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The aim of this study was to investigate whether the EcoRI polymorphism of the apolipoprotein B (apoB) gene influences the relationships between features of the insulin resistance syndrome and the dense LDL phenotype and apoB concentrations. A sample of 65 men was divided into two groups on the basis of the EcoRI genotype. Forty-four subjects were (+/+) homozygotes for the presence of the EcoRI restriction site that is associated with a glutamic acid at codon 4154. Twenty-one men were (+/−) heterozygotes for the absence of the restriction site resulting from a glutamic acid to a lysine substitution at codon 4154. In the (+/−) group, fasting plasma FFA levels were positively correlated with plasma apoB, LDL-apoB, and the LDL particle score that was calculated from the migration distances of LDL subspecies and their relative band intensities, reflecting the proportion of small dense LDL particles. However, these associations were not found among (+/+) subjects. The two genotypic groups were further divided into two subgroups on the basis of fasting FFA concentrations, and the LDL particle score and the LDL-apoB levels were compared. High FFA levels were associated with a higher proportion of small dense LDL particles, as reflected by a higher mean LDL particle score, irrespective of the genotype. However, the apoB-EcoRI polymorphism appeared to influence the association between high FFA levels and LDL-apoB concentrations because (+/−) heterozygotes with high FFA levels had higher LDL-apoB concentrations than (+/−) heterozygotes with low FFA levels. In addition, the integrated area under the curve of plasma insulin concentrations, measured in response to a 75-g oral glucose challenge, and the amount of visceral adipose tissue, measured by computed tomography, were positively associated with the LDL particle score only in (+/−) heterozygotes. When subjects were divided on the basis of insulin area (low vs. high) or visceral adipose tissue (low vs. high), (+/−) heterozyg

The aim of this study was to investigate in 261 subjects from 58 families the association between DNA variation at the genes coding for the Na,K-ATPase peptides and resting metabolic rate (RMR), respiratory quotient (RQ), and percent body fat (%FAT). Five restriction fragment length polymorphisms (RFLP) at three Na,K-ATPase genes were determined: one at the alpha 1 locus (BglII), and two at the beta locus (beta MspI and beta PvuII). Haplotypes were determined from the two variable sites of the alpha 2 gene (alpha 2 haplotypes) and the beta gene (beta haplotypes). There was a strong trend for %FAT to be related to the RFLP generated by BglII at the alpha 2 exons 21-22 in males (P = 0.06) and females (P = 0.05). RQ was (a) associated with the BglII RFLP at the alpha 2 exon 1 (P = 0.02) and with the alpha 2 8.0 kb/4.3 kb haplotype (P = 0.04) and (b) linked with the beta gene MspI marker (P = 0.04) and with the beta 5.3 kb/5.1 kb haplotype (P = 0.008) based on sib-pair analysis. The present study suggests that the genes encoding Na,K-ATPase may be associated or linked with RQ and perhaps with %FAT but not with RMR

Several investigations have suggested that body fat distribution is influenced by nonpathologic variations in the responsiveness to Cortisol. Genetic variations in the glucocorticoid receptor (GRL) could therefore potentially have an impact on the level of abdominal fat. A restriction fragment length polymorphism (RFLP) has previously been detected with the BelI restriction enzyme in the GRL gene identifying two alleles with fragment lengths of 4.5 and 2.3 kb. This study investigates whether abdominal fat areas measured by computerized tomography (CT) are associated with this polymorphism in 152 middle-aged men and women. The less frequent 4.5-kb allele was found to be associated with a higher abdominal visceral fat (A VF) area independently of total body fat mass (4.5/4.5 vs. 2.3/2.3 kb genotype; men: 190.7 ± 30.1 vs. 150.7 ± 33.3 cm2, p=0.04; women: 132.7 ± 37.3 vs. 101.3 ± 34.5 cm2, p=0.06). However, the association with AVF was seen only in subjects of the lower tertile of the percent body fat level. In these subjects, the polymorphism was found to account for 41% (p=0.003) and 35% (p=0.007), in men and women, respectively, of the total variance in AVF area. The consistent association between the GRL polymorphism detected with BelI and AVF area suggests that this gene or a locus in linkage disequilibrium with the BelI restriction site may contribute to the accumulation of AVF.

A rare polymorphism in the human sex hormone-binding globulin (SHBG) gene was detected using a human SHBG cDNA probe. It is the first DNA sequence variation reported in this gene.

