Sleep bruxism in children: relationship with screen-time and sugar consumption.

OBJECTIVE/BACKGROUND: Consumption of added sugar and excessive screen-time is increasing worldwide and is associated with sleeping and behavior disorders, which are related with possible Sleep Bruxism (SB) in children. Therefore, the objective of this investigation was to examine the relationship between screen-time and sugar-consumption and possible SB in children. PATIENTS/METHODS: A cross-sectional study, including parents of 460 4- to 8-year-old children, was performed. Frequency of possible SB was assessed with the Children's Sleep Habits Questionnaire; sugar consumption with the Health Behaviour in School-Aged Children Food-Frequency Questionnaire. Comprehensive measures of screen-time (including cell phones, computers, electronic devices, electronic games, and TV) were taken. The time was recorded in hour/day. All data were analyzed with STATA© data analysis and statistical software version 13.0 (Copyright 1996-2016; Stata-Corp LP, College Station, TX, USA). Spearman correlation test and ordinal-multiple-variable regression analyses were used. RESULTS: Data of 440 subjects Mean age 6.2 years (S.D. 1.8) were analyzed. Prevalence of possible SB was 35% and screen-time was available for 92.9% of the children. Mean screen-time was 2.1 h/day. Parents reported 73% of the children (n = 319) to consume added sugar once a day every day and 20% more than once every day. Correlations of possible SB were statistically significant with screen-time (Rho = 0.8; p = 0.002) and sugar-consumption (Rho = 0.7; p = 0.03). Associations were found between possible SB and increase-to-increase screen-time and sugar-consumption (OR > 2). CONCLUSION: The results of this study demonstrated that as screen-time and sugar consumption increased, the frequency of bruxism in children increased.

Effects of DRD2 splicing-regulatory polymorphism and DRD4 48 bp VNTR on crack cocaine addiction.

There is evidence that dopamine receptors D2 (DRD2) and D4 (DRD4) polymorphisms may influence substance use disorders (SUD) susceptibility both individually and through their influence in the formation of DRD2-DRD4 heteromers. The dopaminergic role on the vulnerability to addiction appears to be influenced by sex. A cross-sectional study with 307 crack cocaine addicts and 770 controls was conducted. The influence of DRD2 rs2283265 and DRD4 48 bp VNTR in exon 3 variants, as well as their interaction on crack cocaine addiction susceptibility and severity were evaluated in women and men separately. An association between the DRD2 T allele and crack cocaine addiction was found in women. In this same group, interaction analysis demonstrated that the presence of DRD2-T allele and concomitant absence of DRD4-7R allele were associated with risk for crack cocaine addiction. No influence of DRD2 and DRD4 variants was observed in men regarding addiction severity. This study reinforces the role of dopaminergic genes in externalizing behaviors, especially the influence of DRD2-DRD4 interaction on SUD. This is the fourth sample that independently associated the DRD2-DRD4 interaction with SUD itself or related disorders. In addition, our findings point out to a potential difference of dopaminergic neurotransmission across sex influencing addiction susceptibility.

Recurrent miscarriage is associated with the dopamine receptor (DRD2) genotype.

The purpose of this research is to compare the prevalence of dopamine receptor D2 polymorphisms in women with recurrent miscarriage (RM) and healthy patients. Fifty-four women were enrolled in this case-control study. We performed DNA extraction of peripheral blood, followed by polymerase chain reaction to confirm single-strand polymorphisms and to sequence two polymorphisms: polymorphism 1 (rs6275) and polymorphism 2 (rs6277) in exon 7 of the dopamine receptor D2 (DRD2). The frequency of DRD2 polymorphism 2 (rs6277) was increased in the subjects with RM. An analysis of the DRD2 genotypes demonstrated an odds ratio of 2.37 (1.05-5.36, 95% confidence interval) for the polymorphism 2 (rs6277) in RM. The mean of the serum prolactin level was higher in the patients with RM (12.5 ng/ml) than in healthy women (8.1 ng/ml) p = 0.03. An excess homozygosity of the DRD2 polymorphism suggests a genetic predisposition to RMs, which could result in a mild serum prolactin increase. Thus, because of the potential role of prolactin in reproductive regulation, this polymorphism could play an important role in early pregnancy implantation and pregnancy maintenance.