Higher cardiorespiratory fitness attenuates arterial stiffening associated with the Ala54Thr polymorphism in FABP2

Genetic polymorphism of fatty acid binding protein-2 in hyperlipidemic Asian Indians in North India

BACKGROUND

Fatty acid binding protein-2 (FABP-2) is involved in the metabolism of lipids in the intestine. FABP-2 Ala54Thr polymorphism involves a transition of G to A at codon 54 of FABP-2, resulting in an amino acid substitution Ala54 to Thr54 and is associated with elevated fasting triglycerides in some hyperlipidemic populations. In current genome builds and gene databases the variant of the Ala54Thr FABP-2 (rs 1 799 883) is annotated as c.163A>G (p. Thr55Ala).

AIM AND OBJECTIVE

The status of this polymorphism in hyperlipidemic Asian Indians from North India has not been investigated. This study was aimed to evaluate the distribution of the polymorphic variants of the Ala54Thr FABP-2 and their association with lipids in hyperlipidemic subjects.

METHODS

Ala54Thr FABP-2 polymorphism in both hyperlipidemic (n = 210) and normolipidemic (n = 342) subjects was assessed by PCR-RFLP.

RESULTS

Ala54Thr genotypes and alleles distribution did not differ between the hyperlipidemic and normolipidemic groups. The heterozygous genotype FABP-2 Ala/Thr was significantly associated with higher levels of triglycerides and very low-density lipoproteins as compared to the homozygous variant (Thr/Thr) genotype and the wild type homozygous (Ala/Ala) genotype.

CONCLUSIONS

The heterozygous genotype FABP-2 Ala54Thr is a risk factor for the development of hypertriglyceridemia and increased levels of VLDL-c in Asian Indians from North India.

FABP2 Ala54Thr Polymorphism and Post-Training Changes of Body Composition and Biochemical Parameters in Caucasian Women

The functional FABP2 Ala54Thr polymorphism (rs1799883) is strongly associated with lipid and carbohydrate metabolism, although the function of its potential modifying effect on training-induced changes in obesity-related parameters is still unknown. The aim of the present study was to investigate the influence of the Ala54Thr polymorphism on post-training changes of selected body mass and body composition measurements, as well as with biochemical parameters of energy metabolism. Accordingly, alleles and genotypes distribution in a group of 168 young, nonobese Caucasian women measured for chosen body composition parameters, lipid profile, and glucose levels before and after the completion of a 12-week aerobic training program were studied. Although the obtained results showed changes in body mass, BMI, FM, %FM, FFM, TBW, HDL-C, and glucose levels during the training program, none of the examined parameters changed significantly across the FABP2 genotypes. Instead, we found a main effect of genotype on BMI (p = 0.033), with carriers of the Thr54 allele having a higher BMI during the whole study period compared with the Ala54 carriers. We confirm that the FABP2 Ala54Thr polymorphism may help identify women at risk for overweight and obesity. However, we did not notice evidence of an interaction between physical activity and the Ala54Thr polymorphism on the examined parameters.

Intestinal fatty acid binding protein Ala54Thr polymorphism is associated with peripheral atherosclerosis combined with type 2 diabetes mellitus

BACKGROUND

Intestinal fatty acid-binding protein 2 (FABP2) is expressed in enterocytes and binds saturated and unsaturated long-chain fatty acids. The FABP2 Ala54Thr polymorphism has been reported to effect lipid metabolism. The aim of the present study was to assess the relationship between this polymorphism and peripheral atherosclerosis combined with type 2 diabetes mellitus (T2DM) in an Egyptian population.

METHODS

The study was performed on 100 T2DM patients with peripheral atherosclerosis and 100 control subjects. The Ala54Thr polymorphism was analyzed by polymerase chain reaction-restriction fragment length polymorphism, whereas serum FABP2 levels were determined using ELISA. Fasting blood glucose, fasting serum insulin concentrations, HbA1c, lipid profile, body mass index (BMI) and systolic and diastolic blood pressure (SBP and DBP, respectively) were determined.

