Does ancestry influence health-related quality of life in type 1 diabetes patients? A nationwide study in Brazil

The aim of the present study was to evaluate the relationship between self-reported color/race and genomic ancestry with HRQoL of patients with type 1 diabetes in a highly admixed population. This was a nationwide, cross-sectional study conducted with 1760 patients with type 1 diabetes from 2011 to 2014 at public clinics in all five Brazilian geographical regions. Information on HRQoL was obtained from two self-completed questionnaires: Short Form-6 Dimensions (SF-6D) and EuroQol-5 Dimensions (EQ-5D) with a visual analogue scale (EQ-VAS). Genomic ancestry was assessed using a Multiplex PCR methodology. Utility scores generated from the questionnaires were analyzed with multivariate logistic regression models. We included 1698 patients. Those patients who self-reported as black had lower EQ-VAS scores compared to the patients who self-reported as white (67.46 +/- 18.45; 72.37 +/- 16.44, respectively, p = 0.02). In a linear regression model, each 1% increase in African ancestry resulted in a 9.5 point decrease in EQ-VAS score (p < 0.001). In a multivariate logistic regression, after adjusting for demographic, socioeconomic status and diabetes-related variables, African ancestry remained associated with lower EQ-VAS scores. A higher level of African ancestry implicates on lower quality of life even after adjustments for sociodemographic and diabetes-related data. Gender, physical activity and diabetes-related microvascular complications were strongly associated with low HRQoL in all three questionnaires used. This fact highlights the importance of social aspects when assessing quality of life, as well as the need for regular practice of physical activity and prevention of chronic complications to improve patients' quality of life.