Variation of the fatty acid binding protein 2 gene is not associated with obesity and insulin resistance in Japanese subjects.

An alanine to threonine substitution at codon 54 of the fatty acid binding protein 2 (FABP2) gene has been associated with insulin resistance in Pima Indians and with obesity in aboriginal Canadians. We investigated whether this polymorphism contributes to obesity and insulin resistance in 258 Japanese subjects. Thirty-six subjects (13.9%) were homozygous for the Thr54 allele, 106 (41.1%) were heterozygous for the Ala54/Thr54 allele, and 116 (45.0%) were homozygous for the Ala54 allele. The frequency of the Thr54 allele was 0.34 and did not differ significantly between men and women. The incidence of non-insulin-dependent diabetes mellitus (NIDDM) was not different among the three genotypes. The variation at codon 54 of the FABP2 gene was not associated with obesity, hypertension, dyslipidemia, hyperuricemia, or hyperinsulinemia. These results suggest that the polymorphism at codon 54 of the FABP2 gene is not a major contributing factor to obesity and insulin resistance in Japanese subjects.     

Association between Ala54Thr substitution of the fatty acid-binding protein 2 gene with insulin resistance and intra-abdominal fat thickness in Japanese men

Summary Alanine to threonine substitution at codon 54 of the fatty acid-binding protein 2 (FABP2) gene was recently shown to be associated with insulin resistance in Pima Indians. It has been hypothesized that the mutation may result in enhanced intestinal uptake of fatty acids, and thereby an impairment of insulin action. We analysed the association of the Ala54Thr substitution with insulin sensitivity and abdominal fat thickness in 395 Japanese men aged 50.5 ± 8.8 years (mean ± SD) with a body mass index of 24.4 ± 3.0 kg/m². The frequency of the Thr54 allele was 0.34. Although the polymorphism was not significantly associated with diabetes or impaired glucose tolerance, subjects homozygous for the Thr54 allele had higher basal insulin levels. Analysis by homeostasis model assessment showed an association between the amino acid substitution and greater insulin resistance, and slightly higher beta-cell function. Oral glucose tolerance tests performed in 392 subjects without fasting hyperglycaemia showed higher 2-h insulin concentrations in individuals homozygous for the Thr54 allele when compared with heterozygotes or homozygotes for the Ala54 allele. No significant association was obtained between the polymorphism of the FABP2 gene and body mass index. However, ultrasound measurements of abdominal fat thickness revealed a greater accumulation of intra-abdominal fat in subjects homozygous for the Thr54 allele, whereas subcutaneous fat thickness was not associated with the polymorphism. These observations suggest that the Ala54Thr substitution in the FABP2 gene is associated with insulin resistance in Japanese men, and that visceral fat accumulation might be involved in the impaired insulin action associated with the substitution. [Diabetologia (1997) 40: 706–710] Received: 30 December 1996 and in revised form: 10 March 1997     

Codon 54 polymorphism of the fatty acid binding protein 2 gene is associated with increased fat oxidation and hyperinsulinemia, but not with intestinal fatty acid absorption in Korean men

The alanine to threonine substitution at codon 54 (Ala54Thr) of the fatty acid binding protein 2 (FABP2) gene has been reported to be associated with increased fat oxidation and insulin resistance in several populations. It has been hypothesized that Ala54Thr substitution results in enhanced intestinal uptake of fatty acids and thereby an impairment of insulin action, but this hypothesis has not been proven in vivo. We studied the association between the Ala54Thr polymorphism of the FABP2 gene and intestinal (3)H-oleic acid absorption, as well as basal insulin level, basal metabolic rate, and fat oxidation rate in 96 healthy young Korean men. Among our subjects, the allele frequency of the Ala54Thr substitution was 0.34. Subjects with Thr54-encoding allele were found to have a higher mean fasting plasma insulin concentration and a higher basal fat oxidation rate compared with the subjects who were homozygous for the Ala54-encoding allele. However, there was no significant difference in basal metabolic rate or (3)H-oleic acid absorption according to the FABP2 gene polymorphism. These results suggest that the Ala54Thr substitution in the FABP2 gene is associated with increased fat oxidation and hyperinsulinemia in normal Korean men, but these effects are not mediated by an increase in the intestinal fatty acid absorption.     

