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Open access

Flavia Letícia Martins Peçanha, Reinaldo Sousa dos Santos, and Wagner Seixas da-Silva

The thyroid hormones (THs), triiodothyronine (T3) and thyroxine (T4), are very important in organism metabolism and regulate glucose utilization. Hexokinase (HK) is responsible for the first step of glycolysis, catalyzing the conversion of glucose to glucose 6-phosphate. HK has been found in different cellular compartments, and new functions have been attributed to this enzyme. The effects of hyperthyroidism on subcellular glucose phosphorylation in mouse tissues were examined. Tissues were removed, subcellular fractions were isolated from eu- and hyperthyroid (T3, 0.25 µg/g, i.p. during 21 days) mice and HK activity was assayed. Glucose phosphorylation was increased in the particulate fraction in soleus (312.4% ± 67.1, n = 10), gastrocnemius (369.2% ± 112.4, n = 10) and heart (142.2% ± 13.6, n = 10) muscle in the hyperthyroid group compared to the control group. Hexokinase activity was not affected in brain or liver. No relevant changes were observed in HK activity in the soluble fraction for all tissues investigated. Acute T3 administration (single dose of T3, 1.25 µg/g, i.p.) did not modulate HK activity. Interestingly, HK mRNA levels remained unchanged and HK bound to mitochondria was increased by T3 treatment, suggesting a posttranscriptional mechanism. Analysis of the AKT pathway showed a 2.5-fold increase in AKT and GSK3B phosphorylation in the gastrocnemius muscle in the hyperthyroid group compared to the euthyroid group. Taken together, we show for the first time that THs modulate HK activity specifically in particulate fractions and that this action seems to be under the control of the AKT and GSK3B pathways.

Open access

Sarah J Hall, Brad Aisbett, Samuel J Robertson, Sally A Ferguson, and Anne I Turner

The effect of working on-call from home on the sympatho-adrenal medullary system activity is currently unknown. This study had two aims, Aim 1: examine salivary alpha amylase awakening response (AAR) and diurnal salivary alpha amylase (sAA) profile in fire and emergency service workers who operate on-call from home following a night on-call with a call (NIGHT-CALL), a night on-call without a call (NO-CALL) and an off-call night (OFF-CALL), and Aim 2: explore whether there was an anticipatory effect of working on-call from home (ON) compared to when there was an off-call (OFF) on the diurnal sAA profile. Participants wore activity monitors, completed sleep and work diaries and collected seven saliva samples a day for one week. AAR area under the curve with respect to ground (AUCG), AAR area under the curve with respect to increase (AUCI), AAR reactivity, diurnal sAA slope, diurnal sAA AUCG and mean 12-h sAA concentrations were calculated. Separate generalised estimating equation models were constructed for each variable of interest for each aim. For Aim 1, there were no differences between NIGHT-CALL or NO-CALL and OFF-CALL for any response variable. For Aim 2, there was no difference between any response variable of interest when ON the following night compared to when OFF the following night (n = 14). These findings suggest that there is no effect of working on-call from home on sAA, but should be interpreted with caution, as overnight data were not collected. Future research, using overnight heart rate monitoring, could help confirm these findings.

Open access

Charlotte Janus, Dorte Vistisen, Hanan Amadid, Daniel R Witte, Torsten Lauritzen, Søren Brage, Anne-Louise Bjerregaard, Torben Hansen, Jens J Holst, Marit E Jørgensen, Oluf Pedersen, Kristine Færch, and Signe S Torekov

Rationale

The hormone glucagon-like peptide-1 (GLP-1) decreases blood glucose and appetite. Greater physical activity (PA) is associated with lower incidence of type 2 diabetes. While acute exercise may increase glucose-induced response of GLP-1, it is unknown how habitual PA affects GLP-1 secretion. We hypothesised that habitual PA associates with greater glucose-induced GLP-1 responses in overweight individuals.

Methods

Cross-sectional analysis of habitual PA levels and GLP-1 concentrations in 1326 individuals (mean (s.d.) age 66 (7) years, BMI 27.1 (4.5) kg/m2) from the ADDITION-PRO cohort. Fasting and oral glucose-stimulated GLP-1 responses were measured using validated radioimmunoassay. PA was measured using 7-day combined accelerometry and heart rate monitoring. From this, energy expenditure (PAEE; kJ/kg/day) and fractions of time spent in activity intensities (h/day) were calculated. Cardiorespiratory fitness (CRF; mL O2/kg/min) was calculated using step tests. Age-, BMI- and insulin sensitivity-adjusted associations between PA and GLP-1, stratified by sex, were evaluated by linear regression analysis.

