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Daniel Gaudet

Publications and source records attributed to Daniel Gaudet.

41 records · Page 3Linked to original sources

Determinants of HDL particle size in patients with the null (P207L) or defective (D9N) mutation in the lipoprotein lipase gene: the Québec LipD Study.

The aim of the present study was to examine the impact of the defective D9N and the null P207L mutations in the lipoprotein lipase (LPL) gene on high density lipoprotein (HDL) particle size in relation to specific environmental factors such as obesity, gender and menopausal status. Analyses were carried out in 118 heterozygous carriers of the D9N mutation and 88 heterozygous for the P207L mutation. HDL particle size was measured on whole plasma by non-denaturing 4-30% polyacrylamide gradient gel electrophoresis. Although carriers of the P207L mutation presented a more deteriorated lipoprotein-lipid profile compared with carriers of the D9N mutation, there was no difference in HDL particle size between the P207L and D9N carriers (81.9+/-4.5 vs. 82.7+/-4.4 A, respectively, P=0.2). Multivariate analyses indicated that waist circumference (P=0.001) and HDL cholesterol levels (P<0.001) were independent predictors of HDL particle size among carriers of the defective D9N mutation. On the other hand, gender (P=0.03), plasma cholesterol (P=0.01) and TG (P=0.04) levels were significant predictors of HDL particle size among carriers of the null P207L mutation in multivariate analyses. These results suggest that the nature of the mutation in the LPL gene modifies the relationship of HDL particle size to other metabolic variables and secondary factors such as abdominal obesity and gender.

Adult↗

A genealogical study of essential hypertension with and without obesity in French Canadians.

OBJECTIVES: To investigate genetic homogeneity in a set of hypertensive families and in subsets chosen for high and low prevalence of obesity; and to compare fasting insulin and lipids, ion transport, and water homeostasis in the obese and lean families. RESEARCH METHODS AND PROCEDURES: The study was carried out in a relative population isolate of the Saguenay/Lac St. Jean region in Canada. Genetic homogeneity was evaluated with the mean coeffigcients of kinship (phi) and inbreeding (F) computed with ascending genealogies. Serum insulin and lipids were measured after overnight fasting. Total body water was estimated with bioelectrical impedance. Sodium-lithium countertransport and sodium-potassium co-transport were determined in freshly isolated erythrocytes. RESULTS: F and phi were increased in hypertensive families compared with families selected at random. F and phi were further increased within the subsets of obese and lean families. In addition, fasting insulin, total body water, sodium-lithium countertransport, and sodium-potassium co-transport were higher in the obese than in the lean families. The two subsets of families did not differ by fasting lipids. DISCUSSION: In the Saguenay/Lac St. Jean population, the degree of genetic homogeneity was increased in families selected for hypertension, and it was further increased in subsets of hypertensive families with high and low prevalence of obesity. This suggests that hypertension in lean and obese individuals may represent, at least in part, separate genetic entities. Some of the extra genes shared in common within the subsets may contribute to their differences in body weight, insulin sensitivity, ion transport, and water homeostasis.

Antiporters↗

Effect of apolipoprotein E, peroxisome proliferator-activated receptor alpha and lipoprotein lipase gene mutations on the ability of fenofibrate to improve lipid profiles and reach clinical guideline targets among hypertriglyceridemic patients.

Fenofibrate is a peroxisome proliferator-activated receptor alpha (PPARalpha) agonist which regulates the transcription of genes encoding proteins involved in triglyceride (TG)-rich lipoproteins and lipoprotein lipase (LPL) metabolism. The aim of the present study was to investigate the relation between TG-related parameters considered in different clinical guidelines used in industrialized countries for the management of lipid disorders (namely fasting plasma TG, high density-lipoprotein cholesterol (HDL-C), non-HDL-C concentrations and total-C/HDL-C ratio) and the presence of LPL-null (P207L), LPL-defective (D9N), PPARalpha -L162V, apolipoprotein (apo) E and PPARgamma-P12A gene mutations, in a sample of 292 hypertriglyceridemic subjects treated with fenofibrate for 3 months. Although fenofibrate induced a decrease in plasma TG level and an increase in HDL-C level in all studied genotypes, mutation-specific differences were observed. After adjustment for age, gender, body mass index and the presence of apo E2 genotype, the LPL-P207L mutation was associated with residual post-treatment hypertriglyceridemia [TG > 2.0 mmol/l, odds ratio (OR) = 3.07, P = 0.005] and total-C/HDL-C ratio > 5 (OR = 2.68; P = 0.03). This effect was significantly related to higher plasma TG concentrations at baseline among carriers of a LPL-null mutation. Compared to apo E3 and E4 variants, the apo E2 allele was associated with a better response to fenofibrate on all lipid parameter, especially among PPARalpha -L162V carriers, whereas the simultaneous presence of apo E2 and PPARalpha -L162V tended to improve fenofibrate response among LPL-P207L heterozygotes. Finally, the LPL-D9N and PPARgamma -P12A mutations did not affect fenofibrate lipid-lowering action. This study suggests that frequent genetic variations in genes encoding proteins involved in TG-rich lipoprotein metabolism could modulate the response to fenofibrate treatment, as defined in clinical guidelines.

Adult↗

5' flanking variants of resistin are associated with obesity.

Diabetes and obesity have long been known to be related. The recently characterized adipocyte hormone resistin (also called FIZZ3/ADSF) has been implicated as a molecular link between impaired glucose tolerance (IGT) and obesity in mice. A search for sequence variants at the human resistin locus identified nine single-nucleotide polymorphisms (SNPs) but no coding variants. An investigation into the association of these SNPs with diabetes and obesity revealed two 5' flanking variants (g.-537 and g.-420), in strong linkage disequilibrium, that are associated with BMI. In nondiabetic individuals from the Quebec City area and the Saguenay-Lac-St-Jean region of Quebec, the g.-537 mutation (allelic frequency = 0.04) was significantly associated with an increase in BMI (P = 0.03 and P = 0.01, respectively). When the data from these two populations were combined and adjusted for age and sex, both the g.-537 (odds ratio [OR] 2.72, 95% CI 1.28-5.81) and the g.-420 variants (1.58, 1.06-2.35) were associated with an increased risk for a BMI > or =30 kg/m(2). In contrast, in case/control and family-based study populations from Scandinavia, we saw no effect on BMI with either of these promoter variants. No association was seen with diabetes in any of the population samples.

5' Untranslated Regions↗