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M Chagnon

Publications and source records attributed to M Chagnon.

At least 37 records · Page 2Linked to original sources
PubMed2000

A polymorphism of the 5'-flanking region of the glucocorticoid receptor gene locus is associated with basal cortisol secretion in men.

There is growing evidence that cortisol secretion and/or metabolism is associated with cardiovascular risk factors. Previous studies have shown that cardiovascular risk factors are associated with stimulated cortisol secretion and not with basal cortisol secretion. With the restriction enzyme Tth111I, a variant of the 5'-flanking region of the glucocorticoid receptor gene locus (GRL) was identified. The genotypes were compared for measurements of cortisol secretion and cardiovascular risk factors in a cohort (N = 284) of randomly selected middle-aged men. The frequency of the 3.4/3.4-, 3.4/3.8-, and 3.8/3.8-kilobase (kb) genotypes was 49.6%, 41.4%, and 9.0% respectively. The 3.8-kb homozygotes showed higher total and evening cortisol levels with a trend for elevated levels over the day. Neither stimulated or suppressed cortisol secretion nor anthropometric, endocrine, metabolic, and hemodynamic cardiovascular risk factors were significantly different among the genotypes. Since the polymorphism studied herein is localized at the 5'-flanking region of the GRL, the results suggest that elevated basal cortisol secretion is associated with a polymorphism of the promoter region.

Alleles↗
PubMed2000

A polymorphism in the alpha2a-adrenoceptor gene and endurance athlete status.

PURPOSE: In a case control study, we examined the allelic frequencies and genotype distributions of two restricted fragment length polymorphisms (RFLP) in the alpha-2A-adrenoceptor gene (ADRA2A) and beta-2-adrenoceptor gene (ADRB2) among elite endurance athletes (EEA) and sedentary controls (SC). METHODS: The EEA group included 148 Caucasian male subjects recruited on the basis that they had a VO2max > 74 mL O2 x kg(-1) x min(-1). The SC group comprised 149 unrelated sedentary male subjects, all Caucasians, from the Quebec Family Study. After digestion with the restriction enzymes Dra I (ADRA2A) and Ban I (ADRB2), Southern blotting and hybridization techniques were used to detect the mutations in the two ADR genes, which are encoded on chromosomes 10 (q24-26) and 5 (q31-32), respectively. RESULTS: For the Dra I ADRA2A RFLP, we observed a significant difference in genotype distributions between the two groups (P = 0.037). A higher frequency of the 6.7-kb allele was observed in the EEA group compared with the SC group (P = 0.013). No statistically significant difference was found between groups for the Ban I ADRB2 polymorphic site. Genotype frequencies for both genes in both groups were in Hardy-Weinberg equilibrium. CONCLUSIONS: In summary, we found evidence that ADRA2A gene variability detected with Dra I is weakly associated with elite endurance athlete status, and we conclude that genetic variation in the ADRA2A gene or a locus in close proximity may play a role in being able to sustain the endurance training regimen necessary to attain a high level of maximal aerobic power.

Alleles↗
PubMed2000

Associations between the leptin receptor gene and adiposity in middle-aged Caucasian males from the HERITAGE family study.

Linkage and association studies between three exonic polymorphisms in the leptin receptor gene and body composition variables in the HERITAGE Family Study were undertaken. Polymorphisms K109R, Q223R, and K656N have been analyzed with body mass index (BMI), sum of height skinfolds (SF8), fat mass (FM), percent body fat (%FAT), fat free mass, and plasma leptin level. Single-point linkage analysis and covariance analysis across genotypes were performed, by race, on phenotypes adjusted for age and sex. Blacks (88 parents; 231 adult offspring) from 115 nuclear families (72-119 sibpairs) and Caucasians (192 parents; 330 adult offspring) from 99 nuclear families (319-364 sibpairs) were used for these analyses. In Caucasians, BMI and FM showed suggestive linkages with K109R (P = 0.02 and P = 0.05, respectively) and associations with Q223R (P = 0.005 and P = 0.03, respectively). In blacks, no statistically significant linkage or association was observed. In Caucasians, associations with Q223R were observed in parents, but not in offspring, for BMI, FM, and %FAT (0.04< or =P< or =0.0001). Males, not females, showed differences across genotypes for the same phenotypes plus SF8 and leptin (0.03< or = P< or =0.0002). Carriers of the R223 allele showed higher values than noncarriers for BMI (+4 U, P = 0.0001), SF8 (+30 mm, P = 0.01), FM (+7 kg, P = 0.0004), %FAT (+5%, P = 0.0002), and leptin (+4 ng/mL, P = 0.0006). These results indicate a significant effect of leptin receptor on adiposity in middle-aged Caucasian males.

