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Biomedical subjects

N Attia

Publications and source records attributed to N Attia.

At least 19 recordsLinked to original sources

Association between dietary fat and antioxidant status of Tunisian type 2 diabetic patients.

BACKGROUND: The antioxidant enzymes: superoxide dismutase (Cu/Zn SOD) and glutathione peroxidase (GSH-Px) provide a defense against the damage of cells by reactive oxygen species, which increased in diabetic state. It was demonstrated that dietary treatment could improve the antioxidant status in patients with type 2 diabetes mellitus. This study was undertaken to determine if erythrocyte Cu/Zn SOD and GSH-Px activities correlate with dietary nutrients in 35 selected type 2 diabetic patients (21 women and 14 men) without diabetic complications. RESULTS: We found that erythrocyte Cu/Zn SOD was diminished in patients with poor controlled diabetes and GSH-Px activity was significantly decreased in obese compared with non-obese type 2 diabetic patients (1.07+/-0.87 and 2.36+/-1.99 U/ml, respectively; P=0.024). Both erythrocyte Cu/Zn SOD and GSH-Px activities were positively correlated to erythrocyte omega3-polyunsaturated fatty acids (PUFA). In non-obese diabetic patients, only GSH-Px activity was correlated negatively to the fraction of linoleic acid (18:2omega6) and arachidonic acid (20:4omega6) in erythrocytes phospholipids. CONCLUSIONS: The data of this study reveal that activities of erythrocyte antioxidant enzymes were altered in type 2 diabetic patients. Further studies are needed to determine if diet supplemented with omega3-PUFA is required to improve antioxidant defense system in diabetic state.

Adiposity↗

[Thyroid carcinoma and Hashimoto thyroiditis].

OBJECTIVES: To study of the association between thyroid carcinoma and Hashimoto's thyroiditis (HT). MATERIAL AND METHODS: [corrected] Retrospective study of 78 patients undergoing surgery between 2001 and 2002, with a pathological diagnosis of Hashimoto's thyroiditis. The clinical data and complementary tests performed before surgery are reported. RESULTS: The mean age was 44.6 years, with 77 females and only one male. There were 12 cases of thyroid cancer associated with HT, mostly with the nodular form, with 11 papillary carcinoma (14.1%) and one non-hodgkin B lymphoma of the thyroid. Tumor size varied from 4 to 60 mm with a mean of 26 mm. There was one microcancer (size<10 mm). CONCLUSIONS: We did not find an increased incidence of thyroid cancer associated with this highly selected population of HT patients.

Adolescent↗

Modulation of plasma cholesteryl ester transfer protein activity by unsaturated fatty acids in Tunisian type 2 diabetic women.

BACKGROUND AND AIM: Type 2 diabetes mellitus is associated with atherosclerosis, which has been, in part, ascribed to abnormalities in the reverse cholesterol transport system. Among the key actors involved in this pathway is cholesteryl ester transfer protein (CETP) which mediates the transfer of cholesteryl esters (CE) from HDL to apoB-containing lipoproteins. METHODS AND RESULTS: The purpose of this study was to examine CETP activity in 220 patients with type 2 diabetes mellitus (type 2 DM) treated with diet alone or diet and sulphonylurea drugs and to identify the factors that may regulate it in the diabetic state. We also examined the effect of diet on the activity of plasma CETP in a subgroup of type 2 DM women. CETP activity was assessed by measuring plasma-mediated cholesteryl ester transfer (CET) between pooled exogenous HDL and apoB-containing lipoproteins. In 220 patients with type 2 DM, CET was significantly higher in conjunction with higher plasma triglycerides and lower HDL-cholesterol compared to 100 matched healthy controls. Correlation analysis showed that CETP activity was significantly correlated with the HDL-C to apoA1 ratio (r = -0.205, P = 0.003) and to LDL-C to HDL-C ratio in diabetic women (P = 0.010). Furthermore, CETP activity was correlated marginally with total energy intake (P = 0.052) but to a statistically significant extent with the amount of fat consumed daily (P = 0.008). A significant negative correlation was found between plasma CETP activity and MUFA of plasma phospholipids or free PUFA (P = 0.032), especially with omega3-fatty acids (P = 0.001). CONCLUSION: Our findings indicate that CET is accelerated in patients with type 2 DM and that this may be regulated by dietary fatty acids in the diabetic state.

