Background: Acne vulgaris (AV) is a common chronic inflammatory disease of the pilosebaceous units associated with long-term sequelae and complications. Little is known about the association of acne with body mass index (BMI). Among retinoic acid receptors (RARs) α, β, and γ, the messenger RNA level of RAR-γ is the most readily detectable by Northern blotting in human and mouse skin. This observation suggests that RAR-γ may play a critical role in the modulation of the therapeutic benefits of isotretinoin in the skin.
Objective: The present study aimed to investigate the relation between BMI and severity of acne, and to find out if there is a link between BMI and RAR-γ in skin tissues of acne patients and the subsequent supposed effect on therapy response by isotretinoin.
Patient and Methods: In this study, 60 acne vulgaris patients were conducted. They were classified according to their BMI into 3 subgroups; group I: 12 normal weight, group II: 21 overweight, and group III: 27 obese individuals. Global Acne Grading System (GAGS) was calculated for acne severity. Insulin resistance was checked (by measuring serum glucose level, insulin level, and Homa-IR score) and RAR-γ levels were evaluated in skin biopsies by ELISA.
Results: Serum glucose level, insulin level, and Homa-IR score were significantly higher in obese patients as compared to both normal weight and overweight ones, while no significant difference was observed between patients of normal weight and overweight. The RAR-γ level was significantly lower in obese individuals than those with normal weight, and it was also significantly lower in overweight than normal weight. There was a non-statistically significant difference in RAR-γ levels between overweight and obese individuals. A statistically significant linear negative correlation was noticed between RAR-γ levels and the serum glucose level (r= -0.519, p=0.001), insulin (r= -0.485, p=0.001), Homa-IR (r= -0.485, p=0.001), and BMI (r= -0.470, p=0.001) in all studied subjects collectively.
Conclusion: Tissue levels of RAR-γ were downregulated in acne patients regarding BMI. There was no association between BMI and the severity of acne in the current study. Larger studies are needed to confirm these findings. Better
characterization of the role of RAR-γ could constitute a therapeutic avenue for the treatment of Acne Vulgaris