Therapeutic implications for sphingolipid metabolism in metabolic dysfunction-associated steatohepatitis.

The prevalence of metabolic dysfunction-associated steatotic liver disease (MASLD), a leading cause of chronic liver disease, has increased worldwide along with the epidemics of obesity and related dysmetabolic conditions characterized by impaired glucose metabolism and insulin signaling, such as type 2 diabetes mellitus (T2D). MASLD can be defined as an excessive accumulation of lipid droplets in hepatocytes that occurs when the hepatic lipid metabolism is totally surpassed. This metabolic lipid inflexibility constitutes a central node in the pathogenesis of MASLD and is frequently linked to the overproduction of lipotoxic species, increased cellular stress, and mitochondrial dysfunction. A compelling body of evidence suggests that the accumulation of lipid species derived from sphingolipid metabolism, such as ceramides, contributes significantly to the structural and functional tissue damage observed in more severe grades of MASLD by triggering inflammatory and fibrogenic mechanisms. In this context, MASLD can further progress to metabolic dysfunction-associated steatohepatitis (MASH), which represents the advanced form of MASLD, and hepatic fibrosis. In this review, we discuss the role of sphingolipid species as drivers of MASH and the mechanisms involved in the disease. In addition, given the absence of approved therapies and the limited options for treating MASH, we discuss the feasibility of therapeutic strategies to protect against MASH and other severe manifestations by modulating sphingolipid metabolism.

The Link between Abdominal Obesity Indices and the Progression of Liver Fibrosis: Insights from a Population-Based Study.

There is currently no available information on the correlation between abdominal obesity indices and the risk of liver fibrosis progression. We aimed to investigate the relationship between the body mass index (BMI), waist circumference (WC), and the visceral adiposity index (VAI) with the progression of liver fibrosis. The study also evaluated the association between these indices and the prevalence of metabolic dysfunction-associated steatotic liver disease (MASLD) and liver fibrosis. A total of 1403 subjects participated in the cross-sectional and longitudinal population-based study. Liver stiffness was assessed via transient elastography, at baseline and follow-up (median: 4.2 years). The subgroup with dysglycemia was also analyzed. In the cross-sectional study, the highest quartile of VAI, BMI ≥ 30 kg/m2, and abdominal obesity showed significant associations with the prevalence of MASLD and liver fibrosis, as well as with fibrosis progression. However, VAI showed no association with MASLD incidence. Among the dysglycemic subjects, there was no observed association between VAI and the incidence of MASLD or the progression of fibrosis. In conclusion, the BMI, WC, and the VAI are associated with an increased risk of progression to moderate-to-advanced liver fibrosis in the general population. However, the VAI does not perform better than the BMI and WC measurement.

The double burden: type 1 diabetes and heart failure-a comprehensive review.

Heart failure (HF) is increasing at an alarming rate, primary due to the rising in aging, obesity and diabetes. Notably, individuals with type 1 diabetes (T1D) face a significantly elevated risk of HF, leading to more hospitalizations and increased case fatality rates. Several risk factors contribute to HF in T1D, including poor glycemic control, female gender, smoking, hypertension, elevated BMI, and albuminuria. However, early and intensive glycemic control can mitigate the long-term risk of HF in individuals with T1D. The pathophysiology of diabetes-associated HF is complex and multifactorial, and the underlying mechanisms in T1D remain incompletely elucidated. In terms of treatment, much of the evidence comes from type 2 diabetes (T2D) populations, so applying it to T1D requires caution. Sodium-glucose cotransporter 2 inhibitors have shown benefits in HF outcomes, even in non-diabetic populations. However, most of the information about HF and the evidence from cardiovascular safety trials related to glucose lowering medications refer to T2D. Glycemic control is key, but the link between hypoglycemia and HF hospitalization risk requires further study. Glycemic variability, common in T1D, is an independent HF risk factor. Technological advances offer the potential to improve glycemic control, including glycemic variability, and may play a role in preventing HF. In summary, HF in T1D is a complex challenge with unique dimensions. This review focuses on HF in individuals with T1D, exploring its epidemiology, risk factors, pathophysiology, diagnosis and treatment, which is crucial for developing tailored prevention and management strategies for this population.