The aim of this study was to investigate whether the EcoRI restriction fragment length polymorphism (RFLP) of the apolipoprotein (apo) B-100 gene influences the associations described among obesity, regional adipose tissue distribution, and plasma lipoprotein levels. For this purpose, blood samples were collected from 56 healthy men for whom we had extensive measurements of regional adipose tissue distribution (both anthropometric and computed tomography-derived measurements) and data on the plasma lipoprotein-lipid profile. DNA was extracted from white blood cells, and RFLP analysis was performed. Subjects were classified into two groups on the basis of their apoB-100 EcoRI genotype: subjects homozygous for the major 11-kb allele, the 11/11 group (n = 40), and subjects carrying the minor 13-kb allele, the 13/11 group (n = 16). Subjects carrying the 13-kb allele had lower percent body fat and abdominal adipose tissue accumulation than subjects homozygous for the 11-kb allele (P < .05). Although leaner, the 13/11 group did not show a more favorable plasma lipoprotein-lipid profile than the group homozygous for the 11-kb allele. In fact, after statistical control for the difference in percent body fat between the two genotype groups, the 13/11 group showed significantly higher plasma cholesterol levels (P < .05) and nearly significantly higher apoB levels than the 11/11 group (P = .06). The association patterns between indices of regional adiposity and plasma cholesterol and apoB levels were also different between the two EcoRI genotype groups. Only in the 13/11 group was the abdominal visceral adipose tissue area significantly associated with these plasma variables.

Abdominal visceral fat is associated with a BclI restriction fragment length polymorphism at the glucocorticoid receptor gene locus. Obes Res. 1997;5: 186-192. Several investigations have suggested that body fat distribution is influenced by nonpathologic variations in the responsiveness to cortisol. Genetic variations in the glucocorticoid receptor (GRL) could therefore potentially have an impact on the level of abdominal fat. A restriction fragment length polymorphism (RFLP) has previously been detected with the BcZI restriction enzyme in the GRL gene identifying two alleles with fragment lengths of 4.5 and 2.3 kb. This study investigates whether abdominal fat areas measured by computerized tomography (CT) are associated with this polymorphism in 152 middle-aged men and women. The less frequent 4.5-kb allele was found to be associated with a higher abdominal visceral fat (AVF) area independently of total body fat mass (4.514.5 vs. 2.312.3 kb genotype; men: Submitted for publication March I I, 1996. Accepted for publication October 18, 1996. From the 'Physical Activity Sciences Laboratory, Laval University, PEPS, Ste-Foy, Quebec, G1K 7P4, Canada; 'Present address: Research Department of Human Nutrition, The Royal Veterinary and Agricultural University, Rolighedsvej 30, 1958 Frederiksberg, Denmark; 'Lipid Research Center, and 4Diabetes Research Unit, CHUL Research Center, Ste-Foy, Quebec, GIV 4G2, Canada. Reprint requests to Claude Bouchard, Ph.D., Physical Activity Sciences Laboratory, Laval University, Ste-Foy, Qubbec, GIK 7P4, Canada Copyright 0 1997 NAASO. 190.7 f 30.1 vs. 150.7 2 33.3 cm', p=0.04; women: 132.7 f 37.3 vs. 101.3 34.5 cm', p=0.06). However, the association with AVF was seen only in subjects of the lower tertile of the percent body fat level. In these subjects, the polymorphism was found to account for 41% @=0.003) and 35% @=0.007), in men and women, respectively, of the total variance in AVF area. The consistent association between the GRL polymor

The aim of this study was to investigate whether the EcoRI polymorphism of the apolipoprotein B (apoB) gene influences the relationships between features of the insulin resistance syndrome and the dense LDL phenotype and apoB concentrations. A sample of 65 men was divided into two groups on the basis of the EcoRI genotype. Forty-four subjects were (+/+) homozygotes for the presence of the EcoRI restriction site that is associated with a glutamic acid at codon 4154. Twenty-one men were (+/−) heterozygotes for the absence of the restriction site resulting from a glutamic acid to a lysine substitution at codon 4154. In the (+/−) group, fasting plasma FFA levels were positively correlated with plasma apoB, LDL-apoB, and the LDL particle score that was calculated from the migration distances of LDL subspecies and their relative band intensities, reflecting the proportion of small dense LDL particles. However, these associations were not found among (+/+) subjects. The two genotypic groups were further divided into two subgroups on the basis of fasting FFA concentrations, and the LDL particle score and the LDL-apoB levels were compared. High FFA levels were associated with a higher proportion of small dense LDL particles, as reflected by a higher mean LDL particle score, irrespective of the genotype. However, the apoB-EcoRI polymorphism appeared to influence the association between high FFA levels and LDL-apoB concentrations because (+/−) heterozygotes with high FFA levels had higher LDL-apoB concentrations than (+/−) heterozygotes with low FFA levels. In addition, the integrated area under the curve of plasma insulin concentrations, measured in response to a 75-g oral glucose challenge, and the amount of visceral adipose tissue, measured by computed tomography, were positively associated with the LDL particle score only in (+/−) heterozygotes. When subjects were divided on the basis of insulin area (low vs. high) or visceral adipose tissue (low vs. high), (+/−) heterozyg

