The adipokines in the pathogenesis and treatment of nonalcoholic fatty liver disease

Insulin resistance, abdominal obesity, and inflammation play important roles in the pathogenesis of nonalcoholic fatty liver disease (NAFLD). Several adipokines, particularly adiponectin but also leptin, resistin, irisin, ghrelin, and visfatin modulate these pathogenetic mechanisms and appear to play a role in the development of hepatic steatosis and the progression to steatohepatitis and cirrhosis. Accordingly, these adipokines might represent attractive targets in patients with NAFLD. Notably, both lifestyle changes and many pharmacological agents that are used in the management of NAFLD, particularly pioglitazone and statins, exert favorable effects on adipokine levels. However, it is unclear whether these effects play a role in the improvement in liver histology. Therefore, mechanistic studies are needed to clarify the contribution of changes in adipokine levels to the effects of these interventions on hepatic steatosis, inflammation, and fibrosis. In parallel, the development of novel agents that specifically target adipokine levels might offer additional insights into the potential role of adipokines as therapeutic targets in NAFLD. Hippokratia 2016, 20(4): 259-263.

Cardiovascular effects of dipeptidyl peptidase-4 inhibitors

Dipeptidyl peptidase-4 (DPP-4) inhibitors are effective glucose-lowering agents that do not increase body weight and are associated with a low risk for hypoglycemia. Also, they appear to exert beneficial effects on other established cardiovascular risk factors, including dyslipidemia and hypertension. Moreover, DPP-4 inhibitors exert antiinflammatory and antioxidant actions, improve endothelial function and reduce urinary albumin excretion. In contrast to these favorable cardiovascular effects, three recent large, randomized, placebo-controlled trials in patients with type 2 diabetes mellitus (T2DM) and established cardiovascular disease or multiple cardiovascular risk factors showed that DPP-4 inhibitors do not affect the risk of myocardial infarction or ischemic stroke and might increase the risk of heart failure. The findings of the former randomized studies highlight the limitations of surrogate markers and show that beneficial effects on cardiovascular risk factors do not necessarily translate into reductions in hard clinical endpoints. Ongoing trials will shed more light on the safety profile of DPP-4 inhibitors and will clarify whether they will improve the cardiovascular outcomes of patients with T2DM. Hippokratia 2015; 19 (3): 195-199.

Clinical controversies in lipid management

Even though it is firmly established that statins are the cornerstone of management of dyslipidemias, several controversies still exist in this area. In the present review, the most pertinent controversies in lipid management are discussed and the current evidence is summarized. Treatment with statins increases the risk for type 2 diabetes mellitus (T2DM) but this increase appears to be small and outweighed by the benefits of statins on cardiovascular disease prevention. Accordingly, statin treatment-associated T2DM should not affect management decisions. In patients who cannot achieve low-density lipoprotein cholesterol (LDL-C) targets despite treatment with the maximum tolerated dose of a potent statin, adding ezetimibe appears to be the treatment of choice. Finally, patients who achieved LDL-C targets with a statin but have elevated triglyceride levels appear to have increased cardiovascular risk and adding fenofibrate appears to reduce this risk. Even though additional large randomized controlled trials are unlikely to be performed with the existing lipid-lowering agents, mechanistic, genetic and epidemiological studies, as well as careful analyses of the existing trials will provide further insights in these controversial issues and will allow the optimization of the management of dyslipidemia aiming at further reductions in cardiovascular morbidity.

Selenium status in patients with autoimmune and non-autoimmune thyroid diseases from four European countries

CONTEXT

Selenium supplementation has been suggested for Hashimoto thyroiditis and Graves' ophthalmopathy. Objective, Design: Our aim is to measure selenium status (p-Se, p-SePP), urine iodine (UI) levels and urine iodine/creatinine ratio (UI/C) in different thyroid diseases (n = 416) from four European countries and to compare the results between patients with and without thyroid autoimmunity.