Adipose Tissue↗
PubMed2000

Hypertension in obesity and the leptin receptor gene locus.

Recent animal studies indicate that leptin is involved in the regulation of blood pressure through the leptin receptor. Therefore, 51-yr-old men (N = 284) were selected; and anthropometric, endocrine, metabolic, and hemodynamic variables were examined in relation to polymorphisms of the leptin receptor gene (LEPR), by restriction fragment length polymorphism technique. Three polymorphisms were examined: Lys109Arg in exon 4, Gln223Arg in exon 6, and Lys656Asn in exon 14. In comparison with Lys109 homozygotes, Arg109 homozygotes (9%) showed lower body mass index (BMI) and abdominal sagittal diameter, as well as lower systolic (10.0 mm Hg) and diastolic (7.8 mm Hg) blood pressure. Additionally, Arg223 homozygotes (26.8%) showed lower blood pressure (7.6/5.7 mm Hg) than Gln223 homozygotes. These lower blood pressure levels were independent of other variables. No differences were found with the Lys656Asn polymorphism. Measurements of body fat mass correlated with leptin concentration in Lys109 homozygotes and in Lys109 heterozygotes but not in Arg109 homozygotes. Blood pressure correlated with leptin only in men carrying the wild-type allele Lys109. With both elevated BMI and leptin, Lys109 homozygotes had higher blood pressure than the Arg109 homozygous men (12.4/6.9 mm Hg). Men with blood pressure > or = 140/90 mm Hg had, in comparison with normotensive men, increased BMI and leptin levels, and Lys109 homozygotes were significantly more prevalent. These results suggest that leptin is associated with blood pressure regulation in men through the leptin receptor. When BMI and leptin are elevated, increased blood pressure is found only with the most prevalent LEPR genotype at codons 109 and 223, whereas variants of this receptor seem to protect from hypertension. This might explain why not all obese men are hypertensive.

Adult↗
PubMed1999

Linkages and associations between the leptin receptor (LEPR) gene and human body composition in the Québec Family Study.

OBJECTIVE: To investigate linkage and association between the leptin receptor (LEPR) gene and body composition variables in the Quebec Family Study (QFS). DESIGN: Single-point linkage analysis using families, and covariance and chi-square analyses using normal weight and obese unrelated subjects from QFS. SUBJECTS: 169 nuclear families were used for linkage study. 308 unrelated subjects (146 males; 162 females) from these families were used for chi-square testing of genotype and allele distributions between subjects with body mass index (BMI) < 27 kg/m2 (n = 167) and those with BMI > or = 27 kg/m2 (n = 141), and for a series of covariance analyses using age, plus height for fat mass (FM) and fat free mass (FFM), as covariates. A corrected P value (P*) for multiple tests has been calculated according to P* = 1-(1-P)(number of phenotypes). MEASUREMENTS: Variables were BMI (in kg/m2), sum of six skinfolds (SF6 in mm), FM (in kg), percent body fat (%FAT) and FFM (in kg). Polymerase chain react restricted fragment length polymorphisms PCR-RFLP) was used to identified a K109R substitution in exon 4, a Q223R in exon 6, a K656N in exon 14 and an automatic DNA sequencer for a CA microsatellite repeat in intron 3, and heteroduplex pattern on non-denaturing gel for a CTTT repeat in intron 16. RESULTS: Good evidence of linkage was observed for Q223R with FM (P = 0.005; P* = 0.02), and for the CTTT repeat with FFM (P = 0.007; P* = 0.03). Weaker linkages (0.02 < or = P < or = 0.05) were also observed between Q223R and BMI, SF6 and FFM, between the CA repeat and BMI, SF6 and FM, and between the CTTT repeat and FM. Moreover, FFM values were found to be different among genotypes for the CTTT repeat polymorphism with heavier females, carriers of the 123* allele at the CTTT repeat, showing 4 kg less of FFM (43.6 +/- 1.0, n = 21 vs 47.7 +/- 0.8, n = 30; P = 0.005; P* = 0.02) than non-carriers. Also, at the Q223R polymorphism, in lower BMI males, carriers of the Q223 allele were 4 kg lighter in FFM (53.4 +/- 0.6, n = 47 vs 56.6 +/- 0.9, n = 18; P = 0.005; P* = 0.02) than non-carriers. No significant differences were observed between lower and higher BMI subjects in genotype and allele frequency distributions for any of the polymorphisms. CONCLUSIONS: These results indicate that the LEPR gene is involved in the regulation of the body composition in human particularly of FFM in the QFS.

