P–033 In vitro protective effect of α -tocopherol and anthocyanin against TiO2-NPs induced genotoxicity on human spermatozoa

Study question

Do α -tocopherol and anthocyanin counteract human sperm DNA damage provoked by titanium dioxide nanoparticles (TiO2-NPs)? Summary answer: ↑-tocopherol and anthocyanin are able to counteract TiO2-NPs genotoxicity on human sperm cells reducing oxidative stress.

What is known already

The environmental release and the extensive use of TiO2-NPs have been implicated in poor human sperm functionality.TiO2-NPs is genotoxic on human sperm cells causing a loss of sperm DNA integrity, an increase of apoptotic process and a reduction of genomic stability related to an over production of intracellular ROS.Antioxidants are the substances that can scavenge free radicals. α -tocopherol, present in vegetables, is the most important lipophilic antioxidant involved in restore sperm parameters in several experimental models. Anthocyanin, present in Aronia melanocarpaand belonging to the flavonoid family, is able to prevent damage caused by varicocele-induced ROS in rats.

Study design, size, duration

Semen samples from 132 men were obtained by masturbation following 3–5 days sexual abstinence and were examined for sperm concentration, viability, motility and morphology according to WHO 2010. The sperm cells, after purification with 45–90% double density gradient, were exposed in vitro to 1 µg/L of TiO2-NPs, 1 µg/L of TiO2-NPs whit 1 mg/L of anthocyanin and 1 µg/L of TiO2-NPs plus 1 mg/L of α -tocopherolfor 15,30,45 and 90 minutes at 37 °C.

Participants/materials, setting, methods

Sperm motility and concentration were analyzed with Makler camber while sperm viability and morphology were evaluated by Eosin-Nigrosin Test and by Testsimplets® prestained slides respectively. Antigenotoxicity was evaluated by Comet assay, TUNEL test and RAPD-PCR technique and Genomic Template Stability (GTS,%) calculation. The intracellular ROS level was assessed by DFC Assay. The data were analyzed using ANOVA test by GraphPad Prism 6 and considered significant if p-value ≤ 0.05.

Main results and the role of chance

Sperm analyses showed none statistically significant changes in sperm viability and motility (progressive and non-progressive) for each treatment. Anthocyanin and α -tocopherol counteracted sperm DNA damage induced in vitro by TiO2-NPs neutralizing ROS in a time-dependent way. Comet assay displayed that both antioxidants reduced sperm DNA strand breaks produced by TiO2-NPs, in particular the damage was no longer statistically significant starting from 30 and 90 minutes of anthocyanin-TiO2-NPs and α-tocopherol-TiO2-NPs co-exposure respectively. The antioxidant supplementation induced a statistically decrease of sperm DNA fragmentation provoked by TiO2-NPs after 45 co-treatment minutes.The RAPD-PCR technique evidenced variations of bands number in the TiO2-NPs treated sperm compared to the negative control and anthocyanin and α -tocopherol-TiO2-NPs co-treated samples. Human sperm genomic stability increased after anthocyanin and α -tocopherol TiO2-NPs co-exposure respect to the TiO2-NPs single treatment, until it almost reaches the negative control at 90 minutes. Intracellular ROS percentage was significantly lower both in anthocyanin and α -tocopherol TiO2-NPs co-treated compared to TiO2-NPs alone starting from 45 minutes.

Limitations, reasons for caution

In vitro study. Wider implications of the findings: Our results showed a protective effect of anthocyanin and α -tocopherol on human DNA by neutralizing intracellular ROS induced by TiO2NPs. We suggest anthocyanin and α -tocopherol as suitable molecules to defend human sperm DNA from oxidative stress, with a potentially role in treatmentof male infertility due to environmental factors.

Trial registration number

None

Effects on the incidence of cardiovascular events of the addition of pioglitazone versus sulfonylureas in patients with type 2 diabetes inadequately controlled with metformin (TOSCA.IT): a randomised, multicentre trial

BACKGROUND

The best treatment option for patients with type 2 diabetes in whom treatment with metformin alone fails to achieve adequate glycaemic control is debated. We aimed to compare the long-term effects of pioglitazone versus sulfonylureas, given in addition to metformin, on cardiovascular events in patients with type 2 diabetes.

METHODS

TOSCA.IT was a multicentre, randomised, pragmatic clinical trial, in which patients aged 50-75 years with type 2 diabetes inadequately controlled with metformin monotherapy (2-3 g per day) were recruited from 57 diabetes clinics in Italy. Patients were randomly assigned (1:1), by permuted blocks randomisation (block size 10), stratified by site and previous cardiovascular events, to add-on pioglitazone (15-45 mg) or a sulfonylurea (5-15 mg glibenclamide, 2-6 mg glimepiride, or 30-120 mg gliclazide, in accordance with local practice). The trial was unblinded, but event adjudicators were unaware of treatment assignment. The primary outcome, assessed with a Cox proportional-hazards model, was a composite of first occurrence of all-cause death, non-fatal myocardial infarction, non-fatal stroke, or urgent coronary revascularisation, assessed in the modified intention-to-treat population (all randomly assigned participants with baseline data available and without any protocol violations in relation to inclusion or exclusion criteria). This study is registered with ClinicalTrials.gov, number NCT00700856.

FINDINGS

Between Sept 18, 2008, and Jan 15, 2014, 3028 patients were randomly assigned and included in the analyses. 1535 were assigned to pioglitazone and 1493 to sulfonylureas (glibenclamide 24 [2%], glimepiride 723 [48%], gliclazide 745 [50%]). At baseline, 335 (11%) participants had a previous cardiovascular event. The study was stopped early on the basis of a futility analysis after a median follow-up of 57·3 months. The primary outcome occurred in 105 patients (1·5 per 100 person-years) who were given pioglitazone and 108 (1·5 per 100 person-years) who were given sulfonylureas (hazard ratio 0·96, 95% CI 0·74-1·26, p=0·79). Fewer patients had hypoglycaemias in the pioglitazone group than in the sulfonylureas group (148 [10%] vs 508 [34%], p<0·0001). Moderate weight gain (less than 2 kg, on average) occurred in both groups. Rates of heart failure, bladder cancer, and fractures were not significantly different between treatment groups.

INTERPRETATION

In this long-term, pragmatic trial, incidence of cardiovascular events was similar with sulfonylureas (mostly glimepiride and gliclazide) and pioglitazone as add-on treatments to metformin. Both of these widely available and affordable treatments are suitable options with respect to efficacy and adverse events, although pioglitazone was associated with fewer hypoglycaemia events.

FUNDING

Italian Medicines Agency, Diabete Ricerca, and Italian Diabetes Society.

Polyphenol intake and cardiovascular risk factors in a population with type 2 diabetes: The TOSCA.IT study

BACKGROUND

The role of polyphenol intake on cardiovascular risk factors is little explored, particularly in people with diabetes.

AIM

To evaluate the association between the intake of total polyphenols and polyphenol classes with the major cardiovascular risk factors in a population with type 2 diabetes.

METHODS

Dietary habits were investigated in 2573 males and females participants of the TOSCA.IT study. The European Prospective Investigation on Cancer and Nutrition (EPIC) questionnaire was used to assess dietary habits. In all participants, among others, we assessed anthropometry, plasma lipids, blood pressure, C-reactive protein and HbA1c following a standard protocol. The USDA and Phenol-Explorer databases were used to estimate the polyphenol content of the habitual diet.

RESULTS

Average intake of polyphenols was 683.3 ± 5.8 mg/day. Flavonoids and phenolic acids were the predominant classes (47.5% and 47.4%, respectively). After adjusting for potential confounders, people with the highest intake of energy-adjusted polyphenols (upper tertile) had a more favorable cardiovascular risk factors profile as compared to people with the lowest intake (lower tertile) (BMI was 30.7 vs 29.9 kg/m², HDL-cholesterol was 45.1 vs 46.9 mg/dl, LDL-cholesterol was 103.2 vs 102.1 mg/dl, triglycerides were 153.4 vs 148.0 mg/dl, systolic and diastolic blood pressure were respectively 135.3 vs 134.3 and 80.5 vs 79.6 mm/Hg, HbA1c was 7.70 vs 7.67%, and C-reactive Protein was 1.29 vs 1.25 mg/dl, p < .001 for all). The findings were very similar when the analysis was conducted separately for flavonoids or phenolic acids, the two main classes of polyphenols consumed in this population.