Adult↗

Association of plasma cholesteryl ester transfer protein activity and polymorphism with coronary artery disease extent in Tunisian type II diabetic patients.

INTRODUCTION: Cholesteryl ester transfer protein (CETP), a key protein in reverse cholesterol transport, has a controversial role in atherosclerosis. OBJECTIVES: : We investigated CETP activity and polymorphism in Tunisian type II diabetes and its relationship with coronary artery disease (CAD). DESIGN AND METHODS: 173 type II diabetic patients with or without CAD were compared to 67 controls. RESULTS: The HDL cholesterol concentration was low in a Tunisian population. The B1 allele of the CETP gene was associated with a low concentration of HDL cholesterol and was more frequent in Tunisians than in other populations. In type II diabetic patients, the B1 allele was associated with increased prevalence of CAD only in men (OR=0.357, CI=0.161-0.791, P=0.01). The CETP activity increased in type II diabetic patients compared to controls (P=0.05). Furthermore, the CETP activity was increased in patients with double or triple vessel disease compared to those with single vessel disease (P=0.025). CONCLUSIONS: Our data are in favour of an association between CETP and developing CAD, as well as the extent of CAD.

Adult↗

[Lipoprotein (a) and ischemic heart diseases in patients with type 2 diabetes].

Lipoprotein (a) is a new independent coronary risk factor, but the role of lipoprotein (a) in type 2 diabetes remains controversial. The objective of this study was to demonstrate the relationship between the level of lipoprotein (a) and the coronary artery diseases (CAD) in type 2 diabetes. Recruitment was carried out in 3 groups of patients: Group 1: 110 control subjects, Group 2: 115 diabetics (D), Group 3: 105 diabetics with CAD (DC). The mean age was, 51 + 7; 52 + 6; 56 + 6 respectively. Total cholesterol, triglyceride, HDL-C, LDL-C, Apo A-I, Apo B and lipoprotein (a) were measured for the patients. The Lp (a) level was significantly higher in the diabetic groups as compared to the controls (p < 0.05), but this level was different between D and DC: 312 + 232 vs 347.8 + (NS). However, when the Lp (a) level is higher than 300 mg/ml, there is a significant difference between DC and D (53% vs 42% p = 0.05). There is no correlation between Lp level and total cholesterol; however, there is a significant variation of Lp (a) level with LDL-C (r = -0.14, P = 0.01). There is a negative correlation between Lp (a) and HDL-C (r = -0.13, p = 0.03), Lp (a) and ApoA-I (r = - 0.11, p = 0.05); but there is a positive correlation between Lp (a) and ApoB (r = 0.14, p = 0.02). Lp(a) level higher than 300 mg/L constitutes a coronary risk factor in type 2 diabetes. This contributes, with the other lipid disorders, to the increase of the coronary risk factors in diabetes.

Apolipoprotein A-I↗

Analysis of the postprandial lipid metabolism: use of a 3-point test.

OBJECTIVES: The oral fat load tests used to study postprandial lipemia are complex and costly and time consuming. A simplified fat load test could be more convenient and more appropriate in routine clinical practice because of the number of lipid determinations required. RESEARCH DESIGN AND METHODS: We evaluated the capacity of a postprandial test model that reduced the number of blood samples taken in thirty three normal weight controls and 17 normotriglyceridemic obese patients (study 1), 10 normolipidemic type 2 diabetic patients and 7 healthy controls (study 2), and 10 hyperlipidemic type 2 diabetic patients studied before and after hypolipidemic therapy (study 3). Blood samples were taken before and up to 8 hours after giving the oral fat load containing retinol. Triglyceride (TG) and retinyl palmitate (RP) concentrations in the plasma, chylomicrons (CM) and non-chylomicron (nCM) fractions were measured. Postprandial lipid responses using conventional area under the curves (AUCc using 5 to 7 lipid determinations) were compared to a 3-point test that uses only three sample points to predict the area under the curve (AUCp: triglycerides at T0, triglycerides at average peak-time (T4), and triglycerides at T8). RESULTS: The AUCc and AUCp for triglycerides and retinyl palmitate were highly correlated in each of the groups and whatever the lipid subfraction (r=0.664 - 0.995, p<0.0001). When incremental AUC (iAUC) were used, the coefficients of correlation for triglycerides remained highly significant between iAUCc and iAUCp (r=0.718 - 0.979, p<0.01 - 0.0001). The same trend of differences was found between cases and controls when AUCp was used instead of AUCc. The means of differences between AUCc and AUCp for triglyceride values were small (0.34 - 0.74 mmol/L.h), and the confidence intervals were acceptable considering the range of the AUCs values (5.60 to 79.8 mmol/L.h for plasma triglycerides). CONCLUSIONS: We found that data obtained with a simplified model of AUC using only 3 points to analyse postprandial lipemia are well correlated with those obtained by conventional AUC, and that the AUCp allows to the same conclusions as AUCc when healthy subjects were compared to patients with altered postprandial metabolism. Thus AUCp may be a good evaluation of the AUCc, and the simplified 3-point protocol may well be used and suitable for studies on large groups of subjects who are eligible for an oral fat load test.

