José I. González

Association of TaqIB polymorphism in the cholesteryl ester transfer protein gene with plasma lipid levels in a healthy Spanish population

Genetic variants at the cholesteryl ester transfer protein (CETP) locus have been associated with CETP activity and mass, as well as plasma high density lipoprotein cholesterol (HDL-C) and apolipoprotein A-I levels. We have examined allele frequencies and lipid associations for the common CETP TaqIB polymorphism in a sample of 514 healthy subjects (231 men, mean age 37.4 years, and 283 women, mean age 35.7 years) residing in Valencia (Spain). The frequency of the less common TaqIB2 allele (0.351; 95% CI: 0.322-0. 380) was significantly lower than those reported for Northern European populations. Consistent with previous studies, we found a significant association of the TaqIB polymorphism with HDL-C levels. Homozygotes for the B1 allele had lower HDL-C levels than subjects carrying the B2 allele (P trend<0.001 and 0.002, for men and women, respectively). No statistically significant genotype effects were observed for any of the other lipid measures. Multivariate models including TaqIB genotype, body mass index, smoking, alcohol, physical activity, marital status and education were fitted to predict HDL-C levels. The TaqIB polymorphism was consistently an independent predictor of HDL-C levels (P<0.001), and explained 5.8% of its variance. To evaluate gene-environmental interactions, first order interaction terms were tested into the multivariate model. No statistically significant interactions between the TaqIB genotypes and smoking, alcohol, physical activity or education were detected. In conclusion, we observed a significant association of the TaqIB polymorphism with HDL-C levels, which remained consistent across different levels of behavioral factors. Moreover, we found that the TaqIB2 allele frequency was lower in our sample than in other European populations, which could be a contributing factor to the unexpectedly high prevalence of coronary heart disease observed in the region of Valencia.

Dietary Inflammatory Index and Incidence of Cardiovascular Disease in the PREDIMED Study

Previous studies have reported an association between a more pro-inflammatory diet profile and various chronic metabolic diseases. The Dietary Inflammatory Index (DII) was used to assess the inflammatory potential of nutrients and foods in the context of a dietary pattern. We prospectively examined the association between the DII and the incidence of cardiovascular disease (CVD: myocardial infarction, stroke or cardiovascular death) in the PREDIMED (Prevención con Dieta Mediterránea) study including 7216 high-risk participants. The DII was computed based on a validated 137-item food frequency questionnaire. Multivariate-adjusted hazard ratios (HR) and 95% confidence intervals of CVD risk were computed across quartiles of the DII where the lowest (most anti-inflammatory) quartile is the referent. Risk increased across the quartiles (i.e., with increasing inflammatory potential): HRquartile2 = 1.42 (95%CI = 0.97–2.09); HRquartile3 = 1.85 (1.27–2.71); and HRquartile4 = 1.73 (1.15–2.60). When fit as continuous the multiple-adjusted hazard ratio for each additional standard deviation of the DII was 1.22 (1.06–1.40). Our results provide direct prospective evidence that a pro-inflammatory diet is associated with a higher risk of cardiovascular clinical events.

Mediterranean Diet Reduces the Adverse Effect of the TCF7L2-rs7903146 Polymorphism on Cardiovascular Risk Factors and Stroke Incidence A randomized controlled trial in a high-cardiovascular-risk population

OBJECTIVE Transcription factor 7-like 2 (TCF7L2) polymorphisms are strongly associated with type 2 diabetes, but controversially with plasma lipids and cardiovascular disease. Interactions of the Mediterranean diet (MedDiet) on these associations are unknown. We investigated whether the TCF7L2-rs7903146 (C>T) polymorphism associations with type 2 diabetes, glucose, lipids, and cardiovascular disease incidence were modulated by MedDiet. RESEARCH DESIGN AND METHODS A randomized trial (two MedDiet intervention groups and a control group) with 7,018 participants in the PREvención con DIetaMEDiterránea study was undertaken and major cardiovascular events assessed. Data were analyzed at baseline and after a median follow-up of 4.8 years. Multivariable-adjusted Cox regression was used to estimate hazard ratios (HRs) for cardiovascular events. RESULTS The TCF7L2-rs7903146 polymorphism was associated with type 2 diabetes (odds ratio 1.87 [95% CI 1.62–2.17] for TT compared with CC). MedDiet interacted significantly with rs7903146 on fasting glucose at baseline (P interaction = 0.004). When adherence to the MedDiet was low, TT had higher fasting glucose concentrations (132.3 ± 3.5 mg/dL) than CC+CT (127.3 ± 3.2 mg/dL) individuals (P = 0.001). Nevertheless, when adherence was high, this increase was not observed (P = 0.605). This modulation was also detected for total cholesterol, LDL cholesterol, and triglycerides (P interaction < 0.05 for all). Likewise, in the randomized trial, TT subjects had a higher stroke incidence in the control group (adjusted HR 2.91 [95% CI 1.36–6.19]; P = 0.006 compared with CC), whereas dietary intervention with MedDiet reduced stroke incidence in TT homozygotes (adjusted HR 0.96 [95% CI 0.49–1.87]; P = 0.892 for TT compared with CC). CONCLUSIONS Our novel results suggest that MedDiet may not only reduce increased fasting glucose and lipids in TT individuals, but also stroke incidence.