CONCLUSIONS

Polyphenol intake is associated with a more favorable cardiovascular risk factors profile, independent of major confounders. These findings support the consumption of foods and beverages rich in different classes of polyphenols particularly in people with diabetes.

CLINICAL TRIAL

http://www.clinicaltrials.gov; Study ID number: NCT00700856.

Sex differences in food choices, adherence to dietary recommendations and plasma lipid profile in type 2 diabetes - The TOSCA.IT study

BACKGROUND AND AIMS

Diabetic women have a more adverse plasma lipid profile than men. Sex differences in dietary habits may play a role, but are little investigated. The study evaluates the quality of diet, adherence to the nutritional recommendations of the Diabetes and Nutrition Study Group and their relation with plasma lipid in men and women with diabetes.

METHODS AND RESULTS

We studied 2573 people, aged 50-75, enrolled in the TOSCA.IT study (clinicaltrials.gov; NCT00700856). Plasma lipids were measured centrally. Diet was assessed with a semi-quantitative food frequency questionnaire. Women had a more adverse plasma lipid profile than men. Women consumed significantly more legumes, vegetables, fruits, eggs, milk, vegetable oils, and added sugar, whereas men consumed more starchy foods, soft drinks and alcoholic beverages. This stands for a higher proportion (%) of energy intake from saturated fat and added sugar (12.0 ± 2.4 vs 11.5 ± 2.5 and 3.4 ± 3.2 vs 2.3 ± 3.2, P < 0.04), and a higher intake of fiber (11.2 ± 2.8 vs 10.4 ± 2.6 g/1000 Kcal/day) in women. Adherence to the recommendations for saturated fat and fiber consumption was associated with significantly lower LDL-cholesterol regardless of sex. Adherence to the recommendations for added sugars was associated with significantly lower triglycerides and higher HDL-cholesterol in men and women.

CONCLUSIONS

Men and women with diabetes show significant differences in adherence to nutritional recommendations, but sex differences in plasma lipid profile are unlikely to be explained by nutritional factors. Adherence to the nutritional recommendations is associated with a better plasma lipid profile regardless of sex, thus reinforcing the importance of substituting saturated for unsaturated fat sources, increasing fiber and reducing added sugar intake.

Impact of three phthalate esters on the sexual reproduction of the Monogonont rotifer, Brachionus calyciflorus

Phthalate esters are widespread contaminants that can cause endocrine disruption in vertebrates. Studies showed that molecules with hormonal activities in vertebrates and invertebrates can affect asexual and sexual reproduction in rotifers. We investigated the impact of di-hexylethyl phthalate (DEHP), di-butyl phthalate (DBP) and butylbenzyl phthalate (BBP), on the asexual and sexual reproduction of the freshwater monogonont rotifer Brachionus calyciflorus in order to determine a potential environmental risk for sexual reproduction. We observed that DEHP has no significant impact on both asexual and sexual reproduction up to 2 mg/L. DBP has a positive effect on asexual reproduction at concentrations from 0.05 to 1 mg/L, but depresses it at 2 mg/L. Sexual reproduction is only affected at 2 mg/L and the impact observed is negative. BBP displayed a negative impact on both asexual and sexual reproduction at 1 and 2 mg/L. However we showed that the impacts of BBP on mixis and fertilization rates observed are due to the decrease in population growth rates at these concentrations and not to a direct impact of BBP on the mixis and the fertilization processes. Our results show that sexual reproduction in B. calyciflorus is not more sensitive than asexual reproduction to any of the substances tested which indicates the mode of action of these molecules is related to general toxicity and not to an interference with potential endocrine regulation of sexual reproduction. Comparison of effect concentrations and surface water contamination by phthalate esters suggests these compounds do not constitute a risk for primary consumers in these environments.

Influence of dietary fat and carbohydrates proportions on plasma lipids, glucose control and low-grade inflammation in patients with type 2 diabetes-The TOSCA.IT Study

PURPOSE

The optimal macronutrient composition of the diet for the management of type 2 diabetes is debated, particularly with regard to the ideal proportion of fat and carbohydrates. The aim of the study was to explore the association of different proportions of fat and carbohydrates of the diet-within the ranges recommended by different guidelines-with metabolic risk factors.

METHODS

We studied 1785 people with type 2 diabetes, aged 50-75, enrolled in the TOSCA.IT Study. Dietary habits were assessed using a validated food-frequency questionnaire (EPIC). Anthropometry, fasting lipids, HbA1c and C-reactive protein (CRP) were measured.

RESULTS

Increasing fat intake from <25 to ≥35 % is associated with a significant increase in LDL-cholesterol, triglycerides, HbA1c and CRP (p < 0.05). Increasing carbohydrates intake from <45 to ≥60 % is associated with significantly lower triglycerides, HbA1c and CRP (p < 0.05). A fiber intake ≥15 g/1000 kcal is associated with a better plasma lipids profile and lower HbA1c and CRP than lower fiber consumption. A consumption of added sugars of ≥10 % of the energy intake is associated with a more adverse plasma lipids profile and higher CRP than lower intake.

CONCLUSIONS

In people with type 2 diabetes, variations in the proportion of fat and carbohydrates of the diet, within the relatively narrow ranges recommended by different nutritional guidelines, significantly impact on the metabolic profile and markers of low-grade inflammation. The data support the potential for reducing the intake of fat and added sugars, preferring complex, slowly absorbable, carbohydrates.

Atorvastatin or fenofibrate on post-prandial lipaemia in type 2 diabetic patients with hyperlipidaemia

BACKGROUND

Post-prandial lipid abnormalities might contribute to the excess of cardiovascular risk typical of type 2 diabetic patients. The study evaluated the effects of atorvastatin (20 mg d(-1)) vs. fenofibrate (200 mg d(-1)) on post-prandial lipids in type 2 diabetic patients with mixed hyperlipidaemia.

MATERIALS AND METHOD

Eight type 2 diabetic patients, male/female (M/F) 6/2, age 58 +/- 5 years, body mass index (BMI) 28 +/- 3 kg m(-2) with cholesterol of low-density lipoprotein (LDL) between 100-160 mg dL(-1) and triglycerides between 150-400 mg dL(-1), participated in a randomized, cross-over study (3 months on atorvastatin and 3 months on fenofibrate). At baseline and at the end of the two treatments, the patients were given a standard fat meal; blood samples were taken before the meal and every 2 h after for the assay of cholesterol, triglycerides, apoB-48 and apoB-100 (determined by sodium dodecyl sulphate-polyacrylamide gel electrophoresis) in plasma lipoproteins and very low-density lipoprotein (VLDL) subfractions (large and small VLDL), separated by density gradient ultracentrifugation.

RESULTS

Data on fasting lipids confirmed that atorvastatin was more effective on the reduction of LDL-cholesterol, whereas fenofibrate was a better triglyceride-lowering agent. Concerning the post-prandial phase, the incremental areas under the curve (IAUC) for chylomicrons and large VLDL were reduced after both treatments, reaching statistical significance for cholesterol, triglyceride and apoB-100 content of chylomicrons only after fenofibrate administration [IAUC, (5.2 +/- 4.6 vs. 10.7 +/- 9.3) mg dL(-1) h(-1), P = 0.03; (131.3 +/- 95.1 vs. 259.1 +/- 201.5) mg dL(-1) h(-1), P = 0.02; (0.46 +/- 1 vs. 3 +/- 3.7) mg dL(-1) h(-1), P = 0.025, all respectively].

CONCLUSIONS

During the post-prandial state fenofibrate appeared to be more effective than atorvastatin in reducing the chylomicron response.

