Spinal glycinergic currents are reduced in a rat model of neuropathic pain following partial nerve ligation but not chronic constriction injury.

Animal models have consistently indicated that central sensitization and the development of chronic neuropathic pain are linked to changes to inhibitory signaling in the dorsal horn of the spinal cord. However, replication of data investigating the cellular mechanisms that underlie these changes remains a challenge and there is still a lack of understanding about what aspects of spinal inhibitory transmission most strongly contribute to the disease. Here, we compared the effect of two different sciatic nerve injuries commonly used to generate rodent models of neuropathic pain on spinal glycinergic signaling. Using whole cell patch-clamp electrophysiology in spinal slices, we recorded from neurons in the lamina II of the dorsal horn and evoked inhibitory postsynaptic currents with a stimulator in lamina III, where glycinergic cell bodies are concentrated. We found that glycine inputs onto radial neurons were reduced following partial nerve ligation (PNL) of the sciatic nerve, consistent with a previous report. However, this finding was not replicated in animals that underwent chronic constriction injury (CCI) to the same nerve region. To limit the between-experiment variability, we kept the rat species, sex, and age consistent and had a single investigator carry out the surgeries. These data show that PNL and CCI cause divergent spinal signaling outcomes in the cord and add to the body of evidence suggesting that treatments for neuropathic pain should be triaged according to nerve injury or cellular dysfunction rather than the symptoms of the disease.NEW & NOTEWORTHY Neuropathic pain models are used in preclinical research to investigate the mechanisms underlying allodynia, a common symptom of neuropathic pain, and to test, develop, and validate therapies for persistent pain. We demonstrate that a glycinergic dysfunction is consistently associated with partial nerve ligation but not the chronic constriction injury model. This suggests that the cellular effects produced by each injury are distinct and that data from different neuropathic pain models should be considered separately.

Assessment of preoperative noninvasive ventilation before lung cancer surgery: The preOVNI randomized controlled study.

OBJECTIVES: The preOVNI study was a randomized, controlled, open-label study that investigated whether preoperative noninvasive ventilation (NIV) could reduce postoperative complications after lung cancer surgery. METHODS: Adult patients with planned lung cancer resection and with at least 1 cardiac or respiratory comorbidity were included and randomly assigned to preoperative NIV (at least 7 days and 4 h/day) or no NIV. The primary endpoint was the rate of postoperative protocol-defined complications. RESULTS: Three hundred patients were included. In the NIV group, the median NIV duration was 8 days. No difference of postoperative complication rates was evidenced: 42.6% in NIV group and 44.8% in no-NIV group (P = .75). The rate of pneumonia was greater in no-NIV group compared with the NIV group, but statistical significance was not achieved (28.0 vs 37.7%, respectively; P = .08). The type of surgery (open or minimally invasive) did not impact these results after multivariable analysis. CONCLUSIONS: No benefit was evidenced for preoperative NIV before lung cancer surgery. Further studies should determine the optimal perioperative management to decrease the rate of postoperative complications.

Management of war-related vascular wounds in French role 3 hospital during the Afghan campaign.

OBJECTIVES: To describe the management of war-related vascular injuries in the Kabul French military hospital. METHODS: From January 2009 to April 2013, in the Kabul French military hospital, we prospectively included all patients presenting with war-related vascular injuries. We collected the following data: site, type, and mechanism of vascular injury, associated trauma, type of vascular repair, amputation rate and complications. RESULTS: Out of the 922 soldiers admitted for emergency surgical care, we recorded 45 (5%) patients presenting with vascular injuries: 30 (67%) gunshot-related, 11 (24%) explosive device-related, and 4 (9%) due to road traffic accident. The majority of injuries (93%) involved limbs. Vascular injuries were associated with fractures in 71% of cases. Twelve (26.7%) had an early amputation performed before evacuation. Twenty (44.4%) patients underwent fasciotomy and three (6.6%) sustained a compartment syndrome. CONCLUSIONS: This was the first French reported series of war-related vascular injuries during the last decade's major conflicts. The majority of injuries occurred in the limbs. Autologous vein graft remains the treatment of choice for arterial repair. Functional severity of these injuries justifies specific training for military surgeons.

