Genetic study of clock genes in the pathophysiology of obesity and type 2 diabetes

In recent years an increasing number of studies that establish a relationship between circadian dysregulation and an increased susceptibility to develop obesity and type 2 diabetes. To determine if deregulation of the circadian cycle would be more related to the development of obesity or type 2 diabetes, we decided to sequence the promoter and coding regions and 3’UTRs areas of gene BMAL1, PER1, PER2, PER3, CRY1 , CRY2, NR1D1, RORA and CKIe, all components of the circadian cycle, in 800 obese patients with and without type 2 diabetes and 800 healthy controls, all matched for age and sex for the search for new SNPs and haplotypes associated with these two diseases. The sample size was calculated to detect the presence of variants with at least a 10% frequency in patients with a power of 90%.
Mutation analysis will be performed by PCR amplification of the promoter and coding each of the genes and subsequent analysis with technical HRM (High Resolution Melting) held in the team Real Time-PCR LightCycler ® 480 from Roche.The characterization of new variations found will be performed by automatic sequencing with the team 3100ABI Applied Biosystems DNA Service of the Hospital Clinic, Barcelona. Later, we will study the frequency of new variants found in healthy controls and perform a statistical analysis using logistic regression models to determine if any of the variants may be associated with the presence of obesity and type 2 diabetes, as well as characteristics of the same as the Body Mass Index (BMI), fasting glucose, Hb1c%, triglycerides, total cholesterol and HDL, presence or absence of complications and levels of cortisol and melatonin, performance indicators of the circadian cycle.