The effect of polymorphism in the intestinal fatty acid-binding protein 2 gene on fat metabolism is associated with gender and obesity amongst non-diabetic Japanese-Americans

Aim:  The role of the codon 54 polymorphism of the fatty acid-binding protein 2 (FABP2) gene on fat metabolism has been controversial. Assuming that the effects of the polymorphism were modulated by gender and obesity which were related to lipid and glucose metabolism, we investigated this polymorphism and its effect on fat metabolism according to such factors.
Methods:  Subjects were Japanese–Americans (123 men and 126 women) who were diagnosed as non-diabetic by a 75 g oral glucose tolerance test at the baseline.
Results:  During approximately 7.8 years, 49 (24 men and 25 women) were diagnosed with type 2 diabetes. In a Cox proportional hazards model, this polymorphism was not a significant variable in the incidence of diabetes in either gender. Amongst non-obese men with the Thr54 allele, there was a significant elevation of triglycerides (TGs) (p = 0.033) compared with alanine (Ala) homozygotes. Women with the Thr54 allele had significantly elevated total cholesterol (p = 0.033) and low-density lipoprotein-cholesterol (LDL-C) (p = 0.023) compared with Ala54 homozygotes.
Conclusions:  These results therefore suggested that the effects of the FABP2 polymorphism on TG, LDL-C and body mass index were associated with gender difference and obesity amongst non-diabetic Japanese–American subjects.     

Comparison of the acute response to meals enriched with cis- or trans-fatty acids on glucose and lipids in overweight individuals with differing FABP2 genotypes

Trans-fatty acids have been implicated as a risk factor for cardiovascular disease and diabetes. In addition, a polymorphism at codon 54 (Ala54Thr) in the fatty acid-binding protein 2 (FABP2) gene has been suggested to modify an interaction between dietary fat and insulin sensitivity. We examined the postprandial metabolic profiles after meals enriched with C18:1trans- relative to a similar meal with C18:1cis-fatty acid in individuals who were either FABP2 Ala54 homozygotes or Thr54 carriers. Moderately overweight men and women ate 2 breakfast test meals, separated by 1 week, each providing 40% of their daily energy requirement and containing 50% of energy as fat. In one meal, 10% of energy was from C18:1trans, and in the other meal, the C18:1trans was replaced with C18:1cis. Metabolic parameters were assessed during an 8-hour period. Insulin and C-peptide levels increased more after the C18:1trans meal, and this was associated with a greater fall in free fatty acids. Postprandial glucose levels and oxidation of fatty acids and carbohydrate were not different between the 2 test meals. The Thr54 allele for FABP2 increased the rise in postprandial glucose but not triacylglycerols. Fractional triacylglycerol synthetic rates were higher after consumption of the C18:1trans meal relative to the C18:1cis meal only in Thr54 carriers. These data show that a single meal enriched with C18:1trans-fatty acids can significantly increase insulin resistance, and that in the presence of the FABP2 Thr54 allele, may contribute to increased partitioning of glucose to triacylglycerols and insulin resistance.     

Thr54 allele of the FABP2 gene affects resting metabolic rate and visceral obesity

We investigated the relationship between Ala54Thr variant allele of the fatty acid-binding protein 2 (FABP2) gene (Ala54Thr) and development of obesity in Japanese obese women. FABP2 genotypes were determined with a fluorescent allele-specific DNA primer assay system. Body weight, waist and hip circumference, amounts of visceral and subcutaneous white adipose tissue measured by computed tomography (CT) were compared between subjects with Thr allele and without Thr allele before and after the diet and exercise therapy in 80 Japanese obese women. The frequency of the Thr54 allele did not differ between obese and control subjects (0.388 versus 0.329, respectively). In subjects with Ala/Thr and Thr/Thr genotype, adjusted resting metabolic rate (RMR) was significantly lower than the subjects with Ala/Ala genotype. Subjects with the Thr54 allele showed significantly greater waist circumference after diet and exercise therapy than subjects with Ala/Ala genotype. They also demonstrated greater body weight at 20 years of age compared to subjects with Ala/Ala genotype. In conclusion, Thr54 allele of FABP2 has associations with lower adjusted resting metabolic rate, resistance in reducing visceral white adipose tissue (WAT) and early onset of obesity in Japanese obese women.     