Area Under Curve↗

Postprandial reverse cholesterol transport in type 2 diabetic patients: effect of a lipid lowering treatment.

Deterioration of reverse cholesterol transport (RCT), an important anti-atherogenic process, may contribute to the largely unexplained severity of cardiovascular risk in type 2 diabetic patients. Among other relevant metabolic perturbations is the impairment in type 2 patients of the postprandial increase in RCT which, in normal subjects, is associated with the transfer to HDL of PL from lipolyzed chylomicrons. We have explored the possibility that improvement of postprandial lipolysis by bezafibrate might also restore the stimulated level of postprandial RCT. Twelve male patients (HbA1c 7.6 +/- 1.6% triglycerides (TG) 4.5 +/- 2.4 mmol/l) were treated for 4 weeks with 400 mg bezafibrate and compared with seven age-matched controls. Lipoproteins were analyzed over 8 h after a 1000 Kcal fat load (80% lipid), serum mediated cholesterol efflux was evaluated using 3H-cholesterol labelled Fu5AH cells. Fasting efflux was lower in patients (17.9 +/- 3.3 vs 19.9 +/- 3.0 a. units, P < 0.05) and decreased postprandially in most instead of increasing, so that area under the time-curve (AUC) was 23% lower than in controls (140 +/- 23 vs 170 +/- 25 units x h, P < 0.001) The patients' HDL failed to acquire PL and gained TG in proportion to lipemia (r = 0.660, P < 0.001). Bezafibrate restored fasting efflux (19.6 +/- 3.6 units, P < 0.005 vs pretreatment) but not postprandial increase of efflux or HDL-PL. AUC of efflux was however improved to 155 +/- 23 units h (P < 0.02). Postprandial efflux related mainly to HDL-PL in controls and patients before treatment. HDL-TG emerged as a significant negative correlate common to all groups (r = -0.674, P < 0.001 8 h after the meal). Impairment of reverse cholesterol transport in diabetic patients might therefore be due to combined postprandial deficit of PL transfer and excess accumulation of TG in HDL. The significant improvement due to fibrate treatment might thus be related to the reduction of HDL-TG contents associated with the improvement of postprandial hyperlipemia.

Bezafibrate↗

Postprandial concentrations and distribution of apo C-III in type 2 diabetic patients. Effect Of bezafibrate treatment.

Apo C-III plays a key role in the metabolism of triglyceride-rich lipoproteins. It has recently been implicated as a potential determinant of the triglyceride (TG) lowering effect of fibrates, which down-regulate its expression. This hypothesis has been explored in ten moderately hypertriglyceridemic (TG 4.50+/-2.40 mmol/l) male type 2 diabetic patients tested with a lipid load before and after 4 weeks of treatment with 400 mg bezafibrate daily. Treatment lowered apo C-III concentrations by 20%, mainly in VLDL. Postprandially, apo C-III was transferred to chylomicrons in proportion to their TG content exclusively from HDL. VLDL retained their apo C-III and the apo C-III:TG ratio decreased as TG contents increased. At the end of the absorptive period (8 h) HDL did not recover the totality of their apo C-III (net loss 19 and 28% respectively before and after treatment, P<0.0001 for time effect). Bezafibrate lowered apo E by 33% (P<0.03). The apo C-III:apo E ratio did not vary significantly under treatment but underwent a postprandial decrease: 13% before and 18% (P=0.01) after treatment. These results indicate that repression of apo C-III expression and lowering of the apo C-III:E ratio are not likely mechanisms for the lipid-lowering effects of fibrates in type 2 diabetic patients. The potent effects on postprandial lipemia are suggestive of an apo C-III-independent stimulation of lipolysis.

