The differential effect of the phytoestrogen genistein on cardiovascular risk factors in postmenopausal women: relationship with the metabolic status.
BACKGROUND
The wide family of the phytoestrogens has become an alternative to the classical hormonal therapy in menopause; nevertheless, some findings are still conflicting.


OBJECTIVE
To examine the effect of genistein administration on metabolic parameters and vascular reactivity considering the basal endocrine status of the patients.


METHODS
A randomized placebo controlled study was conducted at a university hospital.


METHODS
Fifty postmenopausal women participated.


METHODS
Thirty subjects (group A) were randomized to receive 54 mg/d genistein while 20 subjects (group B) were treated with the placebo for 24 wk. In group A, we distinguish two subgroups: 14 normoinsulinemic and 12 hyperinsulinemic patients.


METHODS
Anthropometric measures, hormonal and lipid assays, oral glucose tolerance test with glycemic, insulin, and C-peptide evaluation, indexes of insulin sensitivity and endothelial function, and euglycemic-hyperinsulinemic clamps were performed.


RESULTS
The insulin basal values significantly decreased in group A, whereas the homeostasis model index of insulin sensitivity and the fasting glucose levels significantly improved compared with placebo group. The genistein administration decreased fasting glucose and area under the curve glucose levels in the normoinsulinemic patients after treatment. In the hyperinsulinemic patients, a significant reduction in fasting insulin, fasting C-peptide, and area under the curve insulin levels as well as an increase in fractional hepatic insulin extraction was shown. In these patients, high-density lipoprotein cholesterol levels were significantly improved. The endothelium-dependent and -independent dilatation improved in the treated group. Normoinsulinemic patients showed both a significantly enhanced flow-mediated and nitrate-mediated dilatation, whereas no significant changes were found in the hyperinsulinemic group.


CONCLUSIONS
The glycoinsulinemic metabolism and the endothelial function were significantly influenced by genistein. In particular, normoinsulinemic patients showed an improvement in glycemic and vascular reactivity indexes. Conversely, an improvement in the insulin sensitivity indexes was noted in hyperinsulinemic patients.
Villa
Paola
P
Department of Obstetrics and Gynaecology, Catholic University of Sacred Heart, Rome, Italy. paolavilla@rm.unicatt.it
Costantini
Barbara
B
Suriano
Rosanna
R
Perri
Concetta
C
Macrì
Francesca
F
Ricciardi
Luigi
L
Panunzi
Simona
S
Lanzone
Antonio
A
D015415:Biomarkers / Q000378:metabolism; D001786:Blood Glucose / Q000378:metabolism; D015992:Body Mass Index; D001916:Brachial Artery / Q000187:drug effects / Q000502:physiology; D002318:Cardiovascular Diseases / Q000209:etiology*; D004730:Endothelium, Vascular / Q000187:drug effects / Q000502:physiology; D005260:Female; D019833:Genistein / Q000494:pharmacology*; D015309:Glucose Clamp Technique; D006801:Humans; D007328:Insulin / Q000097:blood; D007333:Insulin Resistance / Q000502:physiology; D008875:Middle Aged; D048789:Phytoestrogens / Q000494:pharmacology; D010919:Placebos; D017698:Postmenopause / Q000097:blood / Q000187:drug effects* / Q000378:metabolism*; D012039:Regional Blood Flow / Q000187:drug effects; D012307:Risk Factors
D015415:Biomarkers; D001786:Blood Glucose; D007328:Insulin; D048789:Phytoestrogens; D010919:Placebos; D019833:Genistein