Nicotinamide Prevents Diabetic Brain Inflammation via NAD+-Dependent Deacetylation Mechanisms.

This study investigated the effect of nicotinamide (NAM) supplementation on the development of brain inflammation and microglial activation in a mouse model of type 1 diabetes mellitus. C57BL/6J male mice, which were made diabetic with five consecutive, low-dose (55 mg/kg i.p.) streptozotocin (STZ) injections. Diabetic mice were randomly distributed in different experimental groups and challenged to different doses of NAM (untreated, NAM low-dose, LD, 0.1%; NAM high-dose, HD, 0.25%) for 25 days. A control, non-diabetic group of mice was used as a reference. The NAD+ content was increased in the brains of NAM-treated mice compared with untreated diabetic mice (NAM LD: 3-fold; NAM HD: 3-fold, p-value < 0.05). Immunohistochemical staining revealed that markers of inflammation (TNFα: NAM LD: -35%; NAM HD: -46%; p-value < 0.05) and microglial activation (IBA-1: NAM LD: -29%; NAM HD: -50%; p-value < 0.05; BDKRB1: NAM LD: -36%; NAM HD: -37%; p-value < 0.05) in brains from NAM-treated diabetic mice were significantly decreased compared with non-treated T1D mice. This finding was accompanied by a concomitant alleviation of nuclear NFκB (p65) signaling in treated diabetic mice (NFκB (p65): NAM LD: -38%; NAM HD: -53%, p-value < 0.05). Notably, the acetylated form of the nuclear NFκB (p65) was significantly decreased in the brains of NAM-treated, diabetic mice (NAM LD: -48%; NAM HD: -63%, p-value < 0.05) and inversely correlated with NAD+ content (r = -0.50, p-value = 0.03), suggesting increased activity of NAD+-dependent deacetylases in the brains of treated mice. Thus, dietary NAM supplementation in diabetic T1D mice prevented brain inflammation via NAD+-dependent deacetylation mechanisms, suggesting an increased action of sirtuin signaling.

Fatty Acid Binding Proteins 3 and 4 Predict Both All-Cause and Cardiovascular Mortality in Subjects with Chronic Heart Failure and Type 2 Diabetes Mellitus.

Subjects with type 2 diabetes mellitus (T2D) are at increased risk for heart failure (HF). The cardiac-specific (FABP3) and adipose-tissue-specific (FABP4) types of the fatty acid binding proteins have been associated with both all-cause and cardiovascular (CV) mortality. The aim of this study was to explore the prognosis value of FABP3 and FABP4 in ambulatory subjects with chronic HF (CHF), with and without T2D. A prospective study involving 240 ambulatory CHF subjects was performed. Patients were followed-up for a mean of 5.78 ± 3.30 years and cause of death (if any) was recorded. Primary endpoints were defined as all-cause and CV death, and a composite endpoint that included CV death or hospitalization for HF was included as a secondary endpoint. Baseline serum samples were obtained and the serum FABP3 and FABP4 concentrations were assessed by sandwich enzyme-linked immunosorbent assay. Survival analysis was performed with multivariable Cox regressions, using Fine and Gray competing risks models when needed, to explore the prognostic value of FABP3 and FABP4 concentrations, adjusting for potential confounders. Type 2 diabetes mellitus was highly prevalent, accounting for 47.5% for total subjects with CHF. Subjects with T2D showed higher mortality rates (T2D: 69.30%; non-T2D: 50.79%, p = 0.004) and higher serum FABP3 (1829.3 (1104.9-3440.5) pg/mL vs. 1396.05 (820.3-2362.16) pg/mL, p = 0.007) and FABP4 (45.5 (27.6-79.8) ng/mL vs. 34.1 (24.09-55.3) ng/mL, p = 0.006) concentrations compared with non-T2D CHF subjects. In the whole study cohort, FABP3 was independently associated with all-cause death, and both FABP3 and FABP4 concentrations were associated with CV mortality. The predictive values of these two molecules for all-cause (FABP3: HR 1.25, 95% CI 1.09-1.44; p = 0.002. FABP4: HR 2.21, 95% CI 1.12-4.36; p = 0.023) and CV mortality (FABP3: HR 1.28, 95% CI 1.09-1.50; p = 0.002. FABP4: HR 4.19, 95% CI 2.21-7.95; p < 0.001) were only statistically significant in the subgroup of subjects with T2D. Notably, FABP4 (HR 2.07, 95% CI 1.11-3.87; p = 0.022), but not FABP3, also predicted the occurrence of the composite endpoint (death or hospitalization for HF) only in subjects with T2D. All these associations were not found in CHF subjects without T2D. Our findings support the usefulness of serum FABP3 and FABP4 concentrations as independent predictors for the occurrence of all-cause and CV mortality in ambulatory subjects with CHF with T2D.