Polymorphisms Cyclooxygenase-2 -765G>C and Interleukin-6 -174G>C Are Associated with Serum Inflammation Markers in a High Cardiovascular Risk Population and Do Not Modify the Response to a Mediterranean Diet Supplemented with Virgin Olive Oil or Nuts

Inflammation is involved in cardiovascular diseases. Some studies have found that the Mediterranean diet (MD) can reduce serum concentrations of inflammation markers. However, none of these studies have analyzed the influence of genetic variability in such a response. Our objective was to study the effect of the -765G>C polymorphism in the cyclooxygenase-2 (COX-2) gene and the -174G>C polymorphism in the interleukin-6 (IL-6) gene on serum concentrations of IL-6, C-reactive protein, intercellular adhesion molecule 1 (ICAM-1) and vascular cell adhesion molecule-1 as well as their influence on the response to a nutritional intervention with MD. An intervention study in a high cardiovascular risk Mediterranean population (314 men and 407 women) was undertaken. Participants were randomly assigned to consume a low-fat control diet or a MD supplemented with virgin olive oil or nuts. Measures were obtained at baseline and after a 3-mo intervention period. At baseline, the COX-2 -765G>C polymorphism was associated with lower serum IL-6 (5.85 +/- 4.82 in GG vs. 4.74 +/- 4.14 ng/L in C-allele carriers; P = 0.002) and ICAM-1 (265.8 +/- 114.8 in GG vs. 243.0 +/- 107.1 microg/L in C-carriers; P = 0.018) concentrations. These differences remained significant after multivariate adjustment. The IL-6 -174G>C polymorphism was associated with higher (CC vs. G-carriers) serum ICAM-1 concentrations in both men and women and with higher serum IL-6 concentrations in men. Following the dietary intervention, no significant gene x diet interactions were found. In conclusion, although COX-2 -765G>C and IL-6 -174G>C polymorphisms were associated with inflammation, consuming a MD (either supplemented with virgin olive oil or nuts) reduced the concentration of inflammation markers regardless of these polymorphisms.

Association of the LCT-13910C>T polymorphism with obesity and its modulation by dairy products in a Mediterranean population

The −13910C>T polymorphism (rs4988235) upstream from the lactase (LCT) gene, strongly associated with lactase persistence (LP) in Europeans, is emerging as a new candidate for obesity. We aimed to analyze the association of this polymorphism with obesity‐related variables and its modulation by dairy product intake in an elderly population. We studied 940 high‐cardiovascular risk Spanish subjects (aged 67 ± 7 years). Dairy product consumption was assessed by a validated questionnaire. Anthropometric variables were directly measured, and metabolic syndrome‐related variables were obtained. Prevalence of genotypes was: 38.0% CC (lactase nonpersistent (LNP)), 45.7% CT, and 16.3% TT. The CC genotype was not associated with lower milk or dairy product consumption in the whole population. Only in women was dairy intake significantly lower in CC subjects. The most important association was obtained with anthropometric measurements. CC individuals had lower weight (P = 0.032), lower BMI (29.7 ± 4.2 vs. 30.6 ± 4.2 kg/m2; P = 0.003) and lower waist circumference (101.1 ± 11.8 vs. 103.5 ± 11.5 cm; P = 0.005) than T‐allele carriers. Obesity risk was also significantly higher in T‐allele carriers than in CC individuals (odds ratio (OR): 1.38; 95% confidence interval (CI): 1.05–1.81; P = 0.01), and remained significant even after adjustment for sex, age, diabetes, physical activity, and energy intake. However, in subgroup analysis, these associations were found to be significant only among those consuming moderate or high lactose intakes (>8 g/day). No significant associations with lipids, glucose, or blood pressure were obtained after adjustment for BMI. In conclusion, despite not finding marked differences in dairy product consumption, this polymorphism was strongly associated with BMI and obesity and modulated by lactose intake in this Mediterranean population.