The aim of this study was to investigate the association between a restriction fragment length polymorphism (RFLP) at the 3β‐hydroxysteroid dehydrogenase locus and adipose tissue distribution pheno‐types. A total of 132 unrelated individuals from the Quebec Family Study were followed prospectively for an average period of 11.3 years. The Bgl II polymorphism in exon 4 of the 3β‐HSD gene was detected by PCR. Body mass, body fat, and regional fat distribution indicators were adjusted for age and age2 within each gender. Associations were assessed in unrelated adults with ANOVA across three genotypes. No association was found for the indicators of body mass, body fat, and regional distribution of adipose tissue measured in 1992. In women, the changes (difference between data collected in 1992 and at entry) in the sum of six skinfolds (p=0.04), abdominal skinfold (p=0.01), and abdominal skinfold adjusted (p=0.03) for the sum of six skinfolds at entry were related to the Bgl II polymorphism at the 3β‐HSD locus. These relations were not found in men, but they gained less body mass and body fat over the 11.3‐year period. This suggests that sequence variation at the 3β‐HSD locus or in neighboring genes on chromosome 1 may contribute to individual differences in body fat content and adipose tissue distribution in adult women, particularly in abdominal adipose tissue deposition as they grow older and gain body fat.

The aim of this study was to investigate in 261 subjects from 58 families the association between DNA variation at the genes coding for the Na,K-ATPase peptides and resting metabolic rate (RMR), respiratory quotient (RQ), and percent body fat (%FAT). Five restriction fragment length polymorphisms (RFLP) at three Na,K-ATPase genes were determined: one at the alpha 1 locus (BglII), and two at the beta locus (beta MspI and beta PvuII). Haplotypes were determined from the two variable sites of the alpha 2 gene (alpha 2 haplotypes) and the beta gene (beta haplotypes). There was a strong trend for %FAT to be related to the RFLP generated by BglII at the alpha 2 exons 21-22 in males (P = 0.06) and females (P = 0.05). RQ was (a) associated with the BglII RFLP at the alpha 2 exon 1 (P = 0.02) and with the alpha 2 8.0 kb/4.3 kb haplotype (P = 0.04) and (b) linked with the beta gene MspI marker (P = 0.04) and with the beta 5.3 kb/5.1 kb haplotype (P = 0.008) based on sib-pair analysis. The present study suggests that the genes encoding Na,K-ATPase may be associated or linked with RQ and perhaps with %FAT but not with RMR

A rare polymorphism in the human sex hormone-binding globulin (SHBG) gene was detected using a human SHBG cDNA probe. It is the first DNA sequence variation reported in this gene.

The aim of this study was to investigate whether the EcoRI restriction fragment length polymorphism (RFLP) of the apolipoprotein (apo) B-100 gene influences the associations described among obesity, regional adipose tissue distribution, and plasma lipoprotein levels. For this purpose, blood samples were collected from 56 healthy men for whom we had extensive measurements of regional adipose tissue distribution (both anthropometric and computed tomography-derived measurements) and data on the plasma lipoprotein-lipid profile. DNA was extracted from white blood cells, and RFLP analysis was performed. Subjects were classified into two groups on the basis of their apoB-100 EcoRI genotype: subjects homozygous for the major 11-kb allele, the 11/11 group (n = 40), and subjects carrying the minor 13-kb allele, the 13/11 group (n = 16). Subjects carrying the 13-kb allele had lower percent body fat and abdominal adipose tissue accumulation than subjects homozygous for the 11-kb allele (P < .05). Although leaner, the 13/11 group did not show a more favorable plasma lipoprotein-lipid profile than the group homozygous for the 11-kb allele. In fact, after statistical control for the difference in percent body fat between the two genotype groups, the 13/11 group showed significantly higher plasma cholesterol levels (P < .05) and nearly significantly higher apoB levels than the 11/11 group (P = .06). The association patterns between indices of regional adiposity and plasma cholesterol and apoB levels were also different between the two EcoRI genotype groups. Only in the 13/11 group was the abdominal visceral adipose tissue area significantly associated with these plasma variables.