Do data in the literature indicate that glycaemic variability is a clinical problem? Glycaemic variability and vascular complications of diabetes.

In recent years glycaemic variability (GV) has emerged as a determinant of vascular complications of both type 1 and type 2 diabetes mellitus. In type 1 diabetes analysis of data of GV show conflicting results on both micro- and macro-vascular complications. In non-diabetic subjects blood glucose after loading is a stronger predictor of cardiovascular complications than fasting glucose. In type 2 diabetes both coefficient of variation of fasting blood glucose and postprandial blood glucose predict cardiovascular events. Also, long term variability of HbA1c has been associated predominantly with diabetic nephropathy, less frequently with retinopathy. Intervention trials to evaluate the effect of postprandial glucose have been conducted only in prediabetes or in type 2 diabetes and the data are not conclusive. In vitro and in vivo data have shown the mechanisms that are at the basis of the adverse cardiovascular effects of GV, mainly associated with oxidative stress; the atherogenic action of postprandial glucose also involves insulin sensitivity, postprandial increase in serum lipids and glycaemic index of food. Thus, correction of GV emerges as a target to be pursued in clinical practice in order to safely reduce mean blood glucose (and thus glycated haemoglobin) and for its direct effects on vascular complications of diabetes.

How can we monitor glycaemic variability in the clinical setting?

No universal consensus exists on how to express glycaemic variability. Among other parameters, standard deviation of blood glucose values, mean amplitude of glycaemic excursions (MAGE), the Low Blood Glucose Index (LBGI) and the High Blood Glucose Index (HBGI), which were subsequently combined into the Average Daily Risk Range (ADRR), mean of daily differences (MODD) and glycaemic variability index (GVI) are highlighted. The continuous glucose monitoring in research and clinical settings has been a great help for a comprehensive approach to circadian blood glucose evaluation and identification of individual patterns, mainly in type 1 diabetes, but recently also in type 2 diabetes. In everyday clinical practice the judicious use of self-monitoring of blood glucose in an educational setting involving the patient and the care team is an unreplaceable tool to effectively and safely guide behavioural and drug therapy.

Women show worse control of type 2 diabetes and cardiovascular disease risk factors than men: results from the MIND.IT Study Group of the Italian Society of Diabetology.

BACKGROUND AND AIMS: The study explores the degree of control of hyperglycaemia and cardiovascular (CV) disease risk factors in men and women with type 2 diabetes and the impact thereon of obesity, central adiposity, age and use of medications. METHODS AND RESULTS: A cross-sectional survey was conducted at 10 hospital-based outpatients diabetes clinics. 1297 men and 1168 women with no previous CV events were studied. Women were slightly (only one year) older and more obese than men: average BMI was respectively 30.7 ± 5.7 vs 28.6 ± 4.1 kg/m(2) (p < 0.001), and prevalence of abdominal obesity was 86% vs 44% (p < 0.001). Women smoked less, but had higher HbA1c, LDL cholesterol, non-HDL cholesterol, systolic blood pressure and serum fibrinogen than men. Accordingly optimal targets for HbA1c (<7%), LDL cholesterol (<100 mg/dL), HDL cholesterol (>40 for men, >50 for women, mg/dL), and systolic blood pressure (<130 mmHg) were less frequently achieved by women than men (respectively 33.8% vs 40.2%; 14.6% vs 19.2%; 34.1% vs 44.5%; 68.8% vs 72%; p < 0.05 for all). Findings were confirmed after stratification for waist circumference (< or ≥ 88 cm for women; < or ≥ 102 cm for men), BMI (< or ≥ 25 kg/m(2)) or age (< or ≥ 65 years). As for treatment, women were more likely than men to take insulin, alone or in combination with oral hypoglycaemic drugs, to be under anti-hypertensive treatment, whereas the use of lipid lowering drugs was similar in men and women. CONCLUSIONS: Control of hyperglycaemia and major CVD risk factors is less satisfactory in women than men. The gender disparities are not fully explained by the higher prevalence of total and central obesity in women; or by a less intensive medical management in women.

Metabolic syndrome in subjects at high risk for type 2 diabetes: the genetic, physiopathology and evolution of type 2 diabetes (GENFIEV) study.