Nutrient determinants of postprandial triglyceride response in a population-based sample of type II diabetic patients

BACKGROUND

Nutrient determinants of postprandial triglyceride (TG) are matter of debate, especially for type II diabetes.

OBJECTIVE

This study was performed to evaluate the impact of dietary habits on postprandial TG response in a population-based sample of type II diabetic patients.

DESIGN

One-hundred and forty type II diabetic patients (63 men/77 women, age 45-70 years) referring to the same health district, not on hypolipidemic drugs and without any other chronic disease, performed four TG profiles (at fasting, before, 2 and 3 h after lunch) with a specific device (Accutrend GCT, Roche Diagnostics Mannheim, Germany) validated previously. Dietary habits were recorded by a dietitian utilizing a previously validated semiquantitative questionnaire.

RESULTS

Triglyceride values (mmol/l, mean +/- s.d.) were 2.22 +/- 0.93 at fasting, decreased before lunch (2.03 +/- 0.81), reached peak values 3 h after lunch (2.73 +/- 1.11). Postprandial TG increments (3 h after lunch minus pre-lunch concentration) significantly correlated with the intake (g/day) of animal protein (r = 0.20, P < 0.02), total fat (r = 0.21, P < 0.01), animal fat (r = 0.19, P < 0.03) and vegetable fat (r = 0.19, P < 0.03), also after adjusting for fasting TG and high-density lipoprotein cholesterol levels. Expressing nutrient intake as percentage of total calorie intake, total and animal fat remained significantly and directly related to postprandial TG increment (r = 0.21, P < 0.01 for total fat; r = 0.19, P < 0.03 for animal fat) whereas the percentage of carbohydrates was inversely related (r = -0.23, P < 0.007).

CONCLUSIONS

Fat intake seems the major nutritional determinant of postprandial TG response in type II diabetic patients.

Insulin Resistance Is Independently Associated With Postprandial Alterations of Triglyceride-Rich Lipoproteins in Type 2 Diabetes Mellitus

OBJECTIVE

To evaluate the role of insulin resistance in development of postprandial dyslipidemia in type 2 diabetic patients in an experimental setting in which these patients were compared with nondiabetic subjects at similar glucose and insulin blood levels.

METHODS AND RESULTS

Eight type 2 diabetic patients in optimal blood glucose control and 7 control subjects (aged 50.0+/-2.6 and 48.1+/-1.3 years; body mass index 28.3+/-1.2 and 25.6+/-1.1 kg/m2; fasting plasma triglycerides 1.12+/-0.13 and 0.87+/-0.08 mmol/L, respectively; mean+/-SEM; NS) consumed a mixed meal during an 8-hour hyperinsulinemic glycemic clamp. Mean blood glucose during clamp was approximately 7.8 mmol/L, and plasma insulin during the preprandial steady state was approximately 480 pmol/L in both groups, that differed for insulin sensitivity (M/I value lower in diabetic subjects [1.65+/-0.30 and 3.42+/-0.60; P<0.05]). Subjects with diabetes had higher postprandial levels of lipids and apolipoprotein B (apoB) in large very low-density lipoprotein (incremental area for triglycerides 1814+/-421 versus 549+/-153 micromol/Lx6 hours; P<0.05; cholesterol 694+/-167 versus 226+/-41 micromol/Lx6 hours; P<0.05; apoB-48 6.3+/-1.0 versus 2.6+/-0.7 mg/Lx6 hours; P<0.05; apoB-100 56.5+/-14.9 versus 26.2+/-11.0 mg/Lx6 hours; NS). Basal lipoprotein lipase (LPL) activity before and after meal was higher in diabetic subjects, whereas postheparin LPL activity 6 hours after the meal was similar.

CONCLUSIONS

Insulin resistance is also associated with postprandial lipoprotein abnormalities in type 2 diabetes after acute correction for hyperglycemia and hyperinsulinemia.

Self-monitoring of plasma triglyceride levels to evaluate postprandial response to different nutrients

Self-monitoring of plasma triglycerides (TG) may be a very useful tool to monitor, on a daily basis, the TG responses to different nutrients, particularly carbohydrates (CHO) and fat, whose influence on postprandial TG levels is not very well known. Therefore, the aim of the present study was to evaluate the TG response of hypertriglyceridemic patients to a similar amount of calories deriving from different sources of CHO and fat. Thirty-nine hypertriglyceridemic patients were randomly assigned to 1 of 2 experimental groups. In 1 group (the fat group), patients were given a standard meal plus a fat supplement of 300 kcal derived from different types of fat (butter, sunflower margarine, olive oil) for dinner, once a week for 3 weeks. In the other group (the CHO group), patients consumed the same standard meal plus a supplement of 300 kcal derived from different types of CHO (bread, coke, fruit). In both groups, patients measured their plasma TG before and 3 hours after each meal by Accutrend GCT (ROCHE, Mannheim, Germany). A subgroup of patients (n = 18) also performed TG determinations 2 hours after the test meals. The 3-hour TG increments were not significantly different between the different test meals (f = 0.671; P =.52); instead, the TG increments induced by fat supplements were significantly higher than those induced by the CHO supplements (f = 14.31; P =.0001). Similar results were also obtained 2 hours after the test meals. In conclusion, this study shows that the 2- and 3-hour TG responses to fat are higher compared with that induced by carbohydrate. This point, especially if confirmed by experiments with more frequent after meal measurements and of longer duration, should be taken into account in defining the best dietary approach to lower plasma TG levels throughout the whole day.

Exogenous and endogenous postprandial lipid abnormalities in type 2 diabetic patients with optimal blood glucose control and optimal fasting triglyceride levels

The aim of this study was to evaluate exogenous and endogenous lipoprotein responses to a standard fat-rich meal in type 2 diabetic patients with optimal fasting triglyceridemia and optimal blood glucose control. Seven type 2 diabetic patients and five nondiabetic controls (age, 49 +/- 7 and 48 +/- 4 yr; body mass index, 28.3 +/- 3.6 and 25.1 +/- 3.6 kg/m(2); mean +/- SD) were given, after at least 12 h of fasting, a standard fat-rich meal. Before and over the 6 h after the meal, serial blood samples were taken for determination of glucose, insulin, lipids, lipoproteins, apolipoprotein B-48 (apo B-48), apo B-100, free fatty acids, and lipoprotein lipase activity. The main abnormality in the postprandial lipid response of diabetic patients involved large very low density lipoproteins. In these particles, apo B-48, apo B-100, cholesterol, and triglyceride incremental areas were, in fact, significantly higher in diabetics compared with controls [7.08 +/- 2.65 vs. 1.17 +/- 0.88 mg/liter.h, 65.5 +/- 11.5 vs. 12.4 +/- 1.77 mg/liter.h, 29.7 +/- 3.9 vs. 13.1 +/- 3.1 mg/dl.h (0.77 +/- 0.10 vs. 0.34 +/- 0.08 mmol/liter.h), 170 +/- 31 vs. 94 +/- 22 mg/dl.h (1.93 +/- 0.35 vs. 1.06 +/- 0.25 mmol/liter.h)] (all P < 0.05; mean +/- SEM). Postprandial preheparin lipoprotein lipase plasma activity was, if anything, higher in diabetic patients. In conclusion, even with fasting normotriglyceridemia and optimal blood glucose control, type 2 diabetic patients are characterized, in the postprandial period, by a significant increase in large very low density lipoproteins of both endogenous and exogenous origins.

Post-prandial triglyceride profile in a population-based sample of Type 2 diabetic patients

AIMS/HYPOTHESIS

Postprandial lipaemia is considered an emerging risk factor for cardiovascular disease also in the Type 2 diabetic population. However, little information exists on the daily triglyceride profile of these patients, especially during everyday life. The aim of the study was to evaluate the daily triglyceride profile of Type 2 diabetic patients during their everyday life.

METHODS

145 Type 2 diabetic patients (66 men/79 women, age range 45-65 years) at a health district near Naples, Italy, participating in a screening survey for the evaluation of diabetic complications, and 30 non-diabetic subjects of the same area underwent four daily capillary triglyceride profiles by Accutrend (Roche)-a previously validated method.

