The effect of a vegetarian versus conventional hypocaloric diet on serum concentrations of persistent organic pollutants in patients with type 2 diabetes.

BACKGROUND AND AIMS: The aim of this study was to explore the effect of a vegetarian versus conventional diet on the serum levels of persistent organic pollutants (POPs) in patients with T2D after 12 weeks of dietary intervention and to assess their relationships with metabolic parameters. METHODS AND RESULTS: Men and women with T2D were randomly assigned to follow either a vegetarian diet without fish or meat (n = 37) or an isocaloric conventional antidiabetic diet (n = 37). Both diets were energy restricted (minus 500 kcal/day). All foods were provided to the participants. At randomization (week 0) and 12 weeks, the meal test was performed to assess the ß-cell function and serum levels of 24 POPs. Dioxins and dioxin-like POPs were analyzed by isotope dilution high-resolution gas chromatography (HRGC) and mass spectrometry after cleanup of the silica and carbon columns. Non-dioxin-like POPs were analyzed by gas chromatography with an electron capture detector (GC-ECD). Statistical analyses used were repeated-measures analysis of variance (ANOVA), a multivariate regression model, and Pearson's correlations. We observed a statistically nonsignificant trend toward increases in the serum levels of most POPs in response to both hypocaloric diets with no differences between groups. In the groups combined, the change in serum concentrations of total POPs was correlated to changes in HbA1c (r = +0.34; p < 0.01), fasting plasma glucose (r = +0.41; p < 0.01) levels, and ß-cell function measured as insulin secretion at a reference glucose level (r = -0.37; p < 0.01), independent of the changes in body weight and volume of visceral fat. CONCLUSION: Short-term hypocaloric vegetarian and conventional diets did not reduce the POP levels, possibly due to mobilization of fat stores. Our findings support the relationship between POPs and diabetes, especially ß-cell function. TRIAL REGISTRATION: ClinicalTrials.gov number, NCT00883038, completed.

Effect of acute hyperinsulinemia on brain metabolism evaluated by 1H MR spectroscopy--a pilot study.

To determine whether acutely-induced supraphysiological hyperinsulinemia influences brain metabolism in patients with type 1 diabetes (D) and healthy controls (C) as detected by MR Spectroscopy. Group D consisted of 4 patients with the average duration of diabetes for 7 years. They were matched according to age, sex and BMI to 4 healthy controls. 1H MR Spectroscopy was performed with a 1.5 Tesla. Spectra were obtained from parietooccipital white matter repeatedly during a 3-h hyperinsulinemic euglycemic clamp with 2 mU.kg(-1).min(-1). In group D, significantly lower basal concentrations of N-acetylaspartate (p=0.02), choline (p=0.03), creatine (p=0.002) and inositol (p=0.007) were detected compared to C. After the induction of hyperinsulinemia, concentrations of choline, creatine, GABA, inositol, lactate, NAA and composite signal glutamate + glutamine (Glx) stayed stable. The detection of glucose signal is less realiable at 1.5 Tesla but we registered the alteration in glucose concentration (p=0.003) in the whole group. Originally sightly elevated glucose concentration in D decreased on the contrary to the increase of originally lower glucose level in C. In conclusions, brain metabolism was altered in D. Short term supraphysiological euglycemic hyperinsulinemia induced changes in the concentration of brain glucose in both C and D.

Tagging rs10811661 variant at CDKN2A/2B locus is not associated with type 2 diabetes mellitus in Czech population.

Genome-wide association studies have resulted in the identification of the CDKN2A/2B locus as an important genetic determinant of type 2 diabetes mellitus development. The aim of this study was to investigate the role of this locus in the development of type 2 diabetes mellitus in Czech Slavonic population. Groups of 1,149 type 2 diabetic patients and a group of 2,312 healthy controls, both of Czech origin, were successfully genotyped for the rs10811661 CDK2A/2B tagging polymorphism. The "risky" TT genotype frequencies were almost identical in both examined groups (69.3 % in patients and 68.9 % in controls, P = 0.52; OR [95% CI] = 1.02 [0.87 - 1.19] for TT versus C allele carriers). Similar negative results were obtained when males (P = 0.93) and females (P = 0.23) were analysed separately. We have not confirmed the association between rs10811661 SNP and susceptibility to the type 2 diabetes mellitus in Czech Slavonic population.

