Variations in Proliferation of Adipocytes within Normal and Polycystic Ovarian Syndrome under the effect of Insulin

David Cadagan, Christopher Towlson, Raheela Khan, Saad Amer. University of Nottingham, Nottingham, UK

The overall aim of this pilot study was to examine the influence of varying doses of insulin on the proliferation of adipocytes in both normal and PCOS samples.

PCOS is a female endocrine disorder and one of the leading causes of infertility affecting 5-10% of all women of a reproductive age. It is associated with obesity and insulin resistance, which increase the risk for type 2 diabetes and cardiovascular disease (Norman et al., 2007). Biochemical characteristics of PCOS include hyperandrogenemia, hyperinsulinemia and increased luteinsing hormone secretion. Recent research has suggested that insulin resistance found within PCOS adipocytes is not inherent (Corbould et al., 1997) and with 50% of women suffering from PCOS also showing abdominal obesity (Mannerås-Holm et al., 2011) we decided to examine whether a biochemical association existed and whether increased insulin secretion lead to an increase in adipocyte proliferation.

Following ethical approval volunteers were recruited from patients attending the Gynaecology clinic at The Royal Derby Hospital (n = 9, 4 non-PCOS vs. 5 PCOS). With fully informed written consent a subcutaneous adipose biopsy was taken from the abdominal wall processed for cell culture as described by Quinkler et al., 2004, and analysed over 5 days using an MTS proliferation assay (Buttke et al., 1992).

Results are expressed as mean ± S.E.M. and were compared using non-parametric unpaired t-test with Bonferroni’s post-hoc test where appropriate. A significant increase in PCOS adipocyte proliferation was seen when treated with increased insulin treatments (100ng/ml) by day 5 of proliferation and measured as absorbance @490 through MTS colorimetric changes (Day 5, 0.61 ± 0.072 N = 4 non-PCOS vs. 0.98 ± 0.076 N = 5 PCOS * p <0.019).

In conclusion our data within this pilot study suggests that symptomatic hyperinsulinemia within PCOS may have an association to increased adipocyte proliferation. Collection and analysis is on going.

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