Rouen, P., N.E. Reame, and J. Lukacs
To distinguish the effects of ovulation on adiponectin concentrations in healthy cycling women
Concentrations of adiponectin (AD), an adipocyte-secreted peptide, are sexually dimorphic implying a role for the sex steroids. Studies of the relationship between estradiol (E2) and AD have been inconsistent. Increased, decreased or unchanged levels of AD are reported with menopause. No difference in AD levels between the proliferative and secretory phase of the menstrual cycle was observed in a study of women with endometriosis but the comparison utilized unrelated samples. Methods: New data on AD concentrations were analyzed from archived blood samples of 31 normal weight (BMI: 24.0 ± 0.5 kg/m2) healthy women (aged 37.3 ± 2.2 yrs) well characterized for ovarian function with weekly measures of E2 and progesterone (P). Participants were studied in the early follicular phase (cycle day 4 ± 1) and completed at least two of three weekly blood samples during the subsequent menstrual cycle. All volunteers had evidence of ovulation (progesterone > 3 ng/ml on at least one occasion). Menstrual diaries documented cycle length. Weekly concentrations of E2, P, and AD were compared by repeated measures ANOVA. AD concentrations from the early follicular (EF) and midluteal (ML) phase samples were compared by paired t test.
E2 and P varied as expected across the menstrual cycle, but no differences in AD concentrations (EF: 13.0 ± 0.8 g/ml, EF + 1 wk: 12.7 ± 0.7 g/ml, EF + 2 wks: 13.5 ± 0.8 g/ml, EF + 3wks: 12.8 ± 0.8 g/ml; p = 0.26) were detected. EF and ML levels of AD were similar. E2 and P values were not correlated to AD.
Changes in E2 and P across the menstrual cycle do not affect AD concentrations, suggesting a direct relationship between estrogen and AD is not likely.