Vegetarian diet-induced increase in linoleic acid in serum phospholipids is associated with improved insulin sensitivity in subjects with type 2 diabetes.

BACKGROUND AND AIMS: Fatty acids are important cellular constituents that may affect many metabolic processes relevant for the development of diabetes and its complications. We showed previously that vegetarian diet leads to greater increase in metabolic clearance rate of glucose (MCR) than conventional hypocaloric diet. The aim of this secondary analysis was to explore the role of changes in fatty acid composition of serum phospholipids in diet- and exercise-induced changes in MCR in subjects with type 2 diabetes (T2D). METHODS: Subjects with T2D (n=74) were randomly assigned into a vegetarian group (VG, n=37) following vegetarian diet or a control group (CG, n=37) following a conventional diet. Both diets were calorie restricted (-500 kcal day(-1)). Participants were examined at baseline, 12 weeks of diet intervention and 24 weeks (subsequent 12 weeks of diet were combined with aerobic exercise). The fatty acid composition of serum phospholipids was measured by gas liquid chromatography. MCR was measured by hyperinsulinemic isoglycemic clamp. Visceral fat (VF) was measured by magnetic resonance imaging. RESULTS: Linoleic acid (LA; 18:2n6) increased in VG (P=0.04), whereas it decreased in CG (P=0.04) in response to dietary interventions. It did not change significantly after the addition of exercise in either group (group × time P<0.001). In VG, changes in 18:2n6 correlated positively with changes in MCR (r=+0.22; P=0.04) and negatively with changes in VF (r=-0.43; P=0.01). After adjustment for changes in body mass index, the association between 18:2n6 and MCR was no longer significant. The addition of exercise resulted in greater changes of phospholipid fatty acids composition in VG than in CG. CONCLUSION: We demonstrated that the insulin-sensitizing effect of a vegetarian diet might be related to the increased proportion of LA in serum phospholipids.

[Diabetic retinopathy in the Czech National Diabetes Programme 2012-2022]. / Diabetická retinopatie v národním diabetologickém programu 2012-2022.

Diabetic retinopathy (DR) develops in patients with both type 1 and type 2 diabetes and is the major cause of vision loss and blindness in people of working age. In the Czech Republic, the number of patients with diabetic retinopathy is still increasing as well as the number of diabetic patients. It is known, that the comprehensive preventive and therapeutic procedures reduce the risk of visual loss by more than 90%. These procedures include intervention of modifiable risk factors (especially hypertension and hyperglycaemia), active screening of DR and specialized ophthalmologic treatment. The Czech National Diabetes Programme 2012-2022, which is built on similar initiatives as in 1984 and 2000, has been completed in late 2012. Its main goal is to improve the health outcomes for people diabetes in the Czech Republic. The programme includes specific procedures aimed at improvement of organization and treatment providing to patients with diabetic retinopathy.

Improvement in ß-cell function after diet-induced weight loss is associated with decrease in pancreatic polypeptide in subjects with type 2 diabetes.