Polyphenol-rich diets improve glucose metabolism in people at high cardiometabolic risk: a controlled randomised intervention trial.

AIM/HYPOTHESIS: Dietary polyphenols and long chain n-3 polyunsaturated fatty acids (LCn3) are associated with lower cardiovascular risk. This may relate to their influence on glucose metabolism and diabetes risk. We evaluated the effects of diets naturally rich in polyphenols and/or LCn3 of marine origin on glucose metabolism in people at high cardiometabolic risk. METHODS: According to a 2 × 2 factorial design, individuals with high waist circumference and at least one more component of the metabolic syndrome were recruited at the obesity outpatient clinic. Eighty-six participants were randomly assigned by MINIM software to an isoenergetic diet: (1) control, low in LCn3 and polyphenol (analysed n = 20); (2) rich in LCn3 (n = 19); (3) rich in polyphenols (n = 19); or (4) rich in LCn3 and polyphenols (n = 19). The assigned diets were known for the participants and blinded for people doing measurements. Before and after the 8 week intervention, participants underwent a 3 h OGTT and a test meal with a similar composition as the assigned diet for the evaluation of plasma glucose, insulin and glucagon-like peptide 1 (GLP-1) concentrations, and indices of insulin sensitivity and beta cell function. RESULTS: During OGTT, polyphenols significantly reduced plasma glucose total AUC (p = 0.038) and increased early insulin secretion (p = 0.048), while LCn3 significantly reduced beta cell function (p = 0.031) (two-factor ANOVA). Moreover, polyphenols improved post-challenge oral glucose insulin sensitivity (OGIS; p = 0.05 vs control diet by post hoc ANOVA). At test meal, LCn3 significantly reduced GLP-1 total postprandial AUC (p < 0.001; two-factor ANOVA). CONCLUSION/INTERPRETATION: Diets naturally rich in polyphenols reduce blood glucose response, likely by increasing early insulin secretion and insulin sensitivity. These effects may favourably influence diabetes and cardiovascular risk. The implications of the decrease in insulin secretion and postprandial GLP-1 observed with diets rich in marine LCn3 need further clarification. TRIAL REGISTRATION: ClinicalTrials.gov NCT01154478. FUNDING: The trial was funded by European Community's Seventh Framework Programme FP7/2009-2012 under grant agreement FP7-KBBE-222639, Etherpaths Project and 'Ministero Istruzione Università e Ricerca' PRIN 2010-2011 - 2010JCWWKM.

Congenital pulmonary airway malformation and sequestration: Two standpoints for a single condition.

UNLABELLED: In adults, congenital pulmonary malformations are candidates for surgery due to symptoms. A pre-natal diagnosis is simple and effective, and allows an early thoracoscopic surgical treatment. A retrospective study was performed to assess management in two different populations of adults and children to define the best strategy. SUBJECTS AND METHODS: Pulmonary malformations followed at the University Hospital from 2000 to 2012 were reviewed. Clinical history, malformation site, duration of hospitalisation, complications and pathology examinations were collected. RESULTS: A total of 52 cases (33 children, 19 adults) were identified. In children, 28 asymptomatic cases were diagnosed pre-natally and 5 during the neonatal period due to infections. Surgery was performed on the children between the ages of 2 and 6 months. Nineteen adults underwent surgery, 16 because of symptoms and 3 adults for anomalies mimicking tumours. The mean age within the adult group was 42.5 years. In children, there was one thoracotomy and 32 thoracoscopies, with 7 conversions for difficult exposure, dissection of vascular pedicles, bleeding or bronchial injury. In the adults, there were 15 thoracotomies and 4 thoracoscopies, with one conversion. Post-operative complications in the adults were twice as frequent than in children. The mean time of the children's hospitalisation was 7.75 days versus 7.16 days for the adults. Pathological examinations showed in the children: 7 sequestrations, 18 congenital cystic pulmonary malformations (CPAM), 8 CPAM associated sequestrations; in adults: 16 sequestrations, 3 intra-pulmonary cysts. CONCLUSION: Early thoracoscopic surgery allows pulmonary parenchyma conservation with pulmonary development, reduces respiratory and infectious complications, eliminates a false positive cancer diagnosis later in life and decreases risks of thoracic parietal deformation.