Aged↗

Changes in free insulin-like growth factor-1 and leptin concentrations during acute metabolic decompensation in insulin withdrawn patients with type 1 diabetes.

UNLABELLED: To determine the effect of acute insulin withdrawal and its subsequent replacement on components of the insulin-like growth factor (IGF)-1 binding protein system and on circulating leptin levels in patients with type 1 diabetes. Seventeen patients (age 31 yr +/-10) with type 1 diabetes treated with continuous subcutaneous insulin infusion (HbA1c 7.6% +/-1.0) were studied. The protocol consisted of two phases: acute insulin withdrawal of up to 8 h followed by a further 2-h period of insulin replacement. For the first phase the basal insulin infusion was stopped (at 0300 h), and for the second a single dose of either regular human or insulin lispro was given subcutaneously (0.2 U/kg). Plasma insulin, glucose, growth hormone, glucagon, IGF-1, free IGF-1, IGFBP-1, -2, -3 and leptin were measured. RESULTS: After interruption of the basal insulin infusion, plasma free insulin levels fell from 60+/-12.0 pmol/L to 10.8+/-4.2 pmol/L, and plasma glucose rose from 5.6+/-0.4 mmol/L to 14.8+/-1.2 mmol/L (P< 0.01). During insulin withdrawal, IGFBP-1 increased by more than 6-fold (from 32+/-8 to 205+/-17 ng/mL, P<0.001), IGFBP-3 increased significantly (from 2631+/-118 to 3053+/-101 ng/mL, P<0.001), and total IGF-1 levels declined modestly (from 226+/-33 to 182+/-26 ng/mL, P<0.001). In contrast, free IGF-1 concentrations (0.72+/-0.22 ng/mL at baseline) were markedly suppressed during insulin withdrawal to values below the detection limit of the assay (0.08 ng/mL) in 15 of the 17 patients (P<0.001). Circulating plasma leptin declined markedly in females from 20+/-3 ng/mL to 11+/-2 ng/mL (P<0.0001) and in males from 10+/-2 ng/mL to 7+/-2 ng/mL (P<0.02). Within 2 h of insulin replacement, the changes in circulating concentrations of IGFBP-1 and IGFBP-3 were partially reversed, and free IGF-1 levels rebounded to 0.54+/-0.22 ng/mL (P<0.1 vs. insulin withdrawal). Growth hormone, glucagon, and IGFBP-2 levels did not change significantly throughout the study. Despite the rapid restoration of plasma insulin and substrate levels, circulating leptin levels continued to fall in the 2-h period after insulin replacement in both females and males. The marked reduction in circulating free IGF-1 after insulin withdrawal and its increase after insulin administration suggest that acute changes in IGFBP concentrations induced by insulin are important regulators of IGF-1 bioavailability in patients with type 1 diabetes. In both males and females, the rapid induction of severe insulin deficiency is associated with a consistent fall in plasma leptin levels.

Adolescent↗

Different faces of non-autoimmune diabetes of infancy.

The aim of this report is to describe four cases of non-autoimmune diabetes that presented in infancy. Three had transient neonatal diabetes mellitus (TNDM) with diabetic ketoacidosis at onset, followed by complete remission after several months of insulin treatment. While the fourth case was initially diagnosed as TNDM, she had renal, hepatic and pancreatic dysplasia. These cases illustrate that diabetes in infants can be difficult to diagnose and that patients with TNDM can have a recurrence of diabetes several years later.

Blood Glucose↗

The metabolic syndrome and insulin-like growth factor I regulation in adolescent obesity.

