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Multicenter Study
. 2011 Feb 28;6(2):e17435.
doi: 10.1371/journal.pone.0017435.

Ghrelin, sleep reduction and evening preference: relationships to CLOCK 3111 T/C SNP and weight loss

Marta Garaulet  1 , Carmen Sánchez-Moreno, Caren E Smith, Yu-Chi Lee, Francisco Nicolás, Jose M Ordovás
Affiliations
Multicenter Study

Ghrelin, sleep reduction and evening preference: relationships to CLOCK 3111 T/C SNP and weight loss

Marta Garaulet et al. PLoS One. .

Abstract

Background: 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.

Methodology/principal findings: 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.

Conclusions/significance: 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.

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Conflict of interest statement

Competing Interests: The authors have declared that no competing interests exist.

Figures

Figure 1
Figure 1. CLOCK 3111T/C genotype and weight loss progression during 28 weeks of treatment.
Figure 2
Figure 2. Significant associations between CLOCK 3111T/C and fasting ghrelin.
See this image and copyright information in PMC

References

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