Surgical management for the first 48 h following blunt chest trauma: state of the art (excluding vascular injuries).

This review aims to answer the most common questions in routine surgical practice during the first 48 h of blunt chest trauma (BCT) management. Two authors identified relevant manuscripts published since January 1994 to January 2014. Using preferred reporting items for systematic reviews and meta-analyses statement, they focused on the surgical management of BCT, excluded both child and vascular injuries and selected 80 studies. Tension pneumothorax should be promptly diagnosed and treated by needle decompression closely followed with chest tube insertion (Grade D). All traumatic pneumothoraces are considered for chest tube insertion. However, observation is possible for selected patients with small unilateral pneumothoraces without respiratory disease or need for positive pressure ventilation (Grade C). Symptomatic traumatic haemothoraces or haemothoraces >500 ml should be treated by chest tube insertion (Grade D). Occult pneumothoraces and occult haemothoraces are managed by observation with daily chest X-rays (Grades B and C). Periprocedural antibiotics are used to prevent chest-tube-related infectious complications (Grade B). No sign of life at the initial assessment and cardiopulmonary resuscitation duration >10 min are considered as contraindications of Emergency Department Thoracotomy (Grade C). Damage Control Thoracotomy is performed for either massive air leakage or refractive shock or ongoing bleeding enhanced by chest tube output >1500 ml initially or >200 ml/h for 3 h (Grade D). In the case of haemodynamically stable patients, early video-assisted thoracic surgery is performed for retained haemothoraces (Grade B). Fixation of flail chest can be considered if mechanical ventilation for 48 h is probably required (Grade B). Fixation of sternal fractures is performed for displaced fractures with overlap or comminution, intractable pain or respiratory insufficiency (Grade D). Lung herniation, traumatic diaphragmatic rupture and pericardial rupture are life-threatening situations requiring prompt diagnosis and surgical advice. (Grades C and D). Tracheobronchial repair is mandatory in cases of tracheal tear >2 cm, oesophageal prolapse, mediastinitis or massive air leakage (Grade C). These evidence-based surgical indications for BCT management should support protocols for chest trauma management.

Recurrent spontaneous pneumomediastinum in an adult.

Spontaneous pneumomediastinum (SP) is defined as the presence of free air in mediastinal space without any apparent cause. This rare entity is most likely to occur in young males often related to an episode of vomiting, asthma or sustained physical activity. SP usually resolves spontaneously in few days of treatment based on rest and analgesia. Complications are extremely rare. Its recurrence has been poorly reported but seems exceptional. We present a case of recurrent SP occurring in a 21-year-old male with a mental deficiency. The recurrence occurred after a free-interval of 12 months. We proposed a literature review.

Effects of baked products enriched with n-3 fatty acids, folates, ß-glucans, and tocopherol in patients with mild mixed hyperlipidemia.

OBJECTIVE: To assess whether a diet containing foods enriched with ß-glucans (3.6 g/d), folic acid (1600 µg/d), long-chain (800 mg/d) and short-chain (400 mg/d) n-3 fatty acids, and tocopherols (120 mg/d) is able to modulate positively the cardiovascular risk profile in people at slightly increased cardiovascular risk. METHODS: Sixteen subjects with mild plasma lipid abnormalities were studied according to a randomized crossover design. After a 2-week run-in period, they followed a diet containing baked products enriched with active nutrients (active diet) or a diet containing the same products but without active nutrients (control diet) for 1 month and then crossed over to the other diet. At the end of each period, a test meal of the same composition as the corresponding diet was administered, and plasma samples were obtained before and for 6 hours after the meal. Hunger and satiety were evaluated by the visual analog scale at fasting and after the meal. RESULTS: Fasting plasma triglycerides were significantly lower after the active versus the control diet (1.56 ± 0.18 vs 1.74 ± 0.16 mmol/l, p < 0.05), as was the postprandial level of chylomicron triglycerides and the insulin peak (p < 0.05). The active diet also reduced fasting homocysteine (8 ± 0.6 vs 10 ± 0.8 µmol/l, p < 0.05) and the feeling of hunger at the fifth and sixth hour (p < 0.05). CONCLUSIONS: Baked functional products enriched with n-3 fatty acids, folates, ß-glucans, and tocopherols within the context of a balanced diet lower fasting and postprandial plasma triglycerides, fasting homocysteinemia, and the postprandial insulin peak. They induce a greater feeling of satiety with possible beneficial implications on energy intake.

