The geospatial relation between UV solar radiation and type 1 diabetes in Newfoundland.

Type 1 diabetes (T1DM) has been previously associated with northern latitude and vitamin D insufficiency. This study investigates the geospatial association between average daily ultraviolet B (UVB) irradiance and T1DM across the province of Newfoundland (NL), Canada. NL has one of the highest documented incidences of T1DM worldwide. A complete list of patients diagnosed (1987-2005) with T1DM in the province of Newfoundland and Labrador (NL) was constructed using multiple sources. All places of habitation at diagnosis were ascertained. Ecological analysis using Bayesian estimation was performed employing both NASA UVB data and latitude. Correlation of T1DM to both UVB irradiation and latitude was measured. A statistically significant correlation of erythemal UVB irradiance was observed (-0.0284: 95% CI -0.0542 to -0.0096). A more significant correlation of T1DM was observed with erythemal UVB irradiance than with latitude. This study suggests that erythemal UVB radiation may be geospatially associated with the incidence of T1DM in NL.