Chronological Age Interacts with the Circadian Melatonin Receptor 1B Gene Variation, Determining Fasting Glucose Concentrations in Mediterranean Populations. Additional Analyses on Type-2 Diabetes Risk

Gene-age interactions have not been systematically investigated on metabolic phenotypes and this modulation will be key for a better understanding of the temporal regulation in nutrigenomics. Taking into account that aging is typically associated with both impairment of the circadian system and a decrease in melatonin secretion, we focused on the melatonin receptor 1B (MTNR1B)-rs10830963 C>G variant that has been associated with fasting glucose concentrations, gestational diabetes, and type-2 diabetes. Therefore, our main aim was to investigate whether the association between the MTNR1B-rs10830963 polymorphism and fasting glucose is age dependent. Our secondary aims were to analyze the polymorphism association with type-2 diabetes and explore the gene-pregnancies interactions on the later type-2 diabetes risk. Three Mediterranean cohorts (n = 2823) were analyzed. First, a cross-sectional study in the discovery cohort consisting of 1378 participants (aged 18 to 80 years; mean age 41 years) from the general population was carried out. To validate and extend the results, two replication cohorts consisting of elderly individuals were studied. In the discovery cohort, we observed a strong gene-age interaction (p = 0.001), determining fasting glucose in such a way that the increasing effect of the risk G-allele was much greater in young (p = 5.9 × 10-10) than in elderly participants (p = 0.805). Consistently, the association of the MTNR1B-rs10830963 polymorphism with fasting glucose concentrations in the two replication cohorts (mean age over 65 years) did not reach statistical significance (p > 0.05 for both). However, in the elderly cohorts, significant associations between the polymorphism and type-2 diabetes at baseline were found. Moreover, in one of the cohorts, we obtained a statistically significant interaction between the MTNR1B polymorphism and the number of pregnancies, retrospectively assessed, on the type-2 diabetes risk. In conclusion, the association of the MTNR1B-rs10830963 polymorphism with fasting glucose is age-dependent, having a greater effect in younger people. However, in elderly subjects, associations of the polymorphism with type-2 diabetes were observed and our exploratory analysis suggested a modulatory effect of the number of past pregnancies on the future type-2 diabetes genetic risk

Ghrelin, Sleep Reduction and Evening Preference: Relationships to CLOCK 3111 T/C SNP and Weight Loss

Circadian Locomotor Output Cycles Kaput (CLOCK), an essential element of the positive regulatory arm in the human biological clock, is involved in metabolic regulation. The aim was to investigate the behavioral (sleep duration, eating patterns and chronobiological characteristics) and hormonal (plasma ghrelin and leptin concentrations) factors which could explain the previously reported association between the CLOCK 3111T/C SNP and weight loss.We recruited 1495 overweight/obese subjects (BMI: 25-40 kg/m(2)) of 20-65 y. who attended outpatient obesity clinics in Murcia, in southeastern Spain. We detected an association between the CLOCK 3111T/C SNP and weight loss, which was particularly evident after 12-14 weeks of treatment (P = 0.038). Specifically, carriers of the minor C allele were more resistant to weight loss than TT individuals (Mean±SEM) (8.71±0.59 kg vs 10.4±0.57 kg) C and TT respectively. In addition, our data show that minor C allele carriers had: 1. shorter sleep duration Mean ± SEM (7.0±0.05 vs 7.3±0.05) C and TT respectively (P = 0.039), 2. higher plasma ghrelin concentrations Mean ± SEM (pg/ml) (1108±49 vs 976±47)(P = 0.034); 3. delayed breakfast time; 4. evening preference and 5. less compliance with a Mediterranean Diet pattern, as compared with TT homozygotes.Sleep reduction, changes in ghrelin values, alterations of eating behaviors and evening preference that characterized CLOCK 3111C carriers could be affecting weight loss. Our results support the hypothesis that the influence of the CLOCK gene may extend to a broad range of variables linked with human behaviors

Integrative development of a short screening questionnaire of highly processed food consumption (sQ-HPF)

Background: Recent lifestyle changes include increased consumption of highly processed foods (HPF), which has been associated with an increased risk of non-communicable diseases (NCDs). However, nutritional information relies on the estimation of HPF consumption from food-frequency questionnaires (FFQ) that are not explicitly developed for this purpose. We aimed to develop a short screening questionnaire of HPF consumption (sQ-HPF) that integrates criteria from the existing food classification systems. Methods: Data from 4400 participants (48.1% female and 51.9% male, 64.9 +/- 4.9 years) of the Spanish PREDIMED-Plus (PREvention with MEDiterranean DIet) trial were used for this analysis. Items from the FFQ were classified according to four main food processing-based classification systems (NOVA, IARC, IFIC and UNC). Participants were classified into tertiles of HPF consumption according to each system. Using binomial logistic regression, food groups associated with agreement in the highest tertile for at least two classification systems were chosen as items for the questionnaire. ROC analysis was used to determine cut-off points for the frequency of consumption of each item, from which a score was calculated. Internal consistency of the questionnaire was assessed through exploratory factor analysis (EFA) and Cronbach's analysis, and agreement with the four classifications was assessed with weighted kappa coefficients. Results: Regression analysis identified 14 food groups (items) associated with high HPF consumption for at least two classification systems. EFA showed that items were representative contributors of a single underlying factor, the HPF dietary pattern (factor loadings around 0.2). We constructed a questionnaire asking about the frequency of consumption of those items. The threshold frequency of consumption was selected using ROC analysis. Comparison of the four classification systems and the sQ-HPF showed a fair to high agreement. Significant changes in lifestyle characteristics were detected across tertiles of the sQ-HPF score. Longitudinal changes in HPF consumption were also detected by the sQ-HPF, concordantly with existing classification systems. Conclusions: We developed a practical tool to measure HPF consumption, the sQ-HPF. This may be a valuable instrument to study its relationship with NCDs

An approximation to the temporal order in endogenous circadian rhythms of genes implicated in human adipose tissue metabolism

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Genotype distribution of <i>CLOCK 3111T/C</i> according to Morningness/Eveningness characteristics.

<p>ORs were calculated for combined groups of minor allele carriers (<i>CC+TC</i>) compared with <i>TT</i> subjects. Adjusted for sex, age and study site.</p

Significant associations between <i>CLOCK 3111T/C</i> and fasting ghrelin.

<p>Significant associations between <i>CLOCK 3111T/C</i> and fasting ghrelin.</p

Associations of <i>CLOCK 3111TC</i> SNP with dietary intake.

<p>Abbreviations used: MUFA; Monounsaturated fatty acids, PUFA; Polyunsaturated fatty acids, SFA; Saturated fatty acids.</p><p>Adjusted for sex, age and study site.</p