Liver fat in obesity: role of type 2 diabetes mellitus and adipose tissue distribution.

BACKGROUND: Fatty liver is commonly associated with insulin-resistant conditions, often related to increased abdominal visceral fat. Our objective was to elucidate the specific roles of obesity, type 2 diabetes mellitus, insulin-resistance and abdominal fat distribution. MATERIALS AND METHODS: The study population comprised 13 diabetic obese (DO), 10 nondiabetic obese (NDO), and nine normal-weight control (C) men aged 28-65 years, with normal plasma triglyceride levels. DO were in good glycaemic control (HbA1c = 6·8 ± 0·8%) (M ± SD) with diet (n = 8) or diet + metformin (n = 5). Liver fat content was measured by (1) H-magnetic resonance spectroscopy, abdominal fat distribution by magnetic resonance imaging and insulin sensitivity by hyperinsulinaemic euglycaemic clamp. RESULTS: DO and NDO subjects had similar whole-body insulin resistance, BMI and waist circumference, higher than those of C subjects (P < 0·001). DO had more liver fat (11·9 ± 7·0%) than NDO (5·2 ± 2·8%, P < 0·05) and C (1·6 ± 1·0%, P < 0·001). Abdominal fat was greater in DO and NDO than in C (visceral: DO 3184 ± 843, NDO 2843 ± 1378 vs. C 1212 ± 587 cm(3), P < 0·001; subcutaneous: DO 4029 ± 362, NDO 5197 ± 1398 vs. C 2312 ± 626 cm(3), P < 0·001), visceral fat being not significantly different between the two obese groups, and subcutaneous fat significantly less in DO than in NDO (P < 0·05). CONCLUSIONS: Type 2 diabetes is associated with increased fat accumulation in the liver, independent of obesity and whole-body insulin resistance. The increased liver fat in DO patients may be part of an altered regional fat distribution that includes an inadequate subcutaneous fat storing capacity, rather than simply being a consequence of increased abdominal visceral content.

Type 2 diabetes mellitus is characterized by reduced postprandial adiponectin response: a possible link with diabetic postprandial dyslipidemia.

We investigated postprandial plasma and adipose tissue (AT) adiponectin changes in relation to obesity and type 2 diabetes mellitus. Fasting and 6 hours after a standard fat-rich meal blood samples (adiponectin, glucose, insulin, lipids) and needle biopsies of abdominal subcutaneous AT (adiponectin messenger RNA, lipoprotein lipase activity) were taken in 10 obese diabetic (OD), 11 obese nondiabetic (OND), and 11 normal-weight control (C) men. The OD and OND subjects had similar adiposity (body mass index, waist circumference) and insulin resistance (hyperinsulinemic euglycemic clamp). Fasting plasma adiponectin and AT gene expression were not significantly different between groups. After meal, plasma adiponectin decreased in OD but significantly increased in OND and C, the changes being significantly different between groups (analysis of variance, P = .01); adiponectin messenger RNA decreased in OD (-0.27 +/- 0.25 AU, P = .01) but was unchanged in OND (P = .59) and C (P = .45). After meal, plasma adiponectin correlated inversely with triglyceride and cholesterol concentrations in chylomicrons and large very low-density lipoprotein, and directly with AT lipoprotein lipase activity (P < .05 for all). Type 2 diabetes mellitus is associated with lower postprandial plasma levels and AT gene expression of adiponectin independently of degree of adiposity and whole-body insulin sensitivity. In patients with diabetes, this may exacerbate postprandial abnormalities of lipoprotein metabolism.

Effects of a plant-based high-carbohydrate/high-fiber diet versus high-monounsaturated fat/low-carbohydrate diet on postprandial lipids in type 2 diabetic patients.

