RESUMO
The incidence of malignant melanoma worldwide continues to grow despite the enormous advances in topical and systemic therapy. This increase is recorded regularly even in countries where, as a result of public health campaigns, dermatological examination and subsequent treatment have become more frequent. However, there have been reports of a stable or even decreasing mortality rate that seem to contradict the objective increase in its incidence. The well-known risk factors for malignant melanoma include sunburns and occasional sunbathing, whereas regular sunbathing is associated with a lower incidence. Besides DNA damage, exposure to the sun also results in the synthesis of vitamin D (cholecalciferol) in the skin, which contributes to over 90% of circulating Calcidiol (25 (OH) D) in serum. Current cultural norms (dressing, working indoors, avoiding sun exposure, and dietary choices) affect the serum vitamin D level, resulting in severely low serum levels of vitamin D in some sectors of todays society. Emerging data suggests that mild, unprotected exposure to UV radiation or dietary supplementation with oral vitamin D can reduce cancer mortality. Supplementation with vitamin D or alternatively UV exposure may be regarded as an adjuvant for the treatment of many types of tumors (e.g. tumors of the colon, prostate, and breast). The effect of vitamin D on malignant melanoma may be due to its non-calcemic systemic effects. Additionally, vitamin D may have more pronounced effects locally in the skin because of the unique ability of keratinocytes to synthesize the active form of vitamin D.Key words: malignant melanoma - vitamin D - adjuvant treatment therapy - clinical oncology The authors declare they have no potential conflicts of interest concerning drugs, products, or services used in the study. The Editorial Board declares that the manuscript met the ICMJE recommendation for biomedical papers.Submitted: 7. 10. 2016Accepted: 26. 7. 2017.
Assuntos
Suplementos Nutricionais , Vitamina D , Humanos , Melanoma , Neoplasias Cutâneas , Melanoma Maligno CutâneoRESUMO
BACKGROUND: Dyslipidemia in type 2 diabetes has been shown to be related to the incidence of macrovascular events. Increased carotid intima-media thickness is considered to be a marker of macrovascular disease. MAIN PURPOSE: To investigate a possible relationship between lipoprotein levels and carotid intima-media thickness as a marker of early atherosclerosis in patients with type 2 diabetes. METHODS: Seventy-one consecutively selected eligible patients (31 males, 40 females) with type 2 diabetes were studied. Common carotid intima-media thickness was measured bilaterally by high-resolution ultrasound and the mean value from both sides was used for further analysis. Fasting blood samples were taken from each individual and their serum was analyzed for lipoprotein levels. RESULTS: In the entire group of patients, intima-media thickness was inversely related to apoprotein A-I (r = -0.33, p = 0.008) and HDL cholesterol (r = -0.23, p = 0.059) in univariate correlation analysis, and a positive correlation between intima-media thickness and apoprotein B/apoprotein A-I ratio was found (r = 0.33, p = 0.007). When genders were analyzed separately, intima-media thickness was significantly correlated with apoprotein A-I and apoprotein B/apoprotein A-I ratio in females, while no significant correlation of any lipid variable with intima-media thickness was observed in males. In multiple linear regression analysis, age (p = 0.005), male gender (p = 0.002) and apoprotein A-I (p = 0.035) were the only risk factors in the entire group of diabetic patients, which significantly predicted carotid intima-media thickness in models adjusted for demographic and other known risk factors. As was the case in the univariate analysis, no risk factor significantly predicted carotid intima-media thickness in males while age, apoprotein A-I and B significantly predicted intima-media thickness in females. CONCLUSIONS: In the present study, low serum apoprotein A-I, a major protein component of HDL, was found to be related to increased carotid intima-media thickness. This relationship was stronger in females than in males, which suggests possible gender differences in the relationship between apoprotein A-1 and early atherosclerotic lesions in subjects with type 2 diabetes mellitus.