Thr-encoding allele homozygosity at codon 54 of FABP 2 gene may be associated with impaired delta 6 desatruase activity and reduced plasma arachidonic acid in obese children

BACKGROUND: Alanine-for-threonine substitution at codon 54 (A54T polymorphism) in the fatty acid-binding protein 2 gene (FABP2) has been associated with hypertriglyceridemia and insulin resistance. Impairment in the activity of delta 6 and 5 desaturases is also supposed to be a factor predisposing the development of insulin resistance syndrome. AIM: We investigated the relationship between A54T polymorphism in FABP2 and the impairment of long-chain polyunsaturated fatty acid metabolism in obese children. METHODS: Thirty-two obese children participated. During the study, the children continued their habitual diet, which was documented in a 3-day food record using household measures. Anthropometry was performed, and serum lipid and fatty acid composition in plasma were analyzed. The polymorphism of codon 54 in the FABP 2 gene was analyzed. RESULTS: The allele frequency was 0.66 and 0.34 for Ala54 and Thr54, respectively. There were no significant differences in age, body mass index, fasting serum glucose, insulin or serum lipoproteins among the three polymorphism groups. These were also no significant differences in the intake of energy, the percentage of energy nutrients or in the dietary lipid composition. The content of arachidonic acid (AA) in plasma was lowest in Thr/Thr54 (p < 0.05). The indices of delta-6 desaturase (D6D) activity in Thr/Thr54 were significantly lower than in Thr/Ala54 or Ala/Ala54 (p < 0.05, p < 0.01, respectively). CONCLUSIONS: In obese children, Thr/Thr54 of the FABP 2 gene is associated with impaired activation of D6D and reduced AA content. The results in the LCPUFA profile suggest that Thr/Thr54 may predispose the to development of insulin resistance.     

Type 2 diabetes mellitus: association study of five candidate genes in an Indian population of Guadeloupe, genetic contribution of FABP2 polymorphism.

We studied by PCR-RFLP 6 polymorphisms in these 5 candidate genes: Ala54Thr in the fatty acid binding protein 2 gene (FABP2), A to G substitution in the uncoupling protein type 1 gene (UCP1), Asp905Tyr in the protein phosphatase type 1 gene (PP1G), Trp64Arg in the human beta 3 adrenergic receptor gene (beta 3AR) and 2 RFLP sites of the vitamin D receptor (VDR) gene (VDRTaq1 and VDRApa1). This study was conducted among 89 cases and 100 controls matched according to age, gender and absence of first degree family link (11 triplets with 2 controls for 1 case and 78 pairs with 1 control for 1 case). Cases and controls were taken among a sample of 429 individuals selected for the study of the prevalence of diabetes in this ethnic group from Guadeloupe. By conditional logistic regression analysis, there was a significant relation (p = 0.02) between the Ala54Thr FABP2 polymorphism and Type 2 DM. Multivariate analysis discriminate the FABP2 polymorphism (p = 0.10), a triglyceridemia over 2 g/l (p < 10(-3)) and high blood pressure (p = 10(-2)) as variables associated with Type 2 DM in this population. These findings suggest that FABP2 does not represent a major gene for Type 2 DM in this migrant Indian population living in Guadeloupe, but seems to be related to the metabolic insulin resistance syndrome.     

No association found between the Ala54Thr polymorphism of FABP2 gene and obesity and obesity with dyslipidemia in Japanese schoolchildren

To investigate whether the Ala54Thr polymorphism of the fatty acid binding protein 2 gene is associated with obesity and obesity with dyslipidemia in Japanese schoolchildren, we analyzed 370 children with morbid obesity and 463 control children of normal weight. The allele frequencies did not differ significantly between the control group and the morbidly obese group. The odds ratio (95% confidence interval CI) in obesity of the The54 allele was 1.0 (0.9-1.3). There were no significant differences in obesity index and metabolic characteristics between the two groups. The odds ratio (95% CI) in dyslipidemia of the Thr54 allele was 1.1 (0.8-1.4) in the morbidly obese group. Our data suggested that Ala54Thr polymorphism of the FABP2 gene is not a major contributing factor for obesity and obesity with dyslipidemia in Japanese children.     