Prevalence of the methylenetetrahydrofolate reductase 677C > T mutation in the Mediterranean Spanish population. Association with cardiovascular risk factors

Methylenetetrahydrofolate reductase (MT-HFR) is a key enzyme involved in folate metabolism. A common cytosine (C) to a thymine (T) mutation at nucleotide 677 (677C > T) in the MTHFR gene which converts an alanine residue to a valine, has been related with several biochemical phenotypes and with cardiovascular risk, depending on the population studied. Our objective was to estimate the prevalence of the 677C > T mutation in a large and randomly selected sample (289 men and 427 women) from the Mediterranean Spanish population, and to test the association between this genetic variant and some cardiovascular risk factors. For both genders, the prevalence of CC, CT and TT subjects was 32.0, 52.2 and 15.8%, respectively. The frequency (95% confidence interval) of the 677T allele was 0.44 (0.40–0.48) in men and 0.40 (0.37–0.44) in women. This prevalence was significantly different from other European countries, and among the highest reported in the world for any healthy population. We found no association between the 677C > T gene variants and age, body mass index (BMI), total cholesterol, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, triglycerides or diastolic blood pressure in men and women. However, in men, a statistically significant increase of systolic blood pressure with the number of mutant alleles was found (122.2 mmHg in CC, 125.1 mmHg in CT and 128.5 mmHg in TT subjects; p for trend = 0.030). This association remained significant (p = 0.047) even after adjustment for age, BMI, alcohol consumption, tobacco smoking, education and physical activity.

Education modulates the association of the FTO rs9939609 polymorphism with body mass index and obesity risk in the Mediterranean population

OBJECTIVE To define whether the rs9939609 FTO (fat mass and obesity associated) single nucleotide polymorphism (SNP) is associated with anthropometric measurements and its modulation by educational level in a Mediterranean population. METHODS We studied 3 independent adult samples: a random sample (n = 1580) from the general population (GP), obese hospital patients (OHP) (n = 203) and elderly subjects (n = 1027) with high cardiovascular risk (HCR). Weight and height were directly measured. Education and physical activity (PA) were measured using questionnaires. RESULTS The rs9939609 presented heterogeneous associations with BMI. In the GP, the minor A-allele was significantly associated with greater BMI, following a co-dominant pattern (P = 0.009), whereas in the OHP this association was recessive (P = 0.004). Conversely, we did not find a significant association with BMI in the HCR group (P < 0.596). In the GP we found a significant interaction between the FTO SNP and education (P = 0.048). In the stratified analysis, no association of the FTO SNP with greater BMI in university subjects was detected (P = 0.786), whereas the association was observed in non-university subjects (P = 0.001). The FTO × education interaction (P = 0.020) was also observed in determining obesity risk in the GP. A-allele carriers had a greater risk of being obese only if they had no university education (OR: 1.56; 95%CI: 1.09-2.23 for TA and OR: 2.01; 95%CI: 1.27-3.26 for AA subjects). The interaction of the FTO with education remained significant even after adjustment for PA. CONCLUSIONS The association of the FTO SNP with greater BMI and obesity risk in the GP was strongly modulated by education.

Association between dietary fibre intake and fruit, vegetable or whole-grain consumption and the risk of CVD: results from the PREvención con DIeta MEDiterránea (PREDIMED) trial

Prospective studies assessing the association between fibre intake or fibre-rich food consumption and the risk of CVD have often been limited by baseline assessment of diet. Thus far, no study has used yearly repeated measurements of dietary changes during follow-up. Moreover, previous studies included healthy and selected participants who did not represent subjects at high cardiovascular risk. We used yearly repeated measurements of diet to investigate the association between fibre intake and CVD in a Mediterranean cohort of elderly adults at high cardiovascular risk. We followed-up 7216 men (55-80 years) and women (60-80 years) initially free of CVD for up to 7 years in the PREvención con DIeta MEDiterránea study (registered as ISRCTN35739639). A 137-item validated FFQ was repeated yearly to assess diet. The primary end point, confirmed by a blinded ad hoc Event Adjudication Committee, was a composite of cardiovascular death, myocardial infarction and stroke. Time-dependent Coxs regression models were used to estimate the risk of CVD according to baseline dietary exposures and to their yearly updated changes. We found a significant inverse association for fibre (P for trend=0·020) and fruits (P for trend=0·024) in age-sex adjusted models, but the statistical significance was lost in fully adjusted models. However, we found a significant inverse association with CVD incidence for the sum of fruit and vegetable consumption. Participants who consumed in total nine or more servings/d of fruits plus vegetables had a hazard ratio 0·60 (95 % CI 0·40, 0·96) of CVD in comparison with those consuming <5 servings/d.