RESULTS

Triglyceride values (mmol/l; Means +/- SE) were 2.22+/-0.08 at fasting, decreased before lunch (2.03+/-0.07), reached a peak 3 h after lunch (2.73+/-0.09) and remained substantially high before dinner (2.47+/-0.09) (all p<0.001 vs fasting). The triglyceride profile of non-diabetic subjects was significantly lower at each point (average difference of 0.73 mmol/l). The percentage of patients with values above 2.25 mmol/l was 61% 3 h after lunch and 49% before dinner. Moreover, in 30% of patients with optimal fasting values (<1.69 mmol/l) triglyceride concentrations 3 h after lunch ranged between 1.69 and 2.25 mmol/l, and in 31% they were above 2.25 mmol/l.

CONCLUSION/INTERPRETATION

Most Type 2 diabetic patients have postprandial triglycerides above optimal concentrations for several hours after meals. Moreover, optimal fasting concentrations are not always a good predictor of postprandial triglycerides.

Impact of known and unknown diabetes on in-hospital mortality from ischemic stroke

BACKGROUND AND AIMS

The effect of known diabetes on in-hospital mortality from ischemic stroke is still debated whereas the role of unknown diabetes is virtually unexplored. This study evaluates the impact of known and unknown diabetes on in-hospital mortality from ischemic stroke.

METHODS AND RESULTS

We have retrospectively evaluated the records of 286 consecutive cases of ischemic stroke hospitalized from January 1998 to December 2000 at the Department of Internal Medicine of the General Hospital located in the western area of Naples. Fasting plasma glucose level < 7 mmol/L identified non diabetic subjects. Known diabetes mellitus was diagnosed by history of diabetes and/or hypoglycemic therapy, unknown diabetes was defined as a random plasma glucose level > or = 11 mmol/L and/or in-hospital fasting glucose > or = 7 mmol/L on two or more occasions. Severity of stroke was defined using the Canadian Neurological Score (CNS). According to these criteria, 144 subjects were non diabetics, 99 had known diabetes and 43 had unknown diabetes. Subjects with known diabetes showed a higher prevalence of female sex, hypertension and increased triglyceride levels as compared with non diabetic subjects (p < 0.01). Subjects with unknown diabetes were older (p < 0.01) and showed a more severe CNS (3.4 +/- 2.7) than non diabetic and diabetic subjects (5.8 +/- 2.6 and 5.8 +/- 2.6, respectively; p < 0.01). In-hospital mortality was significantly higher in the unknown diabetic group (44%) as compared with known diabetic (15%) and non diabetic groups (12%) (p < 0.001). This finding was independent of neurological deficit, age, atrial fibrillation and history of previous stroke.

CONCLUSIONS

Our study shows that unknown diabetes, more than known diabetes, is a strong risk factor for in-hospital mortality in subjects with acute ischemic stroke.

Fasting plasma free fatty acid concentrations and Pro12Ala polymorphism of the peroxisome proliferator-activated receptor (PPAR) gamma2 gene in healthy individuals

BACKGROUND

The Pro12Ala polymorphism of the peroxisome proliferator-activated receptor (PPAR) gamma gene has been associated in some, but not all, studies with lower body mass index (BMI) and improved insulin sensitivity; how an altered transcriptional activity of PPARgamma2 could influence insulin sensitivity is currently unclear. The free fatty acids (FFAs) released from adipose tissue triglycerides via lipolysis are key mediators of impaired insulin sensitivity; however, no study has described the relationship of the Pro12Ala mutation with circulating levels of FFAs under physiological conditions.

OBJECTIVE

To investigate in a population-based sample of Caucasians the relation of the Pro12Ala polymorphism with plasma concentrations of FFAs and other markers of lipid and glucose metabolism described as components of the insulin resistance syndrome.

SUBJECTS

Four hundred and thirty-eight nondiabetic employees of the Italian Telephone Company, aged 35-65 years, randomly selected from a total population of 3900 participants in a company-sponsored health screening.

MEASUREMENTS

The Pro12Ala polymorphism of the PPARgamma was studied together with plasma FFAs, insulin, glucose, triglycerides, high density lipoprotein (HDL) cholesterol, blood pressure and anthropometry. The Homeostatic Model Assessment (HOMA) index was calculated as a measure of insulin resistance.

RESULTS

Carriers and noncarriers of the Pro12Ala polymorphism showed very similar circulating levels of FFA (0.46 +/- 0.2 vs. 0.47 +/- 0.2, NS); plasma glucose, triglycerides, HDL cholesterol and blood pressure were also similar in the two groups with or without the polymorphism. To allow for the possible confounding effect of obesity, a separate analysis was conducted in overweight (BMI > or = 25 kg/m(2)) and normal-weight people (BMI < 25 kg/m(2)). Circulating plasma FFA concentrations, as well as triglycerides, blood pressure and HOMA, were significantly higher in overweight than normal-weight, as expected, but no significant differences were detected between carriers and noncarriers of the Pro12Ala polymorphism within each BMI group (0.49 +/- 0.2 vs. 0.48 +/- 0.2, NS, and 0.44 +/- 0.2 vs. 0.47 +/- 0.2, NS, in overweight and normal-weight, respectively). The Pro12Ala polymorphism was also analysed across increasing quartiles of FFA concentrations and no relationship was observed between the frequency of the polymorphism and FFA values (overall chi2 = 0.48, NS).

CONCLUSION

This study does not show any relationship between the Pro12Ala polymorphism of the PPARgamma gene and fasting FFAs in the general population. The possibility of a different handling of FFAs under different conditions (i.e. postprandial) cannot be excluded and remains to be explored.

[The role of anti-endomysium and anti-transglutaminase antibodies in the diagnosis and follow-up of celiac disease]

Available, non invasive, serological tests such as the anti-endomysium antibodies (EmA) and anti-transglutaminase antibodies (Anti-tTg) has allowed better outlining of the clinical presentation as well as the pathogenesis of Coeliac Disease (CD). The aim of the study was to evaluate the reliability and concordance of EmA and anti-tTg at the diagnosis (T0) of CD and after 12 months (T12) of Gluten-Free Diet (GFD). Serum EmA and Anti-tTg were evaluated in 78 patients aged 6.3 +/- 4.7 SD yrs at diagnosis, in 56 of them at T0 and T12, as well as in a control group of 88 children aged 6.9 +/- 3.8 yrs. EmA were evaluated by indirect immunofluorescence and Anti-tTg by ELISA. All subjects had normal circulating IgA levels. In the control group, EmA and Anti-tTg resulted negative in all cases. At T0, 77/78 pts had both EmA and Anti-tTg positive, one pt (1.3%) had only EmA positive, demonstrating an overall positive concordance of 98.7%. At T12, 16 pts (28.6%) had both tests positive, 8 (14.3%) had only Anti-tTg positive (all of them were no fully compliant to GFD) and 32 (57.1%) had both tests negative. The overall concordance at T12 was 85.7%. The concordance between EmA and Anti-tTg at T0 is nearly absolute (98.7%). The higher prevalence of elevated anti-tTg than of positive EmA at T12 suggests a higher sensitivity of anti-tTg following intake of even small amounts of gluten.

Assay of erythrocyte membrane fatty acids. Effects of storage time at low temperature

The study of the stability of saturated mono-, or polyunsaturated fatty acids, both esterified and not esterified, in plasma, circulating cells, and tissues is extremely important to validate the use of biological samples stored at low temperature in "biological banks", which are used for experimental, observational, dietary, or pharmacological studies. Since red blood cells are easily accessible cells, they are used as a marker of less-accessible tissues, especially in large-scale epidemiological studies. Data from the literature suggest that the addition of an antioxidant and the freezing of red blood cells do not cause any variation in the fatty acid composition for a period of 2-6 months up to 1 year. We evaluated the fatty acid concentration in red blood cells isolated from venous blood samples of one subject, preserved with butylated hydroxytoluene and N2 and stored at -80 degrees C for up to 2 years. Erythrocytes of venous samples of six subjects stored at -20 degrees C for 6 months without butylated hydroxytoluene and in the presence of air were used for comparison purposes. Our data demonstrate that a long storage time (2 years) does not significantly influence the erythrocyte fatty acid concentration when using very low temperatures (-80 degrees C) and antioxidants (butylated hydroxytoluene) in the presence of N2.