Lack of association between the fatty acid binding protein 2 (FABP2) polymorphism with obesity and insulin resistance in two aboriginal populations from Chile

Abstract The aim of this study was to assess the frequency of fatty acid binding protein 2 (FABP2) Ala54Thr genetic polymorphism and to evaluate its association with obesity and insulin resistance in Chilean aboriginal populations. A sample of 96 urban Aymara and 111 urban Mapuche subjects aged 20–80 years were recruited for this cross-sectional study. Glucose, insulin and lipid profile were measured in fasting plasma samples. Insulin resistance was estimated through the HOMA-IR model. FABP2 Ala54Thr genotypes were determined by PCR followed by RFLP analysis. The allele frequency of Thr54 variant was estimated as 18.2% in Aymara subjects, which is one of the lowest reported to date. The corresponding frequency in Mapuche subjects was 31.9% (p<0.002). Regarding genotype–phenotype associations, no significant differences were found in any of the anthropometric or metabolic variables according to Ala54Thr genotypes. After adjustment by BMI and metabolic variables through a logistic regression analysis, the association of the FABP2 polymorphism with ethnic group persisted (Mapuche group: OR=2.37, 95% CI 1.319–4.277, p=0.004) It is unlikely that Ala54Thr polymorphism of the FABP2 gene plays a relevant role in obesity and insulin resistance in Chilean ethnic groups.     

Variation in the fatty acid binding protein 2 gene is not associated with markers of metabolic syndrome in patients with coronary heart disease

BACKGROUND AND AIM: It has been suggested that the threonine (Thr) 54 allele of the intestinal fatty acid binding protein 2 (FABP2) gene is associated with insulin resistance and affects the fatty acid composition of serum lipids. Our aim was to investigate the frequency of the alanine (Ala) 54Thr polymorphism of the FABP2 gene in patients with coronary heart disease (CHD), and the association between the polymorphism and the markers of metabolic syndrome, serum lipid levels and the fatty acid profile of serum lipids. METHODS AND RESULTS: A total of 414 CHD patients (mean age 61 years, range 33-74) participated in the cross-sectional EUROASPIRE (European Action on Secondary Prevention through Intervention to Reduce Events) Study. Markers of metabolic syndrome included fasting plasma glucose concentration, serum high-density lipoprotein cholesterol and triglycerides (TG), waist circumference, the waist/hip ratio, body mass index (BMI) and blood pressure (BP). The frequency of the Thr54 allele was similar in the CHD patients (27.2%) and control subjects from two independent studies (27.8% and 28.7%). There were no significant differences in plasma glucose, serum lipids, BP, BMI, waist circumference or waist/hip ratio among the genotypes. Genotype frequency was not associated with the prevalence of diabetes or metabolic syndrome, but metabolic syndrome (as defined by National Cholesterol Education Program criteria) tended to be more frequent in subjects with the Thr/Thr genotype (p = 0.095). There were no differences in the fatty acid profiles of serum cholesteryl esters, TG or phospholipids among the genotypes. CONCLUSIONS: The Ala54Thr polymorphism of the FABP2 gene is not associated with CHD, markers of the metabolic syndrome, or the fatty acid profile of serum lipids in Finnish CHD patients.     