Adipose Tissue↗
PubMed1999

Linkage of the Na,K-ATPase alpha 2 and beta 1 genes with resting and exercise heart rate and blood pressure: cross-sectional and longitudinal observations from the Quebec Family Study.

OBJECTIVE: To investigate whether genetic variations in the genes encoding the alpha and beta subunits of the Na,K-ATPase are linked with hemodynamic phenotypes. DESIGN AND PARTICIPANTS: Cross-sectional data based on 533 subjects (no antihypertensive medication) were obtained from 150 families of phase 2 of the Quebec Family Study, together with longitudinal data from 338 subjects (105 families) who had been measured 12 years earlier in phase 1 of the Quebec Family Study. MAIN OUTCOME MEASURES: Restriction fragment length polymorphisms were examined at the alpha 2 (exon 1 and exon 21-22 with BglII) and beta 1 (Msp I and Pvu II) loci of Na,K-ATPase. Hemodynamic phenotypes measured included systolic and diastolic blood pressure, heart rate and rate-pressure product at rest and during low-intensity exercise. RESULTS: Sib-pair analysis revealed relatively strong linkages (P = 0.0003-0.002) between the resting heart rate and rate-pressure product and the alpha 2 exon 21-22 marker and alpha 2 haplotype. Moreover, the alpha 2 exon 21-22 marker showed suggestive linkages (P = 0.01 to 0.043) with resting systolic blood pressure and exercise diastolic blood pressure, heart rate and rate-pressure product, and the alpha 2 haplotype with exercise diastolic blood pressure and rate-pressure product and the 12-year change in resting systolic blood pressure (P = 0.03 to 0.05). Both the beta 1 Msp I marker and the beta 1 haplotype were linked with the resting rate-pressure product (P = 0.007 and 0.003, respectively), and all beta 1 markers showed linkage with the change in resting systolic blood pressure (P = 0.00005 to 0.024). In men, there was a significant (P = 0.01) interaction between the alpha 2 exon 21-22 genotype and the postglucose plasma insulin level with regard to resting systolic blood pressure. CONCLUSIONS: These data suggest that the alpha 2 and beta 1 genes of Na,K-ATPase contribute to the regulation of hemodynamic phenotypes in healthy subjects.

Blood Pressure↗
PubMed1998

Subchronic toxicity study of tetrahydroisohumulone and hexahydroisohumulone in the beagle dog.

Hops and hop extracts are approved and widely used bittering agents in the brewing of beer. During recent years, preisomerized alpha hop acids and reduced preisomerized alpha hop acids have been introduced as effective and economical bittering agents that may be added late in the brewing process. Although hops have been used for centuries, there are few studies in the literature on the safety of this ingredient. The study herein was conducted to determine the effects associated with subchronic oral administration of the reduced preisomerized hop acids, hexahydroisohumulone and tetrahydroisohumulone, in the dog. The results show that these materials are generally well tolerated in the dog. At high dose levels they induce vomiting, and much of the material administered was excreted in the faeces. The no-observed-adverse-effect level (NOAEL) of the compounds were 50 and 100 mg/kg body weight, respectively. Consumption of these ingredients by adult humans drinking 1 litre of beer daily is less than 0.25 mg/kg body weight; their use is thus associated with wide safety margins.

Administration, Oral↗
PubMed1998

Three mitochondrial DNA restriction polymorphisms in elite endurance athletes and sedentary controls.