RESULTS

There was a higher frequency of the Thr54 allele among the patient group (P = 0.002). In Ala54/Thr54 heterozygotes and carriers of the rare Thr54/Thr54 genotype, there were significant increases in BMI and FABP2. Those with the Thr54/Thr54 genotype had significantly decreased high-density lipoprotein cholesterol (HDL-C) concentrations; in addition, those with the Thr54/Thr54 genotype had significantly higher SBP and DBP than subjects with the Ala54/Ala54 and Ala54/Thr54 genotypes. There was a positive correlation between FABP2 levels and BMI, SBP and DBP, and a negative correlation with HDL-C.

CONCLUSIONS

The Thr54 allele of the FABP2 Ala54Thr polymorphism was associated with an increased incidence of peripheral atherosclerosis combined with T2DM in the population studied.

Relation of C-reactive protein, fibrinogen, and cardiorespiratory fitness to risk of systemic hypertension in men

We investigated the relation between inflammation and incident hypertension, independent of obesity, and tested the associations of cardiorespiratory fitness (fitness) and indexes of inflammation for the development of hypertension in 2,475 normotensive men. Inflammatory markers were C-reactive protein (CRP) and fibrinogen. Fitness was directly measured by peak oxygen uptake during sign/symptom-limited treadmill exercise testing to volitional fatigue; 266 men (10.7%) developed hypertension during an average of 4 years follow-up. After adjusting for potential confounding variables, the relative risk (RR) and 95% confidence interval (CI) for incident hypertension in those in the upper tertile versus lower tertile were 1.55 (95% CI 1.15 to 2.09) for CRP and 1.51 (95% CI 1.10 to 2.06) for fibrinogen. Although the association between fibrinogen and incident hypertension persisted after adjusting for body mass index (p = 0.049), the relation between CRP and incident hypertension was no longer statistically significant (p = 0.08). Fit men had a 27% decreased (RR 0.73, 95% CI 0.56 to 0.94) risk of incident hypertension compared with unfit men in a multivariable adjusted model. In the joint analysis, unfit men with upper CRP had 1.81 times (95% CI 1.21 to 2.70) and unfit men with upper fibrinogen had 2.03 times (95% CI 1.33 to 3.12) greater risks of incident hypertension compared with fit men with low CRP and fibrinogen, respectively. However, these risks did not significantly increase in fit men with upper CRP (RR 1.12, 95% CI 0.76 to 1.63) and fibrinogen (RR 1.26, 95% CI 0.86 to 1.85) groups. In conclusion, these results suggest that heightened levels of fibrinogen, but not CRP, are associated with incident hypertension, independent of body weight, and that high fitness attenuates the risk of incident hypertension across upper levels of inflammatory markers in men.

The effect of Tai Chi training on cardiorespiratory fitness in healthy adults: a systematic review and meta-analysis

Background

Tai Chi may be efficient for healthy adults to improve the cardiorespiratory fitness, but there is no systematic evaluation for its effectiveness.

Objective

To systematically assess the effectiveness of Tai Chi on cardiorespiratory fitness in healthy adults.

Methods

Seven electronic databases were searched from their inception to October 2013. The controlled trails including randomized controlled trial (RCT), non-randomized controlled trial (NRCT), self-controlled trial (SCT), and cohort study (CS) testing Tai Chi exercise against non-intervention control conditions in healthy adults that assessed any type cardiorespiratory fitness outcome measures were considered. Two reviewers independently performed the selection of the studies according to predefined criteria. The risk of bias was assessed using Cochrane criteria. RevMan 5.2 software was applied for data analysis.

Results

Twenty studies (2 RCTs, 8 NRCTs, 3 SCTs, and 7 CSs) with 1868 participants were included, but most of them belonged to low methodological quality. The results of systematic review showed that Tai Chi exercise had positive effect on majority outcomes of cardio function (Blood pressure: n = 536, SPB SMD = -0.93, 95% CI -1.30 to -0.56, P < 0.00001; DBP SMD = -0.54, 95% CI -0.90 to -0.18, P < 0.00001; heart rate at quiet condition: n = 986, SMD = -0.72, 95% CI -1.27 to -0.18, P = 0.010; stroke volume: n = 583, SMD = 0.44, 95% CI 0.28 to 0.61, P < 0.00001; cardio output: n = 583, MD = 0.32 L/min, 95% CI 0.08 to 0.56, P = 0.009), lung capacity (FVC at quiet condition: n = 1272, MD = 359.16 mL, 95% CI 19.57 to 698.75, P = 0.04 for less than one year intervention, and MD = 442.46 mL, 95% CI 271.24 to 613.68, P<0.0001 for more than one year intervention; V·O₂peak: n = 246, SMD = 1.33, 95% CI 0.97 to 1.70, P < 0.00001), and cardiorespiratory endurance (O₂ pulse at quiet condition: n = 146, SMD = 1.04; 95% CI 0.69 to 1.39; P < 0.00001; stair test index at quiet condition: n = 679, SMD = 1.34, 95% CI 0.27 to 2.40, p = 0.01). No adverse events were reported.

