RESUMO
Acne vulgaris is a very common skin disease being diagnosed in Westernized populations, however, its multifactorial etiopathogenesis still remains unclear. Recent research has demonstrated a possible linkage between acne and insulin resistance (IR), which is the topic of our review. In addition to an inappropriate diet, excessive androgen production or obesity, it is the IR which might be responsible for lack of efficacy of classical treatment strategy in acne. Interestingly, in all such cases an increased activity of mammalian target of rapamycin kinase complex 1 (mTORC1) has been detected. This observation might be considered as the basis of the possible role of metformin as an adjunct therapeutic modality for patients suffering from acne. The aim of our review is to present the possible etiological correlation between acne and insulin resistance, as well as metformin therapy, which might be highly useful in the treatment to resistant forms of acne.
RESUMO
Acne vulgaris presents multifactorial pathogenesis, which may include insulin resistance. To investigate whether insulin resistance is a causative factor in acne vulgaris development, this cohort study and a systematic review were conducted. A cohort of 41 acne vulgaris patients and 47 healthy BMI-matched controls were recruited. Glucose and insulin fasting serum levels were obtained and the HOMA-IR was calculated; insulin resistance was diagnosed in cases with a HOMA-IR value over 2.1. The mean ± SD values for glucose fasting serum level were as follows: 94.88 ± 7.731 (mg/dL) in the study group and 79.51 ± 7.175 (mg/dL) in the controls (p < 0.001). The mean ± SD insulin fasting serum levels were 14.47 ± 6.394 (µIU/mL) and 11.83 ± 4.309 (µIU/mL) (p = 0.059), respectively. The HOMA-IR mean ± SD value calculated for the study group was 3.4 ± 1.49 and, in the control group, it was 2.34 ± 0.909 (p < 0.001). Out of 41 patients, 32 were diagnosed with insulin resistance (78%), and 26 of the 47 controls were diagnosed with IR (55%) (p = 0.026). An insulin resistance diagnosis was statistically more common among the acne patients, compared to the controls. In the articles reviewed in this paper, insulin resistance was found to be more frequent in acne vulgaris patients. Both our study and the papers analyzed in the review indicate that insulin resistance might be an independent factor in acne vulgaris development and should be considered when diagnosing and treating acne.