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Biomedical subjects

J Hebebrand

Publications and source records attributed to J Hebebrand.

At least 127 records · Page 7Linked to original sources
PubMed1997

Leptin levels in patients with anorexia nervosa are reduced in the acute stage and elevated upon short-term weight restoration.

Circulating leptin concentrations are known to be low in acute anorexia nervosa (AN), which is characterized by low weight, amenorrhea and specific psychopathological features. In this study plasma leptin concentrations were determined during inpatient treatment of 23 adolescent females with AN using a sensitive radioimmunoassay (RIA) and set into relationship to leptin levels of females matched for age, body mass index (BMI; kg m-2) and/or percent body fat. At referral patients had leptin concentrations well below the female controls. Weight gains led to steep increases of leptin levels which peaked at values well in excess of those observed in controls matched for BMI. In patients who reached the final treatment stage and who were followed-up after discharge, levels subsequently fluctuated and finally dropped into or below the control range. The low leptin levels at referral are likely to be involved in the pathogenesis of amenorrhea and the reduced metabolic state of acutely ill patients. Peak leptin levels reached after weight gain are possibly the cause of increased energy expenditure during this stage of the disorder.

Adolescent↗
PubMed1997

Low leptin levels predict amenorrhea in underweight and eating disordered females.

Evidence that leptin plays an important role in reproductive function is accumulating rapidly. We hypothesized that low leptin synthesis is associated with amenorrhea. We therefore determined serum leptin levels in 43 underweight female students, who were screened for lifetime occurrence of amenorrhea. We assessed the predictive value of leptin, body mass index (BMI), fat mass and percent body fat, respectively, for lifetime occurrence of amenorrea. Factors predicting amenorrhea were tested for their capability to predict current amenorrhea in a second cohort of 63 inpatients with anorexia nervosa (AN) or bulimia nervosa (BN). Furthermore, the relationships between serum leptin levels and of follicle stimulating hormone (FSH), luteinizing hormone (LH), estradiol and progesterone, respectively, were evaluated. Only leptin predicted lifetime occurrence of amenorrhea in the student cohort. The critical leptin level was in the range of 1.85 micrograms L-1. This level served to largely separate anorectic from bulimic patients. In patients with AN mean serum log10 leptin levels over the first 4 weeks of inpatient treatment were correlated with mean FSH, LH and estradiol levels, respectively. Evidently, a critical leptin level is needed to maintain menstruation. In affluent populations eating disorders are likely to be a major cause of a low leptin synthesis.

Adolescent↗
PubMed1997

Restrained eating is associated with low leptin levels in underweight females.

Psychometrically defined restrained eaters consume fewer calories, take fewer meals, show higher preference for low calorie foods, have lower energy expenditure and a higher rate of ovarial dysfunction than unrestrained eaters. We hypothesized that restrained eaters as assessed with the factor cognitive restraint of the Three-Factor Eating Questionnaire have low leptin levels; therefore, we measured serum leptin levels in 136 underweight students and 49 overweight students, who had filled out the Three-Factor Eating Questionnaire. Body mass indexes, fat mass and percent body fat were determined. Spearman correlations revealed that log10 leptin levels of only the 67 underweight females were negatively correlated with cognitive restraint scores (r = -0.5; nominal P-value < 0.001). The restraint score explained 22% of the total variance of leptin levels in underweight females; in combination with percent body fat, 52% of the variance was accounted for. To our knowledge this is the first study to identify a relationship between a score on a psychometric scale and leptin levels. Restrained eating has a biological correlate in underweight females.

Adult↗
PubMed1997

Further support for linkage of extreme obesity to the obese gene in a study group of obese children and adolescents.

The role of the obese gene in human obesity is presently unclear. Evidence for linkage of markers flanking the gene to obesity has been found in some but not all studies. We investigated transmission disequilibrium between two highly polymorphic microsatellite markers (D7S504 and D7S1875) flanking the human obese gene (OB) and extreme obesity in a study group of German children and adolescents. Due to the early onset and severity of obesity in the ob/ob mouse we hypothesized that especially children and adolescents with extreme obesity are enriched for possible mutations in the human OB. The analysis of 88 trios (index probands and both parents) for transmission disequilibrium of a haplotype which has previously been determined to be linked to extreme obesity (Reed et al., 1996) revealed a one-sided transmission disequilibrium test (TDT) p-value of 0.039. Post hoc analyses revealed one-sided TDT p-values of 0.015 for the 214 bp allele of D7S1875 (corrected p-value = 0.03) and 0.215 for the 145 bp allele of D7S504 (corrected p-value = 0.43). These findings substantiate the evidence for linkage of extreme obesity to OB.