OBJECTIVE: The aim of our study was to evaluate the effect of a lifestyle intervention program on ß-cell function and to explore the role of gastrointestinal peptides in subjects with T2D. METHODS: Subjects with T2D (n=74) received 24 weeks of intervention: 12 weeks of slimming diet (-500 kcal/day) and the subsequent 12 weeks of diet were combined with aerobic exercise. All subjects were examined at weeks 0, 12 and 24. ß-cell function was assessed during standard meal tests. Insulin secretory rate (ISR) was calculated by C-peptide deconvolution, and ß-cell function was quantified with a mathematical model. Plasma concentrations of gastrointestinal peptides were measured in a fasting state and during hyperinsulinemia induced by hyperinsulinemic isoglycemic clamp. RESULTS: Mean weight loss was 5.03±4.38 kg (p<0.001) in weeks 0-12. Weight did not change significantly in weeks 12-24. Both insulin secretion at the reference level and glucose sensitivity increased in weeks 0-12 (by 33%±54% and by 26%±53%, respectively, p<0.001) and remained unchanged in weeks 12-24. Both fasting and hyperinsulinemic plasma concentrations of pancreatic polypeptide (PP) decreased in weeks 0-12 (p<0.05 for both) and did not change significantly in weeks 12-24. Changes in insulin secretion at the reference level correlated negatively with plasma concentrations of PP during hyperinsulinemia (r=-0.36; p<0.001). Changes in glucose sensitivity correlated negatively with changes in plasma concentrations of PP, both in fasting and during hyperinsulinemia (r=-0.2; p=0.01 for both). The correlations remained significant after adjustment for changes in body-mass-index. CONCLUSIONS: After diet-induced weight loss, ß-cell function improved in T2D subjects and remained unchanged after the addition of exercise. We demonstrate for the first time that these changes are associated with a decrease in PP secretion.

[A recommended approach to evaluate cardiovascular risk and to prevent cardiovascular diseases and type 2 diabetes mellitus in women with polycystic ovary syndrome]. / Doporucený postup k posouzení kardiovaskulárního rizika a prevenci kardiovaskulárních onemocnení a diabetes mellitus 2. typu u zen se syndromem polycystických ovarií

Polycystic ovary syndrome is one of the most common endocrinopathy in women of fertile age. It is commnoly accompanied by an increased occurence of cardiovascular risk factors. This association led to a consensus statement of Androgen Excess Society for screening of cardiovascular risk factors. We present the recommendations of Czech Endocrine and Czech Diabetological Societies for the screening and primary prevention of cardiovascular diseases and diabetes mellitus.

Vegetarian diet improves insulin resistance and oxidative stress markers more than conventional diet in subjects with Type 2 diabetes.

AIMS: The aim of this study was to compare the effects of calorie-restricted vegetarian and conventional diabetic diets alone and in combination with exercise on insulin resistance, visceral fat and oxidative stress markers in subjects with Type 2 diabetes. METHODS: A 24-week, randomized, open, parallel design was used. Seventy-four patients with Type 2 diabetes were randomly assigned to either the experimental group (n = 37), which received a vegetarian diet, or the control group (n = 37), which received a conventional diabetic diet. Both diets were isocaloric, calorie restricted (-500 kcal/day). All meals during the study were provided. The second 12 weeks of the diet were combined with aerobic exercise. Participants were examined at baseline, 12 weeks and 24 weeks. Primary outcomes were: insulin sensitivity measured by hyperinsulinaemic isoglycaemic clamp; volume of visceral and subcutaneous fat measured by magnetic resonance imaging; and oxidative stress measured by thiobarbituric acid reactive substances. Analyses were by intention to treat. RESULTS: Forty-three per cent of participants in the experimental group and 5% of participants in the control group reduced diabetes medication (P < 0.001). Body weight decreased more in the experimental group than in the control group [-6.2 kg (95% CI -6.6 to -5.3) vs. -3.2 kg (95% CI -3.7 to -2.5); interaction group × time P = 0.001]. An increase in insulin sensitivity was significantly greater in the experimental group than in the control group [30% (95% CI 24.5-39) vs. 20% (95% CI 14-25), P = 0.04]. A reduction in both visceral and subcutaneous fat was greater in the experimental group than in the control group (P = 0.007 and P = 0.02, respectively). Plasma adiponectin increased (P = 0.02) and leptin decreased (P = 0.02) in the experimental group, with no change in the control group. Vitamin C, superoxide dismutase and reduced glutathione increased in the experimental group (P = 0.002, P < 0.001 and P = 0.02, respectively). Differences between groups were greater after the addition of exercise training. Changes in insulin sensitivity and enzymatic oxidative stress markers correlated with changes in visceral fat. CONCLUSIONS: A calorie-restricted vegetarian diet had greater capacity to improve insulin sensitivity compared with a conventional diabetic diet over 24 weeks. The greater loss of visceral fat and improvements in plasma concentrations of adipokines and oxidative stress markers with this diet may be responsible for the reduction of insulin resistance. The addition of exercise training further augmented the improved outcomes with the vegetarian diet.