Conclusions

The results are encouraging and suggest that Tai Chi may be effective in improving cardiorespiratory fitness in healthy adults. However, concerning the low methodological quality in the included studies, more larger-scale well-designed trails are needed till the specific and accurate conclusions can be perorated.

Advances in exercise, fitness, and performance genomics in 2013

The most significant and scientifically sound articles in exercise genomics that were published in 2013 are reviewed in this report. No article on the genetic basis of sedentary behavior or physical activity level was identified. A calcineurin- and alpha actinin-2-based mechanism has been identified as the potential molecular basis for the observed lower muscular strength and power in alpha actinin-3-deficient individuals. Although baseline muscle transcriptomic signatures were found to be associated with strength training-induced muscle hypertrophy, no predictive genomic variants could be identified as of yet. One study found no clear evidence that the inverse relation between physical activity level and incident CHD events was influenced by 58 genomic variants clustered into four genetic scores. Lower physical activity level in North American populations may be driving the apparent risk of obesity in fat mass- and obesity-associated gene (FTO)-susceptible individuals compared with more active populations. Two large studies revealed that common genetic variants associated with baseline levels of plasma HDL cholesterol and triglycerides are not clear predictors of changes induced by interventions focused on weight loss, diet, and physical activity behavior. One large study from Japan reported that a higher fitness level attenuated the arterial stiffness-promoting effect of the Ala54 allele at the fatty acid binding protein 2 locus, which is a controversial finding because previous studies have suggested that Thr54 was the risk allele. Using transcriptomics to generate genomic targets in an unbiased manner for subsequent DNA sequence variants studies appears to be a growing trend. Moreover, exercise genomics is rapidly embracing gene and pathway analysis to better define the underlying biology and provide a foundation for the study of human variation.

Cardiorespiratory Fitness is a Strong Predictor of the Cardio-ankle Vascular Index in Hypertensive Middle-aged and Elderly Japanese Men

AIM

This study aimed to examine whether cardiorespiratory fitness (CRF) is associated with arterial stiffening, evaluated using the cardio-ankle vascular index (CAVI), independent of visceral fat (VF) in middle-aged and elderly Japanese men. We also examined whether the relationship between CRF and the CAVI is modified by age and/or hypertension.

METHODS

The CAVI was determined in 157 Japanese men (age range, 30-79 years), including 96 hypertensive subjects (61.1%). CRF was assessed by measuring the peak oxygen uptake (VO2peak). The subjects were divided into low- and high-CRF groups, and the VF area was assessed using magnetic resonance imaging.

RESULTS

The VO2peak correlated with the CAVI following adjustment for age and body mass index in the middle-aged and elderly groups (all the subjects: r=-0.285, p＜0.001; middle-aged: r=-0.240, p=0.040; elderly: r=-0.225, p=0.049). VF also correlated with the CAVI (r=0.230, p=0.004). A multiple linear regression analysis revealed that age (β=0.406, p<0.001) and the VO2peak (β=-0.186, p=0.015) were associated with the CAVI independently of VF and the mean blood pressure. Two way ANCOVA adjusted for age demonstrated that the hypertensive individuals had higher CAVI values than the normotensive individuals in the low-CRF group, whereas no significant differences in the CAVI were observed in the high-CRF group (p for interaction <0.05).

CONCLUSIONS

In the present study, CRF was found to be associated with the CAVI, independent of age and VF, in hypertensive middle-aged and elderly Japanese men.