Amino Acid Change in the Carbohydrate Response Element Binding Protein Is Associated With Lower Triglycerides and Myocardial Infarction Incidence Depending on Level of Adherence to the Mediterranean Diet in the PREDIMED Trial

Background—A variant (rs3812316, C771G, and Gln241His) in the MLXIPL (Max-like protein X interacting protein-like) gene encoding the carbohydrate response element binding protein has been associated with lower triglycerides. However, its association with cardiovascular diseases and gene–diet interactions modulating these traits are unknown. Methods and Results—We studied 7166 participants in the PREvención with DIeta MEDiterránea trial testing a Mediterranean diet (MedDiet) intervention versus a control diet for cardiovascular prevention, with a median follow-up of 4.8 years. Diet, lipids, MLXIPL polymorphisms, and cardiovascular events were assessed. Data were analyzed at baseline and longitudinally. We used multivariable-adjusted Cox regression to estimate hazard ratios for cardiovascular outcomes. The MLXIPL-rs3812316 was associated with lower baseline triglycerides (P=5.5×10−5) and lower hypertriglyceridemia (odds ratio, 0.73; 95% confidence interval [CI], 0.63–0.85; P=1.4×10−6 in G-carriers versus CC). This association was modulated by baseline adherence to MedDiet. When adherence to MedDiet was high, the protection was stronger (odds ratio, 0.63; 95% CI, 0.51–0.77; P=8.6×10−6) than when adherence to MedDiet was low (odds ratio, 0.88; 95% CI, 0.70–1.09; P=0.219). Throughout the follow-up, both the MLXIPL-rs3812316 (P=3.8×10−6) and the MedDiet intervention (P=0.030) were significantly associated with decreased triglycerides. Likewise in G-carriers MedDiet intervention was associated with greater total cardiovascular risk reduction and specifically for myocardial infarction. In the MedDiet, but not in the control group, we observed lower myocardial infarction incidence in G-carriers versus CC (hazard ratios, 0.34; 95% CI, 0.12–0.93; P=0.036 and 0.90; 95% CI, 0.35–2.33; P=0.830, respectively). Conclusions—Our novel results suggest that MedDiet enhances the triglyceride-lowering effect of the MLXIPL-rs3812316 variant and strengthens its protective effect on myocardial infarction incidence. Clinical Trial Registration—URL: www.controlled-trials.com. Unique Identifier: ISRCTN35739639.

Impact of the -1438G>a polymorphism in the serotonin 2A receptor gene on anthropometric profile and obesity risk: a case-control study in a Spanish Mediterranean population.

Research into the genetic factors that regulate food intake is arousing great interest. The polymorphism -1438G>A in the serotonin 2A receptor or 5-hydroxytriptamine (5-HT) type 2A receptor (5-HTR2A) gene has been associated with alterations in food intake such as anorexia and bulimia. However, its association with obesity has not been studied to the same extent. Our aim, therefore, was to estimate the association between the -1438G>A polymorphism and obesity risk and related anthropometric variables in a Spanish Mediterranean population. A case-control study including 303 cases and 606 controls paired by gender and age was undertaken. The association between the -1438G>A polymorphism and obesity and other anthropometric measures was studied. No association with obesity risk was observed. However, when only the obese group was analyzed, it was observed that AA subjects presented a lower body mass index (BMI) than G allele carriers (35.2+/-5.3 kg/m2 vs 37.5+/-7.8 kg/m2; P=0.039). Moreover, significant differences were also obtained in waist perimeter that was lower in AA subjects compared to G allele carriers (105+/-11 cm vs 112+/-17 cm; P=0.011). In conclusion, although the -1438G>A polymorphism is not a relevant marker for obesity risk, this variant may play a role in determining BMI in obese subjects.