BACKGROUND AND AIM: We evaluated the relationship between insulin resistance (IR) and insulin secretion with the metabolic syndrome (MS) in 885 subjects (377 men/508 women, age 49±11 years, BMI 29±5.2kgm(-2)) at risk of diabetes enrolled in the genetics, pathophysiology and evolution of type 2 diabetes (GENFIEV) study. METHODS AND RESULTS: All subjects underwent a 75-g oral glucose tolerance test (OGTT) for the estimation of plasma levels of glucose and C-peptide, as well as fasting insulin and lipid profile. IR was arbitrarily defined as HOMA-IR value above the 75th centile of normal glucose tolerance (NGT) subjects. Overall MS prevalence (National Cholesterol Treatment Panel-Adult Treatment Panel (NCEP-ATPIII) criteria) was 33%, 19% in subjects with NGT, 42% in impaired fasting glucose (IFG), 34% in impaired glucose tolerance (IGT), 74% in IFG+IGT subjects, and 56% in newly diagnosed diabetic patients. Prevalence was slightly higher with IDF criteria. MS prevalence was >50% in subjects with 2h glucose >7.8mmoll(-1), independently of fasting plasma glucose. IR prevalence was higher in subjects with MS than in those without (63% vs. 23%; p<0.0001) and increased from 54% to 73% and 88% in the presence of three, four or five traits, respectively. IR occurred in 42% of subjects with non-diabetic alterations of glucose homeostasis, being the highest in those with IFG+IGT (IFG+IGT 53%, IFG 45%, IGT 38%; p<0.0001). Individuals with MS were more IR irrespective of glucose tolerance (p<0.0001) with no difference in insulinogenic index. Hypertriglyceridaemia (OR: 3.38; Confidence Interval, CI: 2.294.99), abdominal obesity (3.26; CI: 2.18-4.89), hyperglycaemia (3.02; CI: 1.80-5.07) and hypertension (1.69; CI: 1.12-2.55) were all associated with IR. CONCLUSIONS: These results show that in subjects with altered glucose tolerance (in particular IFG+IGT) MS prevalence is high and is generally associated to IR. Some combinations of traits of MS may significantly contribute to identify subjects with IR.

Dietary habits in type II diabetes mellitus: how is adherence to dietary recommendations?

OBJECTIVE: To clarify adherence of type II diabetic patients to dietary recommendations. SUBJECTS AND METHODS: The dietary habits of a group of 540 patients, with type II diabetes (male 322/female 218, mean age 61+/-5 years, body mass index (BMI) 29.7+/-5.2 kg/m(2); mean+/-s.d.) referring to six Italian diabetes centres were evaluated by means of a 3-day diet record (2 workdays, 1 holiday). Diet records were analysed according to Italian food composition tables and compared with the dietary recommendations of the Diabetes and Nutrition Study Group of the European Association for the study of Diabetes. RESULTS: Calorie intake was 1725+/-497 kcal (1800 for men, 1610 for women). Mean intake for each nutrient was close to the recommended amount, except for fibre (12/1000 vs 20 g/1000 kcal). Calculating the percentage of patients who complied with each recommendation, the intakes of saturated fat and fibre least reflected the dietary target: in 43% of patients saturated fat was >10% of total calories, in only 6% was fibre intake > or =20 g/1000 kcal (considered ideal), and in 25% it was > or =15 g/1000 kcal (acceptable). CONCLUSIONS: These results indicate that compliance to dietary recommendations is not completely satisfactory, even in Italy. Calorie intake is a bit elevated, given the high BMI of our diabetic population. As to dietary composition, there are two crucial issues: the high intake of saturated fat and--most importantly--the low intake of fibre. All strategies aiming to a proper implementation of guidelines should take these results into due account.

Outcomes of integrated management versus specialized care for patients with type 2 diabetes: An observational study.

AIMS: To compare type 2 diabetes (T2D) patients included in a Diabetes Integrated Management (DIM) program with those followed in Diabetes Specialized Care (DSC), investigating differences in general characteristics, changes in clinical outcomes, and factors related with the inclusion in the DIM program. METHODS: T2D patients living in the ASLTO3 district and included into the DIM program, a shared disease management between general practitioners and diabetes specialists, from 2008 to 2014 were compared with T2D patients living in the same district and in charge of the local DSC. Demographic, anthropometric and clinical data for both groups of patients were obtained from the electronic records of DSC. RESULTS: 1326 DIM patients were compared with 3494 DSC patients. A higher proportion of females was observed among DIM patients than among DSC patients. DIM patients were older, more frequently in therapy with diet only or with oral hypoglycemic, and had HbA1c and creatinine lower than DSC patients. The analyses of changes in clinical parameters during the study period showed a good and statistically significant improvement of most parameters, independently of the inclusion in DIM or DSC, with the exception of creatinine level. CONCLUSIONS: Integrated Management is an efficient and effective way to achieve good long-term clinical outcomes for patients with diabetes.

Postprandial blood glucose is a stronger predictor of cardiovascular events than fasting blood glucose in type 2 diabetes mellitus, particularly in women: lessons from the San Luigi Gonzaga Diabetes Study.

