Food Consumption as a Modifier of the Association between LEPR Gene Variants and Excess Body Weight in Children and Adolescents: A Study of the SCAALA Cohort

Genetic risk score based on obesity-related genes and progression in weight loss after bariatric surgery: a 60-month follow-up study

BACKGROUND

Obesity is a polygenic multifactorial disease. Recent genome-wide association studies have identified several common loci associated with obesity-related phenotypes. Bariatric surgery (BS) is the most effective long-term treatment for patients with severe obesity. The huge variability in BS outcomes between patients suggests a moderating effect of several factors, including the genetic architecture of the patients.

OBJECTIVE

To examine the role of a genetic risk score (GRS) based on 7 polymorphisms in 5 obesity-candidate genes (FTO, MC4R, SIRT1, LEP, and LEPR) on weight loss after BS.

SETTING

University hospital in Spain.

METHODS

We evaluated a cohort of 104 patients with severe obesity submitted to BS (Roux-en-Y gastric bypass or sleeve gastrectomy) followed up for >60 months (lost to follow-up, 19.23%). A GRS was calculated for each patient, considering the number of carried risk alleles for the analyzed genes. During the postoperative period, the percentage of excess weight loss total weight loss and changes in body mass index were evaluated. Generalized estimating equation models were used for the prospective analysis of the variation of these variables in relation to the GRS.

RESULTS

The longitudinal model showed a significant effect of the GRS on the percentage of excess weight loss (P = 1.5 × 10-5), percentage of total weight loss (P = 3.1 × 10-8), and change in body mass index (P = 7.8 × 10-16) over time. Individuals with a low GRS seemed to experience better outcomes at 24 and 60 months after surgery than those with a higher GRS.

CONCLUSION

The use of the GRS in considering the polygenic nature of obesity seems to be a useful tool to better understand the outcome of patients with obesity after BS.

Setting references for daily intake of micronutrients: A study on magnesium

OBJECTIVES

The Institute of Medicine stratifies the references for daily nutrient intake into age and sex groups, considering that the basal metabolic rate varies according to these aspects, and in most cases, it extrapolates the values calculated for adults to children, because their body weights are different. In this context, this study aimed to evaluate the recommendation for magnesium in children according to energy expenditure.

METHODS

This was an observational study using the database of the Social Changes, Asthma and Allergy in Latin America (SCAALA) cohort, which randomly collected information from 1445 children ages 4 to 11 y. Of these, 480 (33%) were part of the present study (children between 7 and 11 y old with eutrophic body mass index and adequate growth). Information on food intake was obtained from the child's parents or legal guardians through a 24-h recall. The population was characterized using static analyses such as the Student t test, Pearson correlation coefficient, and linear regression.

RESULTS

The mean age of the sample was 8.5 ± 0.96 y, and 54% were males. The mean magnesium intake was 149 ± 70 mg, with a high correlation observed between energy expenditure and magnesium intake (boys: R, 0.716; P <0.001; girls: R, 0.641; P < 0.001).

CONCLUSIONS

The metabolic rate can be considered a reference variable for recommending the daily intake of the studied nutrient, aiming to avoid deficiencies and food poisoning because of poor intake.

Association between LEPR polymorphism and susceptibility of osteoporosis in Chinese Mulao people

To explore the association between the single nucleotide polymorphism (SNP) of leptin receptor (LEPR) gene and the susceptibility to osteoporosis (OP) among Chinese Mulao people. A total of 738 people were involved. Bone mineral density (BMD) was examined by calcaneus ultrasound attenuation measurement. Six SNPs of LEPR were detected. The genotypes, allele frequencies, linkage disequilibrium, and haplotype were analyzed. BMD decreased with age and males had higher BMD than women. The proportion of normal bone mass decreased with age, and morbidity of OP increased. Three out of six SNPs showed a difference between OP and normal group. Individuals with AA genotype of rs1137100 in OP group outnumber the normal group, AA increased the risk of OP. In rs2767485, CT increased the risk of OP, C allele may be susceptible to OP. TT genotype of rs465555 was susceptible genotype of OP, T locus may be associated with OP. Strong linkage disequilibrium was detected among rs1137100, rs1137101, and rs4655555. Four haplotypes were constructed, among which, AACGCT and GGTGTA increased the risk of OP by 3.9 and 4.2 times, respectively, whereas, GGCGTA reduced 74% of OP susceptibility. The rs1137100, rs2767485, and rs465555 of LEPR were associated with OP in Chinese Mulao people.