RESULTS

p-Se and p-SePP showed positive correlation and did not correlate with UI/C. Also, these measurements were higher in patients from Italy in comparison with the other countries. Austria had the lowest UI/C ratios. Selenium deficiency exists in these four European countries. Selenium status was lower in patients with Hashimoto thyroiditis and Graves' disease in comparison with non-autoimmune thyroid disease patients and did not differ between autoimmune patients with or without thyroid peroxidase antibodies. The latter correlated positively with age.

CONCLUSIONS

Our findings suggest that Se supplementation might have a beneficial effect in autoimmune thyroid patients.

Calcitonin stimulation tests for the early diagnosis and follow-up of patients with C cell disease: a descriptive analysis

BACKGROUND/AIM

Residual or recurrent medullary thyroid carcinoma (MTC) after thyroidectomy is diagnosed by elevated serum calcitonin (CT) levels. However, in minimal residual MTC or C-cell hyperplasia (CCH), where imaging studies are often negative, basal CT levels are frequently normal and CT stimulation tests are required. We aimed to compare CT stimulation tests with calcium, pentagastrin and their combination in identifying minimal residual MTC and CCH.

MATERIAL AND METHODS

We studied 10 post-thyroidectomy patients with MTC and 20 first-degree relatives of the patients who had no clinically apparent MTC. We performed 54 combined (calcium plus pentagastrin) stimulation tests, 35 calcium stimulation tests and 26 pentagastrin stimulation tests.

RESULTS

Basal CT levels were abnormal (≥500 pg/ml) in 4 patients with apparent metastatic disease (Group 1A) and in 2 patients with minimal residual disease (Group 1B) but were normal (0-300 pg/ml) in 4 patients with no residual disease (Group 1C) and in the relatives (Group 2). In Groups 1A, 1B and 1C, maximal elevation in CT levels was greater after the combined stimulation test than after calcium or pentagastrin tests. The combined stimulation test induced the greatest increases (920, 700 and 706 pg/ml, respectively) in 3 relatives (Group 2); CCH was confirmed histologically in these patients. Side-effects were mild, short-lasting and of similar intensity and duration during all tests.

CONCLUSIONS

Patients with subclinical MTC (minimal residual or recurrent MTC) or their relatives (with CCH) usually have normal basal CT levels and stimulation tests are necessary. Combined test represents the most sensitive and safe stimulation test for the diagnosis of subclinical hypercalcitonemia.

Cardiovascular benefits of bariatric surgery in morbidly obese patients

Morbid obesity is associated with increased morbidity and represents a major healthcare problem with increasing incidence worldwide. Bariatric surgery is considered an effective option for the management of morbid obesity. We searched MEDLINE, Current Contents and the Cochrane Library for papers published on bariatric surgery in English from 1 January 1990 to 20 July 2010. We also manually checked the references of retrieved articles for any pertinent material. Bariatric surgery results in resolution of major comorbidities including type 2 diabetes mellitus, hypertension, dyslipidemia, metabolic syndrome, non-alcoholic fatty liver disease, nephropathy, left ventricular hypertrophy and obstructive sleep apnea in the majority of morbidly obese patients. Through these effects and possibly other independent mechanisms bariatric surgery appears to reduce cardiovascular morbidity and mortality. Laparoscopic Roux-en-Y gastric bypass (LRYGB) appears to be more effective than laparoscopic adjustable gastric banding (LAGB) in terms of weight loss and resolution of comorbidities. Operation-associated mortality rates after bariatric surgery are low and LAGB is safer than LRYGB. In morbidly obese patients bariatric surgery is safe and appears to reduce cardiovascular morbidity and mortality.

Effects of buflomedil on skin blood flow in patients with type 2 diabetes mellitus without overt micro- or macroangiopathy

AIM

The aim of this study was to assess the effects of buflomedil on the peripheral microcirculation in patients with type 2 diabetes mellitus (T2DM) without overt micro- or macroangiopathy.