Effect of acute exogenous hyperinsulinaemia on very low density lipoprotein subfraction composition in normal subjects

Subtle abnormalities of very-low-density lipoprotein (VLDL) composition and distribution seem to be associated with increased cardiovascular risk. The aims of this study were first, to evaluate whether hyperinsulinaemia per se is able to produce VLDL abnormalities and second, whether this occurs through a stimulation of lipolytic enzymes. Eight normal male volunteers, age 36 +/- 7 years (M +/- SD), body mass index (BMI) 26+/-3 kg m-2, underwent a 5-h euglycaemic hyperinsulinaemic clamp (1.2 mU insulin/kg b.w. min-1). Nine sex, age and BMI comparable subjects underwent control experiments (saline infusion). Three VLDL subfractions of decreasing size were isolated by density gradient ultracentrifugation; lipoprotein lipase (LPL) and hepatic lipase (HL) post-heparin plasma activities were determined by the 3H-labelled triolein method. Hyperinsulinaemia ( approximately 65 mU mL-1) produced the expected plasma free fatty acid suppression. Triglyceride levels were reduced in total VLDL (- 27 +/- 32% vs. + 38 +/- 52% after saline, P < 0.05) and in the larger VLDL (- 56 +/- 19 vs. + 34 +/- 38, P < 0.001). Moreover the relative contribution of the larger subfraction was decreased (- 39 +/- 15% vs. - 3 +/- 21%, P < 0.01), while the percentage of smaller particles was increased (+17 +/- 20 vs. - 9 +/- 22, P < 0.05). LPL and HL activities were decreased to the same degree during either insulin or saline infusion. Exogenous hyperinsulinaemia produced lipoprotein abnormalities partially similar to those previously shown in type 1 diabetic patients, indicating that these abnormalities may be secondary to insulin therapy.

Plasma homocysteine and microvascular complications in type 1 diabetes

BACKGROUND

Homocysteine is involved in a complex and dynamic system of vascular injury and repair and may thus contribute to the development of diabetic microangiopathy. This still debated issue has important scientific and clinical implications, since hyperhomocysteinemia can be corrected nutritionally.

AIMS

1) To evaluate the association between fasting plasma homocysteine, type 1 diabetes and its microvascular complications; 2) to elucidate the basis of this association by investigating the major determinants of plasma homocysteine in relation to diabetic microangiopathy.

METHODS

We studied sixty-six consecutive patients with type 1 diabetes mellitus of > 10 years duration and normal serum creatinine (< 115 mumol/L, 1.3 mg/dL), and free from clinically detectable cardiovascular diseases. Forty-four non-diabetic controls were also studied. Plasma concentrations of homocysteine, folate and vitamin B12 were investigated together with the C677T mutation in the gene coding for methylenetetrahydrofolate reductase (MTHFR), a key enzyme in homocysteine metabolism. Renal and retinal diabetic complications were evaluated as albumin/creatinine ratio on early-morning, urine spot collection and fundus photographs.

FINDINGS

Fasting plasma homocysteine levels were very similar in patients and controls. Patients with microalbuminuria or proliferative retinopathy had significantly higher values than those without: 9.4 +/- 3.1 vs 7.4 +/- 2.8 mumol/L, p < 0.02 and 9.5 +/- 2.6 vs 7.3 +/- 3.0 mumol/L, p < 0.05. This difference was not attributable to confounders, such as age, sex and smoking, nor to dissimilar plasma folate and vitamin B12 concentrations. In contrast, homozygosity for the C677T mutation in the MTHFR gene--the commonest genetic defect linked to moderately increased plasma homocysteine--was significantly more frequent in patients with microalbuminuria and/or proliferative retinopathy (50% vs 13%, p < 0.004), odds ratio 6.7 (95% CI 1.7-27.6).

CONCLUSIONS

Type 1 diabetes as such is not associated with increased plasma homocysteine levels, though patients with microalbuminuria and/or proliferative retinopathy display significantly higher values than those without. This difference is not attributable to obvious confounders, nor to differences in vitamin status, and may be partly mediated by genetic factors. Plasma homocysteine, together with other diabetes-related noxae, may thus be in a position to contribute to the development of nephropathy and the progression of retinopathy.

Long-term effects of fish oil on lipoprotein subfractions and low density lipoprotein size in non-insulin-dependent diabetic patients with hypertriglyceridemia

The effects of fish oil on lipoprotein subfractions and low density lipoprotein (LDL) size in non-insulin-dependent diabetes mellitus (NIDDM) patients with hypertriglyceridemia are unknown. To elucidate this, 16 NIDDM hypertriglyceridemic patients (plasma triglyceride 2.25- 5.65 mmol/l, plasma cholesterol < or = 7.75 mmol/l) were randomly assigned to a 6-month period with either moderate amounts of fish oil (n = 8) or placebo (n = 8) after 4 weeks of wash-out and 3 weeks of run-in. Diet and hypoglycemic treatment were unchanged throughout the experiment. LDL size were evaluated at baseline and after 6 months. Three VLDL and LDL subfractions were measured at the end of the two periods. The total lipid concentration of all very low density lipoprotein (VLDL) subfractions was lower at the end of fish oil treatment compared with placebo (large VLDL 124.3 +/- 19.7 mg/dl vs 156.7 +/- 45.5 mg/dl; intermediate VLDL 88.5 +/- 9.5 mg/dl vs 113.9 +/- 23.2 mg/dl; small VLDL 105.9 +/- 9.7 mg/dl vs 128.9 +/- 40.7 mg/dl) (mean +/- SEM), although the difference was not statistically significant. Moreover, at the end of the two treatments, the percentage distribution of VLDL subfractions was very similar (large 37.5 +/- 3.3% vs 37.6 +/- 2.6%, intermediate 27.6 +/- 0.9% vs 31.0 +/- 2.4%; small 34.9 +/- 3.7% vs 31.4 +/- 2.1%). Concerning LDL, no significant change in LDL size was observed after the two treatments (255.4 +/- 2.2 A vs 254.2 +/- 1.7 A, fish oil; 253.7 +/- 2.0 A vs 253.3 +/- 1.7 A, placebo). LDL subfraction distribution was also very similar (large 17 +/- 3% vs 17 +/- 2%; intermediate 62 +/- 3% vs 65 +/- 3%; small 21 +/- 3% vs 18 +/- 2%), at the end of the two periods, confirming the lack of effects on LDL size. In conclusion, our study indicates that in NIDDM patients with hypertriglyceridemia, fish oil does not induce any improvement in LDL distribution and LDL size despite its positive effects on plasma triglycerides.

Effects of a 3-month treatment with terazosin on fasting and postprandial glucose and lipid metabolism in type 2 diabetic patients with hypertension

BACKGROUND AND AIM

The effects of the alpha-1-adrenergic blocker terazosin on blood pressure and fasting and postprandial glucose and lipid metabolism were assessed in type 2 diabetic patients with hypertension.

METHODS AND RESULTS

In this single-blind, randomized, crossover, placebo-controlled pilot study, thirteen patients were given terazosin for three months. Blood pressure and metabolic parameters were measured after a 14-hr overnight fast. In addition, a 800-calorie test meal was administered after placebo and terazosin to evaluate blood glucose and lipid changes following a standardized physiological stimulus. Blood pressure was significantly reduced and HDL-cholesterol significantly increased after terazosin. A significant decrease at fasting with a smaller reduction after the meal test was observed for free fatty acids when terazosin was given in comparison to placebo, suggesting an improvement in insulin resistance. A slight decrease in fasting and postprandial triglycerides was also observed. Cardiovascular risk, calculated according to the Framingham formula, was significantly reduced at the end of the terazosin treatment.

