CD36 polymorphism and its relationship with body mass index and coronary artery disease in a Korean population

CD36 gene polymorphism rs1761667 (G > A) is associated with hypertension and coronary artery disease in an Iranian population

Background

CD36 is associated with regulation of lipid metabolism, atherosclerosis, and blood pressure. Moreover, its variation may be involved in the development of hypertension and/or coronary artery disease (CAD). The present study was conducted to investigate the possible association of CD36 rs1761667 (G > A) polymorphism with hypertension and/or CAD in the southeastern of Iran.

Methods

The present observational study was composed of 238 subjects who were admitted for coronary angiography, and divided into four groups: 1) hypertensive without CAD (H-Tens, n = 52); 2) hypertensive with CAD (CAD + H-Tens, n = 57); 3) CAD without hypertension (CAD, n = 65); and 4) non-hypertensive without CAD as the control group (Ctrl, n = 64). The CD36 rs1761667 polymorphism was genotyped with PCR-RFLP method. Association between CD36 rs1761667 genotypes and the risk of CAD and hypertension was assessed using multinomial regression by adjusting for age, sex, creatinine, fasting blood sugar (FBS), systolic blood pressure (SBP) and diastolic blood pressure (DBP).

Results

In the present study, minor allele (A) frequency was 0.36. The genotype, but not allele frequency of the CD36 rs1761667 was significantly different between the four study groups (p = 0.003). Furthermore, using a recessive inheritance model CD36 rs1761667 polymorphism was significantly associated with an increased risk of CAD with hypertension (OR = 5.677; 95% CI = 1.053–30.601; p = 0.043). However, using the dominant model of CD36 rs1761667 had a protective effect on H-Tens and CAD patients.

Conclusion

The present findings revealed an association between CD36 rs1761667 polymorphism and susceptibility to hypertension and/or CAD in a southeastern Iranian population.

Association between rs1761667 polymorphism of CD36 gene and risk of coronary atherosclerosis in Egyptian population

BACKGROUND

Recent studies have demonstrated that CD36 is involved in the progression of atherosclerosis. Associations between rs1761667 polymorphisms of the CD36 gene and susceptibility to coronary artery disease (CAD) are not obvious.

METHODS

We studied the relationship between single nucleotide polymorphisms (SNPs), rs1761667 of CD36 gene and the risk of coronary atherosclerosis in a case-control study composed of 71 CAD patients and 76 healthy controls by assessment of allele frequencies and genotype distributions using real-time polymerase chain reaction (PCR) and the allele discrimination technique. Additionally, we detected CD36 expression by flow cytometry.

RESULTS

The distribution of rs1761667 genotypes between the two groups was significantly different (P<0.001), with the frequency of the AG genotype being significantly higher in the CAD group than in the control group (P<0.001). The expression level of CD36 in the CAD group was significantly higher than that in the control group (P<0.001), with significant differences in the CAD patients with an AG genotype compared with those with an AA and GG genotype (P<0.001). The plasma levels (mg/dL) of low-density lipoprotein (LDL) in the CAD group were much higher than that in the control group (P<0.001). On the other hand, the plasma LDL levels in CAD patients with the AG genotype were remarkably higher than those with the GG and AA genotypes (P=0.046) and AG genotype was significantly more prevalent among type 2 diabetes mellitus (T2DM) and metabolic syndrome (MetS) patients (P<0.05). After adjusted logistic regression analysis, the AG genotype of rs1761667 was associated with an increased risk of CAD (OR=17.97, 95% CI, 3.19-87.85, P=0.001).

CONCLUSIONS

The AG genotype of the rs1761667 polymorphism in the CD36 gene may be involved in CAD pathogenesis as well as increased body mass index (BMI), T2DM and MetS in the Sohag population of Egypt.

CD36 gene variants in early prediction of type 2 diabetes mellitus

Type 2 diabetes (T2DM) is a noncommunicable disease affecting huge populations in India and abroad. Single-nucleotide polymorphisms (SNPs) in CD36, a macrophage scavenger receptor, have been implicated in the pathogenesis of T2DM and its complications. Eleven SNPs in the CD36 gene and their association with 100 each of control subjects and T2DM patients were investigated in the present study. The haplotype analysis of a few significant SNPs was carried out in individuals from families with diabetic history to evaluate its utility in disease prediction. Polymerase chain reaction-restriction fragment length polymorphism was used for genotyping. Ten families with a family history of diabetes were identified and blood samples were collected from as many family members as possible. Genotyping of three SNPs, namely rs1761667 (G>A) in exon 1 A, rs3211938 (T>G) in exon 10, and rs3212018 (16 bp del) in exon 14, was performed in all samples. Our results suggested that individuals having a GATTC1 haplotype might be at risk of developing T2DM (p<0.001) and, therefore, might be susceptible to related complications. Moreover, the presence of A, G, and G alleles of SNPs rs1761667 (G>A), rs3211938 (T>G), and rs1984112 (T>G) tends to have increased BMI, respectively. Such studies may be helpful for disease prediction in individuals at risk of T2DM. The predictive potential of CD36 variants can be explored with more families in the study population to use this as a genetic marker.