Results

In 703 men, fasting GLP-1 concentrations were 20% lower (95% CI: −33; −3%, P = 0.02) for every hour of moderate-intensity PA performed. Higher CRF and PAEE were associated with 1–2% lower fasting GLP-1 (P = 0.01). For every hour of moderate-intensity PA, the glucose-stimulated GLP-1 response was 16% greater at peak 30 min (1; 33%, P rAUC0-30 = 0.04) and 20% greater at full response (3; 40%, P rAUC0-120 = 0.02). No associations were found in women who performed PA 22 min/day vs 32 min/day for men.

Conclusion

Moderate-intensity PA is associated with lower fasting and greater glucose-induced GLP-1 responses in overweight men, possibly contributing to improved glucose and appetite regulation with increased habitual PA.

Open access

Jia Liu, Min Liu, Zhe Chen, Yumei Jia, and Guang Wang

Objective

Autoimmune thyroiditis (AIT) is the most common autoimmune thyroid disease. Longitudinal relaxation time mapping (T1-mapping) measured by MRI is a new technique for assessing interstitial fibrosis of some organs, such as heart and liver. This study aimed to evaluate the relationship between T1-mapping value and thyroid function and determine the usefulness of T1-mapping in identifying thyroid destruction in AIT patients.

Methods

This case–control study recruited 57 drug-naïve AIT patients and 17 healthy controls. All participants were given thyroid MRI, and T1-mapping values were measured using a modified look-locker inversion-recovery sequence.

Results

AIT patients had significantly higher thyroid T1-mapping values than the healthy controls (1.077 ± 177 vs 778 ± 82.9 ms; P < 0.01). A significant increase in thyroid T1-mapping values was presented along with the increased severity of thyroid dysfunction (P < 0.01). Correlation analyses showed that increased thyroid T1-mapping values were associated with higher TSH and lower FT3 and FT4 levels (TSH: r = 0.75; FT3: r = −0.47; FT4: r = −0.72; all P < 0.01). Receiver-operating characteristic curve analysis revealed a high diagnostic value of T1-mapping values for the degree of thyroid destruction (area under the curve was 0.95, 95% CI: 0.90–0.99, P < 0.01).

Conclusions

AIT patients have higher thyroid T1-mapping values than the healthy controls, and the T1-mapping values increased with the progression of thyroid dysfunction. Thyroid T1-mapping value might be a new index to quantitatively evaluate the degree of thyroid destruction in AIT patients.

Open access

Po-Chung Cheng and Chia-Hung Kao

Objective

Coronary heart disease (CHD) is a prevalent complication of type 2 diabetes mellitus (T2DM). The proatherogenic low-density lipoprotein (LDL) cholesterol is an established risk factor of cardiovascular disease, and evidence also suggests that postprandial plasma glucose (PPG) levels closely delineate CHD mortality in diabetes. The investigators hypothesized that the addition of telehealth consultation to standard antidiabetic therapy may help to reduce postprandial glucose variability and plasma LDL cholesterol levels in patients with T2DM.

Methods

This cross-sectional study enrolled patients with newly diagnosed T2DM who received standard antidiabetic therapy with or without additional telehealth consultation. Participants received blood tests for plasma lipid profile and glucose levels at the diagnosis of diabetes and after 1 month of therapeutic intervention. Laboratory results were compared between treatment groups to determine the efficacy of complementary telehealth consultation.

Results

In this study, 375 participants were enrolled. The standard treatment group had considerably greater levels of plasma LDL cholesterol than recipients of telehealth consultation (110 mg/dL vs 93.1 mg/dL, P < 0.001). Moreover, patients receiving standard treatment had greater levels of fasting plasma glucose (104 mg/dL vs 98.5 mg/dL, P = 0.027), 2-h PPG (169 mg/dL vs 111 mg/dL, P < 0.001), and postprandial glucose variability (65.4 mg/dL vs 12.8 mg/dL, P < 0.001) than participants under telehealth consultation.

Conclusions

Telemedicine in addition to standard antidiabetic therapy helped to reduce plasma LDL cholesterol levels and postprandial glucose variability in patients with newly diagnosed T2DM. Therefore, telehealth consultation is a suitable complement to pharmacologic therapy for diabetic patients to assist in the management of proatherogenic dyslipidemia and postprandial glucose variability.