OBJECTIVE: To search for a better dietary approach to treat postprandial lipid abnormalities and improve glucose control in type 2 diabetic patients. RESEARCH DESIGN AND METHODS: According to a randomized crossover design, 18 type 2 diabetic patients (aged 59 +/- 5 years; BMI 27 +/- 3 kg/m(2)) (means +/- SD) in satisfactory blood glucose control on diet or diet plus metformin followed a diet relatively rich in carbohydrates (52% total energy), rich in fiber (28 g/1,000 kcal), and with a low glycemic index (58%) (high-carbohydrate/high-fiber diet) or a diet relatively low in carbohydrate (45%) and rich in monounsaturated fat (23%) (low-carbohydrate/high-monounsaturated fat diet) for 4 weeks. Thereafter, they shifted to the other diet for 4 more weeks. At the end of each period, plasma glucose, insulin, lipids, and lipoprotein fractions (separated by discontinuous density gradient ultracentrifugation) were determined on blood samples taken at fasting and over 6 h after a test meal having a similar composition as the corresponding diet. RESULTS: In addition to a significant decrease in postprandial plasma glucose, insulin responses, and glycemic variability, the high-carbohydrate/high-fiber diet also significantly improved the primary end point, since it reduced the postprandial incremental areas under the curve (IAUCs) of triglyceride-rich lipoproteins, in particular, chylomicrons (cholesterol IAUC: 0.05 +/- 0.01 vs. 0.08 +/- 0.02 mmol/l per 6 h; triglycerides IAUC: 0.71 +/- 0.35 vs. 1.03 +/- 0.58 mmol/l per 6 h, P < 0.05). CONCLUSIONS: A diet rich in carbohydrate and fiber, essentially based on legumes, vegetables, fruits, and whole cereals, may be particularly useful for treating diabetic patients because of its multiple effects on different cardiovascular risk factors, including postprandial lipids abnormalities.

Management of type 2 diabetic patients attending diabetic outpatient clinics compared with those cared for by the general practitioners: an experience of integrated diabetes management.

To improve the quality of diabetes care, a project of integrated diabetes management (PIDM) involving some general practitioner (GPs) has been recently undertaken. The purpose of this study is to compare features and treatment of patients followed by diabetic outpatient clinics (DOCs) with those cared for by GPs trained to the PIDM. Twenty-one DOCs and eleven GPs participated in the study. Patients followed by DOCs (n. = 1110) showed longer duration of diabetes, higher prevalence of metabolic syndrome than patients followed by GPs (n. = 305). More patients followed in DOCs performed insulin therapy, while a lower number received ACE /angiotensin blockers, antiplatelet, lipid lowering drugs and multifactorial intervention than patients followed by GPs. The proportion of patients in good control for glucose, pressure and lipid levels was similar in the two groups. Conversely, a higher number of patients attending DOCs were in poor glycemic, pressure, and lipid control compared with patients followed by GPs. In conclusions, PIDM provides satisfactory results in terms of overall glucose, pressure and lipid control, thus encouraging implementation of PIDM to meet the increasing demand for diabetes care.

Postprandial chylomicrons and adipose tissue lipoprotein lipase are altered in type 2 diabetes independently of obesity and whole-body insulin resistance.