A polymorphism in the cyclooxygenase 2 gene in type 1 diabetic patients with nephropathy.

Diabetic nephropathy (DN), the most serious complication of Type 1 diabetes (DM1), has a strong genetic component. Cyclooxygenase-2 (COX-2), an inducible enzyme by a number of stimuli, has been implicated in pathophysiology of cardiovascular and renal disease, including DN. The allele -765C, of the -765G > C polymorphism (rs20417) in the COX-2 promoter has lower promoter activity compared with the -765G allele and protective effects in cardiovascular disease. This polymorphism was not investigated in patients with DM1 and nephropathy. The study was conducted in 779 Caucasian patients with DM1 and compared to a representative sample of healthy Czech population. The patients demonstrated lower frequencies of the CC genotype (P = 0.005). From the DM1 cohort, 153 patients met the criteria for low risk of the development of DN (LRDN, duration of DM1 > 10 years, normoalbuminuria, normotension) and 139 patients had manifest DN. There were no differences in -765G > C polymorphisms between LRDN and DN patients. Moreover, the C/G allele frequencies did not also differ between the groups. In conclusion, patients with DM1 display lower freqencies of the protective CC genotype as compared to healthy subjects. However, the study did not reveal associations of -765G > C polymorphism with the risk of DN.

Selected adipokines - plasma concentrations and adipose tissue expressions during 24-hour lipid infusion in healthy men.

Our aim was to assess the reaction of TNFalpha, resistin, leptin and adiponectin to lipid infusion. Eight healthy subjects underwent a 24-hour lasting infusion of lipid emulsion. Plasma concentrations and expressions of selected cytokines in subcutaneous fat were measured. TNFalpha plasma concentration did not change during the first 4 hours of hypertriglyceridemia, but a significant increase after 24 hours was detected (p<0.001 for 0; 30; 240 min vs. 24 h). Plasma concentration of resistin significantly increased at 30 min of infusion and remained elevated (p<0.01 for 0 min vs. 30; 240 min; p<0.001 for 0 min vs. 24 h). Plasma concentrations of leptin and adiponectin did not show any significant changes. Although the expression of resistin in the subcutaneous adipose tissue tended to increase, the change was not significant. Expressions of TNFalpha, leptin and adiponectin were unaffected. In conclusions, our results indicate that acutely induced hyperlipidemia could influence the secretion of TNFalpha and resistin.

[Treatment of diabetes in metabolic syndrome]. / Lécba diabetu pri metabolickém syrndromu.