This study examined the associations between elite endurance athlete (EEA) status and three mitochondrial DNA (mtDNA) restriction fragment length polymorphisms (RFLPs) in the subunit 5 of the NADH dehydrogenase (MTND5) locus and one in the D-loop region. A group of 125 Caucasian male EEA well endowed with the phenotypic expression of VO2max (78.9 +/- 3.8 mL x kg(-1) x min(-1), mean +/- SD) and 65 sedentary controls (SCON: VO2max = 39.8 +/- 8.2 mL x kg(-1) x min(-1)) participated in the study. VO2max was determined during an incremental exercise test on a cycle ergometer or a motor-driven treadmill. mtDNA was extracted from white blood cells or lymphoblastoid cell lines and specific regions were amplified by the polymerase chain reaction. The Pearson Chi-square statistic test and Fisher exact test revealed no significant association (P > 0.05) between any of the three mtDNA RFLPs and EEA status. The MTND5-BamHI RFLP at bp 13,470 (morph 3) was found in 12.8% of the EEA and 12.3% of the SCON (chi2 = 0.009, P = 0.92). The prevalence of the MTND5-Ncil RFLP at bp 13,364 (morph 2) was 12.9% and 14% for the EEA and SCON, respectively (chi2 = 0.043, P = 0.83). The D-loop-KpnI RFLP at bp 16,133 (morph 1) was found in 5.8% of the EEA and in 1.6% of the SCON (Fisher exact test = 1.80, P = 0.18). The MTND5-HincII RFLP at bp 12,406 (morph 1) was not present in this study sample. These results indicate no evidence for a difference in the frequency of two polymorphic restriction sites in the subunit 5 of the NADH dehydrogenase gene of mtDNA and one in the D-loop region between elite endurance athletes and sedentary controls.

Adolescent↗
PubMed1997

Abdominal visceral fat is associated with a BclI restriction fragment length polymorphism at the glucocorticoid receptor gene locus.

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 BclI 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 (4.5/4.5 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 BclI and AVF area suggests that this gene or a locus in linkage disequilibrium with the BclI restriction site may contribute to the accumulation of AVF.

Abdomen↗
PubMed1997

Suggestive linkages between markers on human 1p32-p22 and body fat and insulin levels in the Quebec Family Study.

A single-gene rodent mutation (diabetes) and a quantitative trait locus (dietary obese 1) mapped to the mid portion of mouse chromosome 4 have been related to obesity and/or insulin levels. Synteny relationships place their putative human homologs on 1p31 and 1p35-p31, respectively. In 137 sibships of adult brothers and sisters from the Québec Family Study, genetic linkages between seven microsatellite markers from 1p32-p22 and various obesity- and diabetes-related quantitative phenotypes were examined using single locus sibpair linkage analysis. Suggestive linkages were observed between markers D1S476 and body mass index (p = 0.05), fat mass (p = 0.02), the sum of six skinfolds (p = 0.02), the insulin area after an oral glucose tolerance test (p = 0.02), and between the neighboring marker D1S200 and body mass index (p = 0.03), and fat mass (p = 0.009). Suggestive linkages were also observed between the more telomeric markers D1S193 and body mass index (p = 0.03), and between the neighboring marker D1S197 and fasting insulin level (p = 0.05). No linkage was observed with the trunk to extremity skinfolds ratio. These linkages suggest that human homologs of the mouse diabetes or dietary obese 1 and/or other genes in this interval on chromosome 1 play a role in the regulation of body mass, body composition, and insulin levels, but not of subcutaneous fat distribution.

Adolescent↗
PubMed1997

Muscle-specific creatine kinase gene polymorphism and VO2max in the HERITAGE Family Study.