METHODS

Twenty-three patients with T2DM were randomly assigned to receive buflomedil 600 mg/day for six months (N.=12) or no medication (N.=11). Skin blood flow in the lower limbs was assessed at baseline and after 3 and 6 months using Laser Doppler. We measured the following laser Doppler parameters: volume, flow and velocity.

RESULTS

In patients treated with buflomedil, there was a significant increase in volume (P=0.039) and a trend for an increase in both flow and velocity (P=0.097 for both parameters). In contrast, significant decreases in volume and flow were observed in the control group (P=0.045 and P=0.027, respectively) whereas velocity did not change (P=0.150).

CONCLUSION

In conclusion, buflomedil appears to have a beneficial effect on the peripheral microcirculation in patients with T2DM.

Effect of a plant stanol ester-containing spread, placebo spread, or Mediterranean diet on estimated cardiovascular risk and lipid, inflammatory and haemostatic factors

BACKGROUND AND AIMS

Mediterranean diet is associated with a reduced risk for cardiovascular disease (CVD). Use of plant stanols decreases low density lipoprotein cholesterol (LDL-C) concentrations. We compared the effects of the Mediterranean diet and plant stanol esters on vascular risk factors and estimated CVD (eCVD) risk.

METHODS AND RESULTS

In this prospective, randomized, placebo-controlled study, 150 mildly hypercholesterolaemic subjects were randomized to Mediterranean diet, a spread containing plant stanol esters (2 g/day) or a placebo spread. Vascular risk factors were assessed every month for 4 months and the eCVD risk was calculated using the PROspective- Cardiovascular-Munster (PROCAM), Framingham, and Reynolds risk engines. Placebo had no significant effect on risk factors or eCVD risk. Mediterranean diet gradually induced a significant reduction in total cholesterol (TC), LDL-C, triglycerides, high sensitivity C-reactive protein (hsCRP), blood pressure and eCVD risk (24-32%). The plant stanol ester spread reduced (by 1 month) TC (-14%), LDL-C (-16%), hsCRP (-17%), and estimated CVD risk (26-30%). eCVD risk reduction was sustained at 4th months when the gradual Mediterranean diet eCVD risk reduction became comparable to that of the stanol group.

CONCLUSIONS

Plant stanol esters yielded an early, by 1st treatment month, reduction of eCVD risk that resulted from a TC, LDL-C, and hsCRP decrease. eCVD risk reduction on the Mediterranean diet resulted from a change in several CVD risk factors and equaled that of plant stanol at 4 months. The consumption of plant stanol esters by moderately hypercholesterolaemic patients may be a useful option to reduce CVD risk in those who do not adopt a Mediterranean diet.

Can capsule endoscopy be used as a diagnostic tool in the evaluation of nonbleeding indications in daily clinical practice? A prospective study

OBJECTIVE

To evaluate the diagnostic yield of capsule endoscopy (CE) and its impact on treatment and outcome in patients without bleeding indications.

SUBJECTS AND METHODS

One hundred and sixty-five nonbleeding patients were enrolled in the study. The most common indications for CE were chronic abdominal pain alone (33 patients) or combined with chronic diarrhea (31 patients) and chronic diarrhea alone (30 patients). Among the 165 patients, 129 underwent CE for evaluation of gastrointestinal symptoms and 36 for surveillance or disease staging.

RESULTS

CE findings were positive, suspicious and negative in 73 (44.2%), 13 (7.9%) and 79 (47.9%) of cases, respectively. The diagnostic yield was highest in patients with refractory celiac disease (10/10, 100%) and suspected Crohn's disease (5/6, 83.3%), followed by patients with chronic abdominal pain and chronic diarrhea (13/31, 41.9%), established Crohn's disease (2/6, 33.3%), chronic diarrhea alone (8/30, 26.7%), chronic abdominal pain alone (8/33, 24.2%) and other indications (3/13, 23.1%) (p < 0.005). The CE findings led to a change of medication in 74 (47.7%) patients, surgery in 15 (9.7%), administration of a strict gluten-free or other special diet in 13 (8.4%) and had other consequences in 11 (6.7%). Management was not modified in 42 (27.1%) patients. Among symptomatic patients (n = 129), 29 (22.5%) were lost to follow-up. The remaining 100 patients were followed up for 8.7 ± 4.0 months (range 2-19). Among the latter, resolution or improvement of symptoms was observed in 86 (86%) patients, no change in 11 (11%) and 3 (3%) died. All 86 patients who experienced resolution or improvement of their symptoms had a modification of their management after CE; only 7/11 patients whose symptoms did not change (63.6%) and 2/3 patients who died (66.7%) had a modification of management (p < 0.001).