Open access

Chun-feng Lu, Xiao-qin Ge, Yan Wang, Jian-bin Su, Xue-qin Wang, Dong-mei Zhang, Feng Xu, Wang-shu Liu, and Min Su

Background

Prolonged heart rate-corrected QT (QTc) interval may reflect poor prognosis of patients with type 2 diabetes (T2D). Serum adenosine deaminase (ADA) levels are related to hyperglycemia, insulin resistance (IR) and inflammation, which may participate in diabetic complications. We investigated the association of serum ADA levels with prolonged QTc interval in a large-scale sample of patients with T2D.

Methods

In this cross-sectional study, a total of 492 patients with T2D were recruited. Serum ADA levels were determined by venous blood during fasting. QTc interval was estimated from resting 12-lead ECGs, and prolonged QTc interval was defined as QTc > 440 ms.

Results

In this study, the prevalence of prolonged QTc interval was 22.8%. Serum ADA levels were positively associated with QTc interval (r = 0.324, P < 0.0001). The proportion of participants with prolonged QTc interval increased significantly from 9.2% in the first tertile (T1) to 24.7% in the second tertile (T2) and 39.0% in the third tertile (T3) of ADA (P for trend < 0.001). After adjusting for other possible risk factors by multiple linear regression analysis, serum ADA level was still significantly associated with QTc interval (β = 0.217, t = 3.400, P < 0.01). Multivariate logistic regression analysis showed that female (OR 5.084, CI 2.379–10.864, P < 0.001), insulin-sensitizers treatment (OR 4.229, CI 1.290–13.860, P = 0.017) and ADA (OR 1.212, CI 1.094–1.343, P < 0.001) were independent contributors to prolonged QTc interval.

Conclusions

Serum ADA levels were independently associated with prolonged QTc interval in patients with T2D.

Open access

Federica Saponaro, Alessandro Saba, Sabina Frascarelli, Concetta Prontera, Aldo Clerico, Marco Scalese, Maria Rita Sessa, Filomena Cetani, Simona Borsari, Elena Pardi, Antonella Marvelli, Claudio Marcocci, Claudio Passino, and Riccardo Zucchi

Objectives

The aims of this paper were to evaluate the levels of Vitamin D (VitD) in patients with heart failure (HF), compared to a control group, to assess the effects of VitD on HF outcome and to compare VitD measurement between LIAISON immunoassay and HPLC-MS-MS methods in this population.

Design and Methods

We collected clinical, biochemical and outcome data from 247 patients with HF and in a subgroup of 151 patients, we measured VitD both with LIAISON and HPLC-MS-MS.

Results

HF patients had statistically lower 25OHD levels (45.2 ± 23.7 nmol/L vs 58.2 ± 24.0 nmol/L, P < 0.001) and a statistically higher prevalence of VitD insufficiency (61.1% vs 39.5%, P < 0.001) and deficiency (24.7% vs 6.6%, P < 0.001), compared to healthy controls. There was a significant inverse relationship between baseline 25OHD and risk of HF-related death, with a HR of 0.59 (95% CI 0.37–0.92, P = 0.02), confirmed in a multivariate adjusted analysis. Kaplan–Meier survival analyses showed that VitD insufficiency was associated with reduced survival in HF patients (log rank P = 0.017). There was a good agreement between LIAISON and HPLC-MS-MS (Cohen’s kappa coefficient 0.70), but the prevalence of VitD insufficiency was significantly higher with the former compared to the latter method (58.3%, n = 88 vs 55.6%, n = 84, P < 0.001). LIAISON underestimated the 25OHD levels and showed a mean relative bias of −0.739% with 95% of limits of agreement (−9.00 to +7.52%), when compared to HPLC-MS-MS.

Conclusions

25OHD levels adequately measured by HPLC-MS-MS showed to be low in HF population and to be correlated with HF-related risk of death.

Open access

L Johnsen, N B Lyckegaard, P Khanal, B Quistorff, K Raun, and M O Nielsen

Objective

We aimed to test, whether fetal under- or overnutrition differentially program the thyroid axis with lasting effects on energy metabolism, and if early-life postnatal overnutrition modulates implications of prenatal programming.

Design

Twin-pregnant sheep (n = 36) were either adequately (NORM), under- (LOW; 50% of NORM) or overnourished (HIGH; 150% of energy and 110% of protein requirements) in the last-trimester of gestation. From 3 days-of-age to 6 months-of-age, twin lambs received a conventional (CONV) or an obesogenic, high-carbohydrate high-fat (HCHF) diet. Subgroups were slaughtered at 6-months-of-age. Remaining lambs were fed a low-fat diet until 2½ years-of-age (adulthood).

