Abstract
Background
Sunlight exposure, the main source of endogenous vitamin D synthesis, may increase the risk of non-melanoma skin cancer (NMSC) development. Vitamin D receptor (VDR) polymorphisms are associated with 25(OH)D levels, cancer development and insulin resistance.
Objective
This study aimed to examine the associations among vitamin D status, VDR FokI polymorphism, insulin resistance and NMSC.
Methods
This case-control study included 73 diagnosed cases of NMSC and 72 healthy controls from dermatology clinics at Razi Hospital, Tehran, Iran. A questionnaire was used to assess sunlight exposure. The extracted DNA from whole blood samples were genotyped. Fasting serum 25-hydroxyvitaminD (25(OH)D)), lipid profile, glucose, and insulin were measured. To evaluate insulin resistance, HOMA-IR formula was used.
Results
We found a significant higher duration of cumulative sunlight exposure in cases compared with controls (p<0.001). However, 25(OH)D concentrations were not significantly different between cases and controls (30±15 vs. 29±15 ng/mL, p=0.78). Higher levels of insulin (p = 0.004) and HOMA-IR score (p= 0.019) were observed in Ff and ff genotype of FokI. We did not observe any significant increased risk of NMSC due to f allele, as compared with FF (OR =2.33, 95% CI 0.81-6.75, p=0.12). The components of lipid profile, fasting serum glucose, iPTH and anthropometric measures did not differ significantly across VDR genotypes.
Conclusion
In conclusion, sunlight exposure was associated with NMSC risk. VDR FokI polymorphisms appears to influence insulin resistance in the NMSC patients.
Vitamin D status and its association with insulin resistance among type 2 diabetics: A case -control study in Ghana