CONCLUSIONS

Antihypertensive treatment with terazosin is effective, has no adverse effects on fasting and postprandial glucose and lipid metabolisms, and appears to improve the cardiovascular risk profile of hypertensive patients with associated metabolic diseases.

Plasma fibrinogen: a new factor of the metabolic syndrome. A population-based study

OBJECTIVE

To evaluate whether hyperfibrinogenemia represents a component of the metabolic syndrome.

RESEARCH DESIGN AND METHODS

A cross-sectional study was conducted on the relation between fibrinogen and the metabolic syndrome in a working population of 1,252 nondiabetic men, aged 35-64 years, randomly selected among all men participating in a health screening. We measured anthropometric characteristics, blood pressure, fasting plasma fibrinogen, cholesterol (total, LDL, and HDL), triglycerides, glucose, and insulin. Individuals with two or more metabolic abnormalities (defined as being in the highest quartile of the distribution of diastolic blood pressure, plasma glucose, or triglycerides or being in the lowest quartile of HDL cholesterol) were considered to have the metabolic syndrome.

RESULTS

Age-adjusted fibrinogen levels correlated significantly with BMI, waist-to-hip ratio, systolic and diastolic blood pressure, plasma total cholesterol, LDL cholesterol, triglycerides, insulin, and HDL cholesterol (inversely). Subjects with the metabolic syndrome had significantly higher plasma fibrinogen levels than those without (285.1 +/- 1.9 vs. 300.2 +/- 3.0 mg/dl, mean +/- SE, P = 0.0001). Plasma fibrinogen concentrations and the prevalence of hyperfibrinogenemia (defined as > or = 350 mg/dl) increased progressively from 279 to 307 mg/dl (P = 0.0001) and from 9 to 22% (P = 0.0024), respectively, across categories with an increasing number of metabolic disorders characterizing the syndrome (only one, any two, three or more). In multivariate analyses, both plasma insulin and the metabolic syndrome were significantly and independently associated with plasma fibrinogen.

CONCLUSIONS

The finding suggests that hyperfibrinogenemia may be considered a component of the metabolic syndrome. This may also explain the increased cardiovascular risk associated with hyperinsulinemia/insulin resistance.

Long-term effects of fish oil on insulin resistance and plasma lipoproteins in NIDDM patients with hypertriglyceridemia

OBJECTIVE

The aim of this study was to evaluate the long-term (6-month) effects of moderate fish oil supplementation on insulin sensitivity and plasma lipoproteins in NIDDM patients with hypertriglyceridemia.

RESEARCH DESIGN AND METHODS

The study has been performed according to a randomized double-blind placebo-controlled design with a parallel group sequence. After a washout period of 4 weeks and a run-in period of 3 weeks, 16 NIDDM patients with hypertriglyceridemia (triglyceride [TG], 2.25-5.65 mmol/l) were randomly assigned to either fish oil (2.7 g/day eicosapentaenoic plus docosahexaenoic acid for 2 months, then 1.7 g/day for 4 more months) (n = 8) or placebo (n = 8). Diet and hypoglycemic drugs remained unchanged throughout the whole experiment. At baseline and after 6 months, insulin sensitivity was measured by euglycemic hyperinsulinemic clamp (insulin infused, 2.0 mIU.kg-1 body wt.min-1). At the same time, blood glucose control, fasting and postprandial serum insulin and nonesterified fatty acid (NEFA) concentrations, and fasting plasma lipoprotein concentrations were evaluated.

RESULTS

In the group treated with fish oil compared with the baseline, there was: 1) a significant reduction in both plasma TG (2.92 +/- 0.23 vs. 3.85 +/- 0.32 [mean +/- SE] mmol/l, P < 0.001) and VLDL-TG (2.35 +/- 0.24 vs. 4.25 +/- 0.66 mmol/l, P < 0.01), without significant changes in blood glucose control; 2) a significant reduction in fasting NEFA concentrations (572 +/- 100 vs. 825 +/- 131 mumol/l, P < 0.01); and 3) a significant enrichment in long-chain omega-3 fatty acids of erythrocyte membrane phospholipids. In the placebo group, there were no changes in any of the variables analyzed. The insulin-mediated glucose uptake was unchanged in both groups (fish oil, 4.04 +/- 0.82 mg.kg-1.min-1 at baseline and 3.96 +/- 0.50 mg.kg-1.min-1 at 6 months; placebo, 3.51 +/- 0.62 mg.kg-1.min-1 at baseline and 4.09 +/- 0.49 mg.kg-1.min-1 at 6 months).

CONCLUSIONS

In NIDDM patients with hypertriglyceridemia, moderate amounts of fish oil induce a long-term significant reduction in plasma triglycerides, VLDL triglycerides, and NEFA and a significant enrichment in the erythrocyte phospholipid content of long-chain omega-3 fatty acids, without deteriorating blood glucose control. However, this amount of omega-3 fatty acids was unable to improve insulin sensitivity in this group of patients.

[Lipoprotein (a) and serum lipid levels young subjects with parents suffering from myocardial infarct]

BACKGROUND

Elevated concentrations of lipoprotein (a) have been shown to increase the risk of coronary artery disease, especially in females, and have been found to be elevated in white US children with parental myocardial infarction.

METHODS

To confirm the generality of this finding and to determine the influence of gender, we studied 143 children with parental myocardial infarction (cases), 71 males and 72 females, mean age 17 +/- 5 years, body mass index 22.1 +/- 3.8 and 102 controls, 50 males and 52 females, mean age 18 +/- 5 years, body mass index 23 +/- 4.3.

RESULTS

The serum cholesterol and lipoprotein (a) levels were significantly higher, whereas the HDL level was significantly lower in cases than in controls; lipoprotein (a) levels > 30 md/dl were significantly more prevalent in cases than in controls. Among the males, serum HDL cholesterol was significantly lower in cases than in controls, whereas no significant differences were found in serum total cholesterol and in lipoprotein (a). Among the females, cases had lower HDL cholesterol level and higher serum total cholesterol and lipoprotein (a) levels in comparison to controls.

CONCLUSION

Children with parental myocardial infarction, in particular the females, have a more unfavourable serum lipid profile than controls.

Does impaired glucose tolerance predict hypertension? A prospective analysis

This study evaluates prospectively the relationship between impaired glucose tolerance (IGT) and blood pressure. From a population of 1376 men and women aged 40-59 years, all those with IGT (n = 54) plus 133 age- weight- and sex-matched normoglycaemic control subjects were selected after excluding treated hypertensive patients. Blood pressure, fasting and postload blood glucose and plasma insulin were measured. At 11.5 years after the first visit 76% of the IGT patients and 80% of the control subjects were re-examined. At baseline blood pressure was significantly higher in IGT patients than in control subjects (systolic 135.5 +/- 2.3 vs 127.9 +/- 1.4 mmHg, p < 0.001; and diastolic 88.0 +/- 1.5 vs 84.7 +/- 0.7 mm Hg, p < 0.05) independent of age, gender, weight, antihypertensive medication and insulinaemia. Accordingly, hypertension was more frequent in subjects with IGT (odds ratio 2.1, 95% confidence, interval (CI) 0.9-4.9). Postload insulin was significantly associated with hypertension--both at univariate and multivariate analysis--in normoglycaemic subjects, but not in those with IGT. At follow-up systolic blood pressure increased in both groups; the increase was smaller in patients with IGT (6.0 +/- 2.4 vs 12.3 +/- 1.6 mm Hg p < 0.05). Likewise, the 11.5 years' cumulative incidence of hypertension was not significantly different in subjects with baseline IGT or normoglycaemia; if anything it was lower in the IGT group (odds ratio 0.36, 95% CI 0.1-1.2). In multivariate analysis incidence of hypertension was associated positively with baseline blood pressure (p < 0.0003) and negatively with IGT status p < 0.03), while no significant association was found with insulin. In conclusion, the findings of this study question IGT as a risk factor for hypertension. Furthermore, these data do not indicate a major role for hyperglycaemia and hyperinsulinaemia per se in the aetiology of hypertension and suggest that IGT and hypertension share one or more pathogenetic factor(s) (i.e., insulin resistance, hyperactivity of the sympathetic nervous system, etc.), which induce deterioration of blood pressure control first, and hyperglycaemia later.

