THE CONCENTRATIONS OF MONOAMINE METABOLITES AND NEUROPEPTIDES IN THE CEREBROSPINAL-FLUID OF OBESE WOMEN WITH DIFFERENT BODY-FAT DISTRIBUTION

DESIGN AND SUBJECTS: Several studies suggest neuroendocrine abnormalit ies in, particularly, abdominal, central obesity in humans, a conditio n with high morbidity and mortality. Therefore the concentrations of n europeptides and catecholamines in cerebrospinal fluid (CSF) were anal ysed in 48 obese women, subdivided into groups with central, abdominal and gluteo-femoral distribution of body fat, utilising the waist-to-h ip circumference ratio (WHR) for division. RESULTS: In comparisons wit h non-obese control women concentration of 5-hydroxyindol acetic acid (5-HIAA), methoxyhydroxyphenylglycol (MHPG), corticotropin releasing h ormone (CRH), B-endorphins (END) and neuropeptide Y (NPY) were lower, while homovanillic acid (HVA) was not different in obese women, HIAA, HVA and END correlated negatively with the WHR only in abdominally obe se women, suggesting a threshold effect. HIAA vs HVA as well as CRF vs END correlated strongly in the total and both subgroups, An interrela tionship between all these four substances was found in abdominal but not in gluteo-femoral obesity, suggesting a tighter functional couplin g in the former group, Several correlations were found between CSF sub stance levels and appetite registrations, including END vs voracious e ating, and for carbohydrate craving vs HIAA and vs HVA (negatively). T his was also found only in abdominally obese women. CONCLUSION: Althou gh the concentrations of monoamine metabolites and neuropeptides in th e CSF sampled at the level of the lumbar spine might not be representa tive for those at regulatory centers in the brain, the findings sugges t that low 5-HIAA is characteristic of human obesity, and coupled to C RH as well as eating abnormalities, particularly in abdominal obesity. Since CRH is regulating the balance between the autonomic nervous sys tems, insulin secretion and thermogenesis in animals, corresponding an omalies in abdominal obesity in humans may have a central origin.