CONCLUSIONS

CE appears to be a useful tool in the evaluation of patients with nonbleeding indications. The outcome of most patients with negative findings was excellent.

Prevalence of overweight and abdominal obesity in Greek children 6-12 years old: Results from the National Epidemiological Survey

OBJECTIVE

To provide estimates of overweight (OW), obesity (OB) and abdominal obesity (AO) in a sample of children throughout the whole of Greece.

MATERIAL AND METHODS

This epidemiological, cross-sectional survey examined 3,140 children aged 6-12 y (1,589 boys and 1,551 girls) who were selected by stratified sampling through household family members of Greek adolescents attending school. Participants reported data on height, weight and waist circumference (WC). BMI and Waist-to-Height ratio (WHtR) were calculated. AO was estimated using WC and WHtR.

RESULTS

Overall prevalence of OW including OB was 31.2% in boys and 26.5% in girls, while OB prevalence was 9.4% and 6.4% respectively. The prevalence of AO based on WC (AO-WC), was similar in girls (14.2%) and boys (12.5%) while the prevalence of AO, based on WHtR (AO-WHtR), was higher in boys than in girls (25.6% vs 20.0%, p<0.0001). With increasing age, the prevalence of OW and OB decreases in both genders, and AO-WHtR only in girls. Rates of OW were significantly more prevalent in Greeks than in immigrants.

CONCLUSIONS

Overweight and obesity in Greek children is very prevalent, particularly in boys, comparable with that reported for Mediterranean European countries. Abdominal obesity also appears high. Preventive and treatment strategies are urgently needed to combat this national epidemic.

Brain natriuretic peptide and the athlete's heart: a pilot study

BACKGROUND

The role of brain natriuretic peptide (BNP) in differentiating the athlete's heart from maladaptive cardiac hypertrophy is unclear.

METHODS

To address this issue, an integrated M mode, two-dimensional B mode and Doppler echocardiographical study were performed and plasma BNP levels were measured in 25 strength athletes, 25 patients with established hypertrophic cardiomyopathy (HCM) and 25 healthy volunteers.

RESULTS

Among athletes, BNP levels correlated negatively with the total training time (r = -0.79, p = 0.002) and positively with ejection fraction (r = 0.58, p = 0.049) and fractional shortening (r = 0.57, p = 0.049). A BNP cut-off value of 11.8 pg/ml had 88% specificity and 74% negative predictive value for the exclusion of HCM.

CONCLUSIONS

Brain natriuretic peptide might be useful as a preparticipation screening test in athletes.

Endothelial dysfunction in metabolic syndrome: prevalence, pathogenesis and management

The metabolic syndrome (MetS) is characterized by the presence of central obesity, impaired glucose metabolism, dyslipidemia and hypertension. Several studies showed that MetS is associated with increased risk for type 2 diabetes mellitus (T2DM) and vascular events. All components of MetS have adverse effects on the endothelium. Endothelial dysfunction plays a role in the pathogenesis of atherosclerosis and might also increase the risk for insulin resistance and T2DM. We review the prevalence and pathogenesis of endothelial dysfunction in MetS. We also discuss the potential effects of lifestyle measures and pharmacological interventions on endothelial function in these patients. It remains to be established whether improving endothelial function in MetS will reduce the risk for T2DM and vascular events.