Ocular nonsteroidal inflammatory drugs: where do we stand today?

Since their first introduction in ophthalmology, the use of NSAIDs (nonsteroidal anti-inflammatory drugs) has been exponentially expanded, with numerous therapeutic applications. Despite their controversial history, they have proven their efficacy as anti-inflammatory agents in a variety of diseases. Nowadays, NSAIDs are part of surgical protocols of the most commonly performed ophthalmic operations, such as cataract or ocular surgery. They are universally implicated in the management of conjunctivitis, retinal and choroidal disease and miscellaneous inflammatory diseases. Moreover, although linked with serious adverse events and toxicities, their therapeutic magnitude in Ophthalmology should not be affected. This review systematically portrays the variety of ocular NSAIDs available to date, along with their differences in their way of action, indications and potential side effects in various ophthalmologic conditions.

The impact of endocrine disruptors on endocrine targets

Endocrine disruption represents one of the most controversial environmental issues of our époque. So far, many substances, both natural and artificial, have been recognized to interfere with endocrine signaling pathways. In intact laboratory animals, this interaction has been documented to generate adverse health outcomes by impairing normal functions. With regard to humans, evidence is limited and inconsistent to clearly establish a causal inference, however, accumulating data incriminate endocrine disrupting chemicals to reproductive disorders and disturbed thyroid homeostasis. Recently, as a result of animal models and preliminary human studies, a new area of interest has arisen concerning the implication of endocrine disruptors in the etiology of obesity and diabetes, the two major, life-threatening, epidemics of modern world. This article reviews the evidence linking endocrine disrupting chemicals to a broad spectrum of clinical perturbations from reproduction and thyroid to metabolic regulation.

Low free plasma levels of retinol-binding protein 4 in insulin-resistant subjects with polycystic ovary syndrome

BACKGROUND

It has been shown in animals and in humans that retinol-binding protein 4 (RBP4) production from adipose tissue leads to generalized insulin resistance (IR). A more sensitive marker of circulating RBP4 is free plasma RBP4 expressed by RBP4 to transthyretin (TTR) ratio, since in circulation RBP4 is bound to TTR.

AIM

To investigate RBP4 levels in insulin-resistant women with polycystic ovary syndrome (PCOS) and to estimate free plasma RBP4 expressed by RBP4/TTR ratio.

SUBJECTS AND METHODS

Thirty-five PCOS subjects were compared with 45 controls matched for age and body mass index (BMI). In each subject, fasting values of glucose, insulin, gonadotropins, estradiol, androgens, C-reactive protein (CRP), RBP4, and TTR were determined.

RESULTS

PCOS subjects in comparison to controls were more insulin-resistant [homeostasis model assessment for IR (HOMA-IR): 2.6+/-0.3 vs 1.9+/-0.1, p=0.043], and presented lower RBP4 levels (28.3+/-1.1 vs 32.4+/-1.2 microg/ml, p=0.021) and RBP4/TTR ratio (0.26+/-0.01 vs 0.31+/-0.01, p=0.0014). When RBP4 and RBP4/TTR values where stratified according to BMI status (obese, overweight, and lean subjects), it was noticed that both RBP4 and RBP4/TTR values in lean PCOS were significantly lower than in controls (RBP4: 25.0+/-5.5 vs 34.1+/-9.0 microg/ml, p=0.0063, RBP4/TTR: 0.25+/-0.3 vs 0.35+/-0.1, p=0.016). No correlation was observed between RBP4 and RBP4/TTR with any hormonal or metabolic parameter including BMI.

CONCLUSIONS

RBP4 and free plasma RBP4 expressed as RBP4/TTR ratio are statistically and significantly lower in insulin-resistant PCOS subjects in comparison to controls. Therefore, our findings do not confirm a link between IR, neither with RBP4 nor with free plasma RBP4 levels. The significance of these findings remains to be elucidated, since RBP4 might prove to have different actions, like other adipokines, from humans and rodents.