Dysglycemia in young women attenuates the protective effect against fatty liver disease.

Introduction: Sexual dimorphism has been reported in non-alcoholic fatty liver disease (NAFLD), similar to the sex differences evident with cardiovascular disease. Type 2 diabetes mellitus (T2D) significantly increases the risk and severity of NAFLD, but there is scarce information on whether T2D or altered glucose metabolism can modify the prevalence of NAFLD in men and women of reproductive age. Purpose: To investigate the relationship between age, sex and NAFLD in subjects with and without dysglycemia. Materials and methods: We analyzed 2,790 patients. NAFLD was characterized using established diagnostic criteria: one or more positive results on the fatty liver index and hepatic ultrasound. Liver fibrosis (liver stiffness measurement [LSM] ≥8.0 kPa) was assessed by Fibroscan®. For analysis purposes, we included both T2D and prediabetes under the predefined condition of dysglycemia. Results: The global prevalence of NAFLD was higher in men than in women (50% and 34%; P<0.001), and the prevalence increased with age in both sexes. Older women (≥ 50 years) had a higher prevalence than younger women (<50 years), both in the overall cohort and in non-dysglycemic subjects. In dysglycemic subjects, the prevalence of NAFLD was slightly higher in men (68% vs 61%, p=0.021); in younger subjects, there were no differences in the prevalence of NAFLD between men and women (68% vs 64%, respectively; p=0.635). We found an interaction between dysglycemia and female sex (odds ratio [OR] 1.6 95% confidence interval [CI] 1.0-2.4, p=0.030), and between and age ≥50 years (OR 0.6, 95% CI 0.3-1.0, p=0.046). The global prevalence of LSM ≥8.0 kPa was higher in men compared with women (8% vs 4%; p< 0.001). This prevalence increased with age, mainly in men. We did not find any association between liver fibrosis and age and gender. Conclusions: While the global prevalence of NAFLD is higher in men than in women across all ages, younger women with dysglycemia have a similar risk of developing NAFLD as men of a similar age. Therefore, the presence of dysglycemia may erase the protective effect of female sex against fatty liver disease.

Factors associated with critical care requirements in diabetic patients treated with dexamethasone for COVID-19 infection in the first wave of the pandemia.

Introduction: Diabetes mellitus (DM) and hyperglycemia are important risk factors for poor outcomes in hospitalized patients with coronavirus disease 2019 (COVID-19). The aim of the present study was to analyze the factors associated with the composite outcome of the necessity of invasive mechanical ventilation (IMV) or admission to the intensive care unit (ICU) in subjects with severe COVID-19 infection treated with dexamethasone comparing patients with DM vs. patients without DM. Research design and methods: An observational retrospective cohort study was performed, including hospitalized subjects with a diagnosis of SARS-CoV-2 pneumonia. Inclusion criteria were: age ≥18 years old with severe COVID-19 disease requiring daily intravenous 6 mg dexamethasone treatment for 10 days. Exclusion criteria were: <18 years old, non-severe illness and/or patients in charge of ICU. Variables related to clinical and analytical parameters, glycemic control, acquired-hospital superinfections, mortality, IMV requirement, ICU admission and length of stay were included. Results: Two hundred and nine individuals with COVID-19 disease treated with dexamethasone were included. One hundred twenty-five out of these subjects (59.8%) were patients with DM. Overall, from the 209 subjects, 66 (31.6%) required IMV or were admitted to the ICU, with significant differences between patients with DM (n=50) vs. patients without DM (n=16) (76% vs. 24%, p=0.002). Among the group of subjects with DM (n=125), those who required IMV or were admitted to the ICU showed higher serum concentrations of C-reactive protein, interleukin-6, D-dimer, ferritin and pro-calcitonin and significantly lower serum concentrations of albumin compared to those who did not require IMV or were not admitted to the ICU. Besides, between these two groups of patients with DM, we observed no differences in glycemic parameters, including median capillary blood glucose values, glycosylated hemoglobin, coefficient of variability and hypoglycemic episodes. In the multinomial analysis, factors independently associated with the composite outcome of IMV or admission to the ICU in the insulin-treated group were the National Early Warning Score (NEWS) 2 score (OR 1.55 [1.17-2.17], p=0.005) and the presence of hospital-acquired superinfections (OR 35.21 [5.11-386.99], p=0.001). Conclusions: In our study, parameters related to glycemic control were not associated with IMV requirement nor admission to the ICU in patients with DM and severe COVID-19 disease receiving daily 6 mg of dexamethasone for 10 days. However, hospital-acquired superinfections and disease severity at admission were independent factors associated with this composite outcome.