In the context of the triple burden of malnutrition: A systematic review of gene-diet interactions and nutritional status

Genetic background interacts with dietary components to modulate nutritional health status. This study aimed to review the evidence for gene-diet interactions in all forms of malnutrition. A comprehensive systematic literature search was conducted through April 2021 to identify observational and intervention studies reporting the effects of gene-diet interactions in over-nutrition, under-nutrition and micronutrient status. Risk of publication bias was assessed using the Quality Criteria Checklist and a tool specifically designed for gene-diet interaction research. 167 studies from 27 populations were included. The majority of studies investigated single nucleotide polymorphisms (SNPs) in overnutrition (n = 158). Diets rich in whole grains, vegetables, fruits and low in total and saturated fats, such as Mediterranean and DASH diets, showed promising effects for reducing obesity risk among individuals who had higher genetic risk scores for obesity, particularly the risk alleles carriers of FTO rs9939609, rs1121980 and rs1421085. Other SNPs in MC4R, PPARG and APOA5 genes were also commonly studied for interaction with diet on overnutrition though findings were inconclusive. Only limited data were found related to undernutrition (n = 1) and micronutrient status (n = 9). The findings on gene-diet interactions in this review highlight the importance of personalized nutrition, and more research on undernutrition and micronutrient status is warranted.

Obesity in Children with Leptin Receptor Gene Polymorphisms

INTRODUCTION

The study of single nucleotide polymorphisms (SNPs) of the leptin receptor gene (LEPR) based on next generation genomic sequencing (NGS) data is becoming an increasingly important aspect of diagnosis, treatment and prevention of both metabolically healthy (MHO) and metabolically unhealthy obesity (MUO) phenotypes.

MATERIAL AND METHODS

35 obese children 6-18 years old were examined by the NGS method with bioinformatic analysis. The main group (n = 18) was formed by children with MUO, according to the recommendations of the expert group of the National Heart, Lung, and Blood Institute. The control group (n = 17) was represented by children with MHO. Statistical methods were used: analysis of variance, Wald's sequential analysis, Spearman's correlation analysis, analysis of nominal data and multiple discriminant analysis.

RESULTS

10 types of non-synonymous SNPs (rs3790435, rs1137100, rs2186248, rs70940803, rs79639154, rs1359482195, rs1137101, rs1805094, rs13306520, rs13306522) of the LEPR gene in obese children have been identified. Multiple discriminant analysis demonstrated that the following LEPR SNPs are of greatest importance in the development of MUO: rs3790435, rs13306522, rs13306520. Analysis of nominal data revealed significant differences in the groups for Copy number variation (CNV) rs3790435 of the LEPR gene. Wald's analysis allowed us to identify 6 important predictors of MUO (І ≥ 0.5): 2 CNV rs3790435 (Relative Risk, RR = 2, Prognostic coefficient, PC = +2.76); male gender of the child (RR = 1.3, PC = +1.35); rs3790435 (RR = 1.9, PC = +2.76); hyperleptinemia more than 40.56 ng/ml (RR = 2, PC = +3); CNV rs1359482195 ≥ 3 (RR = 1.9, PC = +5.8); SNP of the LEPR gene ≥4 (RR = 3.8, PC = +5.8).

CONCLUSION

Children with the genotype rs3790435 gene LEPR had signs of MUO more often.

The impact of CPT1B rs470117, LEPR rs1137101 and BDNF rs6265 polymorphisms on the risk of developing obesity in an Italian population

OBJECTIVE

This study aimed to analyze 11 single nucleotide polymorphisms (SNPs) belonging to 9 genes involved in metabolic pathways (BDNF rs6265; PNPLA3 rs2294918 and rs2076212; CIDEA rs11545881; NTRK2 rs2289658; ALOX12 rs1126667; ALOX12B rs2304908; LEPR rs1137101; CPT1B rs470117 and rs8142477; rs2305507 CPT1A) in obese patients and controls.

METHODS

Polymorphisms were analyzed in 300 severe obese patients undergoing bariatric surgery (body mass index >30 kg/m²) and 404 control subjects in order to evaluate their association with obesity and clinical variables.

RESULTS

Our findings showed significant differences for the allelic distributions of CPT1B rs470117 and LEPR rs11371010 in obese subjects compared to controls. The BDNF rs6265 correlates with obesity only when associated with the other two SNPs. In particular, for CPT1B rs470117 and LEPR rs1137101, the rare allele was associated with a reduced risk of developing the obese phenotype, whereas the simultaneous presence of the common C allele for rs470117 and A allele for rs1137101 was more frequent in obese patients (p = 0.002, OR = 1.417). A significant association between CPT1B rs470117 and steatosis was found. Moreover, we observed that by associating the rare allele T of the BDNF rs6265 with the most common alleles of the SNPs CPT1B rs470117 and LEPR rs1137101, the combination of T-C-A alleles was associated with a higher risk of developing an obese phenotype (p = 0.001, OR = 1.6679).

CONCLUSIONS

Our results suggest that SNPs CPT1B rs470117 and LEPR rs1137101 taken individually and in association with BDNF rs6265 may be involved in an increased risk of developing obese phenotype in an Italian cohort.