Introduction
Acne vulgaris (AV) is a chronic multifactorial inflammatory disease of the pilosebaceous units of the skin that affects 80% of adolescents and young adults 1. The four main factors implicated in the pathogenesis of AV are the abnormal follicular desquamation, increased sebum production, Propionibacterium acnes proliferation and inflammation 2.
Isotretinoin (13-cis-retinoic acid) is a systematic retinoid and Vitamin A (retinol) metabolite, which constitutes the only available medication with a potential for a long-term cure of acne, as it acts on all the pathogenic mechanisms of acne 3,4. Isotretinoin is the first line treatment for severe nodulocystic and papulopustular acne, acne localized both on face and trunk, acne with tendency to scarring and acne with psychological effects, but it is also indicated in cases with mild to moderate acne, unresponsive to other topical or systematic therapy 3.
Although isotretinoin is an effective and relatively well-tolerated medication, many side effects are related with its intake. In the serum of patients treated with isotretinoin, an increase in the levels of total cholesterol and triglycerides and a decrease in the levels of high density lipoprotein (HDL) are commonly noticed, a phenotype also observed in patients with insulin resistance 5.
Recent studies have shown that adipose tissue, except its main function as an energy-storing organ, has immunological and endocrinological functions. The hormones secreted by fat tissue are called adipocytokines, with the main representative of them, adiponectin. Adiponectin is not only an anti-inflammatory agent, inhibiting inflammation in a wide range of cell types, but also hinders liver glucose production, increases insulin sensitivity and contributes in the maintenance of whole-body’s energy homeostasis 6.
Previous studies with subject the influence of isotretinoin on insulin resistance and serum adiponectin levels in patients with AV have given controversial conclusions 7,8. The objective of this systematic review and meta-analysis is therefore to evaluate the effect of isotretinoin on glucose metabolism, focusing mainly on changes in insulin resistance and levels of adiponectin.