Advanced lipoprotein profile in individuals with normal and impaired glucose metabolism.

INTRODUCTION AND OBJECTIVES: Several types of lipoproteins beyond low-density lipoproteins (LDL) are causally related to cardiovascular disease. We aimed to analyze an advanced lipoprotein profile in individuals with normal and impaired glucose metabolism from different cohorts of a Mediterranean region. METHODS: Cross-sectional study in 929 participants (463 normoglycemia, 250 prediabetes, and 216 type 2 diabetes mellitus) with normal renal function, free from cardiovascular disease, and without lipid-lowering treatment. Conventional and advanced (nuclear magnetic resonance [NMR] spectroscopy) lipoprotein profiles were analyzed. RESULTS: Compared with men, normoglycemic women showed lower serum triglyceride and LDL cholesterol concentrations, lower total LDL particles (P) as well as their subclasses and their cholesterol and triglyceride content, higher high-density lipoproteins (HDL)-P and all HDL-related variables (P≤ .05 for all comparisons). Compared with normoglycemic participants, diabetic participants showed higher large and small very LDL-P concentrations (P <.05) and lower total HDL-P and medium HDL-P concentrations (P <.05). Waist circumference and Fatty Liver Index were positively associated with a proatherogenic profile. CONCLUSIONS: Women had a better advanced lipoprotein profile than did men. Adiposity indexes related to insulin-resistance were positively associated with a proatherogenic lipid profile. NMR revealed altered lipoprotein particles other than LDL in participants with diabetes, frequently associated with an increased cardiovascular risk. Our findings support the usefulness of extended lipoprotein analysis by NMR spectroscopy to uncover new therapeutic targets to prevent cardiovascular events in at-risk participants.

Abdominal obesity and dsyglycemia are risk factors for liver fibrosis progression in NAFLD subjects: A population-based study.

Objective: To investigate longitudinal changes in the liver stiffness measurement (LSM) in the general adult population without known liver disease and to describe its association with metabolic risk factors, with a special focus on subjects with non-alcoholic fatty liver disease (NAFLD) and dysglycemia. Material and Methods: A longitudinal adult population-based cohort study was conducted in Catalonia. LSM was measured by transient elastography (TE) at baseline and follow-up (median: 4.2 years). Subgroup with NAFLD and dysglycemia were analyzed. Moderate-to-advanced liver fibrosis was defined as LSM ≥8.0 kPa and LSM ≥9.2 kPa respectively. Results: Among 1.478 subjects evaluated, the cumulative incidence of LSM ≥8.0 kPa and ≥9.2 kPa at follow-up was 2.8% and 1.9%, respectively. This incidence was higher in NAFLD (7.1% for LSM ≥8.0 kPa and 5% for LSM ≥9.2 kPa) and dysglycemia (6.2% for LSM ≥8.0 kPa and 4.7% for LSM ≥9.2 kPa) subgroups. In the global cohort, the multivariate analyses showed that dysglycemia, abdominal obesity and atherogenic dyslipidemia were significantly associated with progression to moderate-to-advanced liver fibrosis. Female sex was negatively associated. In subjects with NAFLD, abdominal obesity and dysglycemia were associated with changes in LSM to ≥8.0 kPa and ≥9.2 kPa at follow-up. A decline in LSM value to <8 kPa was observed in 64% of those subjects with a baseline LSM ≥8.0 kPa. Conclusions: In this population study, the presence of abdominal obesity and dysglycemia were the main risk metabolic factors associated with moderate-to-advanced liver fibrosis development over time in general populations as well as in subjects with NAFLD.