Methods

Serum hormone levels were determined at 6 months- and 2½ years-of-age. At 2½ years-of-age, feed intake capacity (intake over 4-h following 72-h fasting) was determined, and an intravenous thyroxine tolerance test (iTTT) was performed, including measurements of heart rate, rectal temperature and energy expenditure (EE).

Results

In the iTTT, the LOW and nutritionally mismatched NORM:HCHF and HIGH:CONV sheep increased serum T3, T3:T4 and T3:TSH less than NORM:CONV, whereas TSH was decreased less in HIGH, NORM:HCHF and LOW:HCHF. Early postnatal exposure to the HCHF diet decreased basal adult EE in NORM and HIGH, but not LOW, and increased adult feed intake capacity in NORM and LOW, but not HIGH.

Conclusions: The iTTT revealed a differential programming of central and peripheral HPT axis function in response to late fetal malnutrition and an early postnatal obesogenic diet, with long-term implications for adult HPT axis adaptability and associated consequences for adiposity risk.

Open access

Eng Loon Tng, Yee Sian Tiong, Aye Thida Aung, Nicole Ya Yuan Chong, and Zhemin Wang

Background: Evidence on the efficacy and safety of anticoagulation in preventing stroke and thromboembolic events in people with thyrotoxic atrial fibrillation is scarce.

Objective: We evaluated the efficacy and safety of anticoagulation in people with thyrotoxic atrial fibrillation.

Methods: Our study protocol was published in the International Prospective Register of Systematic Reviews (PROSPERO) (registration number CRD42020222782). Four databases and two systematic review registers were searched through 25 November 2020 for interventional and observational studies comparing anticoagulation therapy with active comparators, placebo, or no treatment in people with thyrotoxic atrial fibrillation. Random-effects meta-analysis and sensitivity analysis were performed. Quality of evidence was described using the GRADE framework.

Results: 23,145 records were retrieved. 1 randomized controlled trial and 8 cohort studies were ultimately included. Effect estimates on the efficacy and safety of anticoagulation were extracted. Meta-analysis using the inverse variance and random-effects methods was conducted on 4 cohort studies with 3443 participants and 277 events. Anticoagulation in people with thyrotoxic atrial fibrillation reduced the risk of ischemic stroke and systemic thromboembolism by 3% (95% confidence interval (CI): 1 – 6%). Warfarin may prevent ischemic stroke in people with thyrotoxic atrial fibrillation if the CHA2DS2-VASc score exceeds 1 and when atrial fibrillation persists beyond 7 days. Direct oral anticoagulants may be associated with fewer bleeding events than warfarin.

Conclusions: Anticoagulation prevents ischemic stroke and systemic thromboembolism in people with thyrotoxic atrial fibrillation. Direct oral anticoagulants may be associated with fewer bleeding events.

Open access

Henri Honka, Jukka Koffert, Saila Kauhanen, Nobuyuki Kudomi, Saija Hurme, Andrea Mari, Andreas Lindqvist, Nils Wierup, Riitta Parkkola, Leif Groop, and Pirjo Nuutila

Aims/hypothesis

The mechanisms for improved glycemic control after bariatric surgery in subjects with type 2 diabetes (T2D) are not fully known. We hypothesized that dynamic hepatic blood responses to a mixed-meal are changed after bariatric surgery in parallel with an improvement in glucose tolerance.

Methods

A total of ten morbidly obese subjects with T2D were recruited to receive a mixed-meal and a glucose-dependent insulinotropic polypeptide (GIP) infusion before and early after (within a median of less than three months) bariatric surgery, and hepatic blood flow and volume (HBV) were measured repeatedly with combined positron emission tomography/MRI. Ten lean non-diabetic individuals served as controls.

Results

Bariatric surgery leads to a significant decrease in weight, accompanied with an improved β-cell function and glucagon-like peptide 1 (GLP-1) secretion, and a reduction in liver volume. Blood flow in portal vein (PV) was increased by 1.65-fold (P = 0.026) in response to a mixed-meal in subjects after surgery, while HBV decreased in all groups (P < 0.001). When the effect of GIP infusion was tested separately, no change in hepatic arterial and PV flow was observed, but HBV decreased as seen during the mixed-meal test.

Conclusions/interpretation

Early after bariatric surgery, PV flow response to a mixed-meal is augmented, improving digestion and nutrient absorption. GIP influences the post-prandial reduction in HBV thereby diverting blood to the extrahepatic sites.