Although low GH levels are commonly seen in obese adults and children, the effects of obesity on the insulin-like growth factor (IGF)/IGF-binding protein (IGFBP) system have not been established. As GH and IGF-I normally increase during adolescence, we investigated the effects of obesity on circulating total and free IGF-I levels and IGFBP-1, -2, and -3 in 19 obese adolescents [14 +/- 1 yr old; body mass index (BMI), 34 +/- 3], 20 lean adolescents (14 +/- 1 yr old; BMI, 23 +/- 0.5), and 10 lean adults (22 +/- 0.7 yr; BMI, 22 +/- 0.7). Fasting plasma insulin levels were significantly greater in obese adolescents than in either lean group, whereas circulating IGFBP-1 levels were suppressed in an inverse relationship to basal insulin (r = -0.49; P < 0.01). Low IGFBP-1 levels were associated with normal to increased free IGF-I levels in obese adolescents, even though total IGF-I values were lower than those in lean adolescents. Basal GH and IGFBP-3 levels were also lower in obese vs. lean adolescents. Basal IGFBP-1 levels were markedly reduced in obese adolescents (14 +/- 3 ng/mL) vs. those in adolescents and adults. No further suppression of IGFBP-1 levels was observed in the obese group during a two-step 8 and 40 mU/m2 insulin clamp. In contrast, IGFBP-1 levels were promptly lowered in lean adults. Basal IGFBP-2 levels were significantly lower in both groups of adolescents vs. lean adults (P < 0.05), and IGFBP-2 levels did not change during euglycemic hyperinsulinemia. These data suggest that the compensatory hyperinsulinemia that characterizes adolescent obesity chronically suppresses levels of IGFBP-1, and low IGFBP-1 concentrations may serve to increase the bioavailability of free IGF-I, which may, in turn, contribute to lower circulating GH, total IGF-I, and IGFBP-3 concentrations.

Adolescent↗

Comparison of human regular and lispro insulins after interruption of continuous subcutaneous insulin infusion and in the treatment of acutely decompensated IDDM.

OBJECTIVE: To compare the rapidity of metabolic decompensation after interruption of CSII between human regular and lispro insulin and to compare these two insulins in the correction of the hyperglycemia and ketosis of mildly decompensated IDDM. Lispro insulin may be especially useful for insulin pump therapy (continuous subcutaneous insulin infusion [CSII]). RESEARCH DESIGN AND METHODS: A total of 18 patients with well-controlled IDDM (HbA1c 7.7 +/- 1.1%, age 30 +/- 11 years) were studied. All were being treated with CSII (nine with human regular and nine with lispro insulin). The study consisted of two phases: 1) an insulin interruption phase, in which the basal insulin infusion was stopped (at 0300) and plasma insulin, glucose, and beta-O-hydroxybutyrate (beta-OHB) were measured every 15-60 min for 6 h after interruption of the insulin infusion and 2) an insulin replacement phase, which involved measuring plasma insulin, glucose, and beta-OHB for 2 h after a single injection of either human regular or lispro insulin to correct the hyperglycemia and ketosis that developed during the first phase of the study. RESULTS: After interruption of the basal insulin infusion during the insulin interruption phase, plasma insulin levels fell gradually in both groups to nadir values of 1.6 +/- 0.8 and 2.0 +/- 1.2 microU/ml in the regular insulin- and insulin lispro-treated groups, respectively. Plasma glucose concentrations rose to 13.8 +/- 1.9 and 16.0 +/- 1.7 mmol/l in the regular insulin- and insulin lispro-treated groups, respectively. No significant differences were seen between the therapy groups at any time in the insulin levels or in the concentrations of plasma glucose or beta-OHB. In the insulin replacement phase, insulin levels rose more rapidly in those treated with lispro insulin, reaching a greater peak value (e.g., at 60 min, plasma insulin 25 +/- 3.4 vs. 15.6 +/- 2.6 microU/ml, P < 0.05). In association with this, plasma glucose decreased to a lower nadir after lispro insulin (9.7 +/- 0.4 vs. 13.7 +/- 0.7 mmol/l, lispro- vs. regular-treated groups at 120 min after insulin administration, P < 0.01). beta-OHB levels decreased rapidly in both groups. CONCLUSIONS: In patients treated with CSII, interruption of the basal insulin infusion in the middle of the night does not result in more rapid metabolic decompensation in patients treated with lispro compared with those treated with regular human insulin. Lispro insulin is effective in treating mild ketosis and hyperglycemia, and its rapid action may be advantageous in the "sick day" management at home of patients with IDDM.