NEUROD polymorphism Ala45Thr is associated with Type 1 diabetes mellitus in Czech children

Association of the NEUROD Ala45Thr polymorphism with Type 1 diabetes mellitus (DM) has been found in some but not all populations. We performed a study on the association of two NEUROD exon 2 polymorphisms, the Ala45Thr and the Pro197His, with childhood-onset Type 1 DM in the Czech population. We compared 285 children with Type 1 DM diagnosed under the age of 15 years with 289 non-diabetic control children. The genotypes were determined using novel real-time allele-specific PCR assays in the TaqMan format, and data were analysed using logistic regression. The numbers of subjects with codon 45 genotypes Ala/Ala, Ala/Thr, Thr/Thr were 95, 145, 45 among cases and 117, 130, 42 among controls. Thr45 phenotypic positivity was associated with a significant risk of Type 1 DM (OR=2.01, CI 95% 1.25-3.24) in a multivariate logistic regression model involving also the insulin gene -23HphI genotype and the presence of Type 1 DM-associated HLA-DQB1*0302-DQA1*03 (DQ8) and DQB1*0201-DQA1*05 (DQ2) molecules. No association was observed for the Pro197His mutation which was carried by 5.3% cases and 5.9% controls. Our results confirm that the NEUROD Ala45Thr polymorphism is associated with childhood-onset Type 1 DM.     

Variation in the<Emphasis Type="Italic"> FABP2</Emphasis> promoter affects gene expression: implications for prior association studies

Aims/hypothesis An Ala54Thr polymorphism in the FABP2 gene has previously been associated with insulin resistance and lipid oxidation rates in Pima Indians. Ala54Thr functionally alters the proteins ability to bind and transport dietary fatty acids. In the current report, we sought additional functional variation in FABP2 by sequencing putative regulatory regions.Methods More than 1.2 Kb of the putative promoter of FABP2 was sequenced in 20 Pima subjects. Variations were genotyped in 84 additional Pima Indian subjects to assess haplotype combinations. Functional activities of variant and nonvariant promoters were compared in Caco-2 cells transfected with luciferase reporter constructs.Results Seven variations were identified in the FABP2 promoter in Pima Indians. Genotypes of these variants were in complete concordance with each other, and were in complete concordance with Ala54Thr. Therefore, only two promoter alleles were observed in Pima Indians, an Ala54-associated promoter and a Thr54-associated promoter. In contrast, genotyping of these variants in Caucasian DNA showed multiple genotypic combinations. In vitro reporter assays indicated that the Thr54-associated promoter in Pima Indians resulted in a threefold reduction in promoter activity as compared to Ala54-associated promoter.Conclusion/interpretation Two functional variations exist in FABP2—the coding Ala54Thr and the variant promoter. In the Pima Indian population, but not the Caucasian population, these two functional variants are always carried on the same allele. Therefore, some of the in vivo phenotypic associations previously attributed to the Ala54Thr substitution, which alters binding characteristics of the protein, could instead be due to promoter variation, which alters expression levels.Abbreviations A, Adenosine - Ala, alanine - CEPH, genomic DNA set, originating from Caucasians from Utah, USA - FABP2, intestinal fatty acid binding protein gene - G, guanosine - IFABP, intestinal fatty acid binding protein - PCR, polymerase chain reaction - Thr, threonine     

Ala54Thr polymorphism of the fatty acid binding protein 2 gene and saturated fat intake in relation to lipid levels and insulin resistance: the Coronary Artery Risk Development in Young Adults (CARDIA) study

The Thr54 allele of the intestinal fatty acid–binding protein Ala54Thr functional polymorphism (FABP2) is associated with increased fat oxidation and insulin resistance. We determined the cross-sectional associations of the FABP2 gene with lipid levels and insulin resistance in 2148 participants who completed the year-20 examination of the Coronary Artery Risk Development in Young Adults (CARDIA) study. No significant difference in total cholesterol, low-density or high-density lipoprotein cholesterol, triglycerides, high-density lipoprotein cholesterol to total cholesterol ratio, or homeostasis model assessment of insulin resistance (HOMA-IR) was found between FABP2 genotypes. However, in the presence of a high–saturated fat diet (≥53.2 g/d, the 90th percentile for the population), the AA/AG genotypes (carriers of the Thr54 allele) of FABP2 had statistically significantly higher levels of log(HOMA-IR) (P = .006) and a lower high-density lipoprotein cholesterol to total cholesterol ratio (P = .03), and borderline statistically significantly higher levels of total cholesterol, low-density lipoprotein cholesterol, and log(triglycerides) (P values = .08, .07, and .05, respectively) compared with those with the GG genotype (Ala54 homozygotes). Lipid levels and log(HOMA-IR) did not vary by genotype with saturated fat intake less than 53.2 g/d. Limiting dietary saturated fat intake may be particularly important among carriers of the A allele of FABP2.     

