Gout and type 2 diabetes have a mutual inter-dependent effect on genetic risk factors and higher incidences

Objective: To explore the causal relationship between gout and Type 2 diabetes based on genetic evidence and national outpatient database. Methods: Twenty male gout patients with early-onset, gout family history, without a habit of alcohol consumption or obesity before the first attack of gout were selected from hospital in 2010; and 42 unrelated male Chinese subjects were selected from HapMap as controls for genome-wide analysis study (GWAS). The comorbid diseases with gout were revealed by applying the significant single nucleotide polymorphisms (SNPs) to MetaCore platform, and the comorbid relationship was analysed by standardized incidence ratio (SIR) from outpatient database. Results: A total of 334 SNPs were significantly related to gout in GWAS (P < 10 ^-7), and Type 2 diabetes was the most significantly associated disease with gout as recognized by 36 gene symbols correspondent to the above significant SNPs. The analysis of national outpatient database showed that the overall incident Type 2 diabetes was 1.50 cases per 1000 person-months among gout patients, which was higher than the overall incident gout (1.06 cases) among Type 2 diabetes. The age-adjusted SIR of incident Type 2 diabetes among gout was 2.59 (95% CI 2.42, 2.78), whereas the age-adjusted SIR for incident gout among Type 2 diabetes was 1.61 (95% CI 1.48, 1.74). Conclusion: After excluding obesity and alcohol consumption behaviour, this study showed that patients with gout and Type 2 diabetes shared the common genetic factors most, and that there existed a mutual inter-dependent effect on higher incidences.