Hyperglycaemia is a typical feature of metabolic syndrome (MeTS) and one of its independent diagnostic criteria. The term includes impaired glucose homeostasis (impaired fasting glucose and impaired glucose tolerance) and type 2 diabetes mellitus. Although glycaemic control has been shown to lower the risk of microvascular events, the effect of intensive glycaemic control on macrovascular outcomes is less clear. Epidemiological studies show hyperglycaemia, particularly the postprandial one, to be a clear risk factor for cardiovascular (CV) mortality and morbidity. However, the intervention studies are less conclusive. The large interventional studies published in 2008 and 2009 (UKPDS, VADT, ACCORD, ADVANCE, RECORD) advocate the controlling of nonglycemic risk factors (through blood pressure control, lipid lowering with statin therapy, aspirin therapy, and lifestyle modifications) as the primary strategies for reducing the burden of CV disease in people with diabetes, and demonstrated the need for individualized approach to the patients' care in terms of blood glucose control. The patients with shorter duration of type 2 diabetes and without established atherosclerosis might reap CV benefit from intensive glycemic control. Conversely, it is possible that potential risks of intensive glycaemic control (hypoglycaemia) may outweigh its benefits in other patients, such as those with a very long duration ofdiabetes, known history of severe hypoglycemia, advanced atherosclerosis, and advanced age/frailty. According to the latest recommendations of the Czech Diabetes Society that are in line with the European and US standards the best way to protect type 2 diabetic patients against coronary and cerebrovascular disease is to target all cardiovascular risk factors (blood pressure treatment, including lipid-lowering with statins, aspirin prophylaxis, smoking cessation, and healthy lifestyle behaviors hypertension, dyslipidemia, obesity and other symptoms of metabolic syndrome. The target HbA1c levels in patients with the low CV risk shoul be below 4.5%. Less strict goals (HbA1c below 6%) may be appropriate for patients with a history of severe hypoglycemia, limited life expectancy, advanced microvascular or macrovascular complications, or extensive comorbid conditions or those with long-standing diabetes. The individual targets should be achieved safely (without hypoglycaemias). Slow advancing in diabetes compensation is preferred. Lifestyle changes are the cornerstone of therapy. Metformin is the drug of choice; its administration, together with lifestyle changes, should be initiated immediately after the diagnoses of diabetes. If monotherapy does not provide satisfactory glucose control, other oral antidiabetic agents or insulin are added to the combination. Since it is not known which hypoglycaemic agents are beneficial from the perspective of long-term patient prognosis, the selection is liberal. Contraindication of the various farmaceuticals must be respected. It is possible to use a range of different combinations, metformin is administered with a glitazone (zero risk of hypoglycaemias is the advantage) with sulphonylurea derivatives (low price is the advantage) with glinides, with incretins, acarbose, antiobesity agents or insulin. The next step is a triple combination of hypoglycaemic agents with different mechanisms of action. Therapy also includes education focusing on changes to dietary and lifestyle habits, including smoking cessation, and education related to the prevention of complications, with particular regard to prevention of diabetic foot and atherosclerosis.

Changes in the content of biologically active polyamines during beef loin storage and cooking.

Dietary polyamines putrescine (PUT), spermidine (SPD) and spermine (SPM) participate in numerous human physiological processes, including tumour growth. Reliable information on their contents in foods is thus needed. Data for processed beef are very limited. Nine experiments with beef loin (longissimus lumborum) were, therefore, carried out. Loin cuts were stored at -18°C for 178 days or beef was stored aerobically, vacuum-packaged (VP) and packaged in a modified atmosphere (MA; 70% N(2) and 30% CO(2), v/v) at +2°C for 9, 21 and 21 days, respectively. The effects of three usual cooking treatments were also tested. Polyamines were determined after extraction with perchloric acid as dansyl derivatives using an HPLC method. Only SPM was detected at initial levels of 23.5-27.5mgkg(-1), PUT and SPD contents were below the detection limits of 1.2 and 1.7mgkg(-1), respectively. SPM content increased during the initial weeks of frozen storage and then gradually decreased to about 70% of the initial values at the end of the storage period (P<0.05). No apparent SPM decrease was observed during aerobic storage for 9 days, while in VP and MA variants the losses were about 20% of the initial values on day 21 (P<0.05). Slightly higher mean SPM losses were observed during boiling and stewing with and without added water. The differences among the cooking treatments were not significant. However, significant differences were observed among the loins used.

Biologically active polyamines in pig kidneys and spleen: Content after slaughter and changes during cold storage and cooking.

Polyamines putrescine, spermidine (SPD) and spermine (SPM) were determined as dansyl derivatives using an HPLC method. Distribution of SPD and SPM in pair kidneys was homogenous. The mean SPD and SPM contents in pig kidneys 24h after slaughter were 9.39±3.35 and 53.1±14.0mgkg(-1), respectively with no significant differences between barrows and gilts. Putrescine content was below the detection limit of 1.2mgkg(-1). In kidneys stored aerobically or vacuum-packaged at 2-3°C for 7 and 21 days, respectively, SPD and SPM decreased significantly. Stewing decreased both polyamines more extensively in kidneys processed on day-1 after slaughter than on day-7 after storage at 2-3°C. The mean SPD and SPM in 10 spleens 24h after slaughter were 36.7±5.70 and 34.0±7.64mgkg(-1), respectively. Thus, both pork kidney and spleen are foods with a high level of SPM and SPD.