Lipoprotein(a) concentrations in non-insulin-dependent diabetes mellitus and borderline hyperglycemia: a population-based study

The objective of the study was to compare lipoprotein(a) [Lp(a)] concentrations in population-based samples of individuals with non-insulin-dependent diabetes mellitus (NIDDM), borderline hyperglycemia, and normoglycemia. From 2,740 male Italian Telephone Company employees aged 40 to 59 years participating in a health screening, we selected all those with NIDDM (n = 100) plus a random sample of 950 nondiabetic individuals. Diabetes was defined as fasting plasma glucose (FPG) of at least 140 mg/dL or current use of hypoglycemic drugs. Among nondiabetic individuals, 854 were defined as normoglycemic (FPG < 115 mg/dL) and 95 were defined as borderline hyperglycemic (115 < FPG < 140 mg/dL). Lp(a) level was measured on frozen plasma by enzyme-linked immunosorbent assay. Lp(a) concentrations were similar in people with NIDDM, borderline hyperglycemia, and normoglycemia: 11.2 +/- 14, 14.1 +/- 20, and 13.9 +/- 18 mg/dL, respectively (F = 1.03). Accordingly, the proportion of subjects with Lp(a) levels of at least 30 mg/dL was comparable in the three groups (12%, 15%, and 14%; chi 2 = 3.95, P = .41). Results were not confounded by differences in age, body mass index (BMI), waist to hip ratio, plasma lipids, alcohol consumption, physical activity, and use of drugs. Furthermore, within the diabetic group Lp(a) levels were not significantly different for those on diet only versus those on oral agents (10.8 +/- 14.1 v 11.7 +/- 14.7, P = .7) or for people with FPG of at least 180 as compared with people with FPG less than 180 mg/dL (9.9 +/- 12.8 v 11.5 +/- 14.8, P = .5).(ABSTRACT TRUNCATED AT 250 WORDS)

Prevention of early-morning hyperglycemia in IDDM patients with long-acting zinc insulin

OBJECTIVE

To evaluate whether an insulin regimen with a long-acting zinc insulin (Ultratard HM) could help control fasting hyperglycemia in insulin-dependent diabetes mellitus (IDDM) patients.

RESEARCH DESIGN AND METHODS

A randomized sequential crossover trial with 6-wk treatment periods was used. Ten IDDM patients from the diabetes clinic at the Medical School who had persistent fasting hyperglycemia (greater than 10 mmol/L) were studied. Patients with nocturnal hypoglycemia were excluded. All patients completed the study. Insulin regimens consisted of three daily injections of a short-acting insulin (Actrapid HM) before meals and either a long-acting zinc insulin (Ultratard HM) or an intermediate isophane insulin (Protaphane HM) before the evening meal. Each regimen was followed for 6 wk.

RESULTS

Fasting blood glucose levels (at 06:00 and 08:00) were significantly lower after the long-acting insulin regimen (6.26 +/- 0.88 vs. 10.82 +/- 4.27 mM, P less than 0.05 and 9.26 +/- 1.02 vs. 14.03 +/- 1.08 mM, P less than 0.05, respectively). Plasma-free insulin levels mirrored blood glucose concentrations because they were significantly higher at 06:00 and 08:00 after the long-acting insulin regimen (49.5 +/- 10.1 vs. 20.1 +/- 4.3 pM, P less than 0.05 and 31.6 +/- 5.0 vs. 16.5 +/- 3.4 pM, P less than 0.05, respectively). At any other time of the day, blood glucose and plasma insulin levels were not significantly different with either one of the two insulin regimens.

CONCLUSIONS

A long-acting zinc human insulin injected before the evening meal can help to control persistent fasting hyperglycemia in IDDM patients.

Responses of serum insulin and blood pressure to cold and handgrip in obese patients

A close correlation between body weight and blood pressure has been frequently observed in both clinical and epidemiological studies. The aim of this clinical trial was to evaluate whether, in obese patients, there is any relationship between blood pressure, at rest or during sympathetic stimulation, and blood glucose and serum insulin, both while fasting and during an oral glucose challenge. Twenty obese patients (age 26-65 years, body weight 97 +/- 16 kg, 11 normotensive and 9 hypertensive) entered the study. After a 4-week run-in period on an isocaloric diet with normal intake of sodium, blood pressure and heart rate were measured at rest and during sympathetic stimulation induced by cold and isometric testing. Responses of glucose and insulin to a standardized 75 g oral glucose tolerance test were also evaluated. The responses of glucose and insulin to glucose challenge were not statistically different in normotensive and hypertensive obese patients. Levels of insulin in the serum in the serum in the fasting state and during glucose load were significantly correlated with the response of blood pressure to cold and isometric exercise, but not to blood pressure at rest. The response of heart rate to cold was closely related to insulin only in the subgroup of normotensives. The present findings support the hypothesis that the sympathetic nervous system, which influences secretion of insulin and regulation of blood pressure, is involved in the pathophysiology of the association of obesity and hypertension.

A controlled study on the effects of n-3 fatty acids on lipid and glucose metabolism in non-insulin-dependent diabetic patients

Eight male non-insulin-dependent diabetic patients participated in a double-blind randomized cross-over study (2 weeks for each period) evaluating the effects of 10 g/day fish oil dietary supplementation on glucose and lipid metabolism. Fasting serum triglyceride concentrations were decreased by fish oil because of a reduction in VLDL (1.4 +/- 0.2 vs. 1.9 +/- 0.2 mmol/l, P less than 0.025). LDL cholesterol concentration was instead increased (3.4 +/- 0.3 vs. 2.8 +/- 0.3 mmol/l, P less than 0.025) and net changes in VLDL triglyceride and in LDL cholesterol were inversely correlated (r = -0.86, P less than 0.01). Plasma free fatty acids concentrations and turnover rate [( 3H]palmitate method) were similar after fish oil and placebo. Fish oil supplement did not induce significant changes in fasting blood glucose (8.1 +/- 1.1 vs. 8.5 +/- 1.2 mmol/l) and average daily blood glucose (BG) (9.4 +/- 3.2 vs. 9.3 +/- 3.5 mmol/l). Glucose stimulated plasma insulin response during a hyperglycemic clamp was not significantly influenced by fish oil both in the early phase and during steady state. Insulin sensitivity (M/I index) was also unchanged. In conclusion, this study shows that a dietary supplement of fish oil decreases plasma triglyceride levels in non-insulin-dependent diabetic patients, an increased conversion rate of VLDL to LDL playing a role in this change. With this dosage of fish oil no relevant variations in glycemic control, insulin secretion and insulin sensitivity occurred.

[Clinico-therapeutic experience with a new antihypertensive drug, ketanserin, in elderly patients]

After a placebo run-in period (one week) 32 hypertensive patients suffering also from other disorders (cardiovascular pathology, diabetes, psychic or neurotic pathology) were treated with ketanserin (20 mg twice daily p.o. for 15 days followed by 40 mg twice daily for another 65 days). The patients' (13 men, 10 women) ages ranged from 54-94 years (average 69 years). Therapeutic results became manifest gradually with significant reductions of systolic and diastolic blood pressure; heart rate, too, had decreased slightly at the end of the treatment period. Global evaluation yielded favorable results in 59% of patients. Topical and systemic tolerance was satisfactory.