Acute Disease↗

Response of apolipoprotein AIV and lipoproteins to glycaemic control in young people with insulin-dependent diabetes mellitus.

Young people with insulin-dependent diabetes mellitus (IDDM) (n = 104, 7 to 19 years old) were classified into groups of good (I), fair (II), and poor (III) diabetic control and compared to 22 healthy controls of same origin and age range. Triglycerides (TG) were significantly elevated with respect to controls only in group III, and total cholesterol was increased by over 40% (p < 0.01) mainly due to low density lipoprotein-cholesterol (LDL-C). Apolipoprotein B (apo B) was over 40% higher in groups II and III. TG, LDL-C, and apo B concentrations all positively correlated with HbA1c levels. Neither HDL-C nor apolipoprotein AI (apo AI) were affected by glycaemic control, but phospholipids were increased in all three subgroups of IDDM subjects (p < 0.001). Over the course of 6 months' treatment, TG, apo B, and LDL-C varied in parallel with HbA1c, confirming a tight association with the quality of glycaemic control. Apolipoprotein AIV (apo AIV) was higher in all groups and closely related to glycaemic control (r = +0.43, p < 0.001), independent of TG or HDL. The specific and sensitive response of apo AIV to insulin deficiency suggests a direct effect at the level of intestinal synthesis.

Adolescent↗

Fatty acid composition of an oral load affects chylomicron size in human subjects.

HDL-phospholipids are determinants in reverse cholesterol transport. They are mostly derived from triacylglycerol (TG)-rich lipoproteins. Chylomicron size is important, therefore, because it is related to the ratio surface phospholipids: core TG and, thus, determines the availability of postprandial phospholipids for transfer to HDL. Eleven healthy young women each ingested four different fat loads supplemented with retinyl palmitate and containing 60 g sunflower oil (SO), oleic-sunflower oil (OSO), mixed oil (MO; (g/kg) linoleic acid 480, oleic acid 380, linolenic acid 13) or beef tallow (BT). At the peak of TG absorption for all loads (4 h) chylomicron diameters, determined by agarose-gel filtration, were larger after SO compared with OSO (P < 0.05) and BT (P = 0.06) and after MO compared with BT (P < 0.05). At 6 h chylomicron size was larger after the vegetable oils compared with BT (P < 0.05 in each case). After each fat load chylomicron size decreased at 6 and 8 h compared with that at 4 h (P < 0.05) except for OSO. Retinyl ester and TG concentrations were lower in chylomicrons after BT than after the other fats but not in the chylomicron-free serum (containing chylomicron remnants), suggesting absorption in the form of very small particles. Compared with the fasting value, the concentration of the Svedberg unit of flotation 20-400 fraction, which contains VLDL and chylomicron remnants, was lower 8 h after MO, the only fat to contain significant amounts of linolenic acid. We conclude that chylomicron size is dependent on the fatty acid composition of ingested fats and the time-course of digestion, being larger for polyunsaturated fatty acid-rich fats and in the early phase of digestion. On the basis of retinyl ester concentration there were no differences between fats in chylomicron-remnant clearance.

Adult↗

Post-prandial metabolism of triglyceride-rich lipoproteins in non-insulin-dependent diabetic patients before and after bezafibrate treatment.

Retarded post-prandial (pp) lipid clearance is potentially a major component of the increased cardiovascular risk incurred by hypertriglyceridaemic non-insulin-dependent diabetic mellitus (NIDDM) patients. The effect of bezafibrate (Bz, 400 mg per day for 5 weeks on chylomicron (CM) and remnant clearance after loads of 100 g of fat and vitamin A was therefore explored in 10 male patients (glycaemia 11.9 +/- 3.3 TG 4.5 +/- 2.4 mmol L(-1)). In all subjects CM-TG and retinyl palmitate (RP) were reduced by 50%, but 8-h non-CM (remnant) RP decreased only in initially mildly hypertriglyceridaemic subjects (-35%, P < 0.05), while in three patients with very elevated initial TG (epsilon3/3, epsilon3/2 and epsilon2/2 genotypes) 8-h remnant RP increased by 100%. The decrease in pp CM-TG correlated with that of fasting Sf 20-400 (r = 0.686, P = 0.026), suggesting that improved lipolysis was a major determinant of hypolipidaemic effect. Apo CIII synthesis is known to be depressed by Bz: concentrations were lower under Bz (P < 0.05). A positive correlation (r = 0.880, P < 0.001) with fasting TG before treatment and its disappearance after treatment suggested an involvement of high concentrations with hypertriglyceridaemia. Post-prandial non-esterified fatty acids were decreased by 35 in correlation with a significant (-19%, P < 0.05) improvement in fasting glycaemia (r = 0.801, P < 0.005). These results suggest that Bz acts both on lipolysis and on removal of CM remnants, but that removal can become saturated when lipolysis is massively improved.