Common variants in the CD36 gene are associated with oral fat perception, fat preferences, and obesity in African Americans

Animal studies show that CD36, a fatty acid translocase, is involved in fat detection and preference, but these findings have not been reported in humans. The objective of this study was to determine whether human genetic variation in 5 common CD36 polymorphisms is associated with oral fat perception of Italian salad dressings, self-reported acceptance of high-fat foods and obesity in African-American adults (n = 317). Ratings of perceived oiliness, fat content, and creaminess were assessed on a 170-mm visual analogue scale (VAS) in response to salad dressings that were 5%, 35%, and 55% fat-by-weight content. Acceptance of added fats and oils and high-fat foods was self-reported and anthropometric measures were taken in the laboratory. DNA was isolated from saliva and genotyped at 5 CD36 polymorphisms. Three polymorphisms, rs1761667, rs3840546, and rs1527483 were associated with the outcomes. Participants with the A/A genotype at rs1761667 reported greater perceived creaminess, regardless of the fat concentration of the salad dressings (P < 0.01) and higher mean acceptance of added fats and oils (P = 0.02) compared to those with other genotypes at this site. Individuals who had C/T or T/T genotypes at rs1527483 also perceived greater fat content in the salad dressings, independent of fat concentration (P = 0.03). BMI and waist circumference were higher in participants who were homozygous for a deletion (D/D) at rs3840546, compared to I/D or D/D individuals (P < 0.001), but only 2 D/D individuals were tested, so this finding needs replication. This is the first study to demonstrate an association between common variants in CD36 and fat ingestive behaviors in humans.

Association of CD36 gene variants and metabolic syndrome in Iranians

AIMS

The CD36 gene encodes for a membrane receptor that facilitates fatty-acid uptake and utilization. Genetic variants of the CD36 gene have been associated with metabolic syndrome (MetS). We aimed to evaluate the association between the rs10499859A>G and rs13246513C>T polymorphisms and MetS components.

METHODS

For this case-control study, 140 MetS and 187 normal subjects were randomly selected from the Tehran Lipid and Glucose Study participants. Biochemical and anthropometrical variables were measured. Genotyping for both single nucleotide polymorphisms (SNPs) was performed by polymerase chain reaction-restriction fragment length polymorphism.

RESULTS

Case and control groups were not different in allele and genotype frequencies for these SNPs. However, the A and T alleles of these SNPs were significantly associated with elevated levels of high-density lipoprotein cholesterol (HDL-C) before age and sex adjustment (p=0.027 and 0.016, respectively). Association between the A allele and body mass index (BMI) was also significant after adjustment for MetS under the dominant model (p=0.009, β(2)=0.68).

CONCLUSIONS

Based on our results, these polymorphisms do affect HDL-C level and BMI (MetS components), although the effect may be slight and restricted specifically to an environment-genotype.

CD36 genetics and the metabolic complications of obesity

PURPOSE OF REVIEW

The review summarizes our current understanding of the function of the fatty acid translocase, CD36, in lipid metabolism with an emphasis on the influence of CD36 genetic variants and their potential contribution to obesity-related complications.

RECENT FINDINGS

Studies in rodents implicate CD36 in a number of metabolic pathways with relevance to obesity and its associated complications. These include pathways related to fat utilization such as taste perception, intake, intestinal processing, and storage in adipose tissue. Dysfunction in these pathways, coupled with the ability of CD36 to transduce intracellular signals that initiate inflammation in response to excess fat supply, promotes metabolic pathology. In the last few years, the relevance of discoveries in rodents to humans has been highlighted by genetic studies, which identified common CD36 variants that influence circulating lipid levels and cardiometabolic phenotypes.

SUMMARY

Recent genetic studies suggest that CD36 plays an important role in lipid metabolism in humans and may be involved in obesity-related complications. These findings may accelerate the translation of CD36 metabolic functions determined in rodents to humans. Importantly, these studies highlight the potential utility of assessing CD36 expression and common single-nucleotide polymorphism genotypes.

Common CD36 SNPs reduce protein expression and may contribute to a protective atherogenic profile

Membrane CD36 functions in the uptake of fatty acids (FAs), oxidized lipoproteins and in signal transduction after binding these ligands. In rodents, CD36 is implicated in abnormal lipid metabolism, inflammation and atherosclerosis. In humans, CD36 variants have been identified to influence free FA and high-density lipoprotein (HDL) levels and to associate with the risk of the metabolic syndrome, coronary artery disease and stroke. In this study, 15 common lipid-associated CD36 single nucleotide polymorphisms (SNPs) were evaluated for the impact on monocyte CD36 expression (protein and transcript) in 104 African Americans. In a subset of subjects, the SNPs were tested for association with monocyte surface CD36 (n=65) and platelet total CD36 (n=57). The relationship between CD36 expression and serum HDL and very low-density lipoproteins (VLDLs) levels was also examined. After a permutation-based correction for multiple tests, four SNPs (rs1761667, rs3211909, rs3211913, rs3211938) influenced monocyte CD36 protein and two (rs3211909, rs3211938) platelet CD36. The effect of the HDL-associated SNPs on CD36 expression inversely related to the impact on serum HDL and potential causality was supported by Mendelian randomization analysis. Consistent with this, monocyte CD36 protein negatively correlated with total HDL and HDL subfractions. In contrast, positive correlations were documented between monocyte CD36 and VLDL lipid, particle number and apolipoprotein B. In conclusion, CD36 variants that reduce protein expression appear to promote a protective metabolic profile. The SNPs in this study may have predictive potential on CD36 expression and disease susceptibility in African Americans. Further studies are warranted to validate and determine whether these findings are population specific.