EARLIER PREDICTORS OF LIPOPROTEIN ALTERATIONS IN THE MENOPAUSAL TRANSITION: INTERMEDIATE DENSITY LIPOPROTEIN CHOLESTEROL (IDL-C) AND Lp(a).

BERG, GABRIELA; SISELES, NESTOR; MESCH, VIVIANA; BOERO, LAURA; PRADA, MARIELA; SAYEGH, FABIANA; ROSALES, MONICA; MAIDANA, PATRICIA; ROYER, MONIQUE; BENENCIA, HAYDEE

FLORENCIA, ITALIA

Congreso; 8TH WORLD CONGRESS OF GYNECOLOGICAL ENDOCRINOLOGY; 2000

INTERNATIONAL SOCIETY OF GYNECOLOGICAL ENDOCRINOLOGY

It is well established that in the post-menopause there is an increase in the atherogenic intermediate (IDL) and low density (LDL) lipoproteins (1) as a consequence of the decrease in the B:E receptors, which are stimulated by estrogens (2). However, limited data are available about these lipoproteins in the menopausal transition, the period of time when the first clinical, endocrinological and metabolic changes related to the menstrual cycle become evident. The aims of this study were: a)       To study the lipid and lipoprotein profile and evaluate their relationship with the hormonal changes in the menopausal transition. b)       To evaluate the body fat distribution and its relationship with lipid parameters and insulin. Forty three healthy women were enrolled in this trial, and divided in two groups: A (n=27), aged 48±3.4 years, still menstruating, and B (n=16), aged 49±2.6 years, and with amenorrhoea of 3-6 months. All women had intact uterus and at least one ovary, and received no HRT in the preceding three months, Informed consent was obtained from patients. The weight and height as well as waist and hip circumference of patients were measured. Body mass index (BMI) was calculated to evaluate the obesity and the waist/hip ratio was used as a marker of body fat distribution. On blood samples obtained after 12 hours fasting, Total cholesterol (TC), triglycerides (TG), LDL-C, IDL-C, HDL-C, Apo B, Lp(a), Insulin,  FSH and Estradiol were determined. No differences were observed in the anthropometrics parameters between groups: BMI (A 28±4.0 vs B 28±4.4) W/H (A 0.86±0.07 vs B 0.87±0.06). All lipidic parameters (mg/dl, mean±SE) showed higher levels in women in amenorrhoea but a significant difference was only found in Lp(a) concentration: (A vs B) TC 207±6.4 vs 225±11.8; TG 110±10.4 vs 72±18.1; HDL-C 52±2.3 vs 56±3.0; LDL-C 135±6.5 vs 144±11.6; IDL-C 12.5±2.0 vs 7.8±1.3; VLDL-C 19.7±2.5 vs 24±3.4; Apo B 114±5.9 vs 122±10.7; Lp(a) 15.7±1.8 vs 26.5±3.9 p<0.01(figure1). Positive correlations between IDL-C and FSH and negative correlations with estradiol were determined, (figure2 and 3). Positive correlation was observed in group B between IDL-C and W/H ratio (r=0.73; p<0.01) and Insulin correlated positively with BMI in both groups (A: r=0.57;p<0.05 and B:r=0.67;p<0.05).                                                                  Conclusions: In the menopausal transition women begin to show changes in the body fat distribution. Although there were no differences between groups, BMI and W/H ratios were higher than desirable values. There was a positive correlation between insulin and BMI in both groups. Lp(a) was the only lipoprotein significantly different between groups, being higher in the amenorrhoea group. Taking into account correlations found between hormonal profile and IDL-C as well as the increase in Lp(a) concentrations, these lipoproteins could be considered early markers of damage in the lipoprotein profile in women at menopause.