Atherogenic dyslipidemia, but not hyperglycemia, is an independent factor associated with liver fibrosis in subjects with type 2 diabetes and NAFLD: a population-based study.

OBJECTIVE: To investigate the prevalence and risks factors associated with the presence of liver fibrosis in subjects with nonalcoholic fatty liver disease (NAFLD) with and without type 2 diabetes mellitus (T2D). DESIGN AND METHODS: This study was part of a population-based study conducted in the Barcelona metropolitan area among subjects aged 18-75 years old. Secondary causes of steatosis were excluded. Moderate-to-advanced liver fibrosis was defined as a liver stiffness measurement (LSM) ≥ 8.0 kPa assessed by transient elastography. RESULTS: Among 930 subjects with NAFLD, the prevalence of moderate-to-advanced liver fibrosis was higher in subjects with T2D compared those without (30.8% vs 8.7%). By multivariable analysis, one of the main factors independently associated with increased LSM in subjects with NAFLD was atherogenic dyslipidemia but only in those with T2D. The percentage of subjects with LSM ≥ 8.0 kPa was higher in subjects with T2D and atherogenic dyslipidemia than in those with T2D without atherogenic dyslipidemia both for the cut-off point of LSM ≥8.0 kPa (45% vs 24% P = 0.002) and ≥13 kPa (13% vs 4% P = 0.020). No differences were observed in the prevalence of LSM ≥8.0 kPa regarding glycemic control among NAFLD-diabetic subjects. CONCLUSIONS: Factors associated with moderate-to-advanced liver fibrosis in NAFLD are different in subjects with and without T2D. Atherogenic dyslipidemia was associated with the presence of moderate-to-advanced liver fibrosis in T2D with NAFLD but not in non-diabetic subjects. These findings highlight the need for an active search for liver fibrosis in subjects with T2D NAFLD and atherogenic dyslipidemia.

Microbiota, Fiber, and NAFLD: Is There Any Connection?

Gut microbiota can contribute to the development and progression of non-alcoholic fatty liver disease (NAFLD). In fact, some specific changes of gut microbiota are observed in patients in what is called dysbiota. There has been a lot of investigation by using a variety of interventions, including diet, showing the possibility to modify components of gastrointestinal dysbiota towards healthy and multivariate microbiota to restore physiologic status. One of the main focuses has been dietary fiber (DF), in which most of its variants are prebiotics. The highest effective treatment for NAFLD is, so far, weight loss achieved by caloric restriction. DF supplementation with oligofructose facilitates weight loss, enhances the production of beneficial metabolites, decreases some pathogenic bacteria population by increasing Bifidobacteria, and has effects on intestinal barrier permeability. DF use has been associated with improvement in diverse metabolic diseases, including NAFLD, by modifying gut microbiota. Additionally, it has been shown that a higher insoluble fiber consumption (≥7.5 g/day) revealed improvements in 3 different scores of liver fibrosis. Further research is needed, but given the evidence available, it is reasonable to prescribe its consumption in early stages of NAFLD in order to prevent disease progression.

Long-term LVEF trajectories in patients with type 2 diabetes and heart failure: diabetic cardiomyopathy may underlie functional decline.

BACKGROUND: Left ventricular ejection fraction (LVEF) trajectories and functional recovery with current heart failure (HF) management is increasingly recognized. Type 2 diabetes mellitus (T2D) leads to a worse prognosis in HF patients. However, it is unknown whether T2D interferes with LVEF trajectories. The aim of this study was to prospectively assess very long-term (up to 15 years) LVEF trajectories in patients with and without T2D and underlying HF. METHODS: Ambulatory patients admitted to a multidisciplinary HF clinic were prospectively evaluated by scheduled two-dimensional echocardiography at baseline, 1 year, and then every 2 years afterwards, up to 15 years. Statistical analyses of LVEF change with time were performed using the linear mixed effects (LME) models, and locally weighted error sum of squares (Loess) curves were plotted. RESULTS: Of the 1921 patients, 461 diabetic and 699 non-diabetic patients with LVEF < 50% were included in the study. The mean number of echocardiography measurements performed in diabetic patients was 3.3 ± 1.6. Early LVEF recovery was similar in diabetic and non-diabetic patients, but Loess curves showed a more pronounced inverted U shape in diabetics with a more pronounced decline after 9 years. LME analysis showed a statistical interaction between T2D and LVEF trajectory over time (p = 0.009), which was statistically significant in patients with ischemic etiologies (p < 0.001). Other variables that showed an interaction between LVEF trajectories and T2D were male sex (p = 0.04) and HF duration (p = 0.008). CONCLUSIONS: LVEF trajectories in T2D patients with depressed systolic function showed a pronounced inverted U shape with a marked decline after 9 years. Diabetic cardiomyopathy may underlie the functional decline observed.