Adolescent↗
PubMed1997

Low body weight in male children and adolescents with schizoid personality disorder or Asperger's disorder.

This study explored the hypothesis that body weight is reduced in male children and adolescents with schizoid personality disorder or Asperger's disorder. The body weights of 33 consecutively admitted male subjects with one of these disorders were retrospectively assessed with percentiles for the body mass index (BMI). The mean percentile (+/- SD) for the BMI was 31.6 +/- 27.6 and differed significantly from the expected value of 50 (P<0.001). Ten subjects had a BMI of < or = 10th age percentile. Post hoc comparisons revealed that BMI percentiles were (a) reduced to a similar extent in patients with schizoid personality disorder and Asperger's disorder and (b) reduced to a greater extent in patients with abnormal eating behaviour. During childhood and adolescence both diagnoses are associated with an increased risk of being underweight. Population-based BMI percentiles are useful for detecting associations between specific psychopathological syndromes and body weight.

Adolescent↗
PubMed1997

Prediction of low body weight at long-term follow-up in acute anorexia nervosa by low body weight at referral.

OBJECTIVE: The authors investigated the hypothesis that in acute anorexia nervosa a low body weight predicts a poor weight prognosis for the future. METHOD: The body mass indexes at referral of 272 female patients were examined in relation to the body mass indexes of these patients after a mean follow-up of 9.5 years. RESULTS: The overall correlation between body mass indexes at referral and at follow-up was r = 0.33. Despite this low correlation, the 100 patients with body mass indexes less than 13 kg/m2 at referral had low weights at long-term follow-up. Eleven of the 12 deceased patients were among these 100 patients, as were 24 of the 46 surviving patients whose body mass indexes were 17.5 kg/m2 or less at follow-up. CONCLUSIONS: For patients with anorexia nervosa, a body mass index less than 13 kg/m2 at referral indicates a substantial risk for chronic anorexia nervosa and death related to emaciation.

Acute Disease↗
PubMed1996

Body weight in acute anorexia nervosa and at follow-up assessed with percentiles for the body mass index: implications of a low body weight at referral.

OBJECTIVE: A systematic epidemiological comparison of body weights of patients with anorexia nervosa can be enhanced by the use of age percentiles for the body mass index. METHOD: To demonstrate the feasibility of this approach, body mass indices of 81 female adolescents with anorexia nervosa were calculated from anthropometric data upon admission for inpatient treatment and at follow-up and set into relationship to the age-dependent distribution of the body mass index in a large and representative sample of the German population. The percentiles were used to visualize the weight increase over time of each former patient by aligning the body mass index at referral with the respective body mass index at follow-up. RESULTS: Upon admission most adolescents had body mass indices below the third age centile. The distribution of body mass indices at outcome suggests a continuum between death of complications related to starvation, chronic anorexia, residual anorexia, and a low body weight Patients with very low body weights at referral had a poor prognosis, because their body weights tended to remain below the minimal normal weight for height. These conditions were statistically best described by categorical analysis, because they were nonlinear to a certain extent. DISCUSSION: The results indicate that the body mass index at referral influences the amount of weight that an individual patient gains in the future.

Adolescent↗
PubMed1996

Use of percentiles for the body mass index in anorexia nervosa: diagnostic, epidemiological, and therapeutic considerations.

OBJECTIVE: Percentiles for the body mass index (BMI) offer a possibility to epidemiologically assess the linear weight criterion of 85% average body weight commonly used for the diagnosis of anorexia nervosa. METHOD: BMI values corresponding to 85% average body weight were calculated and assessed with percentiles derived from epidemiological studies in both the United States and Germany. The underweight range was characterized epidemiologically. RESULTS: The weight criterion used for the diagnosis of anorexia nervosa corresponds to BMI values between the 5th and 10th centiles in both populations. In epidemiological terms the lowest BMI values in individuals aged 10 years and older occur during adolescence. In the general population BMI values <16 kg/m2 are rarely observed. Upon the use of higher BMI cutoffs in the underweight range females clearly predominate. The BMI increase associated with the 5th or 10th centile in the age range between 18 and 30 years is quite low suggesting that many underweight females in the general population gain only minimal weight during this age span. DISCUSSION: The diagnostic, epidemiological, and therapeutic implications for anorexia nervosa are discussed.