Urinary urea nitrogen excretion during the hyperinsulinemic euglycemic clamp in type 1 diabetic patients and healthy subjects.

The hyperinsulinemic euglycemic clamp (HEC) combined with indirect calorimetry (IC) is used for estimation of insulin-stimulated substrate utilization. Calculations are based on urinary urea nitrogen excretion (UE), which is influenced by correct urine collection. The aims of our study were to improve the timing of urine collection during the clamp and to test the effect of insulin on UE in patients with type 1 diabetes (DM1; n=11) and healthy subjects (C; n=11). Urine samples were collected (a) over 24 h divided into 3-h periods and (b) before and during two-step clamp (1 and 10 mIU.kg(-1).min(-1); period 1 and period 2) combined with IC. The UE during the clamp was corrected for changes in urea pool size (UEc). There were no significant differences in 24-h UE between C and DM1 and no circadian variation in UE in either group. During the clamp, serum urea decreased significantly in both groups (p<0.01). Therefore, UEc was significantly lower as compared to UE not adjusted for changes in urea pool size both in C (p<0.001) and DM1 (p<0.001). While UE did not change during the clamp, UEc decreased significantly in both groups (p<0.01). UEc during the clamp was significantly higher in DM1 compared to C both in period 1 (p<0.05) and period 2 (p<0.01). The UE over 24 h and UEc during the clamp were statistically different in both C and DM1. We conclude that urine collection performed during the clamp with UE adjusted for changes in urea pool size is the most suitable technique for measuring substrate utilization during the clamp both in DM1 and C. Urine collections during the clamp cannot be replaced either by 24-h sampling (periods I-VII) or by a single 24-h urine collection. Attenuated insulin-induced decrease in UEc in DM1 implicates the impaired insulin effect on proteolysis.

Effect of acute hyperinsulinaemia with and without angiotensin II type 1 receptor blockade on resistin and adiponectin concentrations and expressions in healthy subjects.

OBJECTIVE: The potential insulin-sensitizing function of angiotensin II type 1 receptor blockade (ARB) with regard to selected adipokines is not fully explained so far. Our study aimed to explore the influence of acute hyperinsulinaemia and acutely induced ARB on resistin and adiponectin concentrations and expressions in healthy subjects. DESIGN AND METHODS: Plasma adipokines were measured: 1) at 0, 30 and 240 min of hyperinsulinaemic (1 mU/kg per min) euglycaemic (5 mmol/l) clamp (HEC), and 2) during HEC after acute ARB (losartan 200 mg; AT-HEC) using the same protocol, in eight healthy subjects. Needle biopsy of abdominal s.c. fat was performed at 0, 30 and 240 min of both clamps to assess the adipokines' expressions. RESULTS: Comparing the glucose disposals of HEC and AT-HEC, no difference in insulin sensitivity was found. Plasma resistin increased equally during HEC and AT-HEC (P < 0.05). The expression of resistin in s.c. fat increased during HEC (P < 0.05), while no significant changes in expression were observed during AT-HEC. Plasma levels of adiponectin did not change during both clamps. Adiponectin expression increased during HEC (P < 0.05), while it did not change during AT-HEC. CONCLUSIONS: In healthy subjects, acute hyperinsulinaemia is associated with an increase in plasma resistin independently of ARB, while plasma adiponectin is not influenced by insulin or ARB. The expressions of both resistin and adiponectin in s.c. adipose tissue are stimulated by acute hyperinsulinaemia, whereas losartan attenuates their insulin-stimulated expressions. This suggests a potential effect of losartanon adipokines' expression.