Ala92 type 2 deiodinase allele increases risk for the development of hypertension

Accumulating evidence suggests that genes of the hypothalamic-pituitary-thyroid pathway influence susceptibility to hypertension. Type 2 iodothyronine deiodinase is responsible for the conversion of thyroxine to tri-iodothyronine for use in peripheral tissues. The present study evaluated whether a type 2 iodothyronine deiodinase nonsynonymous polymorphism, threonine 92 to alanine (Thr92Ala), is a determinant of hypertension susceptibility. A total of 372 euthyroid subjects were genotyped for Thr92Ala polymorphism using the Sequenom MassARRAY platform. Associations with hypertension and hypertension-related intermediate phenotypes were performed with generalized estimating equations. Type 2 iodothyronine deiodinase Thr92Ala allele frequencies differed significantly between hypertensive and normotensive subjects, with an excess of Ala92 carriers in hypertensive compared with normotensive subjects (64.8% versus 47.1%; P=0.011). Adjusted for age, gender and race, the estimated odds ratio for hypertension in Ala92 allele carriers compared with Thr92 homozygotes was 2.11 (95% CI: 1.15 to 3.89). Among euthyroid adults, the common Ala92 allele of the type 2 iodothyronine deiodinase increases risk for the development of hypertension. These data support an important role for genetic variation in the hypothalamic-pituitary-thyroid pathway in influencing susceptibility to hypertension.     

Unlike type 2 diabetes,type 1 does not interact with the codon 54 polymorphism of the fatty acid binding protein 2 gene

In type 2 diabetes, the threonine (Thr) for alanine (Ala) codon 54 polymorphism of the fatty acid binding protein 2 gene is associated with elevated fasting and postprandial triglycerides and dyslipidemia when compared with the wild type (Ala-54/Ala-54). To assess whether this is the case in patients with type 1 diabetes, who usually do not manifest the metabolic syndrome, we screened 181 patients with similar glycemic control as the type 2 patients. Thirty percent were heterozygous, and 9% were homozygous for the polymorphism. Mean (+/-SEM) fasting plasma triglyceride levels in patients with the wild type (n = 84), those heterozygous for Ala-54/Thr-54 (n = 44), and those homozygous for the Thr-54 (n = 13) were 1.0 +/- 0.07, 1.1 +/- 0.17, and 1.2 +/- 0.23 mmol/liter, respectively. In addition, there were no differences in total, low-density lipoprotein, high-density lipoprotein, and non-high density lipoprotein cholesterol among the three groups. After a fat load, the postprandial area under the curve of triglyceride in plasma, chylomicrons, and very low-density lipoprotein were similar between the wild type (n = 18) and the Thr-54 homozygotes (n = 12). In conclusion, in contrast to type 2, type 1 diabetes does not interact with the codon 54 polymorphism of the fatty acid binding protein 2 gene to cause hypertriglyceridemia/dyslipidemia. Insulin resistance could account possibly for this difference.     

Metabolic syndrome and ALA54THR polymorphism of fatty acid-binding protein 2 in obese patients

The prevalence of metabolic syndrome (MS) has been estimated to be approximately 25% of the population at large. A transition G to A at codon 54 of fatty acid-binding protein 2 (FABP2) results in an amino acid substitution (ala54 to Thr54), and this polymorphism was associated with some cardiovascular risk factors. The aim of our study was to investigate the relationship between MS and Thr54 polymorphism in the FABP2 gene in obese patients. A population of 750 (body mass index >30) obese patients was analyzed in cross-sectional survey. Bioimpedance, blood pressure, and serial assessment of nutritional intake with 3-day written food records and biochemical analysis were performed. The statistical analysis was performed for the combined Ala54/Thr54 and Thr54/Thr54 as a mutant group and wild-type Ala54/Ala54 as second group. Prevalence of MS with Adult Treatment Panel III definition was 49.7% (373 patients; 24.9% male and 75.1% female), and 50.3% of the patients had no MS (n = 377; 34.2% male and 65.8% female). Prevalence of FABP genotypes was similar in patients with MS (55.5% wild genotype and 44.5% mutant genotype) and without MS (54.6% wild genotype and 45.4% mutant genotype). Prevalence of each criteria of MS was calculated in wild- and mutant-type genotypes, without statistical differences. No differences in anthropometric and biochemical parameters were detected between genotypes in the same group of MS. The finding of our study is the lack of association of the Thr54/Ala54 and Thr54/Thr54 FABP2 genotypes with MS.     