Aged↗

Postprandial cholesteryl ester transfer and high density lipoprotein composition in normotriglyceridemic non-insulin-dependent diabetic patients.

Altered postprandial HDL metabolism is a possible cause of defective reverse cholesterol transport and increased cardiovascular risk in diabetic patients with a normal fasting lipoprotein profile. Ten normolipidemic, normoponderal non-insulin dependent diabetes mellitus (NIDDM) patients and seven controls received a 980 kcal meal containing 78 g lipids with 100 000 IU vitamin A. Chylomicron clearance was not different, but area under the curve (AUC) for retinyl palmitate in chylimicron-free serum (remnant clearance) was greater in patients (P < 0.02). LCAT activity increased postprandially to the same extent in both groups. In control subjects, cholesteryl ester transfer protein (CETP) activity (CETA) also increased by 20% (P < 0.01 at 6 h) in parallel with a 20% decrease in HDL2-CE (r = -0.55, P = 0.009). In NIDDM patients, on the contrary, CETA which was 35% higher in the fasting state (P < 0.005), decreased postprandially yet HDL2-CE remained unchanged. Postprandial HDL3 of controls were enriched with phospholipid (PL) (30.3 +/- 2.6% at 6 h) with respect to fasting (25.6 +/- 2.5%, P < 0.01) and to NIDDM-HDL3 (25.8 +/- 1.7% at 6 h, P < 0.01). These results show that variation in plasma CETA has little impact on HDL2-CE in NIDDH subjects. They support the concept that, in controls, the combined enrichment of HDL3 with PL, increased LCAT and CETA create the conditions for stimulation of cell cholesterol efflux and CE transfer to apo B lipoproteins. In NIDDM, because of the lesser HDL3 enrichment with PL and of the inverse trend of CETA, these conditions fail to occur, depriving the patients of a potentially efficient mechanism of unesterified cholesterol (UC) clearance, despite their strictly normal preprandial profile.

Adult↗

Modulation of low density lipoprotein subclasses by alimentary lipemia in control and normotriglyceridemic non-insulin-dependent diabetic subjects.

Conventional factors do not fully account for the increased cardiovascular risk in NIDDM but, because of the underlying disorders in lipid metabolism, the postprandial state can be expected to induce temporary changes of a potentially atherogenic nature. The response to a 1000-kcal meal (70% lipid; 100,000 IU vitamin A) over 8 h was compared in 10 normoponderal, normotriglyceridemic NIDDM male patients and 12 controls. In patients lipolysis was normal, but remnant clearance was delayed (P < 0.02) and apo E concentrations were lower. LDL-C decreased postprandially, more in patients (P < 0.05), while LDL-PL accumulated in controls but not in patients. As a result UC:PL decreased in controls (P < 0.05) not in patients. The distribution of LDL subclasses shifted towards large particles in controls (LDL-I, 42%; LDL-II, 50%; LDL-III, 7.6% at 6 h) and smaller ones in patients (LDL-I, 29%; LDL-II, 56%; LDL-III, 16% at 6 h). In controls only, the percentage of LDL-III correlated negatively with apo E (r = -0.97, P < 0.001) suggesting that apo E promotes removal of light particles before they reach LDL-III and may be a limiting factor in patients. We conclude that the postprandial state is potentially more atherogenic in normoponderal, normotriglyceridemic patients than in controls: remnant clearance is delayed, the UC:PL ratio of LDL fails to decrease postprandially as it does in controls, limiting the acceptor capacity of LDL for UC, and the distribution of LDL subclasses is shifted towards a more atherogenic profile.

Analysis of Variance↗