Effect of nicardipine on insulin secretion, glucose and lipid metabolism in hypertensive, non-insulin dependent diabetics

Certain acute and chronic metabolic effects of nicardipine have been studied in 20 patients with non-insulin dependent diabetes (NIDD). An intravenous glucose tolerance test (i.v. GTT, glucose 0.33 g/kg as a bolus) and the corresponding insulin response were assessed at the end of a 4 week placebo period, after the first dose and on administration for 12 weeks of nicardipine 20 mg t.i.d. The glucose and insulin responses to the i.v.GTT, evaluated as incremental AUCs, did not change significantly (glucose 30.5 mg/dl.90 min on placebo, 33.1 mg/dl.90 min acutely and 31.4 mg/dl.90 min on chronic administration of nicardipine; insulin 2.08 microU/ml.90 min on placebo, 1.87 microU/ml.90 min acutely and 1.93 microU/ml.90 min after chronic nicardipine). Glucose removal rate (KG) following the i.v.GTT was 0.73%/min on placebo 0.75%/min on acute administration and 0.8%.min-1 with chronic nicardipine. Active treatment produced a significant reduction of blood pressure (from 187/96 mm Hg on placebo to 166/89 mm Hg acutely and 152/83 mm Hg after 12 weeks of nicardipine treatment). It is concluded that the calcium antagonist nicardipine was an effective antihypertensive drug, and that it did not cause deterioration of metabolic control in hypertensive patients with NIDD.

Association between retinopathy and impaired peripheral arterial circulation in insulin-dependent diabetic patients

This study was undertaken to investigate whether, in insulin-dependent diabetic patients, an association exists between microangiopathy (evaluated as retinopathy) and macroangiopathy (evaluated as impaired arterial circulation of the lower limbs). A total of 38 diabetic outpatients with either background (n = 25) or proliferative (n = 13) retinopathy, plus 18 diabetic outpatients of similar age (46.8 +/- 13.4 vs. 43.0 +/- 11.0 yrs) and duration of diabetes (16.8 +/- 5.8 vs. 14.8 +/- 15.1 yrs) without retinopathy were studied. Retinopathy was defined according to fluorescein angiography. The arterial circulation of the lower limbs was evaluated by the ankle/arm systolic pressure index with ultrasonic Doppler end-point detection and echo-Doppler examination of the pelvic vessels. The ankle/arm index was significantly lower in diabetic patients with retinopathy (0.98 +/- 0.16 vs. 1.12 +/- 0.11, p less than 0.002) and the percentage of persons with definitely impaired arterial circulation of the legs (ankle/arm systolic blood pressure less than 0.95) was significantly higher in this group (36.8% vs. 5.5%, p = 0.038). Of 14 patients with retinopathy and peripheral arterial disease, only three (21%) had detectable stenoses of the pelvic vessels. The overall profile of cardiovascular risk factors was similar in the two groups. The multivariate analysis indicated that retinopathy was the best correlate of impaired peripheral arterial circulation. In conclusion, in our study population, an association between retinopathy and impaired peripheral arterial circulation of the legs existed independently of major cardiovascular risk factors.

Metabolic consequences of feeding a high-carbohydrate, high-fiber diet to diabetic patients with chronic kidney failure

The aim of this study was to compare the metabolic effects of a high-carbohydrate (CHO), high-fiber diet with only moderate protein restriction with those of a low-CHO, low-fiber diet with a low protein content in six diabetic patients with moderate chronic renal failure. The high-CHO, high-fiber diet induced a significant improvement in blood glucose control, a significant decrease in serum cholesterol, and a significant increase in fecal nitrogen losses. Other variables evaluated were not significantly different between the two diets, except for a significant increase in serum phosphorus during the high-CHO, high-fiber diet. N balance was not significantly different from 0 at the end of either dietary period and was very similar for both diets. The high-CHO, high-fiber diet presents many beneficial metabolic effects in diabetic patients with chronic renal failure.

Adrenergic system and carbohydrate metabolism. Effects of beta-receptor blockade on insulin secretion and peripheral insulin sensitivity in normoglycaemic patients

The effects of 3 weeks of treatment with the beta-receptor blocking agent propranolol and a placebo on glucose tolerance, insulin secretion and peripheral insulin sensitivity have been evaluated in 7 normoglycaemic hypertensive patients by an oral glucose tolerance test and the insulin clamp technique. Significant changes in systolic and diastolic blood pressure and heart rate were observed at the end of propranolol treatment, but there were no associated changes in glucose tolerance, insulin secretion or peripheral insulin sensitivity. No difference was observed in glucagon, growth hormone and free fatty acids between propranolol and placebo treatment. The results support the view that the hypothetical pancreatic glucoreceptor, at least in non-acute studies, is not affected by beta blockade. In addition, there was no effect on tissue sensitivity to insulin.

Effects of beta-receptor blockade on carbohydrate metabolism

The effects of beta-blockers on glucose tolerance, insulin secretion and peripheral insulin sensitivity were evaluated by oral glucose tolerance test and euglycaemic insulin technique in six normoglycaemic patients with primary arterial hypertension at the end of 3-week treatments with placebo (one tablet twice daily) and propranolol (80 mg twice daily). Body weight did not change during the study (83 kg at the end of placebo, 83 kg at the end of propranolol), while blood pressure (150 +/- 9/97 +/- 8 mmHg on placebo, 138 +/- 8/89 +/- 8 mmHg on propranolol, P < 0.01) and heart rate (66 +/- 9 beats/min on placebo, 60 +/- 5 beats/min on propranolol, P < 0.05) showed a significant fall on the beta-blocker. No change was observed in glucose tolerance (incremental area for glucose 3462 +/- 1149 mg/dl per min on placebo, 3209 +/- 1695 mg/dl per min on propranolol), insulin secretion (incremental area for serum insulin 7579 +/- 4380 microU/ml per min on placebo, 7934 +/- 4351 microU/ml per min on propranolol) and peripheral insulin sensitivity (metabolic clearance rate 11 +/- 4 ml/kg per min on placebo, 13 +/- 6 ml/kg per min on propranolol). These data support the hypothesis that chronic treatment with adrenergic blocking agents does not induce any significant change in insulin secretion or peripheral insulin sensitivity.

Functionally thrombasthenic state in normal platelets following the administration of ticlopidine

To elucidate the bleeding tendency that follows the administration of ticlopidine, we investigated the skin bleeding time and some ex vivo functions of platelets obtained from eight healthy volunteers before and 1 wk after daily administration of 500 mg of ticlopidine. We found the following: ticlopidine significantly (P less than 0.001) prolonged the skin bleeding time and impaired the binding of radiolabeled fibrinogen and von Willebrand Factor, the clot retraction and the aggregation of platelets in response to ADP, epinephrine, thrombin, ionophore A23187, collagen, or arachidonic acid. In contrast, the administration of this drug did not affect intraplatelet levels of cAMP, agglutination and binding of von Willebrand Factor in response to ristocetin, shape change in response to ADP, collagen, thrombin, or arachidonic acid, or binding of prostaglandin E1 to resting platelets. Secretion of ATP in response to ADP or epinephrine was completely inhibited, whereas secretion as well as thromboxane synthesis in response to high concentrations of collagen, arachidonic acid, calcium ionophore A23187, or thrombin was unaffected. Studies with monoclonal antibodies showed that the glycoprotein IIb-IIIa complex (the putative receptor for fibrinogen and von Willebrand Factor on the surface of platelets exposed to naturally occurring aggregating agents) was quantitatively unaffected by ticlopidine. This observation was further confirmed by densitometric scannings of Periodic Acid-Schiff-stained gels of platelet suspensions. The onset, as well as the cessation of the inhibitory effect of ticlopidine on platelets was very slow, and reached a maximum after a 3-5-d administration. In addition, ticlopidine appeared to be a much more potent inhibitor when administered to subjects than when added in vitro to platelets. Finally, abnormalities comparable to those found in volunteers taking ticlopidine were observed when platelets from untreated subjects were incubated in the plasma of ticlopidine-treated subjects. We conclude that ticlopidine induces a thrombasthenic state in normal platelets without affecting the glycoprotein IIb-IIIa complex quantitatively. Furthermore, our data suggest that one or more active metabolites rather than the native drug mediate the abnormalities of platelet function observed in ticlopidine-treated subjects.