Adolescent↗
PubMed1995

Anorexia nervosa viewed as an extreme weight condition: genetic implications.

In anorexia nervosa, psychopathological features and reduced body weight are inseparable, suggesting a prominent role of behavioral factors in achievement and maintenance of extreme underweight. Due to the considerably higher prevalence of this eating disorder in females, anorexia nervosa contributes to the left end of the distribution of the body mass index, especially in the female sex. By reviewing the relevant literature we examined whether genetic research in anorexia nervosa can profit from considering this disorder as an extreme weight condition. For this purpose we compared genetic studies pertaining to both anorexia nervosa and the heritability of the body mass index. Whereas previous genetic studies in anorexia nervosa have mostly concentrated on the assessment of the familial psychopathology, further studies are warranted that additionally attempt to analyze the complex phenotype body weight in relatives of affected probands. Further insight into pathogenetic mechanisms underlying anorexia nervosa might be gained by contrasting the epidemiological, psychopathological and prognostic factors with those in severe obesity. Thus, epidemiological studies suggest that females are more likely to develop both extreme underweight and extreme obesity. A possible explanation for this phenomenon is that the, on average, higher percentage of total body weight composed of fat mass might predispose females towards the development of both extreme weight conditions.

Anorexia Nervosa↗
PubMed1994

Association analysis of the dopamine D2 receptor gene in Tourette's syndrome using the haplotype relative risk method.

Comings et al. [1991: JAMA 266: 1793-1800] have recently reported a highly significant association between Tourette's syndrome (TS) and a restriction fragment length polymorphism (RFLP) of the dopamine D2 receptor gene (DRD2) locus. The A1 allele of the DRD2 Taq I RFLP was present in 45% of the Tourette patients compared with 25% of controls. We tried to replicate this finding by using the haplotype relative risk (HRR) method for association analysis. This method overcomes a major problem of conventional case-control studies, where undetected ethnic differences between patients and controls may result in a false-positive finding, by using parental alleles not inherited to the proband as control alleles. Sixty-one nuclear families encompassing an affected child and parents were typed for the DRD2 Taq I polymorphism. No significant differences in DRD2 A1 allele frequency were observed between TS probands, subpopulations of probands classified according to tic severity, or parental control alleles. Our data do not support the hypothesis that the DRD2 locus may act as a modifying gene in the expression of the disorder in TS probands.

Adolescent↗
PubMed1994

Partial trisomy 16p in an adolescent with autistic disorder and Tourette's syndrome.

A partial trisomy 16p was identified in a 14-year-old male adolescent with autistic disorder. He additionally showed complex motor and vocal phenomena, including some simple tics which had first appeared in childhood. Whereas these simple tics were of subclinical significance, an additional diagnosis of Tourette's syndrome (TS) appears justified. The case report illustrates the diagnostic difficulties in assessing psychiatric symptomatology associated with both disorders, especially complex motor and vocal phenomena. The cytogenetic finding is discussed critically in the light of other chromosome abnormalities reported in both TS and autistic disorder. Chromosome 16p should be considered as a candidate region especially for autistic disorder.

Adolescent↗
PubMed1994

Human dopamine D4 receptor gene: frequent occurrence of a null allele and observation of homozygosity.

We report a null mutation in the first exon of the human dopamine D4 receptor (DRD4) gene. The mutation is predicted to result in a truncated non-functional protein and is the first natural nonsense mutation found in a human dopamine receptor gene. It occurs with a frequency of about 2% in the general population. The distribution of the mutation was found to be similar in healthy controls and patients suffering from psychiatric diseases which included schizophrenia, bipolar affective disorder and Tourette's syndrome, indicating that heterozygosity for this mutation in the DRD4 gene is not causally related to major psychiatric diseases. We also identified an adult male who is homozygous for this mutation. He shows no symptoms of major psychiatric illness, but he displays somatic ailments including acousticous neurinoma, obesity and some disturbances of the autonomic nervous system. Some of these symptoms might be related to the absence of functional DRD4 protein.

Alleles↗