Role of insulin, insulin‐like growth factor‐1, hyperglycaemic food and milk consumption in the pathogenesis of acne vulgaris

Abstract

It is the purpose of this viewpoint article to delineate the regulatory network of growth hormone (GH), insulin, and insulin-like growth factor-1 (IGF-1) signalling during puberty, associated hormonal changes in adrenal and gonadal androgen metabolism, and the impact of dietary factors and smoking involved in the pathogenesis of acne. The key regulator IGF-1 rises during puberty by the action of increased GH secretion and correlates well with the clinical course of acne. In acne patients, associations between serum levels of IGF-1, dehydroepiandrosterone sulphate, dihydrotestosterone, acne lesion counts and facial sebum secretion rate have been reported. IGF-1 stimulates 5a-reductase, adrenal and gonadal androgen synthesis, androgen receptor signal transduction, sebocyte proliferation and lipogenesis. Milk consumption results in a significant increase in insulin and IGF-1 serum levels comparable with high glycaemic food. Insulin induces hepatic IGF-1 secretion, and both hormones amplify the stimulatory effect of GH on sebocytes and augment mitogenic downstream signalling pathways of insulin receptors, IGF-1 receptor and fibroblast growth factor receptor2b. Acne is proposed to be an IGF-1-mediated disease, modified by diets and smoking increasing insulin ⁄ IGF1-signalling. Metformin treatment, and diets low in milk protein content and glycaemic index reduce increased IGF-1 signalling. Persistent acne in adulthood with high IGF-1 levels may be considered as an indicator for increased risk of cancer, which may require appropriate dietary intervention as well as treatment with insulin-sensitizing agents.Key words: acne -hyperglycaemic food -IGF-1 -insulinmetformin -milk -smoking Please cite this paper as: Role of insulin, insulin-like growth factor-1, hyperglycaemic food and milk consumption in the pathogenesis of acne vulgaris.

Studying the genetic predisposing factors in the pathogenesis of acne vulgaris

“…In the past few years, our view of acne and its pathogenesis has changed. The effect of hormones, the bacterium, and the abnormal keratinocyte function is still unquestionable [2], but new data strengthen the role of the environmental effects, suggesting that the pathogenesis of this common skin disease is even more complex than thought a couple of years ago [23,24,97].…”

“…Consumption of high-glycemic and hyperinsulinemic food leads to increased insulin-like growth factor 1 (IGF-1) levels and subsequently initiates endocrine responses and androgen synthesis [97]. As a consequence, genetic and molecular studies investigating the role of the IGF-1, insulin-like growth factor receptor 1, insulin-like growth factor binding protein 3, and other elements of this cascade, including the nuclear receptors (LXR, RXR, RAR) and downstream targets (e.g., the FoxO1 transcription factor), should be initiated [23,97,98].…”

“…Natural selection is still strong among them because of the lack of antibiotics and other medications, and their immune system is therefore probably more trained to fight various infections. By contrast, the lifelong consumption of low-glycemic food, the resulting enhanced insulin sensitivity, and the low-stress environment possibly lead to a stable homeostasis balance [20 -22], whereas a modern lifestyle may tend to push people out of their natural balance to the border of a chronic metabolic disorder [23,24]. Thus, the populations in developed countries tend to be overweight, with an increased incidence of cardiac disease, type 2 diabetes, and rheumatoid arthritis [25][26][27].…”

An update on the role of the sebaceous gland in the pathogenesis of acne

“…16 Typical western diet, comprised of milk and hyperglycaemic foods, may have potentiating effects on serum insulin and insulin-like growth factor-I (IGF-I) levels, thereby promoting the development of acne. 17 Another hallmark of sebum in acne patients is the presence of lipoperoxides, mainly due to the peroxidation of squalene and a decrease in the level of vitamin E, the major sebum antioxidant. 18 Both lipoperoxides and monounsaturated fatty acid (MUFA) are capable of inducing alteration in keratinocyte proliferation and differentiation, whereas peroxides are capable of inducing production of pro-inflammatory cytokines and activation of peroxisome proliferator-activated receptors (PPAR).…”

Supplementation with Lactobacillus rhamnosus SP1 normalises skin expression of genes implicated in insulin signalling and improves adult acne

“…Insulin and insulin-like growth factor-1 (IGF1) have been shown to exert acne-promoting actions (Melnik and Schmitz, 2009) and raised serum IGF1 levels have been associated with increased risk of postadolescent acne in women (Aizawa and Niimura, 1995). In turn, congenital deficiency of insulin signalling has been linked to lower prevalence rates of acne .…”