More recently, controversy has arisen over the use of COC in patients with PCOS (Nader and Diamanti-Kandarakis 2007) specifically regarding the effects of COCs on carbohydrate metabolism and metabolic parameters such as insulin resistance and glucose tolerance (Korytkowski et al 1995; Nader and Diamanti-Kandarakis 2007).
The most significant change found is a deterioration of insulin sensitivity with the administration of COCs (Korytkowski et al 1995; Dahlgren et al 1998). Two studies conducted in obese women with PCOS also showed a decrease in glucose tolerance demonstrated by the results of an oral glucose tolerance test (Nader et al 1997; Morin-Papunen et al 2000).
Plasma insulin concentrations were constant in both of these studies indicating that the decrease in glucose tolerance was again due to a decrease in insulin sensitivity rather than a change in insulin levels/production. However, other studies performed in non-obese women showed no change in glucose tolerance and insulin sensitivity (Armstrong et al 2001; Cibula et al 2002; Elter et al 2002; Morin-Papunen et al 2003).
This variation in results may suggest that metabolic consequences from COC treatment of PCOS depend on body type (Vrbikova and Cibula 2005).
COC treatment of PCOS also has been shown to cause an increase in total cholesterol, triglycerides, HDL and LDL cholesterol (Creatsas et al 2000; Mastorakos et al 2002; Cibula et al 2005). The opposite finding, however, has been reported with COCs containing the same progestin resulting in an overall decrease in the LDL:HDL ratio (Falsetti and Pasinetti 1995).
Triglycerides and HDL cholesterol did increase in both studies however. While cholesterol levels appear to increase in women with PCOS who are treated with COCs regardless of the COC used, desgetrel containing COCs do not seem to cause changes in triglyceride levels while other COCs do (Escobar-Morreale et al 2000; Mastorakos et al 2002).
The metabolic effects of drospirenone-containing COCs are just beginning to be explored. The European Active Surveillance Study on oral contraceptives followed 58,674 women for a total of 142,475 women years of observation and concluded that the risks of adverse cardiovascular disease and other serious events in users of drospirenone-containing oral contraceptives are similar to those associated with the use of other COCs (Dinger et al 2007).
Because drospirenone is a less androgenic progestin, the metabolic effects appear to be much less severe or entirely non-existent when women with PCOS are treated with drospirenone-containing COCs.
Guido found no significant change in insulin sensitivity in a study of 15 PCOS women treated with drospirenone-containing COCs (Guido et al 2004). The same study also found that drospirenone-containing COCs appear to have the same effect on lipid levels of PCOS women that they do on healthy controls, which is a major improvement from other COCs.
A significant increase in triglycerides and HDL cholesterol has been observed but with no shift in the HDL:LDL ratio (Guido et al 2004).
Thus, although the metabolic concerns typical of COC administration in healthy women still exist when drospirenone-containing COCs are used in the treatment of PCOS, the use of drospirenone appears to alleviate the metabolic concerns that are specific to women with PCOS.