This study examined the association between a DNA polymorphism in the muscle-specific creatine kinase (CKMM) gene and VO2max in the sedentary state, as well as its response (deltaVO2max) to a standardized 20-wk endurance training program. The subjects were 160 biologically unrelated Caucasian parents (80 women, 80 men) and 80 biologically unrelated adult offspring of the HERITAGE Family Study. The CKMM polymorphism was detected by PCR and digestion with the NcoI restriction enzyme. VO2max was measured during maximal cycle ergometer tests. VO2max was 2119 +/- 45 mL x min(-1) (mean +/- SE) or 26 +/- 0.4 mL x kg(-1) x min(-1). Both sexes had a significant (P < 0.05) increase in the deltaVO2max (women = 283 +/- 20 mL x min[-1] and men = 363 +/- 25 mL x min[-1]). Allele and genotype frequencies were not significantly different (P > 0.05) between sexes. Age and sex adjusted VO2max was significantly (P = 0.007) associated with the CKMM genotype in the parents, whereas no association (P > 0.05) was observed in the offspring. DeltaVO2max values adjusted for age, sex, VO2max, and body mass were characterized by genotype differences in both parents (P = 0.0004) and offspring (P = 0.0025). A significantly (P < 0.05) lower deltaVO2max to endurance training was detected in both parents and offspring homozygotes for the rare allele. The genotype accounted for at least 9% of the variance in deltaVO2max. These results indicate that the NcoI polymorphism in the 3' untranslated region of the muscle-specific creatine kinase gene is associated with the deltaVO2max to endurance training.

Adult↗
PubMed1997

Muscle-specific creatine kinase gene polymorphisms in elite endurance athletes and sedentary controls.

The purpose of this study was to investigate the association between elite endurance athlete (EEA) status and two restriction fragment length polymorphisms (RFLPs) at the muscle-specific creatine kinase (CKMM) gene locus. Genomic DNA was extracted from white blood cells or lymphoblastoid cell lines of 124 unrelated Caucasian male EEA (VO2max > 73 mL.kg-1.min-1) and 115 unrelated Caucasian sedentary male controls (SCON). The genetic polymorphism at the CKMM locus was detected by the polymerase chain reaction and DNA digestion with the NcoI and TaqI restriction endonucleases. The allelic frequencies for the NcoI and TaqI RFLPs were not different (P > 0.05) between EEA and SCON subjects. The three expected genotypes for CKMM-NcoI (1170/1170 bp, 1170/985 + 185 bp, and 985 + 185/985 + 185 bp) and CKMM-TaqI (1170/1170 bp, 1170/1020 + 150 bp, and 1020 + 50/1020 + 150 bp) were observed in the EEA and SCON groups. These genotype frequencies were in Hardy-Weinberg equilibrium, but they were not significantly (P > 0.05) different between the EEA and SCON. A strong (P < 0.001) linkage disequilibrium was detected among the NcoI and TaqI RFLPs in both EEA and SCON. These findings indicate that the skeletal muscle CK-NcoI and CK-TaqI gene polymorphisms are not associated with the elite endurance athlete status.

Adult↗
PubMed1997

Variation in plasma fibrinogen over one year: relationships with genetic polymorphisms and non-genetic factors.

We analyzed plasma fibrinogen level in relation to genetic polymorphisms in the alpha- and beta-fibrinogen gene loci. Furthermore, the association of other CVD risk markers with fibrinogen was studied twice, with a time interval of one year in 50 to 60 year old men (n = 183). DNA polymorphisms were detected by PCR and digestion with Taq I (alpha-fibrinogen), Hind III and Bcl I (beta-fibrinogen) restriction enzymes. The correlation coefficient between fibrinogen measurements was 0.48 (p < 0.001). Blood leucocytes and waist-to-hip circumference ratio were the strongest correlates of fibrinogen level in both examinations, and the changes in leucocyte count and plasma fibrinogen correlated positively (r = 0.40, p < 0.001). In Eastern Finnish men, the Taq I, Hind III or Bcl I restriction fragment length polymorphisms of the alpha- or beta-fibrinogen gene loci did not associate with fibrinogen level, either cross-sectionally or longitudinally.

Biomarkers↗
PubMed1997

Linkage and association studies between the melanocortin receptors 4 and 5 genes and obesity-related phenotypes in the Québec Family Study.