Effects of intestinal fatty acid-binding protein gene Ala54Thr polymorphism and beta3-adrenergic receptor gene Trp64Arg polymorphism on insulin resistance and fasting plasma glucose in young to older Japanese men.

The present study was performed to investigate the effects of the intestinal fatty acid-binding protein (FABP2) gene Ala54Thr polymorphism and the beta(3)-adrenergic receptor (beta3AR) gene Trp64Arg polymorphism on body mass index (BMI), blood pressure, heart rate, glucose and lipid profiles, and serum leptin level in 196 young men aged 21 to 39 years, 186 older normoglycemic men (fasting plasma glucose [FPG] < 110 mg/dL) aged 40 to 65 years, and 122 older hyperglycemic men, including 77 type 2 diabetic patients. Genomic DNA was extracted from the peripheral blood, and these polymorphisms were assessed by the polymerase chain reaction (PCR)-restriction fragment length polymorphism (RFLP) method. In the older groups, the beta3AR Arg64-allele frequency tended to be lower and the FABP2 Thr/Thr54 genotype frequency tended to be higher in hyperglycemic patients, although these differences did not reach statistical significance. Also, there were no significant differences in the genotype or allele frequency of either variant between the 27 hyperlipidemic and 204 normolipidemic subjects. In the younger group, there were no significant differences in any of the parameters measured between the genotypes of beta3AR or FABP2. In the older normoglycemic subjects, heart rate was significantly lower (P =.037) in beta3AR Arg64-positive subjects, and FPG was significantly higher in subjects with the FABP2 Thr/Thr genotype than the other genotypes (99.8 +/- 5.6 v 96.5 +/- 5.6 mg/dL, P =.010). In the older hyperglycemic group, the beta3AR Arg64-positive group had significantly lower high-density lipoprotein (HDL) cholesterol and free fatty acid (FFA) levels (P =.024 and P =.043, respectively). There were no synergistic effects of these 2 variants on any measured parameter, but only the FABP2 Thr/Thr genotype was related to a higher FPG in the older normoglycemic men. In conclusion, no major difference was associated with the beta3AR Trp64Arg or FABP2 Ala54Thr polymorphism in terms of type 2 diabetes or hyperlipidemia in young to older Japanese men. However, a slight but significant increase in FPG was observed in older Japanese men with the FABP2 Thr/Thr genotype.     

The role of FABP2 gene polymorphism in alcoholic cirrhosis

Hypertriglyceridemia and dietary lipids have been suggested to modulate the severity of alcoholic liver disease and the progression to alcoholic cirrhosis (AC). The intestinal fatty acid binding protein (IFABP) is the main transporter of dietary fatty acids into the enterocyte and has a genetic polymorphism, FABP2 A54T that has been associated with hypertriglyceridemia. We determined the frequency of the FABP2 gene polymorphism using PCR-RFLP and measured serum triglycerides, HDL, LDL, total lipids and cholesterol in 67 patients with AC and in 124 unrelated healthy individuals. Frequencies of genotypes and alleles were similar between the two groups. The healthy subjects, who were homozygous for the Thr54 genotype had significantly higher mean triglyceride serum concentrations than those homozygous for the Ala54 genotype (P < 0.05). However, AC patients who were homozygous for the Thr54 genotype, had lower mean triglyceride serum concentrations (P < 0.01), and had a significantly longer period of continued alcohol abuse prior to the diagnosis of liver cirrhosis compared to the AC patients homozygous for the Ala54 genotype (P < 0.05).Our data suggests that the polymorphism Thr54 of the FABP2 gene is associated with a later onset of AC in the lower economic status Mexican population studied.