CD26/DPPIV inhibition alters the expression of immune response-related genes in the thymi of NOD mice.

The transmembrane glycoprotein CD26 or dipeptidyl peptidase IV (DPPIV) is a multifunctional protein. In immune system, CD26 plays a role in T-cell function and is also involved in thymic maturation and emigration patterns. In preclinical studies, treatment with DPPIV inhibitors reduces insulitis and delays or even reverses the new -onset of type 1 diabetes (T1D) in non-obese diabetic (NOD) mice. However, the specific mechanisms involved in these effects remain unknown. The aim of the present study was to investigate how DPPIV inhibition modifies the expression of genes in the thymus of NOD mice by microarray analysis. Changes in the gene expression of ß-cell autoantigens and Aire in thymic epithelial cells (TECs) were also evaluated by using qRT-PCR. A DPPIV inhibitor, MK626, was orally administered in the diet for 4 and 6 weeks starting at 6-8 weeks of age. Thymic glands from treated and control mice were obtained for each study checkpoint. Thymus transcriptome analysis revealed that 58 genes were significantly over-expressed in MK626-treated mice after 6 weeks of treatment. Changes in gene expression in the thymus were confined mainly to the immune system, including innate immunity, chemotaxis, antigen presentation and immunoregulation. Most of the genes are implicated in central tolerance mechanisms through several pathways. No differences were observed in the expression of Aire and ß-cell autoantigens in TECs. In the current study, we demonstrate that treatment with the DPPIV inhibitor MK626 in NOD mice alters the expression of the immune response-related genes in the thymus, especially those related to immunological central tolerance, and may contribute to the prevention of T1D.

Type 1 Diabetes Prevention in NOD Mice by Targeting DPPIV/CD26 Is Associated with Changes in CD8⁺T Effector Memory Subset.

CD26 is a T cell activation marker consisting in a type II transmembrane glycoprotein with dipeptidyl peptidase IV (DPPIV) activity in its extracellular domain. It has been described that DPPIV inhibition delays the onset of type 1 diabetes and reverses the disease in non-obese diabetic (NOD) mice. The aim of the present study was to assess the effect of MK626, a DPPIV inhibitor, in type 1 diabetes incidence and in T lymphocyte subsets at central and peripheral compartments. Pre-diabetic NOD mice were treated with MK626. Diabetes incidence, insulitis score, and phenotyping of T lymphocytes in the thymus, spleen and pancreatic lymph nodes were determined after 4 and 6 weeks of treatment, as well as alterations in the expression of genes encoding ß-cell autoantigens in the islets. The effect of MK626 was also assessed in two in vitro assays to determine proliferative and immunosuppressive effects. Results show that MK626 treatment reduces type 1 diabetes incidence and after 6 weeks of treatment reduces insulitis. No differences were observed in the percentage of T lymphocyte subsets from central and peripheral compartments between treated and control mice. MK626 increased the expression of CD26 in CD8+ T effector memory (TEM) from spleen and pancreatic lymph nodes and in CD8+ T cells from islet infiltration. CD8+TEM cells showed an increased proliferation rate and cytokine secretion in the presence of MK626. Moreover, the combination of CD8+ TEM cells and MK626 induces an immunosuppressive response. In conclusion, treatment with the DPPIV inhibitor MK626 prevents experimental type 1 diabetes in association to increase expression of CD26 in the CD8+ TEM lymphocyte subset. In vitro assays suggest an immunoregulatory role of CD8+ TEM cells that may be involved in the protection against autoimmunity to ß pancreatic islets associated to DPPIV inhibitor treatment.