BACKGROUND AND AIMS: Postprandial lipoprotein abnormalities in type 2 diabetes are associated with insulin resistance. The role of other diabetes-related factors is still not clear. The aim of this study is to differentiate the effects of whole-body insulin resistance, obesity, and type 2 diabetes on postprandial dyslipidaemia and lipoprotein lipase (LPL) in adipose tissue. METHODS AND RESULTS: Ten subjects with obesity and diabetes (OD), 11 with obesity alone (O), and 11 normal-weight controls (C) - males, aged 26-59 years, with fasting normo-triglyceridaemia underwent measurements of cholesterol, triglycerides, apo B-48 and apo B-100 concentrations in plasma lipoproteins separated by density gradient ultracentrifugation before and after a fat-rich meal. Fasting and postprandial (6h) LPL activity was determined in abdominal subcutaneous adipose tissue biopsy samples. Insulin sensitivity was measured by hyperinsulinaemic euglycaemic clamp. OD and O subjects had similar degrees of adiposity (BMI, waist circumference, fat mass) and insulin resistance (insulin stimulated glucose disposal and M/I). They also showed a similarly higher postprandial increase in large VLDL lipids (triglyceride incremental AUC 188+/-28 and 135+/-22 mg/dl.6h) than C (87+/-13 mg/dl.6h, M+/-SEM, p<0.05). OD had an increased chylomicron response compared to O (triglyceride incremental AUC 132+/-23 vs. 75+/-14 mg/dl.6h, p<0.05). OD had significantly lower fasting and postprandial adipose tissue heparin-releasable LPL activity than O and C. CONCLUSIONS: In insulin-resistant conditions of obesity, with and without diabetes, large VLDL are increased after a fat-rich meal. In addition, diabetic patients compared to obese subjects have an increased postprandial chylomicron response and a reduced adipose tissue LPL activity.

Effects of monounsaturated vs. saturated fat on postprandial lipemia and adipose tissue lipases in type 2 diabetes.

BACKGROUND: The effects of different dietary fatty acids on postprandial lipid metabolism in type 2 diabetic patients are still debated. AIM: To evaluate the effects of monounsaturated (MUFA) vs. saturated fat (SAFA)-rich diets on postprandial lipemia and adipose tissue lipoprotein lipase (LPL), and hormone-sensitive lipase (HSL) in type 2 diabetes. MATERIALS AND METHODS: Eleven type 2 diabetic patients followed, in random order, a diet rich in MUFA (SAFA 8%, MUFA 23%) and another rich in SAFA (SAFA 17%, MUFA 15%) for a period of 3 weeks each. At the end of the two diets, a standard fat-rich meal was administered and subcutaneous fat biopsies were performed at fasting and 6h after the test meal. RESULTS: Neither diet induced significant changes in meal lipid tolerance, except for a faster (at 2h) increase in chylomicron triglycerides and a significant decrease in small VLDL triglyceride incremental area after the MUFA diet (-13.6+/-4.7 mg/dl*6h vs. -2.2+/-3.7 mg/dl*6h, p<0.005) (M+/-SEM). LPL and HSL activities were significantly increased after the MUFA diet. CONCLUSIONS: A MUFA-rich diet reduces postprandial small VLDL triglycerides in type 2 diabetic patients compared to a SAFA-rich diet, and modifies lipolytic enzymes in adipose tissue.

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.

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.

Type of dietary fat and insulin resistance.

Animal studies have already shown the possibility to modulate insulin action by changing not only the amount of total fat, but also the type of fat. In these studies, saturated fat significantly increased insulin resistance, long- and short-chain omega(3) fatty acids significantly improved it, whereas the effects of monounsaturated and omega(6) polyunsaturated fatty acids ranged somewhere in between the two. A recent multicenter study (the Kanwu study) on humans has shown that shifting from a diet rich in saturated fatty acids to one rich in monounsaturated fat improved insulin sensitivity in healthy people, while a moderate omega(3) supplementation did not affect it; this second finding confirms previous results in type 2 diabetic patients with hypertriglyceridemia. There are also other aspects of the metabolic syndrome that can be influenced by the different type of dietary fat, particularly blood pressure and lipid metabolism. With respect to blood pressure, the majority of studies show that omega(3) fatty acids are able to reduce blood pressure in hypertensive patients, but not in normotensive individuals; this result has been confirmed also by the Kanwu study, where no changes in blood pressure were seen after omega(3) supplementation in healthy people. On the other hand, in this study, the change from saturated to monounsaturated fatty acids was able to significantly reduce diastolic blood pressure. As to the lipid abnormalities more frequently present in the metabolic syndrome (i.e., hypertriglyceridemia and low HDL cholesterol), the main effects are related to omega(3) fatty acids, which surely reduce triglyceride levels, but at the same time increase LDL cholesterol. In conclusion, there is so far sound evidence in humans that the quality of dietary fat is able to influence insulin resistance and some of the related metabolic abnormalities.