Endocrine Abstracts

Visceral obesity among postmenopausal women often leads to the development of metabolic syndrome (MS), but there is a subgroup of normal weight postmenopausal women displaying metabolic disturbances who are diagnosed to have MS. These subjects often show insulin resistance, however little is known about the effects of adiponectin and sex hormone binding globuline SHBG) on MS in this subset of women.

The aim of the study was: i) to assess serum SHBG, total and HMW adiponectin, and HOMA-I in normal weight postmenopausal women with MS, ii) to compare them with concentrations in normal weight postmenopausal women with healthy metabolic profile, iii) to investigate relationships between adiponectin, insulin resistance and SHBG in normal weight women after menopause.

Methods: Metabolic profile, waist circumference and blood pressure were analyzed in ninety four postmenopausal women with BMI < 25 kg/m², aged 53–65. Subjects were classified as:

1. metabolically healthy (having 0 or 1 metabolic abnormalities) - 48 women,: 2. having 2 metabolic abnormalities (29 women),

3. subgroup with metabolic syndrome, according AHA/NHLBI definition (≥3 abnormalities) - 17 women.

Estimation of serum fasting insulin, SHBG, total and HMW adiponectin were done using commercial radioimmunoassay kits and HOMA-I was calculated.

Results: There were no statistically significant differences between groups in age and BMI, however waist circumferences were higher in the MS subgroup when compared with metabolically healthy subgroup. SHBG (P<0.05), total adiponectin (P<0.01) and HMW adiponectin (P<0.05) were lower and HOMA-I (P<0.05) was significantly higher in women with MS when comparing with metabolically healthy subgroup. When analysis was performed for all women, low SHBG concentrations were associated with an elevated HOMA-IR (P<0.01) and waist circumferences (P<0.01). Total and HMW adiponectin levels also correlated inversely with HOMA-I (P<0.01). SHBG was significantly and positively linked with both total and HMW adiponectin (P<0.01).

Conclusion: In normal weight postmenopausal women low SHBG, total and HMW adiponectin concentrations are connected with insulin resistance and may be predictors of the development of metabolic syndrome.