BACKGROUND: The agouti yellow mouse shows adult onset of moderate obesity and diabetes. A depressed basal lipolytic rate in adipocytes or a decreased adrenergic tone arising from antagonizing alpha-melanocyte-stimulating hormone (MSH) activation of melanocortin receptors (MCR) could be at the origin of the obesity phenotype. MATERIAL AND METHODS: MCR 4 and 5 (MC4R, MC5R) genes were studied in the Québec Family Study. Sequence variations were detected by Southern blot probing of restricted genomic DNA, and mRNA tissue expression was detected by RT-PCR. Subjects with a wide range of weight were used for single-point sib-pair linkage studies (maximum of 289 sibships from 124 nuclear families). Analysis of variance across genotypes in unrelated males (n = 143) and females (n = 156) was also undertaken. Body mass index (BMI), sum of six skin-folds (SF6), fat mass (FM), percent body fat (%FAT), respiratory quotient (RQ), resting metabolic rate (RMR), fasting glucose and insulin, and glucose and insulin area during an oral glucose tolerance test were analyzed. RESULTS: MC4R showed polymorphism with NcoI, and MC5R, with PstI and PvuII, with a heterozygosity of 0.38, 0.10, and 0.20, respectively. Linkages were observed between MC5R and BMI (p = 0.001), SF6 (p = 0.005), FM (p = 0.001), and RMR (p = 0.002), whereas associations were observed in females between MC5R and BMI (p = 0.003), and between MC4R and FM (p = 0.002) and %FAT (p = 0.004). After correction for multiple tests, these p values are lowered by one tenth. MC4R and MC5R mRNAs have been detected in brain, adipose tissue, and skeletal muscle. CONCLUSIONS: MC4R and MC5R exhibit evidence of linkage or association with obesity phenotypes, but this evidence is strongest for MC5R.

Adolescent↗
PubMed1996

The Bcl I polymorphism of the human uncoupling protein (ucp) gene is due to a point mutation in the 5'-flanking region.

The polymorphic Bcl I site in the human ucp gene associated to percentage fat gain over time in the Québec Family Study cohort (Oppert et al. Int J Obesity 1994; 18: 526-531) has been positioned to the 5'-flanking region. This polymorphism results from a unique A/G mutation. Oligonucleotides used to amplify the polymorphic region, and allowing future studies of any cohort of patients, are described.

Base Sequence↗
PubMed1995

DNA polymorphisms in the alpha 2- and beta 2-adrenoceptor genes and regional fat distribution in humans: association and linkage studies.

The aim of this study was to investigate the relationships between DNA restriction fragment length polymorphisms (RFLP) in the alpha 2- and beta 2-adrenoceptor genes and body fat distribution in humans. Skinfold thickness measurements and genetic analyses (Southern blot) were performed on 280 individuals (142 parents and 138 offsprings) from the Québec Family Study. Using the association study design in unrelated adults, women but not men carrying the 6.3-kb allele of an alpha 2A-adrenoceptor/DraI RFLP had a significantly higher trunk to extremity skinfold ratio (= sum of subscapular+suprailiac+abdominal skinfolds/sum of biceps+triceps+medial calf skinfolds) compared to women without the allele (1.44 +/- 0.52 vs. 1.12 +/- 0.33; p < 0.005 after adjustment for age, p < 0.002 after adjustment for age and body mass index or for age and subcutaneous fat). Using the sib-pair linkage procedure, a significant inverse relationship was found between the proportion of alleles identical by descent shared by sibs at the alpha 2A RFLP marker locus and the squared differences of the trunk to extremity skinfold ratio (p = 0.02 after adjustment for age or for age and body mass index or for age and subcutaneous fat). For a beta 2-adrenoceptor/BanI RFLP, no significant association or linkage was found between fat distribution indicators and the marker. These results suggest that alpha 2A-adrenoceptor gene variability detected with DraI is associated with a relative subcutaneous fat pattern favoring accumulation of truncal-abdominal fat in women, and that the alpha 2A-adrenoceptor gene, or a locus in close proximity, may be linked to body fat distribution in humans independently of the overall level of fatness.

Adipose Tissue↗
PubMed1994

Relation between BglII polymorphism in 3beta-hydroxysteroid dehydrogenase gene and adipose tissue distribution in humans.

The aim of this study was to investigate the association between a restriction fragment length polymorphism (RFLP) at the 3beta-hydroxysteroid dehydrogenase locus and adipose tissue distribution phenotypes. A total of 132 unrelated individuals from the Quebec Family Study were followed prospectively for an average period of 11.3 years. The BglII polymorphism in exon 4 of the 3beta-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 BglII polymorphism at the 3beta-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 3beta-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.

3-Hydroxysteroid Dehydrogenases↗