV were not associated with macrovascular complications.

Vegetarianism, female gender and increasing age, but not CNDP1 genotype, are associated with reduced muscle carnosine levels in humans.

Carnosine is found in high concentrations in skeletal muscles, where it is involved in several physiological functions. The muscle carnosine content measured within a population can vary by a factor 4. The aim of this study was to further characterize suggested determinants of the muscle carnosine content (diet, gender and age) and to identify new determinants (plasma carnosinase activity and testosterone). We investigated a group of 149 healthy subjects, which consisted of 94 men (12 vegetarians) and 55 women. Muscle carnosine was quantified in M. soleus, gastrocnemius and tibialis anterior using magnetic resonance proton spectroscopy and blood samples were collected to determine CNDP1 genotype, plasma carnosinase activity and testosterone concentrations. Compared to women, men have 36, 28 and 82% higher carnosine concentrations in M. soleus, gastrocnemius and tibialis anterior muscle, respectively, whereas circulating testosterone concentrations were unrelated to muscle carnosine levels in healthy men. The carnosine content of the M. soleus is negatively related to the subjects' age. Vegetarians have a lower carnosine content of 26% in gastrocnemius compared to omnivores. In contrast, there is no difference in muscle carnosine content between omnivores with a high or low ingestion of ß-alanine. Muscle carnosine levels are not related to the polymorphism of the CNDP1 gene or to the enzymatic activity of the plasma carnosinase. In conclusion, neither CNDP1 genotype nor the normal variation in circulating testosterone levels affects the muscular carnosine content, whereas vegetarianism, female gender and increasing age are the factors associated with reduced muscle carnosine stores.

Effects of sprint training combined with vegetarian or mixed diet on muscle carnosine content and buffering capacity.

Carnosine is an abundant dipeptide in human skeletal muscle with proton buffering capacity. There is controversy as to whether training can increase muscle carnosine and thereby provide a mechanism for increased buffering capacity. This study investigated the effects of 5 weeks sprint training combined with a vegetarian or mixed diet on muscle carnosine, carnosine synthase mRNA expression and muscle buffering capacity. Twenty omnivorous subjects participated in a 5 week sprint training intervention (2-3 times per week). They were randomized into a vegetarian and mixed diet group. Measurements (before and after the intervention period) included carnosine content in soleus, gastrocnemius lateralis and tibialis anterior by proton magnetic resonance spectroscopy ((1)H-MRS), true-cut biopsy of the gastrocnemius lateralis to determine in vitro non-bicarbonate muscle buffering capacity, carnosine content (HPLC method) and carnosine synthase (CARNS) mRNA expression and 6 × 6 s repeated sprint ability (RSA) test. There was a significant diet × training interaction in soleus carnosine content, which was non-significantly increased (+11%) with mixed diet and non-significantly decreased (-9%) with vegetarian diet. Carnosine content in other muscles and gastrocnemius buffer capacity were not influenced by training. CARNS mRNA expression was independent of training, but decreased significantly in the vegetarian group. The performance during the RSA test improved by training, without difference between groups. We found a positive correlation (r = 0.517; p = 0.002) between an invasive and non-invasive method for muscle carnosine quantification. In conclusion, this study shows that 5 weeks sprint training has no effect on the muscle carnosine content and carnosine synthase mRNA.

Sustained Impact of Real-time Continuous Glucose Monitoring in Adults With Type 1 Diabetes on Insulin Pump Therapy: Results After the 24-Month RESCUE Study.

OBJECTIVE: In recent years, a growing number of people with type 1 diabetes gained access to real-time continuous glucose monitoring (rtCGM). Long-term benefits of rtCGM are unclear because of a lack of large studies of long duration. We evaluated whether real-world rtCGM use up to 24 months offered benefits, particularly in those living with impaired awareness of hypoglycemia (IAH). RESEARCH DESIGN AND METHODS: This 24-month, prospective, observational cohort study followed 441 adults with insulin pumps receiving full reimbursement for rtCGM. Forty-two percent had IAH. The primary end point was evolution of HbA1c, with secondary end points change in acute hypoglycemia complications, diabetes-related work absenteeism, and quality of life scores. Additionally, we evaluated whether people could achieve glycemic consensus targets during follow-up. RESULTS: After 24 months, HbA1c remained significantly lower compared with baseline (7.64% [60 mmol/mol] vs. 7.37% [57 mmol/mol], P < 0.0001). Sustained benefits were also observed for the score on the hypoglycemia fear survey and hypoglycemia-related acute complications irrespective of hypoglycemia awareness level. People with IAH had the strongest improvement, especially for severe hypoglycemia (862 events in the year before vs. 119 events per 100 patient-years in the 2nd year, P < 0.0001). Over 24 months, more people were able to meet hypoglycemia consensus targets at the expense of slightly fewer people achieving hyperglycemia consensus targets. Furthermore, the number of people with HbA1c <7% (<53 mmol/mol) without severe hypoglycemia events more than doubled (11.0% vs. 25.4%, P < 0.0001). CONCLUSIONS: Use of rtCGM led to sustained improvements in hypoglycemia-related glucose control over 24 months. Lower fear of hypoglycemia, fewer acute hypoglycemia-related events, and fewer diabetes-related days off from work were observed, particularly in those with IAH.