ABSTRACT
PURPOSE: The purpose of this study was to investigate whether values of the respective parameters of the OPTAx test dependently differ due to the medication with methylphenidate (MPH) in children with hyperkinetic disorders (HD) suffering from hyperactivity, impulsivity, and attention deficits. METHODS: The OPTAx test is an infrared motion analysis to record the movement pattern during a continuous performance test. We tested 25 children between 6 and 12 years with HD (ICD-10: F90.0 or F90.1) before and after treatment with MPH. The parameters under investigation were activity (microevents and spatial scaling), impulsivity (errors of commission), and attentiveness (accuracy and variability). For statistical analysis a one-tailed matched pairs test (adj. p = 0.01) was conducted to discriminate differences found from those occurred at random. A post hoc partial correlation of absolute differences in the respective parameters and the daily dose of MPH (adj. for BMI) was performed if p < 0.01. RESULTS: Statistically significant results were found for microevents, spatial scaling, errors of commission, accuracy, and variability. The partial correlation showed significant results for microevents and variability. CONCLUSION: The mean pre-post changes found in all parameters investigated consistently correspond with benefits desired from medication with MPH in children with HD. Absolute differences in microevents and variability seem to depend on the daily dose of MPH after adjustment for BMI.
Subject(s)
Attention Deficit Disorder with Hyperactivity/drug therapy , Attention/drug effects , Central Nervous System Stimulants , Mental Recall/drug effects , Methylphenidate , Attention Deficit Disorder with Hyperactivity/physiopathology , Central Nervous System Stimulants/administration & dosage , Central Nervous System Stimulants/pharmacology , Child , Dose-Response Relationship, Drug , Female , Humans , Impulsive Behavior/drug therapy , Male , Methylphenidate/administration & dosage , Methylphenidate/pharmacology , Reproducibility of Results , Severity of Illness Index , Time Factors , Treatment OutcomeABSTRACT
The 825-C/T polymorphism of the beta 3 subunit of the heterotrimeric G protein gene (GNB3) has been shown to be associated with essential hypertension in humans. Recently, it was also reported that the 825-T allele has a higher frequency in obese than non-obese hypertensives suggesting that the primary effect of this allele is on body weight. The association to hypertension might merely be a secondary effect of the higher weight of the respective allele carriers. To investigate an involvement of the 825-T allele in body weight regulation in young individuals, we evaluated allele frequencies in 440 extremely obese children and adolescents (82.9% had a body mass index [BMI] > or = 99th percentile), 51 obese students (BMI > or = 90th percentile), 110 normal weight students (BMI between 40th and 60th percentile) and 144 underweight students (BMI < or = 15th percentile). The study groups were genotyped by polymerase chain reaction with subsequent restriction fragment length polymorphism analysis (PCR-RFLP). The one-sided Yates-corrected chi(2)-test and the Cochran-Armitage trend test for association were performed. Tests for association were negative. The 825-T allele frequencies were similar in the four study groups belonging to different weight ranges (extreme early onset obesity: 0.29; obesity: 0.28; normal weight: 0.35; underweight: 0.32). Similarly, genotype frequencies did not differ between the groups. We concluded that the 825-T allele of the GNB3 does not play a major role in weight regulation in German children, adolescents and young adults.
Subject(s)
Alleles , Body Weight/genetics , Heterotrimeric GTP-Binding Proteins/genetics , Polymorphism, Genetic , Adolescent , Adult , Body Mass Index , Child , Female , Genotype , Germany , Humans , Male , Obesity/genetics , Polymerase Chain Reaction , Polymorphism, Restriction Fragment LengthABSTRACT
Over the past years substantial progress has been made in the molecular elucidation of monogenic forms of obesity both in rodents and in humans. In addition, several quantitive trait loci have been mapped in mice. In humans, non-parametric linkage studies have led to the identification of relevant chromosomal regions, some of which have already been confirmed. In this review we focus on an interpretation of the heritability estimates obtained in twin, family and adoption studies. These estimates include both direct and indirect genetic effects. Non-additive genetic factors seemingly contribute even more than additive factors. The importance of the non-shared environment is stressed. Gene x gene interactions need to be considered when interpreting recent molecular genetic results pertaining to haplo-insufficiency mutations in the melanocortin-4 receptor gene. We conclude by discussing the implications of the recent molecular findings in humans for phenotypical assessment in ongoing family studies.