Hepatic glycogenosis: An underdiagnosed complication of diabetes mellitus?

Hepatic glycogenosis (HG) is characterized by excessive glycogen accumulation in hepatocytes and represents a hepatic complication of diabetes that particularly occurs in patients with longstanding poorly controlled type 1 diabetes (T1D). HG has been reported to be a very rare disease, although it is believed to be extremely underdiagnosed because it is not possible to distinguish it from non-alcoholic fatty liver disease (NAFLD) unless a liver biopsy is performed. In contrast to HG, NAFLD is characterized by liver fat accumulation and is the more likely diagnosis for patients with type 2 diabetes and metabolic syndrome. The pathogenesis of HG involves the concomitant presence of insulin and excess glucose, which increases glycogen storage in the liver. HG is characterized by a transient elevation in liver transaminases and hepatomegaly. Differentiating between these two conditions is of the utmost importance because HG is a benign disease that is potentially reversible by improving glycemic control, whereas NAFLD can progress to cirrhosis. Therefore, HG should be suspected when liver dysfunction occurs in patients with poorly controlled T1D. The aim of this article is to review the epidemiology, clinical characteristics, pathogenesis and histology of HG.

Intact parathyroid hormone measurement at 24 hours after thyroid surgery as predictor of parathyroid function at long term.

BACKGROUND: There is no consensus about the usefulness of postoperative intact parathyroid hormone (iPTH) determination to predict permanent hypoparathyroidism (pHPP). We evaluated the value of calcium (Ca2+) and iPTH concentration at 24 hours after total thyroidectomy (TT) for predicting pHPP. METHODS: Ca2+ and iPTH levels from 70 consecutive patients who underwent TT were measured at 24 hours and 6 months after TT. RESULTS: Five patients (7.1%) developed pHPP. An iPTH concentration ≤5.8 pg/mL at 24 hours after TT identified patients at risk for pHPP (sensitivity, 100%; specificity, 81.5%), but it was not accurate enough to predict its development (positive predictive value, 30%). Conversely, an iPTH level >5.8 pg/mL predicted normal parathyroid function at 6 months (negative predictive value, 100%). Compared with iPTH, a postoperative Ca2+ level ≤1.95 mmol/L was 60% sensitive and 78.5% specific to predict pHPP. CONCLUSIONS: An iPTH concentration >5.8 pg/mL on the first postoperative day rules out pHPP with much better diagnostic accuracy than Ca2+. Postoperative iPTH could be helpful in identifying patients at risk for developing pHPP.

Leptin and thyrotropin relationship is modulated by smoking status in euthyroid subjects.

BACKGROUND: The relationship between thyrotropin (TSH) concentrations and body mass index (BMI) in euthyroid subjects has been demonstrated only in some studies. Leptin regulates TSH secretion and TSH stimulates leptin secretion. The main aims of our study were to assess the relationship between leptin, the thyroid axis, and thyroid autoimmunity in a representative sample of a nonhospitalized euthyroid adult population of Catalonia and to determine whether smoking status could influence this relationship. METHODS: This cross-sectional population-based study includes 894 euthyroid iodine-sufficient adults (390 men, 44.87±15.03 years old) with BMI 26.19±4.61 kg/m(2), representative of people living in Catalonia. The study analyzes the relationship between TSH, free thyroxine (FT4), leptin, thyroperoxidase and/or thyroglobulin antibodies (thyroid autoimmunity), smoking status, and BMI. Measurements also include glycemia and insulinemia to calculate homeostasis model assessment of insulin resistance (HOMA-IR) index as a measure of insulin sensitivity. RESULTS: In the univariate analysis and in the overall group, TSH correlated directly with BMI, leptin, and HOMA-IR (p=0.039, p<0.001, and p=0.010, respectively). In all men, TSH correlated directly with leptin (p=0.004), and in all women, directly with leptin (p=0.002) and HOMA-IR (p=0.031) and inversely with FT4 (p=0.024). Only in men who smoke, TSH correlated directly with leptin (p=0.010) and HOMA-IR (p=0.024). In women, TSH correlated directly with leptin (p=0.004) and in nonsmoking women, inversely with FT4 (p=0.047). In the multiple regression analysis, age (ß=-0.00310, p=0.0265), smoking status (ß=-0.24085, p=0.0202), and thyroid autoimmunity (ß=0.20652, p=0.0075) were independent predictors of TSH variations. Leptin was a significant independent predictor of TSH variations only in smokers (ß=0.16451, p=0.047). CONCLUSIONS: Leptin is an independent predictor of TSH concentration variations only in euthyroid smoker subjects of both sexes at all ranges of BMI, but not in nonsmokers. Age, smoking status, and positive thyroid autoimmunity also influenced TSH variability.

