Concentraciones plasmáticas de renina y aldosterona en mujeres obesas y no obesas con síndrome de ovarios poliquísticos

Serum free fatty acid levels in PCOS patients treated with glucophage, magnesium oxide and spironolactone

To assess the effect of glucophage, magnesium oxide and spironolactone in altering free fatty acids (FFAs), 36 PCOS women were randomly divided into three groups. Group 1 (n = 14) was treated with 500 mg glucophage po bid, group 2 (n = 10) was treated with 400 mg magnesium oxide po bid and group 3 (n = 12) was treated with 50 mg spironolactone po bid for 12 weeks. A glucose tolerance test with 75 g glucose load was performed before and after treatment, collecting blood at 0, 1 and 2 h for insulin, glucose, FFA and aldosterone. Amount of FFA before and after treatment were compared by repeated measure ANOVA and represented as area under the curve. FFA levels before treatment were 0.83 ± 0.23, 0.77 ± 0.15 and 0.85 ± 0.28 and after treatment were 0.77 ± 0.48, 0.71 ± 0.18 and 0.66 ± 0.25 for glucophage, magnesium oxide and spironolactone-treated patients, respectively. The FFA levels were unchanged in the groups treated with glucophage and magnesium oxide but were significantly (p < 0.03) decreased in the group treated with spironolactone. Since FFAs are known to be involved in the development of insulin resistance, these results suggest that spironolactone may be useful for lowering insulin resistance in PCOS patients.

Increased total Renin levels but not Angiotensin-converting enzyme activity in obese patients with polycystic ovary syndrome

OBJECTIVE

To investigate the renin-angiotensin-aldosterone system and angiotensin-converting enzyme (ACE) activity in patients with polycystic ovarian syndrome (PCOS).

SUBJECTS AND METHODS

In this case-control study, 41 obese (PCOS) women and 29 healthy controls, matched for age and body mass index, were enrolled. Anthropometric, metabolic, and hormonal patterns, including plasma aldosterone, plasma renin, and ACE activity, were measured in each subject.

RESULTS

Plasma renin levels were significantly higher in PCOS patients (19.7 ± 14.5 µg/ml) compared with controls (12.9 ± 9.0 µg/ml, p < 0.05). ACE activity and aldosterone levels did not significantly differ between both groups (p = 0.15 and p = 0.18, respectively). Analysis of PCOS patients showed a significant correlation of fasting insulin levels with levels of renin (r = 0.305, p < 0.01) and free testosterone (r = 0.384, p = 0.001). Similarly, homeostasis model assessment index was positively correlated with total renin concentrations (r = 0.366, p < 0.01) and free testosterone (r = 0.352, p < 0.01).

CONCLUSION

Obese PCOS women had higher total renin levels, but not ACE activity and aldosterone levels, related to insulin resistance compared with controls.

Role of mineralocorticoid receptor in insulin resistance

PURPOSE OF REVIEW

Recent data suggest that mineralocorticoid receptor activation can affect insulin resistance independent of its effects on blood pressure. This review discusses new evidence linking mineralocorticoid receptor to insulin resistance and the underlying mechanisms of these effects.

RECENT FINDINGS

Observational studies have shown mineralocorticoid activity to be associated with insulin resistance irrespective of race, blood pressure or body weight. Increased mineralocorticoid activity may be the common link between obesity, hypertension, dyslipidemia and insulin resistance, features that make up the metabolic syndrome. Treatment of primary aldosteronism is associated with a decrease in insulin resistance and provides one of the most convincing evidences in favor of the contribution of mineralocorticoid receptor to insulin resistance. Dietary salt restriction, which increases aldosterone levels, is also associated with an increase in insulin resistance. Potential mechanisms by which mineralocorticoid receptor may contribute to insulin resistance include a decreased transcription of the insulin receptor gene, increased degradation of insulin receptor substrates, interference with insulin signaling mechanisms, decreased adiponectin production and increased oxidative stress and inflammation. Advantages of mineralocorticoid receptor antagonists on insulin resistance have been demonstrated in animal models.

SUMMARY

There may be a benefit of mineralocorticoid receptor antagonists in human insulin resistance states, but more clinical research is needed to explore these possibilities.