OBJECTIVE: The influence of postprandial blood glucose on diabetes complications is intensively debated. We aimed to evaluate the predictive role of both fasting and postprandial blood glucose on cardiovascular events in type 2 diabetes and the influence of gender. METHODS: In a population of 529 (284 men and 245 women) consecutive type 2 diabetic patients attending our diabetes clinic, we evaluated the relationships, corrected for cardiovascular risk factors and type of treatment, between cardiovascular events in a 5-yr follow-up and baseline values of hemoglobin A1c (HbA1c) and blood glucose measured: 1) after an overnight fast, 2) after breakfast, 3) after lunch, and 4) before dinner. Continuous variables were categorized into tertiles. RESULTS: We recorded cardiovascular events in 77 subjects: 54 of 284 men (19%) and 23 of 245 women (9.4%). Univariate analysis indicated that cardiovascular events were associated with increasing age, longer diabetes duration, and higher HbA1c and fibrinogen in men, and higher systolic blood pressure, albumin excretion rate, HbA1c, and all blood glucose values in women. Smoking was more frequent in subjects with events. When all blood glucose values and HbA1c were introduced simultaneously in the models, only blood glucose after lunch predicted cardiovascular events, with hazard ratio of the third tertile vs. the first and the second tertiles greater in women (5.54; confidence interval, 1.45-21.20) than in men (2.12; confidence interval, 1.04-4.32; P < 0.01). CONCLUSIONS: Postprandial, but not fasting, blood glucose is an independent risk factor for cardiovascular events in type 2 diabetes, with a stronger predictive power in women than in men, suggesting that more attention should be paid to postprandial hyperglycemia, particularly in women.

Insulin directly reduces platelet sensitivity to aggregating agents. Studies in vitro and in vivo.

The aim of this study was to investigate the influence of insulin on platelet function, both in vitro and in vivo. For the in vitro investigation, we evaluated whether insulin affects platelet function at a physiological hormone concentration by incubating the platelet-rich plasma (PRP) of fasting subjects with human regular insulin at the final concentration of 40 microU/ml for 30 min; we observed a significant reduction of platelet sensitivity to all the aggregating agents employed, i.e., ADP, platelet-activating factor (PAF), epinephrine, collagen, and Na+ arachidonate. To investigate whether the insulin effect on platelets is dose dependent, we incubated the PRP of fasting subjects with different concentrations of human regular insulin (40, 80, 120, and 160 microU/ml) for 5 min, and we observed that the insulin-induced reduction of platelet sensitivity to aggregating agents is a dose-dependent phenomenon. Furthermore, the comparison between the platelet responses after 5 and 30 min of incubation with insulin showed that the insulin effect on platelet aggregation is time dependent. The lack of specificity of its inhibiting activity suggests that insulin does not interfere with the initial binding of each aggregating agent at specific sites but does influence a common step of platelet aggregation. Our study rules out the possibility that insulin reduces platelet-function-modifying intraplatelet cAMP levels or thromboxane A2 production, because this hormone decreases the platelet concentrations of cAMP--a phenomenon that, per se, promotes platelet aggregation--and does not modify collagen or Na+ arachidonate--induced platelet production of thromboxane A2, measured by radioimmunoassay of its stable-metabolite thromboxane B2.(ABSTRACT TRUNCATED AT 250 WORDS)

Insulin increases guanosine-3',5'-cyclic monophosphate in human platelets. A mechanism involved in the insulin anti-aggregating effect.

To investigate whether insulin reduces platelet aggregability through a modulation of the guanosine-3',5'-cyclic monophosphate (cGMP) concentrations, we determined by a radioimmunoassay the cGMP values in the platelet-rich plasma (PRP) obtained from 17 healthy volunteers and incubated for 3 min with different concentrations of human recombinant insulin (0, 240, 480, 720, 960, and 1,920 pM). Insulin induced a dose-dependent cGMP increase, from 18.5 +/- 3.3 to 42.0 +/- 6.4 pmol/10(9) platelets (P = 0.0001). This increase was completely blunted when PRP was preincubated for 20 min with the tyrosine kinase inhibitor genistein (10 microM) or with the guanylate cyclase inhibitor methylene blue (10 microM), but the increase remained highly significant (P = 0.003 and 0.009) when PRP was preincubated for 20 min with the phosphodiesterase inhibitor 3-isobutyl-1-methyl-xanthine (IBMX, 500 microM) or with the nitric oxide synthase inhibitor NG-mono-methyl-L-arginine (L-NMMA, 30 microM). Finally, the insulin-induced decrease of platelet aggregability to collagen and ADP was completely blunted when PRP was preincubated with 10 microM of the guanylate cyclase inhibitor methylene blue. This study demonstrates that the platelet anti-aggregatory effect exerted by insulin is attributable to the insulin-induced increase of cGMP that is due to a direct receptor-mediated platelet guanylate cyclase activation.