Germline mutations of AIP gene in somatotropinomas resistant to somatostatin analogues.

OBJECTIVE: Most cases of familial isolated pituitary adenomas with mutated aryl hydrocarbon receptor-interacting protein (AIP:HGNC:358) gene develop somatotropinomas. They are characterised by an aggressive clinical phenotype including early age at diagnosis, large tumours and frequent invasiveness. There is little information on AIP gene mutations' prevalence in isolated somatotropinomas characterised by poor response to somatostatin analogue treatment. The aim of this study was to investigate the prevalence of AIP mutations in non-familial cases of somatotropinomas with poor response to conventional treatment. DESIGN AND METHODS: Fifty patients with acromegaly (22 males/28 females, age 51±18 years) and 60 controls were included in this study performed at eight University Hospitals in Spain. None had family history of pituitary adenomas or other endocrine tumors. All patients failed to respond to conventional treatment including surgery and somatostatin analogues. Some patients received adjuvant radiotherapy and most cases required pegvisomant (PEG) treatment for normalisation of IGF1. AIP analysis was performed in DNA extracted from peripheral leucocytes, using standardised PCR protocol in which the coding regions of exons 1, 2, 3, 4, 5 and 6 were amplified. Possible deletions/duplications were studied using multiplex ligation-dependent probe amplification. RESULTS: SEQUENCE CHANGES OF POTENTIAL DIFFERENT SIGNIFICANCE THAT COULD BE CONSIDERED AS MUTATIONS OR VARIATIONS OF UNKNOWN SIGNIFICANCE (VUS) OF THE AIP GENE WERE FOUND IN FOUR PATIENTS (8%). IN TWO CASES, TWO DIFFERENT MUTATIONS PREVIOUSLY DESCRIBED WERE FOUND: p.Arg9Gln and p.Phe269Phe. Two other VUS were also found: c.787+24C>T in intron 5 and c.100-18C>T in intron 1. Age at diagnosis ranged from 21 to 50 years old, and in all patients, the tumor was a macroadenoma depicting IGF1 normalisation under PEG treatment. CONCLUSIONS: AIP germline mutations show a low, but non-negligible, prevalence in non-familial acromegaly patients with tumors resistant to treatment with somatostatin analogues.

Undiagnosed thyroid dysfunction, thyroid antibodies, and iodine excretion in a Mediterranean population.

The prevalence of thyroid dysfunction varies in different populations. The aim of this cross-sectional study was to analyze the prevalence of undiagnosed thyroid dysfunction and thyroid antibodies and their relationship with urine iodine excretion in a representative sample of 1,124 (55.5% women; mean age: 44.8 ± 15.2 years) non-hospitalized Mediterranean adults, in Catalonia (Spain). Free thyroxine, thyroid-stimulating hormone, thyroperoxidase and thyroglobulin antibodies, and urine iodine were measured. Undiagnosed thyroid dysfunction was 5.3% (hypothyroidism 3.8%; 56.66% of these subjects were women). The total (diagnosed + undiagnosed) thyroid dysfunction was 8.9% (71.15% women). Thyroperoxidase antibodies were positive in 2.4% of men and 9.4% of women and thyroglobulin antibodies, in 1.3% of men and 3.8% of women. No differences were observed in urine iodine between groups with thyroid dysfunction and euthyroidism, or between subjects with positive or negative antibodies. In subjects over 60, undiagnosed thyroid dysfunction was 9.8% (hypothyroidism 6.9%, hyperthyroidism 3.3%; 36.36% women) and total thyroid dysfunction 13.61% (53.12% women). Women and men over 60 had similar thyroid dysfunction prevalence. Thus, aggressive case-finding should be recommended in both, over 60.